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80-533: The Loess Plateau is one of the largest and thickest loess plateaus in the world. Its 635,000 km2 area corresponds to around 6.6% of the land area in China. Around 108 million people inhabit the Loess Plateau. Because of the strong winds, erosion is also powerful across the plateau. Therefore, erosional features, including wind escarpments, loess vertical joints and gullies are present. In the past few decades,

160-475: A {\displaystyle a} and b {\displaystyle b} . If a {\displaystyle a} is less than b {\displaystyle b} ( a < b {\displaystyle a<b} ), then a {\displaystyle a} cannot be greater than b {\displaystyle b} ( a ≯ b {\displaystyle a\ngtr b} ). This highlights how

240-445: A R b {\displaystyle aRb} holds for elements a {\displaystyle a} and b {\displaystyle b} , then b R a {\displaystyle bRa} must be false. Stated differently, an asymmetric relation is characterized by a necessary absence of symmetry of the relation in the opposite direction. Inequalities exemplify asymmetric relations. Consider elements

320-413: A Hermitian Hamiltonian . As of 2006, no violations of CPT symmetry have been observed. The baryons (i.e., the protons and neutrons and the atoms that they comprise) observed so far in the universe are overwhelmingly matter as opposed to anti-matter . This asymmetry is called the baryon asymmetry of the universe. Isospin is the symmetry transformation of the weak interactions . The concept

400-440: A clear violation of parity conservation in the beta decay of cobalt-60. Simultaneously, R. L. Garwin , Leon Lederman , and R. Weinrich modified an existing cyclotron experiment and immediately verified parity violation. After the discovery of the violation of parity in 1956–57, it was believed that the combined symmetry of parity (P) and simultaneous charge conjugation (C), called CP , was preserved. For example, CP transforms

480-527: A deeper understanding of nature. Asymmetries in experimental measurements also provide powerful handles that are often relatively free from background or systematic uncertainties. Until the 1950s, it was believed that fundamental physics was left-right symmetric; i.e., that interactions were invariant under parity . Although parity is conserved in electromagnetism , strong interactions and gravity , it turns out to be violated in weak interactions . The Standard Model incorporates parity violation by expressing

560-537: A distinct 'headscarp' or ' headwall ' and progress by headward (i.e., upstream) erosion . Gullies are commonly related to intermittent or ephemeral water flow, usually associated with localised intense or protracted rainfall events or snowmelt. Gullies can be formed and accelerated by cultivation practices on hillslopes (often gentle gradients) in farmland , and they can develop rapidly in rangelands from existing natural erosion forms subject to vegetative cover removal and livestock activity. The earliest known usage of

640-575: A left-handed neutrino into a right-handed antineutrino. In 1964, however, James Cronin and Val Fitch provided clear evidence that CP symmetry was also violated in an experiment with neutral kaons . CP violation is one of the necessary conditions for the generation of a baryon asymmetry in the early universe. Combining the CP symmetry with simultaneous time reversal (T) produces a combined symmetry called CPT symmetry . CPT symmetry must be preserved in any Lorentz invariant local quantum field theory with

720-672: A longer dust storm event, the loess can travel a longer distance. The dust storm is blown from northwest to the Loess Plateau. Although the source of loess materials is from the Gobi Desert and the sand deserts, they are not produced by those deserts. The three mountains, including the Gobi Altay Mountains, the Hangayn Mountains and the Qilian Mountains are responsible for making loess materials for

800-525: A lot. The grain size will increase in some northwest areas during glacial periods, even though the wind intensity does not change. This may also be associated with the transporting winds. During glacial periods, the Siberian High is enhanced, and the winter monsoon become drier and stronger. Therefore, the amount and grain size of the sediments will increase. More than 90% of the loess is calcite , feldspar , mica and quartz . Among that, around 50%

880-401: A study examined the geoenvironmental causes driving gully erosion. It focuses on catchment management for gully erosion and geotechnical analysis. Through fieldwork, data was gathered utilizing GIS and GPS methods. According to the study, gully erosion occurs throughout, with Nanka/Oko having the highest concentration. The gully characteristic map shows variations in length and depth, emphasizing

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960-435: A system significantly below maximum entropy is very likely to evolve towards higher entropy, it also states that such a system is very likely to have evolved from higher entropy. Symmetry is one of the most powerful tools in particle physics , because it has become evident that practically all laws of nature originate in symmetries. Violations of symmetry therefore present theoretical and experimental puzzles that lead to

1040-450: A system. Due to how cells divide in organisms , asymmetry in organisms is fairly usual in at least one dimension, with biological symmetry also being common in at least one dimension. Louis Pasteur proposed that biological molecules are asymmetric because the cosmic [i.e. physical] forces that preside over their formation are themselves asymmetric. While at his time, and even now, the symmetry of physical processes are highlighted, it

1120-549: A transition from loess accumulation to wind erosion in the Loess Plateau. Many linear bedrock ridges are formed behind the wind escarpment, which are parallel to the wind direction. In the northern Loess Plateau, the bedrock ridges are pointing towards the northeast. However, the direction of the ridges slowly rotates to the North in the central Loess Plateau. At North Loess Plateau, the ridges are oriented 118° ±14° while they are oriented 179° ± 11° at central Loess Plateau. This indicates

1200-631: A variety and combination of processes. The erosion processes include incision and bank erosion by water flow, mass movement of saturated or unsaturated bank or wall material, groundwater seepage - sapping the overlying material, collapse of soil pipes or tunnels in dispersive soils, or a combination of these to a greater or lesser degree. Hillsides are more prone to gully erosion when they are cleared of vegetation cover through deforestation , over-grazing , or other means. Gullies in rangelands can be initiated by concentrated water flow down tracks worn by livestock or vehicle tracks. The flowing water easily carries

1280-405: Is a crucial aspect of design. When designing a facility, it is not always certain, that in the event of fire , which side a fire may come from. Therefore, many building codes and fire test standards outline, that a symmetrical assembly, need only be tested from one side, because both sides are the same. However, as soon as an assembly is asymmetrical, both sides must be tested and the test report

1360-1029: Is a severe environmental problem that lowers crop quality and may cause famine and food shortages. It also causes the soil to lose organic content, which has an impact on plant viability. As items washed from fields end up in rivers, streams, or vacant land, erosion also contaminates the ecosystem. Because of increased population expansion and increasing land demand, erosion also threatens the natural ecosystem, encroaching on natural forests. Important assets including homes, power poles, and water pipelines may also be destroyed. Effective land management techniques can prevent gullies. These techniques include keeping vegetation along drainage lines, using more water, classifying drainage lines as distinct land classes, stabilizing erosion, preventing vermin, distributing runoff evenly, keeping soil organic matter levels high, and avoiding over-cultivation. These tactics guarantee uniform rates of penetration and robust plant coverage. One serious environmental problem endangering sustainable development

1440-525: Is also important to determine the source of loess because monsoon will affect the wind direction. There are winter monsoonal winds flowing from Mongolia because of the high-pressure cell in Siberian-Mongolia. This plays an important role in transporting dust and loess to the Loess Plateau. Dust storm: This is the most important factor. During Spring, many strong dust storms happen in the Loess Plateau which usually last for more than two days. With

1520-395: Is asymmetrical, look for lines of symmetry . For instance, a square has four lines of symmetry, while a circle has infinite . If a shape has no lines of symmetry, then it is asymmetrical, but if an object has any lines of symmetry, it is symmetrical . An asymmetric relation is a binary relation R {\displaystyle R} defined on a set of elements such that if

1600-497: Is flat and with many loess strata. It is mostly located at south Loess Plateau. Loess ridges are formed by erosion and are located at the central Loess Plateau. Loess Hills are conical dunes and are located at the north Loess Plateau. The geomorphology of the Loess Plateau is formed by the erosion and deposition of loess. In the Loess Plateau, the geomorphology usually changes from rocky mountains to Alluvial plain at piedmont to river valley belt. This pattern keeps repeating from

1680-553: Is gully erosion. Gullying prevention and control methods are dispersed and lacking, and they have low success and efficacy rates. This review attempts to make a valuable contribution to effective gully prevention and management techniques by combining information from previous research. It is possible to stop the creation of gullies by changing how land is used, conserving water and soil, or implementing specific actions in areas with concentrated flow. Plant leftovers and other vegetation barriers can prevent erosion, although their usefulness

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1760-442: Is known that there are fundamental physical asymmetries, starting with time. Asymmetry is an important and widespread trait, having evolved numerous times in many organisms and at many levels of organisation (ranging from individual cells, through organs, to entire body-shapes). Benefits of asymmetry sometimes have to do with improved spatial arrangements, such as the left human lung being smaller, and having one fewer lobes than

1840-596: Is limited. The biophysical environment, terrain, climate, and geomorphology are examples of external elements that affect gully prevention and control. Stabilizing gullies entails altering water flow to lessen scouring, sediment buildup, and revegetation. Water can be securely moved from the natural level to the gully floor using a variety of structures, including drop structures, pipe structures, grass chutes, and rock chutes. Structural modifications can be required along steep gully floors. Vegetation can reestablish itself thanks to sediments deposited over flatter gradients. Until

1920-563: Is localized in the Coastal Plain Sands, Nanka Sands, and Nsukka Sandstone of the Anambra-Imo basin region. The most affected deposits are unconsolidated or poorly consolidated and have short dispersion times. Public education is essential for a sustainable termination strategy, and collaboration between the government, donors, the private sector, and rural people is crucial. Gullies are widespread at mid-to high latitudes on

2000-427: Is loess ridge, by strong erosion. If the erosion is weak, the higher terraces will change to loess tableland. These flat river basins , which include valley flat and lower terraces, are important for construction and agricultural activities. Mu Us Desert is located in the northwest of the Loess Plateau. Wind escarpment in the Loess Plateau marks a boundary between Mu Us Desert and the Loess Plateau. It also represents

2080-422: Is loess that is deposited during late Pleistocene and Holocene. It is formed under arid or semi-arid conditions. Secondary loess is loess that is compacted by upper loess and does not experience the weathering and carbonation process. Also, it is formed by the transformation of fluvial and lake loess in semi-arid areas. Both the thickness and the size of loess decrease from northwest to southeast. The figure shows

2160-443: Is only a small effect in most processes that involve the strong interactions, isospin symmetry remains a useful calculational tool, and its violation introduces corrections to the isospin-symmetric results. Because the weak interactions violate parity, collider processes that can involve the weak interactions typically exhibit asymmetries in the distributions of the final-state particles. These asymmetries are typically sensitive to

2240-670: Is quartz. The 10% left are orthoclase , viitaniemiite , sudoite , clinochlore and nimite . From the mineralogical, isotopic, and chemical results, it is easy to find the provenance of the loess. The sources of loess in the Chinese Loess Plateau are the Gobi Desert and the deserts nearby, including the Tengger Desert , Badain Jaran Desert , Ulan Buh Desert, Mu Us Desert and Hobq Desert. However,

2320-609: Is required to state the results for each side. In practical use, the lowest result achieved is the one that turns up in certification listings . Neither the test sponsor, nor the laboratory can go by an opinion or deduction as to which side was in more peril as a result of contemplated testing and then test only one side. Both must be tested in order to be compliant with test standards and building codes . In mathematics, asymmetry can arise in various ways. Examples include asymmetric relations , asymmetry of shapes in geometry, asymmetric graphs et cetera. When determining whether an object

2400-596: Is seen as more attractive in humans, especially in the context of mate selection. In general, there is a correlation between symmetry and fitness-related traits such as growth rate, fecundity and survivability for many species. This means that, through sexual selection , individuals with greater symmetry (and therefore fitness) tend to be preferred as mates, as they are more likely to produce healthy offspring. Pre-modern architectural styles tended to place an emphasis on symmetry, except where extreme site conditions or historical developments lead away from this classical ideal. To

2480-406: The Chinese Loess Plateau, the prevailing wind builds a linkage for all these places. The loess can travel to the plateau through the prevailing wind. No mountain in between: In the transport pathway of the dust, there is no high mountain in between. In the situation where high mountains block the dust when the dust is transporting, the dust may deposit at the windward slope of the mountain. Monsoon

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2560-576: The Loess Plateau was shaped by the tectonic movement since Neogene. After that, because of the East Asia Monsoon in Quaternary, the loess and different erosional features started to form. However, because of human activities, many areas in the Loess Plateau turned into erosional environments. Loess does not necessarily mean the same as silt. Loess is yellow eolian sediments that were transported by wind from an arid or semi-arid region during

2640-410: The Loess Plateau, the contribution of gully erosion on total sediment production in the hilly areas is about 60% to 90%. It is serious in the Loess Plateau. To know the contribution of gully erosion, we can measure the gully volume changes. There are three types of gullies in the Loess Plateau, including floor gullies, hill slope gullies and valley bank gullies. In conclusion, the geomorphic outline of

2720-522: The Northwest to the Southeast of the Loess Plateau. The height of the rocky mountains is much higher than the loess deposit. The height and morphology of the mountains are different in different locations. One of the highest mountains in the Loess Plateau is called Mahan Mountain. The elevation of this mountain is around 3,670 metres (12,040 ft), which is 1,300 metres (4,300 ft) higher than

2800-482: The Quaternary period. Around 6% of the land in the world is covered with loess. Loess record the past climate and environment. The Chinese Loess Plateau is one of the largest sinks of loess in the world. When the sediments are transported to the Loess Plateau, they are silt materials. After they deposit in arid areas and under strong chemical weathering and the process of carbonation, loess is formed. Two types of loess are defined by their formation process. Typical loess

2880-1123: The binary relation "equal to" is a symmetric one. In general an Asymmetric tensor is defined by the change of signs ( − / + ) {\displaystyle (-/+)} of its solution under the interchange of two indexes. The Epsilon-tensor is an example of an asymmetric tensor. It is defined as: ϵ i j k = { 1 i f ( i , j , k ) ∈ { ( 123 ) , ( 231 ) , ( 312 ) } − 1 i f ( i , j , k ) ∈ { ( 213 ) , ( 321 ) , ( 132 ) } 0 e l s e {\displaystyle \epsilon _{ijk}=\left\{{\begin{array}{cc}1&if\;(i,j,k)\in \{(123),(231),(312)\}\\-1&if\;(i,j,k)\in \{(213),(321),(132)\}\\0&else\end{array}}\right.} ,with i , j , k ∈ { 1 , 2 , 3 } {\displaystyle i,j,k\in \{1,2,3\}} . For even or uneven permutations of

2960-618: The contrary, modernist and postmodern architects became much more free to use asymmetry as a design element. While most bridges employ a symmetrical form due to intrinsic simplicities of design, analysis and fabrication and economical use of materials, a number of modern bridges have deliberately departed from this, either in response to site-specific considerations or to create a dramatic design statement. Some asymmetrical structures In fire-resistance rated wall assemblies , used in passive fire protection , including, but not limited to, high-voltage transformer fire barriers , asymmetry

3040-518: The deeper subsurface is also a possible explanation for the formation of some Martian gullies. Asymmetry Asymmetry is the absence of, or a violation of, symmetry (the property of an object being invariant to a transformation, such as reflection). Symmetry is an important property of both physical and abstract systems and it may be displayed in precise terms or in more aesthetic terms. The absence of or violation of symmetry that are either expected or desired can have important consequences for

3120-473: The desert and plateau. High elevation: According to the environmental lapse rate , the air temperature will decrease by 6 °C (43 °F) per 1,000 metres (3,300 ft). Therefore, the higher the mountain, the more extreme climate. All three mountains are higher than 2,500 metres (8,200 ft), ranging from 2,500 to 5,500 metres (8,200 to 18,000 ft). The mountain top may have a temperature around 0 °C (32 °F) or even below lower. This favors

3200-408: The development of the joints. Many vertical loess joints can be easily found on the vertical cliffs of tableland. The joints and the loess-paleosol interface are orientated perpendicularly. Also, in a dry loess layer, vertical loess joints are the wet part of it. Therefore, it is very difficult to notice the loess vertical joints in deep strata. The water from rainfall and irrigation will infiltrate into

3280-463: The different properties of the loess in different sides of the mountain. Most of the loess is deposited and well preserved at "Yuans", which are very flat. Some studies found that the apparent sedimentation rate, which determines the changes of the rate of deposition , has similar changes as the grain size changes. When the grain size increases, the apparent sedimentation rate also increases. There are two reasons. There are other factors that control

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3360-407: The distance between the Gobi Desert and the Chinese Loess Plateau is quite far, it is possible that the loess can travel such a great distance. There are a few reasons why the source of loess is from the Gobi Desert and the sand deserts. Prevailing wind : The prevailing wind of the sand deserts and Gobi Desert are from the northwest. Since the Gobi Desert and the sand deserts are located northwest of

3440-478: The energy of the wind starts to decrease, so it drops the largest and heaviest loess first. It continues to move towards the southeast of the Loess Plateau, the energy of the wind keeps decreasing. Therefore, the finest loess materials are deposited at the southeast end of the Plateau. That is why the coarsest loess is at the northwest of the Loess Plateau while the finest is at the southeast. Some studies found that

3520-409: The environment and climate has changed, including the rainfall pattern, vegetation cover, and the natural hazards . These changes may relate to human development in the plateau; Chinese environmental officials are trying to find sustainable ways to manage the region. There are three main types of morphology in the Loess Plateau. They are loess platform, loess ridges, and loess hills . Loess tableland

3600-443: The eroded soil after being dislodged from the ground, typically when rainfall falls during short, intense storms such as thunderstorms . A gully may grow in length through headward (i.e., upstream) erosion at a knick point . This erosion can result from interflow and soil piping ( internal erosion ) as well as surface runoff . Gully erosion may also advance laterally through similar methods, including mass movement, acting on

3680-422: The frost weathering process and freeze-thaw cycles which lead to physical weathering of the rocks at the mountain top. This process changes the rocks into small sized grains. High relief and gradient: When the melting water and river water from the mountain water flows down from the mountain top, it creates a large amount of potential energy because of the slope gradient and high relief. When the water flows through

3760-408: The grain size changes. Besides the variations in the wind intensity, the grain size may also affect by the aridity of the source areas. This changes the transporting distance of the sediments. During interglacial periods, the Loess Plateau retreated northwesterly while it moves towards the southeast during glacial periods . Therefore, the distance between the source areas and the Loess Plateau changes

3840-432: The gully walls (banks), and the development of 'branches' (a type of tributary ). Gullies reduce the productivity of farmlands where they incise into the land and produce sediment that may choke downstream waterbodies and reduce water quality within the drainage system and lake or coastal system. Because of this, much effort is invested into the study of gullies within the scope of geomorphology and soil science , in

3920-454: The indexes the tensor is either 1 or -1. Certain molecules are chiral ; that is, they cannot be superposed upon their mirror image. Chemically identical molecules with different chirality are called enantiomers ; this difference in orientation can lead to different properties in the way they react with biological systems. Asymmetry arises in physics in a number of different realms. The original non-statistical formulation of thermodynamics

4000-418: The infiltration of water and accumulation of the sediments in the water. In the underdevelopment stage a few or nearly zero joints are found. And lastly in the undeveloped stage no vertical joint is found. The loess is very dry. The average moisture content is 16.22%. Gully erosion acts as an important source for sediments. If an area has gully erosion, it means that the area has serious land degradation. In

4080-413: The least important issue. This implies a notable variation in the average evaluations across impacted individuals, underscoring the necessity for long-term repair approaches. Reducing soil loss, raising public knowledge of environmental issues, passing environmental legislation, and giving residents funds to strengthen their coping mechanisms are all advised by the study. In Agulu-Nanka, Southeast Nigeria,

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4160-446: The loess line. It is a flat-topped mountain and has paleo-peneplain remnants on the mountain top. Some of the mountain slopes, especially the windward slope (north slope), were forested in the past. The alluvial plain at piedmont is composed of Alluvial fans which can be found in this area, and which are located at the foot of the rocky mountains. The size of this belt depends on the amount of runoff and weathering materials from

4240-516: The loess strata through the vertical joint surface and pore concentration zone. The joint systems in the loess strata are of different sizes, properties, periods, and origins. Loess Vertical Joints distribute all over the loess plateau. The joints in landslides can be categorized by their different features. The original joints are formed on the major scarp, minor scarp, original vertical cliffs and flanks. They are no displacement and closed. Unloading vertical joints and weathering vertical joints are at

4320-471: The loess structure, water moisture, strata and microtopography. There are vertical development features and lateral development features. Vertically, joints can be found in different loess strata, including late, middle and early Pleistocene loess layers. It is one of the most significant structures of the Loess Plateau. The development and size of the vertical loess joints depend on the vegetation coverage and slope. Steep slope and poor vegetation coverage favor

4400-429: The loess that formed during Middle Pleistocene is expansive and thick. Therefore, the main period for the formation of the Loess Plateau is Middle Pleistocene. Most of the loess in the west of Liupan Mountain is yellow. However, the loess in the east has many different colors, such as deep reddish-orange, brownish-gold. The color differences indicate that Liupan Mountain was formed before the loess deposition and it caused

4480-413: The main source is the Gobi Desert. This is proven because their minerals, isotopes and chemicals are similar. Both of the places have quartz as the main mineral of the loess. The value of Sr/Sr is extremely high and both of them have high Eu/Yb and Eu/Eu ratios, which are trace elements . These data prove that the loess is from the Gobi Desert. The Gobi Desert is located at the north of the plateau. Although

4560-407: The major sources of loess. Gully A gully is a landform created by running water, mass movement, or commonly a combination of both eroding sharply into soil or other relatively erodible material, typically on a hillside or in river floodplains or terraces. Gullies resemble large ditches or small valleys , but are metres to tens of metres in depth and width, are characterized by

4640-564: The necessity of considering gully vulnerability and giving erosion hazards immediate attention. Gullies can be formed or enlarged by several human activities. Artificial gullies are formed during hydraulic mining when jets or streams of water are projected onto soft alluvial deposits to extract gold or tin ore . The remains of such mining methods are very visible landform features in old goldfields such as in California and northern Spain. The badlands at Las Medulas , for example,

4720-543: The prevention of gully erosion, and the in remediation and rehabilitation of gullied landscapes. The total soil loss from gully formation and subsequent downstream river sedimentation can be substantial, especially from unstable soil materials prone to dispersion . When water is directed over exposed ground, gully erosion removes soil near drainage lines. This may result in divided properties, loss of arable land, diminished amenities, and decreased property values. Additionally, it can lead to sedimentation, discoloration of

4800-654: The rainier months. Gullies develop when a rill is neglected for an extended time, thickening and expanding as soil erosion persists. The factors influencing gully erosion were investigated in Zaria, Kaduna state, Nigeria, utilizing SRTM data, soil samples, rainfall data, and satellite imagery. The findings indicated that the factors that had the biggest effects on gully erosion were slope (56%) and rainfall (26%), land cover (12%), and soil (6%). The investigation concluded that each particular component significantly influenced soil loss. The loss of fertile farmland due to gully erosion

4880-439: The relations "less than", and similarly "greater than", are not symmetric. In contrast, if a {\displaystyle a} is equal to b {\displaystyle b} ( a = b {\displaystyle a=b} ), then b {\displaystyle b} is also equal to a {\displaystyle a} ( b = a {\displaystyle b=a} ). Thus

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4960-408: The restoration is finished, damaged areas should be walled off. Eastern Nigeria's people and ecology are seriously threatened by gully erosion. A research project focused on 370 families and nine risk regions evaluated the region's gully erosion issues. The greatest perceived problem, according to the results, was biodiversity loss. In contrast, damage to properties, roads, and walkways was ranked as

5040-431: The right lung to make room for the asymmetrical heart . In other examples, division of function between the right and left half may have been beneficial and has driven the asymmetry to become stronger. Such an explanation is usually given for mammal hand or paw preference ( handedness ), an asymmetry in skill development in mammals. Training the neural pathways in a skill with one hand (or paw) may take less effort than doing

5120-422: The rocky mountains. Old alluvial fans are covered with eolian loess . Further from the rocky mountains, loess tableland and loess "Ping" can be found and even links with the next belt, which is the river valley belt. The River valley belt includes flood plains , river terraces and river beds. The terraces with higher height are mostly covered with thick loess. It will change to another form of landscape, which

5200-512: The role of wind erosion. The monsoon wind direction in Quaternary is consistent with modern climatology. To observe near-surface wind vectors, they compared the wind in Quaternary and modern wind. The results show that the wind direction in winter and spring-storm events are the same as the orientation of the bedrock ridges. Therefore, modern windstorms also contribute to shaping the eolian geomorphology. The Yellow River has provided sediments supply continuously which has been reworked by wind. Also,

5280-434: The same with both hands. Nature also provides several examples of handedness in traits that are usually symmetric. The following are examples of animals with obvious left-right asymmetries : Since birth defects and injuries are likely to indicate poor health of the organism, defects resulting in asymmetry often put an animal at a disadvantage when it comes to finding a mate. For example, a greater degree of facial symmetry

5360-557: The sediments to the Loess Plateau and sort the sediments. Tectonic activities: When there are tectonic activities in High Asia, energy is released. This causes the denudation of the rock and downcutting of rivers of the mountains. Loess materials are formed from the mountains during tectonic activities. Besides, the sediments are also produced by the eolian abrasion process in the deserts and the Yellow River. However, these are not

5440-531: The strong interactions can be considered as a subset of a larger flavor symmetry group, in which the strong interactions are invariant under interchange of different types of quarks. Including the strange quark in this scheme gives rise to the Eightfold Way scheme for classifying mesons and baryons. Isospin is violated by the fact that the masses of the up and down quarks are different, as well as by their different electric charges. Because this violation

5520-524: The surface of Mars and are some of the youngest features observed on that planet, probably forming within the last few 100,000 years. There, they are one of the best lines of evidence for the presence of liquid water on Mars in the recent geological past, probably resulting from the slight melting of snowpacks on the surface or ice in the shallow subsurface on the warmest days of the Martian year. Flow as springs from deeper seated liquid water aquifers in

5600-837: The term is from 1657. It originates from the French word goulet , a diminutive form of goule which means throat . The term may be connected to the name of a type of knife used at the time, a gully-knife. Water erosion is more likely to occur on steep terrain because of erosive pressures, splashes, scour, and transport. Slope characteristics, such as slope length and amounts proportionate to slope length, affect soil erosion. Relief and soil erosion are positively correlated in southeast Nigeria. There are three types of topography: mountains, cuesta landscapes, and plains and lowlands. While highlands with stable lithology avoid gullying yet allow for vigorous runoff, uplands with friable sandstones are more prone to erosion. Gully erosion can progress through

5680-416: The top and edge of the slope or landslides and mostly in open shape and with little displacement. Sliding joints are in the body of landslides. Usually they are step-shaped and with large displacement. Collapsible joints are formed when there is asymmetrical settlement during rainfall or irrigation. They are located far from the edge of tableland and with apparent displacement. The lateral development of

5760-468: The topography of the Chinese Loess Plateau. The loess near the Liu-p’an Mts is the thickest which is around 200 to 300 metres (660 to 980 ft) while the loess near the Yellow River is around 100 metres (330 ft) thick. This is related to the sorting by wind. When the monsoon wind and dust storm are blown from the northwest, it carries the loess of different sizes. When it arrives at the Loess Plateau,

5840-472: The valleys and unstable rocky slopes, many clastic materials are washed away by the water. The removed materials are transported by the water and deposited in mountain foot and lowland basins. This may even form alluvial fans. There is a huge alluvial fan at the mountain foot of the Gobi Altay Mts. Therefore, the sediments and sands of the desert are from the mountain. After that, the wind will transport

5920-414: The vertical loess joints can be divided into four stages. In the development stage original vertical joints, unloading joints and weathering joints can be found. In this range, the joints are mainly weathering joints and unloading joints. Nothing fill in the joint surfaces. In the micro-development stage, the distribution of the loess joints is sparser. The joints are filling with fine sand. This indicates

6000-410: The water supply, and creating a haven for rodents. Water rushing over exposed, naked soil creates gullies and ridges that erode rock and soil. When water rushes across exposed terrain, it erodes or pushes dirt away, creating rills. Gravity causes rift erosion on a downward slope, with steeper slopes generating greater water flow. Sandier terrains are more commonly affected by rills most prevalent during

6080-530: The weak interaction as a chiral gauge interaction. Only the left-handed components of particles and right-handed components of antiparticles participate in weak interactions in the Standard Model. A consequence of parity violation in particle physics is that neutrinos have only been observed as left-handed particles (and antineutrinos as right-handed particles). In 1956–1957 Chien-Shiung Wu , E. Ambler, R. W. Hayward, D. D. Hoppes, and R. P. Hudson found

6160-495: The wind erosion becomes stronger when it reaches the Loess Plateau wind escarpment. Because of the streamline compression of the wind escarpment, the wind speed is increased. As a result, the Loess Plateau is not only a site of loess deposition but also a source of dust because of strong wind erosion. Wind erosion is very severe during the glacial period. During the glacial period, there is very little vegetation, so it favors wind erosion. Loess vertical joints distribution depends on

6240-537: Was asymmetrical in time : it claimed that the entropy in a closed system can only increase with time. This was derived from the Second Law (any of the two, Clausius ' or Lord Kelvin 's statement can be used since they are equivalent) and using the Clausius' Theorem (see Kerson Huang ISBN   978-0471815181 ). The later theory of statistical mechanics, however, is symmetric in time. Although it states that

6320-791: Was created during the Roman period by hushing or hydraulic mining of the gold-rich alluvium with water supplied by numerous aqueducts tapping nearby rivers. Each aqueduct produced large gullies below by erosion of the soft deposits. The effluvium was carefully washed with smaller streams of water to extract the nuggets and gold dust. Gully initiation results from localized erosion by surface runoff, often focusing on areas where forest cover has been removed for agricultural purposes, uneven compaction of surface soils by foot and wheeled traffic, and poorly designed road culverts and gutters. Termination of gully processes requires water-resource management, soil conservation, and community migration. Gully erosion

6400-429: Was first introduced by Werner Heisenberg in nuclear physics based on the observations that the masses of the neutron and the proton are almost identical and that the strength of the strong interaction between any pair of nucleons is the same, independent of whether they are protons or neutrons. This symmetry arises at a more fundamental level as a symmetry between up-type and down-type quarks . Isospin symmetry in

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