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Arrays deployed in antenna-array-based direct position determination (DPD) systems are conventionally placed parallel to each other with invariant orientations, which may be inappropriate. This paper proposes a novel array orientation adjustment method to achieve optimal DPD performance, in which we seek optimal array orientations that maximize the trace of the Fisher information matrix (FIM) and then minimize localization uncertainty. The optimization problem is unconstrained, multivariable, and can be converted into multiple tractable single-variable optimization problems. An exact solution can be obtained by a straightforward but computationally tedious one-dimensional exhaustive search. To reduce the computational load, we then derive an asymptotic solution in cases where the arrays consist of massive antennas. Numerical examples demonstrate the effectiveness and feasibility of the proposed method in resolution and precision enhancement, especially in a low signal-to-noise ratio (SNR).

This letter considers the direction of arrival (DOA) estimation of non-circular (NC) source using a large uniform linear array with a single snapshot. First, by utilizing the waveform characteristics of the NC signal, the proposed algorithm can enlarge the virtual array aperture that is twice the length of the physical array, and resultantly enhance DOA estimation accuracy. Moreover, by multiplying a correction matrix, the proposed algorithm can offset the NC phase error, thereby obtain further improved DOA estimation performance. Furthermore, the advocated algorithm can reduce the computation complexity by using the Newton-Raphson method instead of the traditional grid-search method. Finally, the numerical simulation results are provided to demonstrate the effectiveness and superiority of the proposed algorithm.

Loess landslides are one of the most serious geological disasters in the Chinese Loess Plateau. Research has revealed that earthquake, rainfall, and human activities are common triggers for loess landslides. In order to study the relationship and characteristics of these landslides triggered by different factors, the paper uses historic landslide data to expound the basic motion indices of landslides triggered by different factors. More than half of loess landslides occurred on concave surface slopes, while nearly 40% of the loess landslides occurred on convex surface slopes. Human activities have a great effect on the occurrence of landslides, and the distribution density of landslides on residential land was almost five times that of bare land. Additionally, earthquake-induced loess landslides had the largest sliding volume, whereas the excavation-induced loess landslide had the smallest sliding volume. The sliding volume of irrigation-induced and rainfall-induced loess landslides were between earthquake-induced loess landslides and excavation-induced loess landslide. Many of loess landslides were induced by a combination of these factors, such as rainfall and excavation, irrigation and excavation. Then a model that described the impact of these factors on the loess landslides was proposed.

On 27 January 2021, at 21:00 (UTC + 8), a shallow loess landslide occurred in Heifangtai, Yongjing County, Gansu Province, northwest of the Chinese Loess Plateau. Fortunately, the independently developed global navigation satellite system predicted the landslide 7 h in advance. Although farmland and channels were buried and destroyed, no damage has been done to the lives and houses of residents. In order to explore the triggering factors and movement process of the landslide, based on the field investigation, we collected the precipitation and temperature data more than 1 year before the landslide and comprehensively used UAV photogrammetry, numerical simulation, and laboratory test for comprehensive research. It was found that as the temperature rose and freeze–thaw cycles, changes in mechanical properties of loess and unique stratum structure were the main factors triggering the landslide. The rise in temperature led to an increase in groundwater levels, and the strength of soil decreased gradually until shear liquefaction occurred. This landslide caused a substantial topographic change, which provided conditions for slope instability in the future. The process of landslide movement can be divided into three stages: start-up stage, severe sliding stage, and deceleration stage. Simulation results show that the maximum velocity was 22 m/s, and the maximum sliding distance was 393 m. The main movement period was 40 s, and the apparent friction angle was 5°. Finally, this study provides a reliable basis for studying the dynamic process and failure mechanism of loess landslides.

Compared with nested array, coprime array can significantly alleviate the mutual coupling between array sensors due to the sparser array structure. However, plenty of holes in its difference co-array extremely reduce the achievable number of uniform degrees of freedom(uDOFs). In this letter, a coprime array with prime integer 3(CAP-3) is proposed, in contrast to several well-known nested arrays, which can offer comparable number of uDOFs, and alleviate mutual coupling simultaneously. Specifically, the CAP-3 consists of three appropriately placed subarrays, and it can eradicate most of the holes in difference co-array except two at both ends. Hence a large number of uDOFs can be obtained. Furthermore, CAP-3 possesses robustness against heavy level of mutual coupling due to the reduced number of sensor pairs with small inter-element spacing. Simulations reveal the advantage of the CAP-3 in uDOF, mutual coupling robustness, and direction of arrival estimation accuracy.

Direction of arrival (DOA) estimation using new proposed array geometries named sparse nested arrays with coprime displacement (SNACD) is discussed in this paper. The SNACD has sparse subarrays with nested relationship, and the displacement between the subarrays is coprime to the inter-element spacing of the smaller subarray. This geometry can combine the properties of nested array and coprime array, which can simultaneously achieve virtual uniform array with large aperture in co-array domain and reduce the mutual coupling influence in physical-array domain. In the co-array domain, the coprime parameter estimations are separated into the virtual direction matrix and source vector, respectively. Based on this data model, several DOA estimation methods can be applied, like the spatial smooth multiple signal classification (SS-MUSIC) and atomic norm minimization based grid-less (ANM-GL) method, which both are robust to the grid mismatch problem. To further reduce the complexity, we proceed to propose a Discrete Fourier transform with offset compensation (DFT-OC) method, which requires neither eigenvalue decomposition nor sparse recovery. The final unique DOA estimation is achieved from the intersection of the coprime estimations, which are achieved with automatically pairing. Compared to coprime array and nested array based methods, the proposed scheme obtains better DOA estimation accuracy and higher angular resolution with mutual coupling influence. Multiple simulations are presented to verify the effectiveness of our approach.

Straw and plastic mulching have been widely used in northwest China because of their ability to improve water use efficiency and increase grain yields. However, the dynamic changes of soil carbon (C) and nitrogen (N) under continuous straw and plastic mulching is rarely mentioned. A field experiment was conducted over four consecutive wheat (Triticum aestivum L.)-maize (Zea mays L.) rotation cycles in Northwest China to determine dynamic changes in soil C and N under three treatments: CK (traditional non-mulched), PM (transparent plastic mulching), and SM (straw mulching). Over the four wheat–maize cycles, soil organic carbon (SOC) in SM increased by 18% in the 0–0.2 m soil layer, while in PM SOC decreased by 15%, and in CK SOC changed little. Total N under CK and SM remained basically unchanged over time, but declined over time under PM. The overall microbial biomass carbon (MBC) and nitrogen (MBN) under SM increased by 32% and 17%, respectively, after four rotation cycles compared with significant decreases of 29% and 22% under PM and little change under CK. SM reduced soil temperature and increased soil water content, while PM increased both ST and water relation to the CK. Both SM and PM treatments increased grain yield and reduced nitrate N leaching. In the long run, straw mulching can improve SOC, MBC, MBN, and wheat–maize yield, and should be the recommended mulching practice for sustainable wheat–maize production in dryland areas in response to the potential challenges of climate change to dryland agriculture.

The coprime array owns a sparse array structure, which can effectively alleviate mutual coupling, while the holes existing in the difference co-array(DCA) greatly reduce the number of uniform degrees of freedom(uDOFs). In this letter, we propose a new coprime array structure called hole-free coprime array (HFCA) by carefully assembling the subarrays, and the resulting HFCA can generate a hole-free DCA. Furthermore, we derive the optimal HFCA that can produce the largest hole-free DCA with a given number of sensors, which contributes to an increase of uDOFs compared with existing coprime array structures. In addition, the simulations are provided to demonstrate the superiority of HFCA in terms of uDOFs, direction of arrival estimation performance, and spatial resolution.

Direction of arrival (DOA) estimation using the improved unfolded coprime array (IUFCA) subject to array motion isdiscussed in this study. Unfolded coprime array (UFCA) consists of two uniform linear subarrays, and the two subarrays are arranged at different sides of theaxis, which leads to a large number of holes in the difference co-array (DCA). With array motion and DCA synthesis,part of the holes can be filled, but there are still holes in the center which lead to the virtual arrays separated.By analyzing the hole positions in the synthetic DCA generated by UFCA motion, the authors improve the originalUFCA by relocating some physical elements, then the two dominantconsecutive DCA segments in the positive and negative sides can be connected. The expression of synthetic DCA is analyzed, and the closed-form expression of theuniform degree of freedom (uDOF) subject to IUFCA motion is studied. Simulation results show that IUFCA motion can obtain a largenumber of uDOFs, which leads to better DOA estimation performance and more identifiable signals compared with existingcoprime array configurations.

This article proposed a novel hybrid-connected boost converter (HCBC) with ultrahigh step-up and ultralow voltage stress. At the input part, a traditional interleaved boost converter structure is adopted based on dual coupled inductors, which can reduce the input current ripple and ease the current stress flowing through main switches and magnetic elements. Then, the voltage doubling capacitors embedded in this circuit can lift voltage and clamp the voltage stress on switches. Therefore, it will not only increase the voltage gain, but also recycle the leakage energy of coupled inductor to alleviate the voltage spikes across the power switches. At the output, the dual secondary windings of coupled inductors are connected in series and combined with a capacitor-diode to form a voltage multiplier module, which is stacked on the output for higher voltage gain. The working principle and steady-state performance of the proposed converter are analyzed in detail, and a 400-W experimental prototype based on HCBC is built to verify the correctness of theoretical analysis.

In this letter, two-dimensional (2D) direction of arrival (DOA) estimation using one-dimensional (1D) nested array motion is studied, and an improved Discrete Fourier transform (DFT) algorithm is proposed. Exploiting nested array to move vertically along its axis enables 2D DOA estimation with large-scale and hole-free difference co-array. DFT algorithm has lower complexity than multiple signal classifications(MUSIC) method, but traditional DFT algorithm still requires multiple extra searches to ensure estimation accuracy. We use DFT to obtain the initial angle estimations, and then compensate the estimation offsets via total least squares (TLS) constructed from Taylor expansion approximation. Compared with the traditional DFT search method, the proposed method has lower complexity and better performance. Multiple simulations are conducted to verify the effectiveness of our approach.

A microirrigation network system is composed of a subunit and main pipeline network. Previous optimization studies generally focused on manifolds or lateral pipes in subunits or main pipeline networks and did not consider systems as a whole; thus, a true optimum was difficult to achieve. In this paper, a microirrigation network system is optimized as a whole, and an innovative approach is proposed to optimize the subunit based on a maximum size objective. Based on four optimization models of a subunit for two optimization objectives and two layout modes, this paper discusses the optimum design criteria for a microirrigation network system by using the lowest annual total cost per unit area of the system as a measurement index. Mathematical optimization models of the subunit and main pipeline network were established and solved with a genetic algorithm. The subunit was treated as a whole to avoid an artificial distribution for the allowable pressure difference between the laterals and manifold in the subunit. The Clement methodology was used to determine the flow rates of pipelines in the peak period of irrigation. The results indicated that the annual total cost per unit area of the microirrigation network system obtained based on the optimization results of subunit model SWPL-A was the lowest considering various parameters. The annual total cost per unit area of the microirrigation network system obtained based on the optimization results of the SWPL-A subunit model was 0.79–14.90%, 0.94–3.01% and 0.28–5.20% lower than the costs obtained based on the optimization results of the SWUL-F, SWPL-F and SWUL-A subunit models, respectively. The results of this paper have some practical significance for the optimization of on-demand pressurized microirrigation network systems and regional pipeline networks.

Bioclogging is a commonly encountered operational issue that lowers hydraulic conductivity and the overall performance of the infiltration systems. In this paper, a novel processing for alleviating bioclogging by filter media surface hydrophobic modification was presented. Two-dimensional porous media cells were used to observe the influence of hydrophobic modification on biofilm growth in the pore structure. Moreover, two continuous-flow columns packed with gravel, one of which half gravel was hydrophobically modified, were operated with artificial wastewater to verify the effect of hydrophobic modification on bioclogging alleviation. The results showed that the biofilm growth in the cell with hydrophobic modification was slow, and the biomass was less and liable to wipe off after hydrophobic treatment. Meanwhile, the hydraulic efficiency of the flow seepage field was also improved after hydrophobic treatment. The column tests results showed that the hydraulic conductivity of the filter bed with hydrophobic modification (Column B) decreased more slowly than that of another without hydrophobic modification (Column A). Column B had the hydraulic conductivity (k) of 0.66 cm/s in the final stage of the experiment, while the k of Column A was 0.14 cm/s. It verified that hydrophobic modification of partial filter media can alleviate the bioclogging problem of the infiltration systems to some extent. The results provide a new idea and potential technical support for solving bioclogging problem.

Loess has a strong water sensitivity, so loess landslides often transform into loess mudflows when water is added on the Chinese Loess Plateau, which results in high casualties and property loss of the Chinese government. In this study, a series of flume tests were designed to study the initiation of loess mudflows. The results reveal that the initiation modes of loess mudflows include large-scale mudflow and retrogressive toe sliding (Type A), and small-scale mudflow and retrogressive toe sliding (Type B). A model was used to analyze the test results that describe the effects of water flow on the potential for hillslope failure and liquefaction. It was found that the soil accumulation was unconditionally stable before a loess mudflow was formed, but as the rainfall continued, the water gradually infiltrated the soil, and the soil accumulation changed from unconditionally stable to unconditionally unstable. Thus, this led to different initiation modes during the tests. For Type A, the water preferentially infiltrated into the area with an uneven density and a large amount of water accumulated. The pore water pressure increased quickly and could not dissipate in time, so the loess liquefied. As the liquefaction area continued to expand and became larger, Type A occurred. Relatively speaking, Type B occurs in soil accumulations with relatively uniform densities. These results provide a certain scientific reference for the study of loess mudflows.

It is of great significance to study the time-dependent mechanical properties of loess, as loess landslides are closely related to them. The purpose of this study is to investigate the effect of moisture content on instantaneous and time-dependent deformation, strength and failure behaviors of undisturbed loess specimens from Nangou in Yan'an City, Shanxi Province, China, via triaxial shearing tests and multi-loading triaxial creep tests under moisture contents of 5%, 10%, 17% and 22%. The results show that the time-dependent deformation of loess increase with the moisture content, while the time-dependent deformation rate decreases slowly. The soil deformation is divided into four stages based on the peak strain rate. Furthermore, the instantaneous and long-term strength of loess decrease with increasing moisture content, and the instantaneous strength decreases more than the long-term strength. The failure mode of undisturbed loess changes from shear failure to homogeneous failure with increasing moisture content; when the failure mode is shear failure, the thickness of the shear band that forms at the specimen surface over time is smaller than the corresponding thickness that forms instantaneously. Finally, the macroscopic morphology and microstructure of loess specimens were considered together to analyze the effect of moisture content on the instantaneous and long-term mechanical behavior of loess and to discuss the process of loess deformation to failure.

This study presents a non-isolated step-up inverter without leakage current for low-voltage renewable energy generation such as photovoltaic (PV) cells grid connection. From the structure of the proposed inverter, the negative terminal of the PV array is directly linked with the grid neutral, so the common mode voltage of the parasitic capacitance can be kept constant and the leakage current will not be generated in theory. Moreover, this transformerless inverter can produce an AC output voltage higher than the input DC voltage, which will reduce the sizes of the generation system. A switching modulation strategy carrier-based is analysed in detail when the input inductor current is operated in discontinuous conduction mode. The operation modes of the proposed inverter are also discussed, respectively, in positive and negative half line cycles. Finally, a digital experimental prototype is tested in the laboratory, and the experimental results are consistent with the theoretical analysis.

In this paper, an integrated step-up inverter without transformer is investigated for photovoltaic (PV) power generation. The proposed topology can be derived by combining a traditional boost converter with a single-phase full bridge dc–ac converter. The main features of the integrated inverter are: First, the leakage current caused by the solar cell array-to-ground parasitic capacitance can be theoretically reduced to zero due to the characteristics of the converter configuration, which can improve the efficiency and the reliability of the PV generation system; second, the output ac voltage of the proposed inverter can be higher than the input dc voltage, which is capable of connecting low voltage PV panels to the grid; third, only five active switches are used in the presented inverter, and those switching devices can be synchronously driven by various sinusoidal pulsewidth modulation methods based on the carrier; therefore, the proposed inverter is compact and with curtailed cost. The working principle and analysis of the proposed integrated inverter are elaborated. Finally, simulation and experimental results are obtained in a lab prototype, which agree well with the theoretical analysis.

The application of soil mulching is widely used to improve crop productivity within semi-arid regions of China, but little is known when using a crop rotation system in the sub-humid drought-prone regions as to whether the mulching practice may perform as well as in semi-arid regions. A field study was conducted during two consecutive cycles of a wheat (Triticum aestivum L.) - maize (Zea mays L.) cropping system within the Yangling District of Northwest China to evaluate the effects of different mulch cultivation practices on soil water contents and soil temperatures (EM50 probes), crop yields, and water use efficiency (WUE). Four treatments were evaluated: (1) a flat plot without mulch control treatment (CK), (2) a flat plot with straw mulch (SM), (3) a flat plot with plastic film mulch (PM), and (4) a ridge-furrow planting with film mulch over the ridge and wheat straw mulch over the furrow (PSM). All mulch treatments significantly improved grain yields and WUE of the winter wheat and summer maize in comparison with CK. The highest grain yields and WUE occurred in the PSM treatment over the two wheat-maize cycles. The average soil water storage within the 0–200 cm soil layer was 3.82%, 2.25%, and 1.31% higher under the PSM, PM, and SM treatments, respectively, in comparison to the CK treatment.Although the soil mulching practices insignificantly changed the total crop evapotranspiration (ET) with a small quantity compared with non-mulched treatment, they tended to reduce non-productive soil evaporation (E) and increase productive plant transpiration (T). All mulching treatments increased the soil temperature of the winter wheat from the seedling to the regreening stages and helped prevent freeze damage. The PSM and SM treatments effectively inhibited the excessive soil temperature rise during the growth stage for summer maize. The PSM treatment resulted in favorable soil moisture and temperature conditions that increased the grain yields and water use efficiency of winter wheat and summer maize. Therefore, we concluded that ridge-furrow planting with film mulch over ridge and wheat straw mulch over the furrow is an effective management practice to increase yields and WUE in a winter wheat-summer maize crop rotation within this sub-humid drought-prone region.

Combined applications of mixed biomaterial amendments and polyacrylamide (MBAP) to maize in semiarid areas have the potential to improve soil physical properties such that improved crop performance may be obtained under deficient irrigation management. In this study, three MBAP applications were C0 (conventional N fertilization application) and C2 and C4 (MBAP applied at rates of 2 and 4 t ha−1, respectively); three irrigation levels were W3 (nearly full irrigation, 85%–100% of field capacity), W2 (light deficit irrigation, 65%–75% of field capacity), and W1 (medium deficit irrigation, 55%–65% of field capacity). Under the same irrigation level, the MBAP significantly decreased soil bulk densities and increased soil hydraulic conductivities and soil water contents. The effects of irrigation levels on soil bulk densities and soil saturated hydraulic conductivities were not significant. Consequently, MBAP improved soil conditions for maize growth and increased grain and biomass yields, especially at the two deficit irrigation levels. Compared with that of C0, grain yields for C2 and C4 were increased by 52.8% and 39.3% under W2, and by 23.5% and 13.7% under W1, respectively. The MBAP and irrigation had significant interaction effects on evapotranspiration during sowing to jointing and on plant heights at 32 d after sowing. The incorporation of MBAP (2 t ha−1) and chemical fertilizer (111.8 kg N ha−1) resulted in the greatest yields under light deficit irrigation and seemed the best approach to improve soil physical properties and sustain maize productivity using limited water resources in dryland regions.

The optimal design for pressurized irrigation subunits is a complicated problem that not only requires a confirmation of the layout but also requires a pipe diameter combination. Using a subunit with single lateral and a subunit with paired laterals as research objects, four mathematical optimization models were established to identify the optimal microirrigation subunit design. The optimization criteria were minimizing the annual total cost (CT) and maximizing the subunit size (A); it was assumed that all the emitters have equal discharge, and only rectangular subunits were considered in this study. No allowable pressure differences allocation between the lateral and the manifold were made in this study, considering that there are many factors that affect the distribution ratio and the overall optimization of the subunit. A genetic algorithm was used to obtain the optimal design when simultaneously considering the layout and pipe diameters of the subunit. The results indicated that the investment cost (Ca) is the most important factor, and it makes up 43–66% of the CT, followed by the water cost (Cw), which accounts for 28–49% of the CT. A subunit with paired laterals is superior to a subunit with single lateral in terms of both the total cost and the control area. On the whole, with the increase in the lateral diameter, both the total cost and the control area will increase. With an increase in the emitter discharge, the total cost increases, while the control area decreases. The change of slope in the lateral direction has little effect on the total cost and control area. The method proposed in this study is applicable to the simultaneous optimization of the subunit in which the layout and area are undetermined, and it may provide a new path towards subunit optimization.

Continuous use of diversion irrigation has been associated with an increase in the frequency of loess landslides on the South Jingyang Platform in Xi’an, China. Continued irrigation results in water content which in turn leads to liquefaction. Causing flowslides characterized by high speed and long distance. After the first flowslide occurs in an area, the seepage field and stress field of the slopes surrounding the flowslide changes, resulting in a decrease in slope stability. This, in turn, leads to the occurrence of retrograde loess slides in the same position that early flowslides occurred. These failures lead to a evolution of the platform. Shear liquefaction occurs in the terrace sand layers, resulting in the liquefied sand layer flows in a non-uniform and irregular manner. This leads to the formation of a thrust nappe structure over a long distance at the distal part of the deposits.

In this study, 14,544 loess landslides collected from the Loess Plateau of China are used to reveal their distribution and origins. Main factors considered include landslide density, regional tectonics, soil properties, geomorphic structure, rainfall distribution, seismic activity, and human activity. Based on these factors, the Loess Plateau is divided into eight zones with high possibilities of landslides that are classified into six genetic types. The first genetic type of clustering distribution of loess landslides is related to several main regional active faults. The second type is related to broken pieces of loess geomorphic structures. The third type is considered to be due to unloading of the geomorphic peripheral slope that can cause the internal structural plane to open and thus controls the prototype and scale of the loess landslide. Change of hydrogeological conditions in the slope softens the loess pedestal and the slippery layer, forming a softening zone and thus controlling the shear crack and slip model of the fourth type of loess landslides. The fifth type is due to seismic activities that can generate additional stress to the Earth's surface and landform slopes, causing the opening of joints and seismic liquefaction. The last type of landslides is caused by human activities by changing the geological structure, hydrogeological conditions, and the inner stress balance of slopes.

Continuous use of diversion-based irrigation has been associated with an increase in the frequency of loess landslides on the South Jingyang Platform, Shaanxi, China. A loess landslide event with a maximum sliding distance of 278 m occurred near the village of Miaodian on May 26, 2015. This landslide event was characterized by four individual landslides. Field investigations, geological exploration, numerical simulation, isotropically consolidated undrained (ICU) triaxial tests, and ring shear tests were conducted to identify its initiation and movement mechanisms. The ICU tests revealed that saturated loess samples were highly liquefiable. High pore water pressure was quickly produced and deviation stress increased the highest value even at low values of axial strain. Geological investigations revealed that cracks penetrated into the saturated zone from the ground surface, and simulation results revealed that these cracks played a dominant role in the infiltration of surface water and led to a rise in the groundwater table. When the infiltration recharge exceeds the holding capacity of the paleosol, the latter behaves as aquifuge under relatively undrained conditions. This process results in the accumulation of water at the bottom of the loess layer, thereby contributing to soil liquefaction and landslide initiation. The ring shear tests revealed that the saturated sand layer of the landslide substrates was subjected to easily inducible high pore water pressure under undrained conditions which led to the thrusting of the sand layer onto the deposit surface and explains the high speed and long runout distance of this landslide.

High group delay dispersion (GDD) is often required for ultrafast laser applications. To achieve GDD level higher than -10000 fs2 in a single mirror setting is difficult due to the high sensitivity to unavoidable production inaccuracies. To overcome the problem, total internal reflection (TIR) based dispersive mirrors have been proposed in theory. In this paper, we report our continuous effort to further design, fabricate and measure TIR based dispersive mirrors.

Loess landslides exhibit strong interactions with the terrace sediments of the Jing River on the South Jingyang Platform, Jingyang, Xi'an, China. Analysis of past landslide events revealed that the sand layer of this terrace was thrust up to the surface, accompanied by other terrace sediments of carrying. This led to the formation of a thrust nappe structure over a long distance. We performed ring shear tests to examine the shear behavior of this sand layer, with the finding that saturated sand was highly susceptible to liquefaction-induced failure. The groundwater level of the study area is high, resulting in near-saturation of the sand layer. Therefore, topographic interferences contributed additional variables and increased interaction complexities. Simulations indicated that the liquefied sand layer was compressed and forced. Due to the absence of constraints, the sand layer near the bottom of the slope was sheared out over a relatively short distance. On the other hand, particle interia and constraints of the stable layer resulted in the sand layer near the distal part of the deposits being sheared upward to the ground. Finally, an initiation-movement model of loess flowslides is proposed. It describes static liquefaction of the loess layer of the slope resulted in occurrence of flowslides. Collisions between the deposits from the platform edge slope and terrace sediments resulted in the shear liquefaction of sands. The landslide experienced four stages as they moved: scraping collisions, floating scrapes, folded thrusts, and nappe accumulation.

The effects of Cr/Mo alloying on the tensile deformation behavior of Fe-Mn-C twinning-induced plasticity steel were investigated. The results showed that Cr/Mo alloying increases both the strength and ductility significantly and concurrently. As compared with the premature saturation of deformation twinning in the Cr/Mo-free steel, a unique twinning behavior occurs in the Cr/Mo-alloyed steel, i.e., retarded but more persistent formation of thinner twins with straining. This unique twinning behavior gives rise to a sustained high strain-hardening rate up to higher strains, which delays the plastic instability and increases both strength and ductility simultaneously.