Disturbances rejection optimization based on improved two-degree-of-freedom LADRC for permanent magnet synchronous motor systems

Permanent magnet synchronous motor(PMSM)speed control systems with conventional linear active disturbance rejection control(CLADRC)strategy encounter issues regarding the coupling between dynamic response and disturbance suppression and have poor performance in suppressing complex nonlinear disturbances.In order to address these issues,this paper proposes an improved two-degree-of-freedom LADRC(TDOF-LADRC)strategy,which can enhance the disturbance rejection performance of the system while decoupling entirely the system's dynamic and anti-disturbance performance to boost the system robustness and simplify controller parameter tuning.PMSM models that consider total disturbances are developed to design the TDOF-LADRC speed controller accurately.Moreover,to evaluate the control performance of the TDOF-LADRC strategy,its stability is proven,and the influence of each controller parameter on the system control performance is analyzed.Based on it,a comparison is made between the disturbance observation ability and anti-disturbance performance of TDOF-LADRC and CLADRC to prove the superiority of TDOF-LADRC in rejecting disturbances.Finally,experiments are performed on a 750 W PMSM experimental platform,and the results demonstrate that the proposed TDOF-LADRC exhibits the properties of two degrees of freedom and improves the disturbance rejection performance of the PMSM system.

Electrode/Electrolyte Interfacial Chemistry Modulated by Chelating Effect for High-Performance Zinc Anode

Although Zn metal has been regarded as the most promising anode for aqueous batteries,its practical application is still restricted by side reactions and dendrite growth.Herein,an in-situ solid electrolyte interphase(SEI)film formed on the interface of electrode/electrolyte during the plating/stripping of zinc anodes by introducing trace amounts of multidentate ligand sodium diethyldithiocarbamate(DDTC)additive into 1 M ZnSO_(4).The synergistic effect of in-situ solid electrolyte interphase forming and chelate effect endows Zn^(2+)with uniform and rapid interface-diffusion kinetics against dendrite growth and surface side reactions.As a result,the Zn anode in 1 M ZnSO_(4)+DDTC electrolytes displays an ultra-high coulombic efficiency of 99.5%and cycling stability(more than 2000 h),especially at high current density(more than 600 cycles at 40 mA cm^(-2)).Moreover,the Zn//MnO_(2)full cells in the ZnSO_(4)+DDTC electrolyte exhibit outstanding cyclic stability(with 98.6%capacity retention after 2000 cycles at 10 C).This electrode/electrolyte interfacial chemistry modulated strategy provides new insight into enhancing zinc anode stability for high-performance aqueous zinc batteries.

Synergistic enhancement of cathode/anode interfaces with high water-retentive organohydrogel enabling highly stable zinc ion batteries

Current aqueous battery electrolytes,including conve ntional hydrogel electrolytes,exhibit unsatisfactory water retention capabilities.The sustained water loss will lead to subsequent polarization and increased internal resistance,ultimately resulting in battery failure.Herein,a double network(DN) orga no hydrogel electrolyte based on dimethyl sulfoxide(DMSO)/H_(2)O binary solvent was proposed.Through directionally reconstructing hydrogen bonds and reducing active H_(2)O molecules,the water retention ability and cathode/anode interfaces were synergistic enhanced.As a result,the synthesized DN organohydrogel demonstrates exceptional water retention capabilities,retaining approximately 75% of its original weight even after the exposure to air for 20 days.The Zn MnO_(2) battery delivers an outstanding specific capacity of275 mA h g^(-1) at 1 C,impressive rate performance with 85 mA h g^(-1) at 30 C,and excellent cyclic stability(95% retention after 6000 cycles at 5 C).Zn‖Zn symmetric battery can cycle more than 5000 h at 1 mA cm^(-2) and 1 mA h cm^(-2) without short circuiting.This study will encourage the further development of functional organohydrogel electrolytes for advanced energy storage devices.

MiR-182 is up-regulated and targeting Cebpa in hepatocellular carcinoma

MicroRNAs （miRNAs） are endogenous small non-coding RNAs that repress their targets at post transcriptional level.Existing studies have shown that miRNAs are important regulatory genes in hepatocellular carcinoma （HCC）,as either tumor suppressors or oncogenes.MiR-122 is normally downregulated in HCC and regarded as a tumor suppressor.Recently miR-122 has been reported to be regulated by CEBPA,which is then involved in a novel pathway to influence proliferation of tumor cells.However it is unknown whether CEBPA is regulated by miRNAs in HCC.In this study,we find that miR182 is upregulated in HCC model rat,and represses CEBPA in both rat and human.This further improves the current CEBPA/miR-122 pathway that controls the proliferation of tumor cells.These results suggest that miR-182 is a potential oncogene in HCC and could be used as a diagnostic marker and drug target of HCC.

Electrolyte additive enhances the electrochemical performance of Cu for rechargeable Cu//Zn batteries

Cu-based cathodes in aqueous batteries become very attractive in view of high theoretical capacity,moderate operation voltage and rich reserves of raw materials.However,their applications are obstructed by serious side reactions.The side reaction mainly arises from the spontaneous formation of Cu_(2)O,which occupies the electrode surface and lowers the reaction reversibility.Here,Na_(2)EDTA is introduced to address these issues.Both experimental results and theoretical calculations indicate that the Na_(2)EDTA reshapes the solvation structure of Cu^(2+)and modifies the electrode/electrolyte interface.Therefore,the redox potential of Cu^(2+)/Cu_(2)O is reduced and the surface of Cu is protected from H2O,thereby inhibiting the formation of Cu_(2)O.Meanwhile,the change in the solvation structure reduces the electrostatic repulsion between Cu^(2+)and the cathode,leading to high local concentration and benefiting uniform deposition.The results shed light on the applications of rechargeable Cu-based batteries.

Semi-Supervised Clustering Algorithm Based on Deep Feature Mapping

Clustering analysis is one of the main concerns in data mining.A common approach to the clustering process is to bring together points that are close to each other and separate points that are away from each other.Therefore,measuring the distance between sample points is crucial to the effectiveness of clustering.Filtering features by label information and mea-suring the distance between samples by these features is a common supervised learning method to reconstruct distance metric.However,in many application scenarios,it is very expensive to obtain a large number of labeled samples.In this paper,to solve the clustering problem in the few supervised sample and high data dimensionality scenarios,a novel semi-supervised clustering algorithm is proposed by designing an improved prototype network that attempts to reconstruct the distance metric in the sample space with a small amount of pairwise supervised information,such as Must-Link and Cannot-Link,and then cluster the data in the new metric space.The core idea is to make the similar ones closer and the dissimilar ones further away through embedding mapping.Extensive experiments on both real-world and synthetic datasets show the effectiveness of this algorithm.Average clustering metrics on various datasets improved by 8%compared to the comparison algorithm.

Variable Rate Technology and Cotton Yield Response in Texas

Variable Rate Technology （VRT） takes within-field variability into consideration and aims to match resource application to crop requirement. Even though Texas is the most important cotton producing state in the US, the rate of VRT adoption is very low here. Hence, analyzing the factors influencing the adoption and providing a regional estimate of the impact of VRT adoption on cotton yield is very important. This study used the 2009 Southern Cotton Precision Farming Survey to analyze the farm and farmer characteristics affecting the adoption of VRT among Texas cotton farmers and to empirically estimate the impact of adoption of VRT on cotton yield in Texas. A two-stage least square procedure with a logistic regression model in the first stage and a multiple linear regression model in the second stage was used to analyze the data. The study revealed that there are significant regional differences in adoption pattern within the state of Texas; and the farmers from the coastal region, where there is higher within-field variability, were more likely to adopt VRT compared to other regions. Younger farmers, farmers managing larger farms, and farmers who use computers for farming operations were more likely to adopt VRT. The results also showed that, on an average, the adoption of VRT does not lead to significant yield improvements for cotton in Texas. Since the impact of VRT adoption on yield is not significant, the source of economic advantage of VRT adoption in Texas may be the reduction of input cost.

Does Climatic Variability Influence Agricultural Land Prices under Differing Uses? The Texas High Plains Case

The Texas High Plains faces projections of increasing temperature and declining precipitation in the future on account of its semi-arid climate. This research evaluated the impact of climatic variability on agricultural land prices under different land uses in the Texas High Plains, employing the Ricardian approach of land climate pricing over a study period of 1991-2011. The results indicate that climatic variability had a greater impact on irrigated land prices as compared to dryland and ranchland. This study could be instrumental in predictive market analyses of rural land values in semi-arid economies which are vulnerable to future climate change.

Objective Synoptic Weather Classification on Air Pollution during Winter Seasons in Hangzhou

Using the 2015-2018 Hangzhou city PM2.5,PM10,SO2,CO,NO2 and O3 mass concentration data,ERA5 reanalysis data and ground observation data,through the PCT classification method,the objective analysis of the winter air pollution weather situation in Hangzhou was obtained.The results showed that the winter air quality concentration in Hangzhou continued to be high from 2015 to 2018,and the air pollution was the most significant.Through objective classification,it is concluded that the main weather conditions affecting the region in winter are divided into 6 types,namely high pressure control,high pressure bottom control equalizing field,L-shaped high pressure control,high pressure front control equalizing field,low pressure control,low pressure front control Equalizing field.Among them,when high pressure control,high pressure bottom control equalizing field,L high pressure control,low pressure control are affected by local sources,the impact of external sources has a greater impact on the air quality in Hangzhou,and air pollution is prone to occur;before low pressure When the pressure equalization field is controlled by the Ministry and the pressure equalization field is controlled by the high pressure front,the local wind and precipitation in Hangzhou are relatively high,which is not conducive to the accumulation of air pollutants.The probability of occurrence of air pollution is small,and air pollution is not easy to occur.

Research on the Implementation of Flipped Classroom in the World Economy Course

In the context by which the World Economy course is restricted by the traditional teaching model,the flipped classroom model can solve the issues in the teaching process.The flipped classroom can systematically strengthen teacher-student interaction during and after classes,optimize students’learning habits,improve students’learning effect,and effectively provide timely feedback on the teaching effect.Therefore,the World Economy course should implement flipped classrooms and put forward corresponding safeguard measures,including actively changing the role of teachers,effectively guiding students to participate in flipped classrooms,equipped with sufficient and high-quality software and hardware equipment,as well as promoting the scientific evaluation of flipped classroom teaching effect.

NixB/rGO as the cathode for high-performance aqueous alkaline zinc-based battery

Aqueous alkaline zinc batteries(AZBs)exhibit great potential due to their high capacity,high safety and low cost.However,despite these advantages,the lack of high stability and high utilization rate makes the search for high-performance cathode materials a great challenge.Here,an amorphous nickel boride/rGO(NixB/rG O)complex structure was designed.As a result of abundant unsaturated active sites and synergistic electronic effects,amorphous NixB exhibits excellent energy storage properties.As well as having high electrical conductivity,rGO avoids aggregation of NixB nanoparticles,ensuring that NixB/rGO electrodes have a high energy storage capacity.The structure has a strong adhesion between NixB and rGO,which protects its stable structure and extends its life.More importantly,the NixB/rGO//Zn full battery shows remarkable capacity(228.4 m Ah/g at 2 A/g),extraordinary cycle durability(93.7%retained after1000 cycles)and strong energy density 399.7 Wh/kg,when coupled with NixB/rGO cathode.This work will also shed light on other nickel-zinc batteries in order to achieve super durability and capacity.

Highly robust zinc metal anode directed by organic–inorganic synergistic interfaces for wearable aqueous zinc battery

Flexible aqueous zinc batteries(FAZBs)with high safety and environmental friendliness are promising smart power sources for smart wearable electronics.However,the bare zinc anode usually suffers from damnable dendrite growth and rampant side reaction on the surface,greatly impeding practical applications in FAZBs.Herein,a composite polymer interface layer is artificially self‐assembled on the surface of the zinc anode by graft‐modified fluorinated monomer(polyacrylic acid‐2‐(Trifluoromethyl)propenoic acid,PAA‐TFPA),on which an organic–inorganic hybrid(PAA‐Zn/ZnF2)solid electrolyte interface(SEI)with excellent ionic conductivity is formed by interacting with Zn2+.Both the pouch cell and fiber zinc anode exhibit excellent plating/stripping reversibility after protecting by this organic–inorganic SEI,which can be stably cycled more than 3000 h in symmetric Zn||Zn cells or 550 h in fiber Zn||Zn cells.Additionally,this interface layer preserves zinc anode with excellent mechanical durability under various mechanical deformation(stably working for another 1200 h after bending 100 h).The corresponding PAA‐Zn/ZnF2@Zn||MnO2 full cell displays an ultra‐long life span(79%capacity retention after 3000 cycles)and mechanical robustness(85%of the initial capacity for another 3000 cycles after bending 100 times).More importantly,the as‐assembled cells can easily power smart wearable devices to monitor the user's health condition.

Impact of the Complex Terrain in Beijing on Formation of Low-Level Jets

This study investigated how the Taihang Mountains and the Yanshan Mountains affect low-level jets(LLJs)in the Beijing area,based on conventional radiosonde observations from Nanjiao Observatory(2016–2017)and high-resolution Weather Research and Forecasting–Advanced Research WRF(WRF-ARW)model simulations.Analysis of radiosonde observations indicated that LLJs in the study area are mainly from the southwest and northwest directions,with occurrence frequency of 44.6%and 33.0%,respectively.Southwest(northwest)LLJs are aligned parallel(perpendicular)to the orientation of the Taihang Mountain Range.Terrain sensitivity experiments using the WRF-ARW model were then conducted to examine the effects of terrain forcing on the northwest and southwest LLJs,with adopted terrain heights of 100%and 50%.The results showed that for northwest LLJs,reduction in the elevation of the Taihang Mountain Range led to weakening of jet intensity by approximately 20%and reduction in jet maximum height by approximately 250 m;lowering the Yanshan Mountain Range had minor influence on the northwest LLJs,with only a 5.2%reduction in intensity and no substantial change in jet maximum height.For southwest LLJs,reduction in the elevation of both the Taihang and Yanshan Mountain ranges resulted in minor changes in the intensity and height of the jets.Further analysis revealed that the topography in the Beijing area could modulate the height and intensity of the stable layer by altering the inversion structure within the boundary layer.The LLJs can develop rapidly within the stable layer,and both the location and the scale of the jet core exhibited reasonable agreement with the extent of the stable layer.

High-performance alkaline aqueous zinc battery enabled by nickel-cobalt-tellurium materials

The capacity and cycling performance of cathodes are key factors in aqueous zinc batteries(AZBs).The search for cathode materials with long cycle lives and high specific capacities is of paramount importance.In this study,a bimetallic telluride with a hollow polyhedral structure was synthesized using a hydrothermal method followed by vapor deposition.This composite exhibits high conductivity,facilitates rapid diffusion of electrolyte ions into the interior,and accelerates redox reactions,thereby enhancing electrochemical performance.The CoTe_(2)-NiTe_(2) electrode demonstrates an impressive specific capacity of 188.8 mAh/g at 1 A/g,highlighting its efficiency in storing a significant amount of charge per unit mass during electrochemical reactions.The assembled CoTe_(2)-NiTe_(2)//Zn battery shows favorable capacity retention(76.4%)after 10000 cycles.The energy density is remarkably high,reaching 290.3 Wh/kg,while maintaining a power density of 1.75 kW/kg.This bimetallic telluride strategy holds great promise as an alternative cathode for AZBs.

Nickel/cobalt based materials for supercapacitors

The electrode materials as the key component of supercapacitors have attracted considerable research interests, especially for nickel/cobalt based materials by virtue of their superior electrochemical performance with multiple oxidation states for richer redox reactions, abundant natural resources, lower prices and toxicity. There are many advanced electrodes based on the nickel/cobalt materials exploited for the application of supercapacitors, however, some controversial statements have induced some confusion. Herein, we refine the mechanism of energy storage for the nickel/cobalt based materials for supercapacitors and reclassify them into battery-type materials with the corresponding devices named as hybrid supercapacitors.

Health Status and Earnings of Migrant Workers from Rural China

The migration of rural laborers into cities for employment has been one of the main driving forces of China＇s economic growth over the past three decades. Based on a dataset collected by the Ministry of Agriculture of China from 2003 to 2007, this paper examines the impact of health on the earnings of migrant workers engaging in physically-intensive work requiring good health. Our findings indicate that a poor health status not only weakens the incentive of rural laborers to participate in the migrant labor force but also significantly reduces their earnings. A migrant worker in poor health only earns 67percent of what a healthy worker makes. Among all the human capital characteristics and family economic factors, health status is the most influential on earnings for less educated workers. Labor productivity has a greater impact on earnings than the annual number of days that aperson works. Ongoing health-care reforms aimed at the improvement of the health-care services available to rural laborers are urged to help reduce poverty in rural China.

Hierarchical CuCo_2O_4@nickel-cobalt hydroxides core/shell nanoarchitectures for high-performance hybrid supercapacitors

Ni0.5Co0.5（OH）2 nanosheets coated CuCo2O4 nanoneedles arrays were successfully designed and synthe- sized on carbon fabric. The core/shell nanoarchitectures directly served as the binder-free electrode with a superior capacity of 295.6 mAh g-1 at 1 Ag-1, which still maintained 220 mAh g-1 even at the high current density of 40 A g-l, manifesting their enormous potential in hybrid supercapacitor devices. The asassembled CuCo2O4@Ni0.5Co0.5（OH）2]]AC hybrid supercapacitor device exhibited favorable properties with the specific capacitance as high as 90 F g 1 at 1 A g-1 and the high energy density of 32 Wh kg 1 at the power density of 800 Wkg-1. Furthermore, the as-assembled device also delivered excellent cycling performance （retaining 91.9% of the initial capacitance after 12,000 cycles at 8 A g 1） and robust mechanical stability and flexibility, implying the huge potential of present hierarchical electrodes in energy storage devices.

耦合无枝晶锌负极和可逆脱嵌钙离子的磷酸钒钠正极实现先进钙锌混合离子电池

混合离子电池综合了单一离子电池的优点,为开发高性能二次电池提供了新的见解.本文合成了一种有无定形活性碳和还原氧化石墨烯包覆的NASICON型正极材料(NVP@AC@rGO)用于钙离子的可逆脱嵌,并组装了一种与锌金属负极和水系混合电解质耦合的Ca/Zn离子混合电池.这种完美的结合不仅充分发挥了钙离子在NASICON结构中优异的扩散动力学,而且巧妙利用钙离子的低还原电位,形成静电屏蔽效应,从而抑制了锌枝晶的形成.因此,该混合电池具有超高的比容量,出色的倍率性能以及循环稳定性.这种巧妙的组合平衡了单一多价离子电池的优缺点,为设计高性能的水性多价离子电池提供了一种新的可行途径.

Amorphous Ni-Co-S nanocages assembled with nanosheet arrays as cathode for high-performance zinc ion battery

The selection and development of cathode of alkaline zinc batteries(AZBs)is still hindered and often leads to poor rate capability and short cycle life.Here,amorphous hollow nickel-cobalt-based sulfides nanocages with nanosheet arrays(AM-NCS)are designed and constructed with ZIF-67 as the selftemplate to exchange with Ni^(2+) and S^(2-) by using a two-step ion exchange method.The synthesized AM-NCS possess the high specific capacity(160 m Ah/g at 2 A/g),and the assembled battery has excellent rate performance(146 m Ah/g reversible capacity at 5 A/g).The assembled device has excellent rate performance(155 m Ah/g at 2 A/g)and long cycling stability(7000 cycles,62.5%of initial capacity).The excellent electrochemical properties of the electrode materials are mainly attributed to the unique structure,in particular,polyhedron structure with hollow structure can improve the cyclic stability,and the amorphous structure can expose more reactive sites on the surfaces of nickel,cobalt and sulfur.This work provides a new strategy for the design and fabrication of high performance cathode materials for AZBs.

Measuring boundary-layer height under clear and cloudy conditions using three instruments

Boundary-layer height （BLH） under clear, altostratus and low stratus cloud conditions were measured by GPS sounding, wind profiler radar, and micro-pulse lidar during the atmospheric radiation measurement experiment from Sep. to Dec. 2008 in Shouxian, Anhui, China. Results showed that during daytime or nighttime, regardless of cloud conditions, the GPS sounding was the most accurate method for measuring BLH. Unfortunately, because of the long time gap between launchings, sounding data did not capture the diurnal evolution of the BLH. Thus, wind profile radar emerged as a promising instrument for direct and continuous measurement of the mixing height during the daytime, accurately determining BLH using the structure parameter of the electromagnetic refractive index. However, during nighttime, radar was limited by weak signal extraction and did not work well for determining the BLH of the stable boundary layer, often recording the BLH of the residual layer. While micro-pulse lidar recorded the evolution of BLH, it overestimated the BLH of the stable boundary layer. This method also failed to work under cloudy conditions because of the influence of water vapor. Future work needs to develop a method to determine BLH that combines the complimentary features of all three algorithms.