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Optical system for extremely large spectroscopic survey telescope

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 158-174页

作者： ding-qiang Su Hua Bai Xiangyan Yuan Xiangqun Cui Key Laboratory of the Ministry of Education School of Astronomy and Space ScienceNanjing UniversityNanjing 210023China Nanjing Institute of Astronomical Optics and Technology(NIAOT) Chinese Academy of SciencesNanjing 210042China University of Chinese Academy of Sciences Nanjing 211135China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 101408China

This article presents research work on a spectroscopic survey *** idea is as follows:for such a telescope,a pure reflecting optical system is designed,which should have an aperture and a field of view(FOV)both as large as possible and excellent image quality,and then a strip lensm(lens-prism)atmospheric dispersion corrector(S-ADC)is added,only for correcting the atmospheric *** the fund limitation and the simplicity of scaling up,some 12-m telescopes are designed as ***,Korsch,and Meinel put forward the four-mirror Nasmyth systems I and II,which are used in this *** of 1.5°,2°,and 2.5°are *** all systems,the image qualities are *** the S-ADC relaxes the optical glass size restriction,this 12-m telescope with a FOV of 2.5°can be magnified in proportion to a 16-m *** etendue(from Frenchétendue)and focal surface will now be the largest in the *** such a telescope,a pure reflecting optical system can also be obtained.A subsequent coudésystem is designed with excellent image quality.

关键词： telescopes spectroscopic survey

Adipokinetic hormone signaling regulates adult dehydration resistance in the migratory locust

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Journal of Integrative Agriculture 2024年第9期23卷 3104-3117页

作者： Xianliang Huang Dai Shi Kai Deng Shuzhen Jia ding ding Li Hou Bing Chen College of Life Sciences Hebei UniversityBaoding 071002China Hebei Basic Science Center for Biotic Interaction Hebei UniversityBaoding 071002China State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijing 100101China

Drought events have become more severe under climate change,and this can pose a major threat to the survival of various *** molecular mechanisms involved in dehydration resistance are not well ***,adults of the migratory locust,Locusta migratoria,were subjected to food-mediated dehydration,and adipokinetic hormone(AKH)signaling was found to play a key role in regulating dehydration ***,dehydration shortened the lifespan,increased the body weight loss,and reduced the water loss rate in adult *** transcriptome profiles revealed variations in tissue-specific gene expression between dehydration-resistant locusts and normal ***,dehydration selection and exposure induced prominent expression of AKH genes in the retrocerebral complex of adult ***,individual knockdown of AKH1,AKH2,or AKH receptor(AKHR)accelerated water loss and shortened the lifespan of adult locusts under dehydration conditions,and trehalose supplementation ameliorated the negative effects caused by interference with AKH or *** findings demonstrated that AKH/AKHR signaling-dependent trehalose metabolism plays a crucial role in regulating locust dehydration resistance and thus provide novel insights into the regulatory mechanism underlying drought resistance.

关键词： adipokinetic hormone adipokinetic hormone receptor trehalose dehydration resistance Locusta migratoria

Late Mesoproterozoic to Early Neoproterozoic Tectonic Evolution of the SW Yangtze Block, South China: Evidence from U-Pb Geochronology and Lu-Hf Isotopes of Detrital Zircons from Sedimentary Rocks

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Journal of Earth Science 2024年第3期35卷 812-827页

作者： Peiwen Liu Xiaozhong ding Yanxue Liu Jibiao Zhang Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China School of Civil and Hydraulic Engineering Xichang UniversityXichang 615000China

In situ zircon U-Pb geochronological and Lu-Hf isotope studies of detrital zircons from Late Mesoproterozoic to Early Neoproterozoic sedimentary units on the southwestern margin of the Yangtze Block have important implications for the tectonic evolution of the Yangtze *** Huili Group contains zircons whose ages are mainly Late Archean to Mesoproterozoic(2650-2450,2100-1800,and 1350-1150 Ma).The Dengxiangying Group has one major age population of 1900-1600 Ma,and two subordinate age populations of 1350-1100 and 2300-2000 *** Group sedimentary rocks have a zircon age population mainly in the range of 970-850 Ma,contemporaneous with the ages of widespread arc-related magmatism in the western Yangtze *** these results with previous work,the Huili and Dengxiangying groups were most likely deposited during ca.1160 to 1000 Ma in an intra-continental rift basin setting,while the Yanbian Group accumulated during>920 to 782 Ma in a back-arc basin setting at the southwestern margin of the Yangtze *** addition,all these results further suggest a tectonic transition from a continental rift basin to a convergent environment at the southwestern margin of the Yangtze Block at 1000-970 Ma.

关键词： Late Mesoproterozoic Early Neoproterozoic zircon U-Pb age Lu-Hf isotope southwestern Yangtze Block geochronology

Compliance motion control of the hydraulic dual-arm manipulator with adaptive mass estimation of unknown object

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Frontiers of Mechanical Engineering 2024年第1期19卷 35-52页

作者： Bolin SUN Min CHENG Ruqi ding Bing XU State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China Key Laboratory of Conveyance and Equipment(Ministry of Education) East China Jiaotong UniversityNanchang 330013China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China

Given the limited operating ability of a single robotic arm,dual-arm collaborative operations have become increasingly *** with the electrically driven dual-arm manipulator,due to the unknown heavy load,difficulty in measuring contact forces,and control complexity during the closed-chain object transportation task,the hydraulic dual-arm manipulator(HDM)faces more difficulty in accurately tracking the desired motion trajectory,which may cause object deformation or even *** overcome this problem,a compliance motion control method is proposed in this paper for the *** mass parameter of the unknown object is obtained by using an adaptive method based on velocity *** to the difficulty in obtaining the actual internal force of the object,the pressure signal from the pressure sensor of the hydraulic system is used to estimate the contact force at the end-effector(EE)of two hydraulic manipulators(HMs).Further,the estimated contact force is used to calculate the actual internal force on the ***,a compliance motion controller is designed for HDM closed-chain *** position and internal force errors of the object are reduced by the feedback of the position,velocity,and internal force errors of the object to achieve the effect of the compliance motion of the HDM,i.e.,to reduce the motion error and internal force of the *** required velocity and force at the EE of the two HMs,including the position and internal force errors of the object,are inputted into separate position *** addition,the position controllers of the two individual HMs are designed to enable precise motion control by using the virtual decomposition control ***,comparative experiments are carried out on a hydraulic dual-arm test *** proposed method is validated by the experimental results,which demonstrate improved object position accuracy and reduced internal force.

关键词： hydraulic dual-arm manipulator compliance motion control unknown object adaptive mass estimation nonlinear control

Distributed Fault Estimation for Nonlinear Systems With Sensor Saturation and Deception Attacks Using Stochastic Communication Protocols

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IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1865-1876页

作者： Weiwei Sun Xinci Gao Lusong ding Xiangyu Chen Institute of Automation Qufu Normal UniversityQufu 273165China

This paper is aimed at the distributed fault estimation issue associated with the potential loss of actuator efficiency for a type of discrete-time nonlinear systems with sensor *** the distributed estimation structure under consideration,an estimation center is not necessary,and the estimator derives its information from itself and neighboring nodes,which fuses the state vector and the measurement *** an effort to cut down data conflicts in communication networks,the stochastic communication protocol(SCP)is employed so that the output signals from sensors can be ***,a recursive security estimator scheme is created since attackers randomly inject malicious signals into the selected *** this basis,sufficient conditions for a fault estimator with less conservatism are presented which ensure an upper bound of the estimation error covariance and the mean-square exponential boundedness of the estimating ***,a numerical example is used to show the reliability and effectiveness of the considered distributed estimation algorithm.

关键词： Actuator fault deception attacks distributed estimation sensor saturation stochastic communication protocol(SCP).

Development of porphyrin-based fluorescent sensors and sensor arrays for saccharide recognition

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Chinese Chemical Letters 2024年第2期35卷 16-23页

作者： Yubin ding Jiaxin Wang Ruinan Wang Yongshu Xie Department of Chemistry College of SciencesNanjing Agricultural UniversityNanjing 210095China Shanghai Key Laboratory of Functional Materials Chemistry Key Laboratory for Advanced Materials and Institute of Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science & TechnologyShanghai 200237China

Saccharide sensing is a very meaningful research topic as saccharides are involved in many biological ***,it is challenging to design molecular sensors for saccharides because this family of compounds is hydromimetic in aqueous solutions and shares a similar chemical *** this review,research progress in the development of porphyrin-based saccharide sensors is described with representative *** focus on using porphyrin as the signal reporter because porphyrins exhibit unique advantages in high chemical stability,long emission wavelength,and multiple structural modification *** literature results have been classified into mainly two sections according to the general working principles of the porphyrin sensor *** the first section,recognition unit,design strategy and sensing performance of traditional porphyrin-based selective saccharide sensors are *** in the second section,development of porphyrin-based sensor arrays for pattern recognition of saccharides has been *** through the design strategy and sensing performance of reported achievements,it is reasonable to anticipate a bright future for designing practical porphyrin-based saccharide sensors.

关键词： Porphyrin Saccharide Fluorescent sensing Selective sensing Pattern recognition

A review on g-C_(3)N_(4)decorated with silver for photocatalytic energy conversion

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Chinese Chemical Letters 2024年第2期35卷 187-196页

作者： Ziyu Pan Wufan ding Hanchun Chen Haodong Ji Eco-environment and Resource Efficiency Research Laboratory School of Environment and EnergyPeking University Shenzhen Graduate SchoolShenzhen 518055China

Artificial photocatalytic energy conversion is considered as the most potential strategy for solving the increasingly serious energy crisis and environmental pollution problems by directly capturing solar ***,high efficiency photocatalyst has drawn significant research attention in recent *** to the excellent electronic,optical,structural,and physicochemical performances,silver-based g-C_(3)N_(4)have become promising *** review emphasizes the recent progresses and challenges on g-C_(3)N_(4)decorated with silver for photocatalytic energy *** extensive use of g-C_(3)N_(4)decorated with silver in diverse photocatalytic reactions,including hydrogen evolution,pollutant degradation and carbon dioxide reduction,is also fully *** addition,we propose the perspectives of g-C_(3)N_(4)decorated with silver on photocatalytic *** hope that this review will shed some light on the photocatalytic energy conversion of g-C_(3)N_(4)decorated with silver.

关键词： g-C_(3)N_(4) Silver-modified g-C_(3)N_(4) Photocatalytic energy conversion H_(2)evolution Pollutant degradation CO_(2)reduction

A new mixed type crack propagation criterion in shale reservoirs

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Petroleum 2024年第1期10卷 85-92页

作者： Muru ding Zhirong Jin Yanjun Zhang Jinghong Hu Beijing Key Laboratory of Unconventional Natural Gas Geology Evaluation and Development Engineering China University of GeosciencesBeijingChina Sinopec Jiangsu Oil Field Branch YangzhouChina Oil&Gas Technology Research Institute Changqing Oilefiled CompanyPetroChinaXi'anChina

Hydraulic fracturing is a mainstream technology for unconventional oil and gas reservoirs development all over the *** to use this technology to achieve high-level oil and gas resource extraction and how to form complex fracture networks as hydrocarbon transportation channels in tight reservoirs,which depends to a large extent on the interaction between hydraulic and pre-existing *** hydraulic fracturing of fractured reservoirs,the impact of natural fractures,perforation direction,stress disturbances,faults and other influencing factors will produce a mixed I&II mode hydraulic *** forecast whether hydraulic fractures cross pre-existing fractures,according to elastic mechanics and fracture mechanics,a stress state of cracks under the combination of tensile(I)and shear(II)is presented.A simple mixed-mode I&II hydraulic fracture's crossing judgment criterion is established,and the propagation of hydraulic fractures after encountering natural fractures is *** results show that for a given approaching angle there exists a certain range of stress ratio when crossing *** high approaching angle and large stress ratio,it is likely that hydraulic cracks will go directly through pre-existing *** reinitiated angle is always controlled within the range of approximately 30among the main direction of penetration.

关键词： Crack propagation criterion Stress ratio Approaching angle Reinitiated angle Mechanical model

Numerical analysis of geosynthetic-reinforced embankment performance under moving loads

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 682-696页

作者： Xuanming ding Jinqiao Zhao Qiang Ou Jianfei Liu College of Civil Engineering Chongqing UniversityChongqing400045China Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqing400045China China United Engineering Corporation Limited Hangzhou310052China

The performance of geosynthetic-reinforced embankments under traffic moving loads is always a hotspot in the geotechnical engineering field.A three-dimensional(3D)model of a geosynthetic-reinforced embankment without drainage consolidation was established using the finite element software *** this model,the traffic loads were simulated by two moving loads of rectangular pattern,and their amplitude,range,and moving speed were realized by a Fortran *** embankment fill was simulated by an equivalent linear viscoelastic model,which can reflect its *** geogrid was simulated by the truss element,and the geocell was simulated by the membrane *** elements were utilized to weaken the boundary effect caused by the model geometry at the *** of the established numerical model was conducted by comparing the predicted deformations in the cross-section of the geosynthetic-reinforced embankment with those from the existing *** this basis,the dynamic stress and strain distribution in the pavement structure layer of the geosynthetic-reinforced embankment under a moving load was also ***,a parametric study was conducted to examine the influences of the different types of reinforcement,overload,and the moving load velocity on the geosynthetic-reinforced embankment.

关键词： Geosynthetic-reinforced layer Numerical model Moving load Embankment Deformation Stress