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Water and thermal conditions variation and the vegetation response at semi⁃ arid Basin

Shengtai Xuebao 2024年第16期44卷 7198-7212页

作者： Fang Q. Zhang S. Wang G. Wang Y. Duan L. Liu T. yao j. School of Water Conservancy and Hydropower Engineering North China Electric Power University Beijing 102206 China College of Water Sciences Beijing Normal University Beijing 100875 China The College of Water Conservancy and Civil Engineering Inner Mongolia Agricultural University Hohhot 010018 China The School of Ecology and Environment Inner Mongolia University Hohhot 010021 China

Recently, most semi⁃arid basins in China have experienced vegetation greening under significant water and thermal conditions changes, which has exacerbated the shortage of water resources despite the positive effect of increasing carbon sinks and reducing carbon emissions. The study of vegetation response under variations of water and thermal conditions can help to understand the mechanism of the balance between the hydrological processes and vegetation pattern and is of great significance for the sustainable utilization of water resources and ecological protection. However, few studies have focused on the time⁃periodic and segmented response mechanisms of vegetation dynamics to variations of water and thermal conditions, resulting in unclear mechanisms of trade⁃off between vegetation greening and water resources. This study analyzed the varied trends of water and thermal conditions and discussed the spatio⁃temporal response of vegetation from two points: overall trends and varied processes at the upper and middle Hailar River Basin from 1980 to 2012 by using trends and wavelet period analysis. The results show that: (1) spatially, the average annual precipitation increased and the temperature decreased from west (grassland) to east (forest). Compared with the grassland area, the runoff and the Normalized Difference Vegetation Index (NDVI) in the forest area showed larger, and indicated slower warming and larger precipitation declining. (2) Temporally, the average annual precipitation and the runoff slightly decreased with a trend of 10 mm/ 10 a and 19.3 mm/ 10 a, respectively; the average annual temperature and NDVI in the growing season increased significantly with a trend of 0.65 ℃ / 10 a and 0.003—0.006/ 10 a, respectively. The results suggested that warming and drying inhibited the runoff and increased the vegetation growth, even in the context of precipitation increased and smooth increasing trend of temperature after 1998, showing the accumulative effect of w

关键词： runoff variations vegetation response water and thermal conditions water stress

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NUMERICAL INVESTIGATION OF STRAIGHT-LINE LASER FORMING UNDER THE TEMPERATURE GRADIENT MECHANISM

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Acta Metallurgica Sinica(English Letters) 2006年第2期19卷 144-150页

作者： Y.j. Shi H. Shen Z.Q. yao j. Hu School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China

Laser forraing is a new flexible and dieless forming technique. To achieve the high accuracy forming, the temperature gradient mechanism （TGM） is studied. In the analysis of TGM, the plate bends about x-axis and about y-axis as well. To understand the deformation trend, the numerical simulation of deformation of plate is conducted by choosing different laser powers, laser spot diameters, scanning speeds, lengths, widths and thicknesses. From the results of simulation, it can be seen that the laser spot diameter, the scanning speed, laser power and thickness of plate play dominant roles in the laser forming process. However, the bending angles αx and αy show different trends with the variation of parameters. In addition, in comparison with above four parameters, the effect of length and width of plate on the beading angle may be neglected, but their effects are significant for the bending radius R.

关键词： laser forming temperature gradient mechanism metal plate

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NUMERICAL INVESTIGATION ON FLOW CHARACTERISTICS IN RIBBED BEND

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j.urnal of Hydrodynamics 2001年第2期13卷 111-120页

作者： yao, j. Fan, j.R. Zhang, X.Y. Cen, K.F. Dept. of Energy Engineering Zhejiang Univ. Hangzhou 310027 China

Previous research by the author has proved that ribbed bend technology is a simple and efficient anti-erosion method. The present paper is a further study to unveil the mechanism of the technology by using numerical method. The flow characteristics in ribbed bend were studied. A k-Ε turbulence model was used and the simulations were carried out in the body-fitted coordinates. This procedure was confirmed to be credible by showing the satisfactory agreement between the predications and experimental results. It is concluded that the character of the longitudinal flow in ribbed bend especially in the concave parts between ribs has a beneficial effect on increasing the anti-erosion ability of ribbed bend but the secondary flow has little effect on determining the particle traj.ctory.

关键词： Boundary conditions Differential equations Erosion Mathematical models Numerical methods Three dimensional

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EXPERIMENTAL RESEARCH AND NUMERICAL SIMULATION OF LASER SHOCK FORMING OF TA2 TITANIUM SHEET

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Acta Metallurgica Sinica(English Letters) 2006年第5期19卷 347-354页

作者： F. Wang Z. Q. yao j. Hu Q.L. Deng School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200030 China

Laser shock forming （ISF） was a new technique realized by applying an impulsive pressure generated by laser-induced shock wave on the surface of metal sheet. LSF of metal sheet was investigated with experiments and numerical simulation. The basic theories were introduced; the surface quality and deformation of the processed titanium sample （TA2） were examined; ABAQUS was used to simulate ISF and the central displacement of the shocked region was measured and compared with the simulation. Overlapped ISF treatment was experimentally carried out to produce groove and simulation. The results showed that the surface quality and the microstructure with single laser pulse had no remarkable change, and ablation was observed on the surface of the sample with overlapped pulses. The deformation observed in the numerical simulation agreeed with that observed in the experimental measurement quite well.

关键词： laser shock forming numerical simulation surface quality deformation

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Role of aminopeptidase N-like in the acquisition of begomoviruses by Bemisia tabaci,the whitefly vector

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Insect Science 2024年第3期31卷 707-719页

作者： Yun-Yun Fan yao Chi Na Chen Wilmer j.Cuellar Xiao-Wei Wang Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang ProvinceInstitute of Insect SciencesZhejiang UniversityHangzhouChina Zhej.ang Tianmushan National Nature Reserve Administration HangzhouChina Institute of Plant Protection Liaoning Academy of Agricultural SciencesShenyangChina Virology Laboratory Cassava ProgramInternational Center for Tropical Agriculture(CIAT)PalmiraColombia

Sri Lankan cassava mosaic virus(SLCMV)is a prominent causative agent of cassava mosaic disease in Asia and relies on the whitefly Bemisia tabaci cryptic complex for its ***,the molecular mechanisms involved in SLCMV transmission by *** have yet to be *** this study,we identified an aminopeptidase N-like protein(BtAPN)in *** Asia II 1,an efficient vector of SLCMV,which is involved in the SLCMV transmission *** the use of glutathione S-transferase pull-down assay and LC-MS/MS analysis,we demonstrated the interaction between BtAPN and the coat protein(CP)of *** interaction was further confirmed in vitro,and we observed an induction of BtAPN gene expression following SLCMV *** interfering with the function of BtAPN,the quantities of SLCMV were significantly reduced in various parts of *** Asia II 1,including the whole body,midgut,hemolymph,and primary salivary ***,we discovered that BtAPN is conserved in *** Middle East-Asia Minor 1(MEAM1)and interacts with the CP of tomato yellow leaf curl virus(TYLCV),a begomovirus known to cause severe damage to tomato *** BtAPN with antibody led to a significant reduction in the quantities of TYLCV in whitefly whole body and organs/*** results demonstrate that BtAPN plays a generic role in interacting with the CP of begomoviruses and positively regulates their acquisition by the whitefly.

关键词： BtAPN coat protein SLCMV TYLCV virus acquisition whitefly

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Synergistic silver-mediated and palladium-catalyzed nondirected olefination of aryl C–H bond: quick access to multi-substituted aryl olefins

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Science China Chemistry 2024年第3期67卷 882-889页

作者： j.an yao Lili Shao Xiaohong Huo Xiaoming Wang Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Frontiers Science Center for Transformative MoleculesSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Organometallic Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 20032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China

Transition metal-catalyzed olefination of aryl C-H bond is a powerful tool for the synthesis of alkenes. While the Pd-catalyzed oxidative C-H olefination of arenes, also known as Fuj.wara-Moritani reaction, has been established as one of the most efficient methods, the substrates are largely limited to terminal olefins with electron-withdrawing group(s). Herein, we report a synergistic silver-mediated and palladium-catalyzed non-directed C-H olefination of arenes with vinyl(pseudo)halides, which offers a complementary strategy to the typical Fuj.wara-Moritani reaction. The reactions proceeded well for a variety of halogenated arenes, heteroarenes, and olefin substrates, providing an efficient access to various multi-substituted aryl olefins, including trisubstituted/tetrasubstituted olefins and several complex olefins derived from medicines or natural products. Mechanistic studies indicated a bimetallic Pd/Ag cooperation is operative in the catalysis, i.e., the reaction is initiated by aryl C-H bond cleavage via ligation with phosphine/Ag species, followed by transferring of the aryl moiety to a vinyl palladium intermediate,which is in turn formed by oxidative addition of vinyl(pseudo)halide to a Pd complex. This method enables the synthesis of a wide range of challenging multi-substituted vinyl products from simple arenes(directing-group free) in a streamlined and controllable fashion.

关键词： direct C–H olefination multi-substituted aryl alkenes bimetallic Pd/Ag cooperation C–H functionalization

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Cobalt-catalyzed reductive alkynylation to construct C(sp)-C(sp^(3))and C(sp)-C(sp^(2))bonds

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Chinese Chemical Letters 2024年第7期35卷 253-258页

作者： Lei Wan Yizhou Tong Xi Lu yao Fu Hefei National Research Center for Physical Sciences at the Microscale iChEMCAS Key Laboratory of Urban Pollutant ConversionAnhui Province Key Laboratory of Biomass Clean EnergyUniversity of Science and Technology of ChinaHefei 230026China Key Laboratory of Precision and Intelligent Chemistry School of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefei 230026China

Transition-metal-catalyzed cross-electrophile coupling has emerged as a reliable method for constructing carbon–carbon ***,we report a general method,cobalt-catalyzed reductive alkynylation,to construct C(sp)-C(sp^(3))and C(sp)-C(sp^(2))*** presented reaction has a broad substrate scope,enabling the efficient cross-electrophile coupling between alkynyl bromides with alkyl halides and aryl or alkenyl(pseudo)*** presented reaction is conducted under mild conditions,tolerating many functional groups,thus suitable for the modification and synthesis of biologically active molecules.

关键词： Cobalt-catalysis Cross-electrophile coupling Carbon-carbon bond formation Reductive alkynylation Alkyne synthesis

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ANovel Non-Isolated Cubic DC-DC Converter with High Voltage Gain for Renewable Energy Power Generation System

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Energy Engineering 2024年第1期121卷 221-241页

作者： Qin yao Yida Zeng Qingui j.a School of Electrical Engineering Southwest Jiaotong UniversityChengdu610036China

In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effectively enhance voltage gain and reduce device *** address the issue of low output voltage in current renewable energy power generation systems,this study proposes a novel non-isolated cubic high-gain DC-DC converter based on the traditional quadratic DC-DC boost converter by incorporating a SC and a SL-SC ***,the proposed converter’s details are elaborated,including its topology structure,operating mode,voltage gain,device stress,and power ***,a comparative analysis is conducted on the voltage gain and device stress between the proposed converter and other high-gain ***,a closed-loop simulation system is constructed to obtain simulation waveforms of various devices and explore the dynamic ***,an experimental prototype is built,experimental waveforms are obtained,and the experimental dynamic performance and conversion efficiency are *** theoretical analysis’s correctness is verified through simulation and experimental *** proposed converter has advantages such as high voltage gain,low device stress,high conversion efficiency,simple control,and wide input voltage range,achieving a good balance between voltage gain,device stress,and power *** proposed converter is well-suited for renewable energy systems and holds theoretical significance and practical value in renewable energy *** provides an effective solution to the issue of low output voltage in renewable energy power generation systems.

关键词： Cubic DC-DC converter high voltage gain low device stress high efficiency renewable energy

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Deciphering a Million-Plus RSA Integer with Ultralow Local Field Coefficient h and Coupling Coefficient j.of the Ising Model by D-Wave 2000Q

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Tsinghua Science and Technology 2024年第3期29卷 874-882页

作者： Chao Wang Qiaoyun Hu Haonan yao Sumin Wang Zhi Pei j.int International Research Laboratory of Specialty Fiber Optics and Advanced Communication Shanghai UniversityShanghai 200444China

This work is the first to determine that a real quantum computer(including generalized and specialized)can decipher million-scale RSA relying solely on quantum algorithms,showing the real attack potential of D-Wave *** influence of different column widths on RSA factorization results is studied on the basis of a multiplication table,and the optimal column method is determined by traversal *** traversal experiment of integer factorization within 10000 shows that the local field and coupling coefficients are 75%–93%lower than the research of Shanghai University in 2020 and more than 85%lower than that of Purdue University in *** low Ising model parameters are crucial to reducing the hardware requirements,prompting factoring 1245407 on the D-Wave 2000Q real machine.D-Wave advantage already has more than 5000 qubits and will be expanded to 7000 qubits during 2023–2024,with remarkable improvements in decoherence and *** machine is expected to promote the solution of large-scale combinatorial optimization *** of the contributions of this paper is the discussion of the long-term impact of D-Wave on the development of post-quantum cryptography standards.

关键词： quantum annealing RSA D-Wave 2000Q post-quantum cryptography

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Oxygen tension modulates cell function in an in vitro three-dimensional glioblastoma tumor model

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Bio-Design and Manufacturing 2024年第3期7卷 307-319页

作者： Sen Wang Siqi yao Na Pei Luge Bai Zhiyan Hao Dichen Li j.ankang He j.Miguel Oliveira Xiaoyan Xue Ling Wang Xinggang Mao State Key Laboratory for Manufacturing System Engineering Xi’an Jiaotong UniversityXi’an 710054China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710054China NMPA Key Laboratory for Research and Evaluation of Additive Manufacturing Medical Devices Xi’an Jiaotong UniversityXi’an 710054China 3B’s Research Group I3Bs–Research Institute on BiomaterialsBiodegradables and BiomimeticsUniversity of MinhoHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineAveParkZona Industrial da Gandra4805-017 BarcoGuimarãesPortugal ICVS/3B’s-PT Government Associate Laboratory 4806-909 Braga/Guimar˜aesPortugal Department of Pharmacology School of PharmacyFourth Military Medical UniversityXi’an 710032China Department of Neurosurgery Xijing HospitalFourth Military Medical UniversityXi’an 710032China

Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor ***,the lack of tumor models able to precisely emulate natural brain tumor tissue has impeded the study of the effects of hypoxia on the progression and growth of tumor *** study reports a three-dimensional(3D)brain tumor model obtained by encapsulating U87MG(U87)cells in a hydrogel containing type I *** also documents the effect of various oxygen concentrations(1%,7%,and 21%)in the culture environment on U87 cell morphology,proliferation,viability,cell cycle,apoptosis rate,and ***,it compares two-dimensional(2D)and 3D *** comparison purposes,cells cultured in flat culture dishes were used as the control(2D model).Cells cultured in the 3D model proliferated more slowly but had a higher apoptosis rate and proportion of cells in the resting phase(G0 phase)/gap I phase(G1 phase)than those cultured in the 2D ***,the two models yielded significantly different cell ***,hypoxia(e.g.,1%O2)affected cell morphology,slowed cell growth,reduced cell viability,and increased the apoptosis rate in the 3D *** results indicate that the constructed 3D model is effective for investigating the effects of biological and chemical factors on cell morphology and function,and can be more representative of the tumor microenvironment than 2D culture *** developed 3D glioblastoma tumor model is equally applicable to other studies in pharmacology and pathology.

关键词： Hypoxia Glioma Three-dimensional glioma model In vitro

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