检索结果-南通市图书馆

Study of thermal decoherence of harmonic oscillators

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

原子与分子物理学报 2025年第5期42卷 108-114页

作者： LI Jian ZHOU Gao-Liang YAN Zheng-Xin LIU wei WANG zhao-Qi College of Science Xi’an University of Science and TechnologyXi’an 710054China

The thermal decoherence of harmonic oscillators is investigated *** quantum system presented here is a one-dimensional oscillator with angular frequency,which is surrounded by a thermal bath of environmental *** are various environmental oscillators with different angular frequency(below an ultraviolet cutoff).At the beginning,the quantum system is a pure state and the environmental oscillators are in thermodynamic equilibrium with *** a period,the system-environment interactions inspire significant decoherence of the quantum *** decoherence is displayed by explicit calculations of the purity and von Neumann entropy of the quantum *** is worth noting that the decoherence could be significant even in the weak coupling and low temperature case due to the large amount of environmental degrees of *** the decoherence process is inspired between the quantum system and an ordinary thermal environment here,the thermal decoherence result is quite general.

关键词： Quantum decoherence Grand canonical ensemble Oscillators

Fatigue Life Prediction for NiTi Shape Memory Alloy Micro-tubes Under Uniaxial Stress-Controlled One-Way Shape Memory Cyclic Loading

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2022年第1期35卷 15-25页

作者： Tianxing zhao Guozheng kang Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and EngineeringSouthwest Jiaotong UniversityChengdu 610031China Institute of Applied Mechanics State Key Laboratory of Traction PowerSouthwest Jiaotong UniversityChengdu 610031China

By choosing the dissipation energy as the damage variable,corresponding damage evolution equations are established,respectively,for the mechanical cyclic loading part and the thermal one during the thermo-mechanical cyclic loading of NiTi shape memory alloys(SMAs)involving one-way shape memory effect(simply denoted as the OWSME cycling).And then,the evolution law of total damage is obtained by a superposition of such two damage ***,the uniaxial OWSME fatigue lives of NiTi SMA micro-tubes are predicted by combining the proposed damage model with an adopted failure *** results show that all the predicted fatigue lives are located within the twice scatter band with regard to the experimental ones,and most of them are located within a scatter band of 1.5 *** is indicated that the predicted OWSME fatigue lives are in good agreement with the experimental ones.

关键词： NiTi shape memory alloy One-way shape memory effect Damage evolution Fatigue life prediction Uniaxial loading

Thienylmethylene Oxindole Based Conjugated Polymers via Direct Arylation Polymerization and Their Electrochromic Properties

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2021年第2期39卷 147-153,I0005页

作者： wei Yang Hao-Guo Yue Dong zhao Hui Yan kang-Li Cao Jin-Sheng zhao Qing Zhang Shanghai Key Laboratory of Electrical Insulation and Thermal Aging School of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai200240China Shanghai Space Environment Simulation and Verification Engineering Technology Research Center Shanghai Institute of Spacecraft EquipmentShanghai 200240China College of Chemistry and Chemical Engineering Liaocheng UniversityLiaocheng 252059China

Direct arylation methods have been used to polymerize thienylmethylene oxindoles(TEIs)and 3,3-bis[[(2-ethylhexyl)oxy]methyl]-3,4-dihydro-2 H-thieno-[3,4-b][1,4]dioxepin(ProDOT)for new donor-acceptor conjugated *** polymers exhibited blue hues in neutralstate with distinct color-to-transmissive reversible electrochromic switching under applied potentials from 0 V to+1.5 V,and showed high coloration efficiencies(436-438 cm^(2)·C^(-1))in near-infrared regions with high switching speeds around 1-2 s under ambient conditions.

关键词： Electrochromic Direct arylation Donor-acceptor polymers Isoindigo Near-infrared

Resolving the developmental mechanisms of cardiac microthrombosis of SARS-CoV-2 based on single-cell transcriptome analysis

在线全文

学校读者我要写书评

暂无评论

Science China Life Sciences 2025年第1期 103-115页

作者： Xizi Luo Nan Zhang Yuntao Liu Beibei Du Xuan Wang Tianxu zhao Bingqiang Liu Shishun zhao Jiazhang Qiu Guoqing Wang State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Key Laboratory for Zoonosis Research of the Ministry of EducationCollege of Basic MedicineJilin University State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Key Laboratory for Zoonosis Research of the Ministry of EducationCollege of Veterinary MedicineJilin University College of Mathematics Jilin University Bioinformatic Lab School of MathematicsShandong University Department of Cardiology China-Japan Union HospitalJilin University

The coronavirus disease 2019（COVID-19） outbreak caused by the severe acute respiratory syndrome coronavirus-2（SARS-CoV-2） developed into a global health emergency. Systemic microthrombus caused by SARS-CoV-2 infection is a common complication in patients with COVID-19. Cardiac microthrombosis as a complication of SARS-CoV-2 infection is the primary cause of cardiac injury and death in patietns with severe COVID-19. In this study, we performed single-cell sequencing analysis of the right ventricular free wall tissue from healthy donors,patients who died during the hypercoagulable period of characteristic coagulation abnormality（CAC）, and patients who died during the fibrinolytic period of CAC. We collected 61,187 cells enriched in 24 immune cell subsets and 13 cardiac-resident cell subsets. We found that in the course of SARS-CoV-2 infected heart microthrombus, MYO1EhighRASGEF1Bhighmonocyte-derived macrophages promoted hyperactivation of the immune system and initiated the extrinsic coagulation pathway by activating chemokines CCL3, CCL5. This series of events is the main cause of cardiac microthrombi following SARS-CoV-2 infection. In a SARS-CoV-2 infected heart microthrombus, excessive immune activation is accompanied by an increase in cellular iron content, which in turn promotes oxidative stress and intensifies intercellular competition. This induces cells to alter their metabolic environment, resulting in increased sugar uptake via the glycosaminoglycan synthesis pathway. In addition, high levels of reactive oxygen species generated by elevated iron levels promote increased endogenous malondialdehyde synthesis in a subpopulation of cardiac endothelial cells. This exacerbates endothelial cell dysfunction and exacerbates the coagulopathy process.

关键词：

同方期刊数据库

Detecting the driving forces underlying the divergence of spruce forests in China: evidence from phytocoenology, morphology and phylogenetics

在线全文

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2020年第1期13卷 59-69页

作者： Guo-Hong Wang Hai-wei zhao Meng An He Li wei-kang Zhang State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesNo.20 NanxincunXiangshanBeijing100093China Beijing Museum of Natural History Beijing100050China

Aims We aimed to elucidate the driving forces underlying the geographical distribution of spruce forests,as well as the morphological and phylogenetic divergence among spruce species in *** One hundred and seventy two sites across the entire range of spruce forests in China(23°–53°N,75°–134°E,250–4300 m a.s.l.)were sampled for species composition,geographical coordinates,and topographic and climatic *** spruce taxa,which are naturally distributed in China,were respectively grouped into morphologically defined sections and phylogenetically distinct *** approaches,including two-way indicator species analysis,principal components analysis,detrended correspondence analysis,canonical correspondence analysis(CCA),and partial CCA,were used for data *** Findings The 172 samples grouped into 13 spruce forests,the geographical distributions of which were closely related to climate and geographical *** variation in species composition explained by the geographical coordinates(32.01%)was significantly higher than that explained by the climatic(27.76%)and topographic variables(23.32%).Of the three morphologically defined sections,*** occurred mainly in wetter habitats with a mean annual precipitation of ca.229 mm and 426 mm higher than the habitats of *** and ***(P<0.01),*** the two phylogenetically distinct clades,Clade-II(an older clade)occurred in habitats with warm winters and cool summers whose mean temperature in the coldest month was ca.8–10℃ higher,yet accumulated temperature during the growing season(≥5℃)was ca.297–438℃ lower,than the habitats of Clade-III(a younger clade)(P<0.01).Our data support the hypothesis that geographical location may be a greater determinant of variation in species *** addition,moisture conditions tend to be the key determinants that account for the divergence among the morphologically defined sections,while the phylogenetic divergenc

关键词： Picea climate biogeography refugia selective pressure

Aperture-averaged scintillation index and fade statistics in weak oceanic turbulence

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第6期30卷 320-328页

作者： Hao Wang Fu-Zeng kang Xuan Wang wei zhao Shu-wei Sun State Key Laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision MechanicsChinese Academy of SciencesXi'an 710119China University of Chinese Academy of Sciences Beijing 100049China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

With the rapid demand for underwater optical communication(UOC), studies of UOC degradation by oceanic turbulence have attached increasing attention worldwide and become a research hot-spot in recent years. Previous studies used a simplified and inaccurate oceanic turbulence spectrum, in which the eddy diffusivity ratio between temperature and salinity is assumed to be unity and the outer scale of turbulence is assumed to be infinite. However, both assumptions are not true in most of the actual marine environments. In this paper, based on the Rytov theory in weak turbulence, we derive analytical expressions of "the aperture-averaged scintillation index"(SI) for both plane and spherical waves, which can clearly demonstrate how SI is influenced by several key factors in UOC. Then, typical fade statistics of the UOC system in weak turbulence is discussed including the probability of fade, the expected number of fades per time, the mean fade time,signal-to-noise ratio and bit error rate. Our results show that spherical wave is preferable in the UOC system in weak turbulence compared to plane wave, and the aperture-averaged effect has a significant impact on UOC system's *** results can be used to determine those key parameters for designing the UOC system over reasonable ranges.

关键词： underwater optical communication(UOC) aperture-averaged scintillation index fade statistics

New insights into eutrophication management:Importance of temperature and water residence time

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2022年第1期34卷 229-239页

作者： Feng zhao Xu Zhan Hai Xu Guangwei Zhu wei Zou Mengyuan Zhu Lijuan kang Yulong Guo Xingchen zhao Zicong Wang wei Tang State Key Laboratory of Lake and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China School of Environmental and Civil Engineering Jiangnan UniversityWuxi 214122China

Eutrophication and harmful cyanobacterial blooms threaten water resources all over the *** is a great controversy about controlling only phosphorus or controlling both nitrogen and phosphorus in the management of lake *** primary argument against the dual nutrients control of eutrophication is that nitrogen fixation can compensate the nitrogen ***,it is of great necessary to study the factors that can significantly affect the nitrogen *** to the difference of climate and human influence,the water quality of different lakes(such as water temperature,N:P ratio and water residence time)is also quite *** studies have reported that the low N:P ratio can intensify the nitrogen fixation ***,the effects of temperature and water residence time on the nitrogen fixation remain ***,30 shallows freshwater lakes in the eastern plain of China were selected to measure dissolved N_(2) and Ar concentrations through N_(2):Ar method using a membrane inlet mass spectrometer to quantify the nitrogen fixation capacities and investigate whether the temperature and water residence time have a great impact on nitrogen *** results have shown that the short lake water residence time can severely inhibit the nitrogen fixation capacities through inhibiting the growth of nitrogenfixing cyanobacteria,changing the N:P ratio and resuspending the solids from ***,lakes with low water temperature also have a low nitrogen fixation capacity,suggesting that controlling nitrogen in such lakes is feasible if the growth of cyanobacteria is limited by nitrogen.

关键词： Eutrophication N_(2):Ar method Temperature N:P ratio Lake water residence time

Paraffin/SiC as a Novel Composite Phase-Change Material for a Lithium-Ion Battery Thermal Management System

在线全文

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2021年第1期27卷 55-63页

作者： wei kang Yiqiang zhao Xueheng Jia Lin Hao Leping Dang Hongyuan wei School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Tianjin Lishen Battery Joint-Stock Co. LtdTianjin 300072China

A lithium-ion battery thermal management system has always been a hot spot in the battery industry. In this study, a novel high-thermal-conductivity composite phase-change material(CPCM) made by paraffin wax and silicon was adopted to facilitate heat transfer. Moreover, high resistance or even insulation of CPCM is capable of preventing short circuits between the cells. The heat transfer mechanism of CPCMs was determined under a scanning electron microscope. A thermogravimetric analyzer was employed to determine the thermal stability. A diff erential scanning calorimeter was used to explore the thermophysical properties of the composite samples. By comparing the results of the experiment, it was reported that under the silicon carbide content of 5%, the parameters were better than others. The phase-change enthalpy of CPCM was 199.4 J/g, the leakage rate of liquid was 4.6%, and the melting point was 53.6℃. To verify the practicality of CPCM, a three-dimensional layered battery pack model was built in the COMSOL Multiphysics software. By simulating the thermal runaway inside the battery packs of various materials, it was reported that the addition of CPCM significantly narrowed the temperature range of the battery pack from 300–370 to 303–304 K. Therefore, CPCM can eff ectively increase the rate of heat transfer to prevent the chain of thermal runaway reactions. It also enables the battery pack to run at a stable temperature.

关键词： Lithium-ion battery Phase-change material Paraffin Silicon carbide Thermal runaway

Low-cost and fluoride-free synthesis of MFI zeolite nanosheets with enhanced stability for benzene alkylation with ethanol

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 458-468页

作者： Peng Zhu Cun Liu Yiren Yu Guoshu Gao Yumeng zhao Xiongfu Zhang Guodong Liu Guohui Yang State Key Laboratory of Fine Chemicals School of Chemical Engineering Dalian University of Technology State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences

Zeolite nanosheets with a short b-axis thickness are highly desirable in lots of catalytic reactions due to their reduced diffusion resistance. Nevertheless, conventional synthesis methods usually require expensive structure-directing agents(SDAs), pricey raw materials, and eco-unfriendly fluorine-containing additives. Here, we contributed a cost-effective and fluoride-free synthesis method for synthesizing high-quality MFI zeolite nanosheets through a Silicalite-1(Sil-1) seed suspension and urea cooperative strategy, only with inexpensive colloidal silica as the Si source. Our approach was effective for synthesizing both Sil-1 and aluminum-containing ZSM-5 nanosheets. By optimizing key synthesis parameters,including seed aging time, seed quantity, and urea concentration, we achieved precise control over the crystal face aspect ratio and b-axis thickness. We also revealed a non-classical oriented nanosheet growth mechanism, where Sil-1 seeds induced the formation of quasi-ordered precursor particles, and the(010)crystal planes of these particles facilitated urea adsorption, thereby promoting c-axis-oriented *** obtained ZSM-5 nanosheets exhibited exceptional catalytic performance in the benzene alkylation with ethanol, maintaining stability for over 500 h, which is 5 times longer than traditional ZSM-5 catalysts. Furthermore, large-scale production of ZSM-5 nanosheets was successfully carried out in a 3 L highpressure autoclave, yielding samples consistent with those from laboratory-scale synthesis. This work marks a significant step forward in the sustainable and efficient production of MFI nanosheets using inexpensive and environmentally friendly raw materials, offering the broad applicability in catalysis.

关键词： MFI zeolite ZSM-5 Nanosheets Scale-up synthesis Aromatic alkylation