检索结果-南通市图书馆

The role and potential application of extracellular vesicles in liver cancer

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2021年第8期64卷 1281-1294页

作者： Xuewei qi Shuzhen Chen Huisi He wen wen Hongyang Wang Cancer Research Center The First Affiliated HospitalDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230026China National Center for Liver Cancer Second Military Medical UniversityShanghai 200438China International Cooperation Laboratory on Signal Transduction Eastern Hepatobiliary Surgery HospitalSecond Military Medical UniversityShanghai 200438China

Liver cancer is one of the most common causes of cancer-related death worldwide and mainly includes hepatocellular carcinoma(HCC)and cholangiocarcinoma(CCA).Extracellular vesicles(EVs)are membrane-derived nanometer-sized vesicles that can be released by different cell types under normal and pathological conditions and thus play important roles in the transmission of biological information between *** evidence suggests that liver cancer cell-derived EVs may help establish a favorable microenvironment to support the proliferation,invasion and metastasis of cancer *** this review,we summarized the role of EVs in the tumor microenvironment(TME)during the development and progression of liver *** messenger carriers,EVs are loaded by various biomolecules,such as proteins,RNA,DNA,lipids and metabolites,making them potential liquid biopsy biomarkers for the diagnosis and prognosis of liver *** also highlighted the progress of EVs as antigen carriers and EV-based therapeutics in preclinical studies of liver cancer.

关键词： cancer invasion diagnosis

Improved three-vector based dead-beat model predictive direct power control strategy for grid-connected inverters

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2018年第11期19卷 1420-1431页

作者： Chen-wen CHENG Heng NIAN Long-qi LI College of Electrical Engineering Zhejiang University

Since only one inverter voltage vector is applied during each duty cycle, traditional model predictive direct power control(MPDPC) for grid-connected inverters(GCIs) results in serious harmonics in current and power. Moreover, a high sampling frequency is needed to ensure satisfactory steady-state performance, which is contradictory to its long execution time due to the iterative prediction calculations. To solve these problems, a novel dead-beat MPDPC strategy is proposed, using two active inverter voltage vectors and one zero inverter voltage vector during each duty cycle. Adoption of three inverter vectors ensures a constant switching frequency. Thus, smooth steady-state performance of both current and power can be obtained. Unlike the traditional three-vector based MPDPC strategy, the proposed three vectors are selected based on the power errors rather than the sector where the grid voltage vector is located, which ensures that the duration times of the selected vectors are positive all the time. Iterative calculations of the cost function in traditional predictive control are also removed, which makes the proposed strategy easy to implement on digital signal processors(DSPs) for industrial applications. Results of experiments based on a 1 kW inverter setup validate the feasibility of the proposed three-vector based dead-beat MPDPC strategy.

关键词： Grid-connected inverter Model predictive control Direct power control Three vectors Constant switching frequency Power errors

Characteristics analysis and parameters optimization for the grating eddy current displacement sensor

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第7期10卷 1029-1037页

作者： Hong-li qi Hui ZHAO Wei-wen LIU Department of Instrument Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China

The grating eddy current displacement sensor (GECDS) for distance or position measurement used in watertight electronic calipers was described. The sensor relies on repetitive variation of inductance against displacement caused by the change of coupling areas between moving coils and static reflectors. The investigations focused on setting up and utilizing a computer model of the 3D eddy current fields and geometry to analyze causes of the production of measurement blind areas, and to investigate effects of the sensor parameters, such as axial gap between coils and reflectors, reflector length and reflector width on characteristics of the sensor. Simulation results indicated that the sensor has the smallest nonlinearity error of 0.15%, which agrees well with the experimental results.

关键词： Grating eddy current displacement sensor (GECDS) Watertight electronic calipers Parameters optimization Nonlinearity

Reducing the biases in shortwave cloud radiative forcing in tropical and subtropical regions from the perspective of boundary layer processes

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2016年第7期59卷 1427-1439页

作者： SUN wen qi LI Li Juan WANG Bin State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences Ministry of Education Key Laboratory for Earth System Modeling Center of Earth System Science Tsinghua University

Biases in shortwave cloud radiative forcing(SWCF), which cause overestimates in tropical regions and underestimates in subtropical marine stratocumulus regions, are common in many climate models. Here, two boundary layer processes are investigated in the atmospheric model GAMIL2, entrainment at the top of the boundary layer and longwave radiative cooling at the top of stratocumulus clouds, in order to reduce biases and reveal the mechanisms underlying these processes. Our results show that including the entrainment process in the model can reduce negative SWCF biases in most tropical regions but increases positive SWCF biases in subtropical marine stratocumulus regions. This occurs because entrainment reduces the low-level cloud fraction and its cloud liquid water content by suppressing the vertical turbulent diffusion in the boundary layer and decreasing the relative humidity when warm and dry free atmosphere is entrained in the boundary layer. Longwave radiative cooling at the top of stratocumulus clouds can enhance turbulent diffusion within the stratocumulus-topped boundary layer. When combined with the entrainment process, longwave radiative cooling reduces the positive SWCF biases in subtropical marine stratocumulus regions that are observed using the entrainment process alone. The incorporation of these two boundary layer processes improves the simulated SWCF in tropical and subtropical regions in GAMIL2.

关键词： SWCF GAMIL2 Boundary layer Entrainment Stratocumulus

Dual characteristic of trace rare earth elements in a commercial casting Al-Cu-X alloy

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2015年第5期34卷 308-313页

作者： Li Fan qi-Tang Hao wen-Ke Han State Key Laboratory of Solidification Processing Northwestern Polytechnical University School of Materials Science and Engineering Northwestern Polytechnical University

The effect of rare earth elements on microstructure and mechanical properties of casting Al-Cu-X alloy （X = Mn, Ti, V, Cd, Zr） was investigated in as-cast and T6 conditions. Microstructure evolution was characterized by optical microscopy, scanning electron microscopy, and transmission electron microscopy. RE-containing intermetallic compounds （IMCs） formed in this alloy were indentified by X-ray diffraction （XRD） and energy dispersive spectroscopy （EDS）. It is shown that the additions of RE （60Ce-40La, wt%） result in the formation of Ce-rich blocky-shaped A12o（Ti, V）2RE and La-rich skeletal-shaped A18Cu4RE. Tensile results of samples after T6 treatment indicate that the strength and ductility increase slightly to 480 MPa and 9.7 %, respectively, with RE content increasing from 0 wt% to 0.3 wt%. This is due to the combinative hardening effects of reduced grain size, enhanced precipitation of 0＇（Al2Cu） phase and Al20 Cu2Mn3 dispersed particles, and minor La-rich IMCs at the grain boundaries of α-Al dendrites. The decrease of strength of 0.5 wt% RE-added sample is ascribed to the aggregation of Al20（Ti, V）2RE IMCs inside the grains. The dual characteristic of rare earth elements was also discussed in terms of its positive and negative effects on mechanical properties.

关键词： Aluminum alloys Rare earth Microstructure Mechanical property Intermetallic compounds

Controlling the entanglement of mechanical oscillators in composite optomechanical system

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第4期27卷 178-183页

作者： Jun Zhang qing-Xia mu wen-Zhao Zhang School of Mathematics and Statistics Guizhou University of Finance and Economics Guiyang 550025 China Mathematics and Physics Department North China Electric Power University Beijing 102206 China Beijing Computational Science Research Center (CSRC) Beijing 100193 China

A controllable entanglement scheme of two mechanical oscillators is proposed in a composite optomechanical *** the case of strong driving and high dissipation,the dynamics of the movable mirror of the optomechanical cavity is characterized by an effective frequency in the long-time evolution of the *** the classical nonlinear effects in an optomechanical system,we investigate the relationship between the effective frequency of the movable mirror and the adjustable parameters of the *** shows that the effective frequency of the movable mirror can be adjusted ranging fromωm（the resonance frequency of the coupling oscillator） to-ω*** the condition of experimental realization,we can generate and control steady-state entanglement between two oscillators by adjusting the effective frequency of the movable mirror and reducing the effective dissipation by selecting the parameter of the cavity driving laser *** scheme provides a promising platform to control the steady-state behavior of solid-state qubits using classical manipulation,which is significant for quantum information processing and fundamental research.

关键词： entanglement optomechanics

Studies on the Electronic Structures and Spectra of C_(78)(CH_2)_3

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2007年第3期26卷 314-320页

作者： TENG qi-wen WU Shi CHEN Si-Cong Department of Chemistry Zhejiang University Hangzhou 310027. China Department of Biomedicine-engineering Zhejiang University Hangzhou 310027 China

The structures and spectra of 20 possible isomers of C78（CH2）3 have been studied by using AMI, INDO/CIS and DFT methods. The results show that the most stable isomer is 1,2,3,4,5,6-C78（CH2）3 （A） with annulene structures, where three -CH2 groups are added to the 6/6 bonds located at the same hexagon passed by the shortest axis of C78 （C2v）. Compared with that of C78 （C2v）, the first absorption in the electronic spectrum of C78（CH2）3 （A） iS blue-shifted because of its wider LUMO-HOMO energy gap. While the IR frequencies of the C-C bonds on the carbon cage are red-shifted owing to the formation of annulene structures and the extension of the conjugated system. The chemical shifts of the carbon atoms in 13C NMR spectra are moved upfield upon the addition.

关键词： C78(CH2)3 DFT electronic spectra IR spectra NMR spectra

Study on UV, IR and NMR Spectra of Double Hydrogen-bonded Complexes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2006年第2期25卷 143-148页

作者： ZHU Liang-Liang TENG qi-wen WU Shi Department of Chemistry Zhejiang University Hangzhou 310027 China

AM 1, PM3 and DPT methods were used to study on the hydrogen-bonded dimer of melamine and [ 1,3] dioxane-2,4,6-trione. The electronic spectra, IR and NMR spectra of some complexes were calculated with INDO/SCI, AM 1 and B3LYP/6-31G（d） methods, respectively. It is demonstrated that the negative stability energy is responsible for the formation of the complexes. Stabilization energies of these complexes were altered among the variations of electric property and steric effects of the monomers. HOMO-LUMO energy gaps were shrunk and the blue-shift of absorptions in the electronic spectra occurred. The vibrations of N-H bonds and chemical shifts of the protons changed with the formation of hydrogen bonds.

关键词： melamine dioxane-2,4,6-trione hydrogen bonds B3LYP

Boosting nitrogen electrocatalytic fixation by three-dimensional TiO_(2-δ)N_δnanowire arrays

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2022年第12期75卷 293-300,I0008页

作者： Jianjia mu Xuan-wen Gao Zhaomeng Liu wen-Bin Luo Zhenhua Sun qinfen Gu Feng Li School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina Institute of Metal Research Chinese Academy of SciencesShenyang 110016LiaoningChina Australian Synchrotron(ANSTO) 800 Blackburn RdClayton 3168VictoriaAustralia

Owing to the environmental and inherent advantages,nitrogen reduction reaction(NRR)by electrocatalysts attracts global *** surface engineering is widely employed to enhance the electrocatalytic activity by atomic defects and heterostructure effects.A three-dimensional(3D)free-standing integrated electrode was fabricated by numerous nearly-single-crystal TiO_(2-δ)N_δnanowire *** on the high electronic conductivity network,it exposes numerous active sites as well to facilitate the selective nitrogen adsorption and*H adsorption *** synergistic effects between Ti^(3+)and oxygen vacancy(O_v)boost the intrinsic catalytic activity,in which Ti^(3+)acquired electrons via Ovcan effectively activate the N≡N bond and make it easy to bind with *** energy barrier of primary protonation process(*N_(2)+H^(+)+e^(-)→*NNH)can be dramatically *** highest ammonia yield rate(14.33μg h^(-1)mgcat^(-1))emerges at-0.2 V,while the optimal ammonia Faradaic efficiency(9.17%)is acquired at-0.1 *** functional theory(DFT)calculation reveals that the Ti^(3+)can be served as the active sites for nitrogen adsorption and activation,while ammonia synthesis is accomplished by the distal *** high electronic conductivity integrated network and synergistic effects can significantly facilitate nitrogen absorption and accelerate electrocatalytic reaction kinetic,which are responsible for the excellent NRR performance at room temperature.

关键词： Nanowires TiO_(2-δ)N_δ Electrocatalysis NRR DFT