检索结果-南通市图书馆

Numerical interpretation of transient permeability test in tight rock

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

Journal of Rock Mechanics and Geotechnical Engineering 2018年第1期10卷 32-41页

作者： Chong cao Department of Civil Engineering and Applied Mechanics McGill University

Pulse-decay method has been widely used to estimate the fluid transport properties of low-permeability geomaterials. In this context, radial flow transient pulse test is conducted to measure the water permeability of Cobourg limestone hollow cylinder. The proposed method applies hydraulic pulses to the sealed central cavity and then the cavity pressure dissipates as the fluid migrates into the saturated rock matrix. The influence of entrapped air bubbles within the pressurized cavity is crucial to interpreting permeability from transient pulse test. The modeling results indicate that the air inclusions can significantly increase the fluid compressibility and thus delay the hydraulic pulse decay process, which may lead to the underestimation of the rock permeability.

关键词： Pulse-decay method Low-permeability Air-water mixture Compressibility

Explicit Reciprocity Law for Lubin-Tate Formal Groups

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2006年第5期22卷 1399-1412页

作者： Lei cao School of Mathematical Sciences Peking University Beijing 100871 P. R. China

In this article, using Fontaine＇s ФГ-module theory, we give a new proof of Coleman＇s explicit reciprocity law, which generalizes that of Artin-Hasse, Iwasawa and Wiles, by giving a complete formula for the norm residue symbol on Lubin-Tate groups. The method used here is different from the classical ones and can be used to study the Iwasawa theory of crystalline representations.

关键词： ФГ-module Formal groups explicit reciprocity law Kummer map

Mesoscopic-Scale Numerical Investigation Including the Influence of Process Parameters on LPBF Multi-Layer Multi-Path Formation

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2021年第1期126卷 5-23页

作者： Liu cao Institute for Systems Rheology School of Mechanical and Electrical EngineeringGuangzhou UniversityGuangzhou Higher Education Mega CenterGuangzhou510006China

As a typical laser additive manufacturing technology,laser powder bed fusion(LPBF)has achieved demonstration applications in aerospace,biomedical and other ***,how to select process parameters quickly and reasonably is still themain concern of LPBF *** order to quantitatively analyze the influence of different process parameters(laser power,scanning speed,hatch space and layer thickness)on the LPBF process,the multilayer and multi-path forming process of LPBF was predicted based on the open-source discrete element method framework Yade and the open-source finite volume method framework *** on the design of experiments method,a four-factor three-level orthogonal test scheme was designed,and the porosity and surface roughness data of each calculation scheme were *** analyzing the orthogonal test data,it was found that as the laser power increased,the porosity decreased,and as the scanning speed,hatch space,and layer thickness increased,the porosity *** addition,the influence of laser power and scanning speed on surface roughness showed a trend of decreasing first and then increasing,while the influence of scanning distance and layer thickness on surface roughness showed amonotonous increasing *** order of the influence of each process parameter on porosity was:scanning speed>laying thickness>laser power>hatch space,and the order of the influence of each process parameter on surface roughness was:hatch space>layer thickness>laser power>scanning *** the porosity of the part is most sensitive to scanning speed,and the surface roughness is the most sensitive to hatch *** above conclusions are expected to provide process control basis for actual LPBF production of the 316L stainless steel alloy.

关键词： Laser powder bed fusion process parameter porosity surface roughness orthogonal test method numerical simulation

Chemical U-Th-Pb Monazite Dating of Deformations versus Pluton Emplacement and the Proterozoic History of the Arkansas River Region,Colorado,USA

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

Acta Geologica Sinica(English Edition) 2009年第5期83卷 917-926页

作者： cao Hui State Key Laboratory of Geological Processes and Mineral Resources and Beijing Key Laboratory of Resources Information Research China University of Geosciences Beijing 100083 China School of Earth and Environmental Sciences James Cook University Townsville Queensland 4811 Australia

Five lengthy periods involving multiple phases of cordierite and andalusite growth were revealed by detailed studies of foliation inflection/intersection axes （FIA） preserved in porphyroblasts in schists from the Arkansas River region in Colorado, USA. The regionally consistent character of the succession of five different FIA trends enabled the relative timing of each FIA with respect to the next to be determined. The FIA succession from first to last is： FIA 1 trending W-E, FIA 2 trending SSW- NNE, FIA 3 trending NNW-SSE, FIA 4 trending NW-SE and FIA 5 trending SW-NE. For four of the FIA sets, samples were found containing monazite grains preserved as inclusions. These were dated on an electron microprobe. The ages obtained concur exactly with the FIA succession, with FIA 1 at 1506±15 Ma, FIA 2 at 1467±23 Ma, FIA 3 at 1425±18 Ma, FIA 4 not dated and FIA 5 at 1366±20 Ma. These ages are directly reflected in a succession of plutons in the surrounding region dated by other isotopic approaches, suggesting that deformation, metamorphism and pluton emplacement occurred together episodically, but effectively continuously, for some 140 Ma.

关键词： monazite dating Arkansas River region foliation inflection/intersection axes

Ferromagnetic Heisenberg spin chain in a resonator

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第9期30卷 178-183页

作者： Yusong cao Junpeng cao Heng Fan Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China Peng Huanwu Center for Fundamental Theory Xi'an 710127China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100190China

We investigate the properties of a generalized Rabi model by replacing the two-level atom in Rabi model with a ferromagnetic Heisenberg spin *** find that the dynamical behavior of the system can be divided into four *** energy spectrum of the ground state and some low excited states are *** the magnons and the photon are in resonance,the model is exactly solvable and the rigorous solution is *** the resonance point where the detuning is small,the system is studied with the help of perturbation *** model has a spontaneously breaking of parity symmetry,suggesting the existence of a quantum phase *** critical exponent from the normal phase is computed.

关键词： magnon resonator quantum phase transition

Toeplitz operators on connected domains

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2006年第6期49卷 827-837页

作者： cao Guangfu School of Mathematics and Information Sciences Guangzhou University Guangzhou 510006 China

The proof of the index formula of the Toeplitz operator with a continuous symbol on the Hardy space for the unit circle in the complex plane depends on the Hopftheorem. However,the analogue result of the Hopf theorem does not hold on a general connected domain. Hence,the extension of the index formula of the Toeplitz operator on a general domain needs a method which is different from that for the case of the unit circle. In the present paper, the index formula of the Toeplitz operator with a continuous symbol on the finite complex connected domain in the complex plane is obtained, and the cohomology groups of Toeplitz algebras on general domains are discussed. In addition, the Toeplitz operators with symbols in QC are also discussed.

关键词： connected domain, Toeplitz operator.

环状RNA CHACR调控压力超负荷诱导心肌肥大和氧化应激损伤

在线全文

学校读者我要写书评

暂无评论

中国组织工程研究 2025年第25期29卷 5362-5373页

作者：王霜韩瑜袁敏曹济民孙腾山西医科大学细胞生理学教育部重点实验室山西省细胞生理学重点实验室山西医科大学基础医学院生理学系山西省太原市030001

背景:病理性心肌肥大是多种心脏疾病的危险促进因素,但其发病机制仍未阐明。环状RNA与心肌肥大密切相关,然而环状RNA CHACR在心肌肥大中的作用及调控机制尚未见报道。目的:探究环状RNA CHACR在压力超负荷诱导心肌肥大中的作用及机制。方... 详细信息

背景:病理性心肌肥大是多种心脏疾病的危险促进因素,但其发病机制仍未阐明。环状RNA与心肌肥大密切相关,然而环状RNA CHACR在心肌肥大中的作用及调控机制尚未见报道。目的:探究环状RNA CHACR在压力超负荷诱导心肌肥大中的作用及机制。方法:①心脏原位注射环状RNA CHACR过表达慢病毒1周后进行横向主动脉缩窄手术诱导小鼠心肌肥大。术后8周,计算心脏质量/胫骨长比值和肺质量/胫骨长比值,测量心肌细胞表面积,检测肥大标志基因表达水平和心肌纤维化程度,评估心功能。②H9c2心肌细胞给予环状RNA CHACR过表达慢病毒处理72 h,然后加入1μmol/L血管紧张素Ⅱ处理24 h诱导心肌细胞肥大。通过检测心肌细胞表面积、肥大标志基因表达水平、蛋白质/DNA比值评估细胞肥大情况,通过检测活性氧水平和线粒体膜电位评估氧化应激损伤情况。结果与结论:①在体内和体外心肌肥大模型中,环状RNA CHACR的表达水平均显著降低(P<0.01);②过表达环状RNA CHACR显著抑制了横向主动脉缩窄手术诱导的小鼠心肌肥大表型,主要表现为心脏体积减小、心脏质量/胫骨长比值显著降低(P<0.05),肺质量/胫骨长比值显著降低(P<0.05),心肌细胞表面积显著减小(P<0.05),以及心肌肥大相关标志基因心房利钠肽(P<0.05)、脑钠肽(P<0.05)表达水平降低;③过表达环状RNA CHACR显著抑制了横向主动脉缩窄手术诱导的小鼠心脏纤维化,表现为纤维化面积减小(P<0.01)和纤维化标志基因Acta1的表达水平降低(P<0.05);④过表达环状RNA CHACR显著改善了小鼠心功能,主要表现为射血分数(P<0.05)和短轴缩短率(P<0.01)显著升高;(5)过表达环状RNA CHACR显著抑制了血管紧张素Ⅱ诱导的心肌细胞肥大,主要表现为心肌细胞表面积显著减小(P<0.05),心房利钠肽(P<0.05)和脑钠肽(P<0.05)表达水平显著下调,以及蛋白质/DNA比值显著减小(P<0.05);(6)过表达环状RNA CHACR显著抑制了血管紧张素Ⅱ诱导的活性氧水平升高(P<0.001)和线粒体膜电位降低(P<0.05)。结果表明,环状RNA CHACR在体内和体外心肌肥大模型中表达水平显著降低,过表达环状RNA CHACR显著抑制心肌肥大,减轻心肌纤维化,改善心功能,并且显著减轻了血管紧张素Ⅱ诱导的心肌细胞氧化应激损伤。

关键词：心肌肥大环状RNA CHACR 血管紧张素Ⅱ 横向主动脉缩窄手术氧化应激损伤

Liouville Type Theorem About p-Harmonic Function and p-Harmonic Map with Finite L^q-Energy

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2017年第5期38卷 1071-1076页

作者： Xiangzhi cao School of Mathematics and Statistics Wuhan University Wuhan 430072 China

This paper deals with the p-harmonic function on a complete non-compact submanifold M isometrically immersed in an(n + k)-dimensional complete Riemannian manifold M of non-negative(n-1)-th Ricci curvature. The Liouville type theorem about the p-harmonic map with finite L^q-energy from complete submanifold in a partially nonnegatively curved manifold to non-positively curved manifold is also obtained.

关键词： p-Harmonic map p-Harmonic map Kato inequality Index Liouvilletheorem

Dynamics of Wetland Landscape Pattern in Kaifeng City from 1987 to 2002

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2008年第2期18卷 146-154页

作者： cao Xinxiang College of History and Culture Henan University Kaifeng 475001 China Key Research Institution of Yellow River Civilization and Sustainable Development Henan University Kaifeng 475001 China

It is very significant for urban development and urban wetland protection and utilization to probe into the process and reasons of urban wetland landscape dynamics. Taking the information of remote sensing and detailed land survey data as the basic information sources, with the help of RS and GIS, according to the principles and methods of landscape ecology, this paper analyzed wetland landscape pattern dynamics and its reasons in Kaifeng City, Henan Province of China, from 1987 to 2002. The results show that the total wetland area in Kaifeng City firstly reduced by 20.1% from 1987 to 1990 and then increased from 1990 to 2002, with an average annual growth rate of 3.3%. At the same time, landscape fragment degree and landscape dominance degree increased, respectively from 0.64 to 0.72 and from 0.3754 to 0.5563, but mean patch area, maximum patch area, patch fractal dimension reduced. As far as single landscape element concerned, fi＇om 1987 to 2002, patch area, patch number, patch density, patch shape and patch location changed in varying degrees in all wetland types in Kaifeng City, among which rice field changed most and others relatively less. In the recent 20 years, rice fields, lake wetlands, puddles and ponds had a higher stability, but river and bottomland wetlands were mostly transformed to land use types. The change of wetland landscape pattern was the result of the combined action of the Huanghe （Yellow） River, urban expansion, wide cultivation of rice, and rapid development of fishery. Among them human activities were the main driving factors for wetland landscape changes.

关键词： wetland landscape pattern landscape dynamics Kaifeng City