检索结果-南通市图书馆

Phase behavior of gas condensate in porous media using real-time computed tomography scanning

Petroleum Science 2024年第2期21卷 1032-1043页

作者： Wen-Long Jing Lei zhang Ai-Fen Li jun-Jie Zhong Hai Sun yong-Fei Yang Yu-Long Cheng jun Yao Institute of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina

The phase behavior of gas condensate in reservoir formations differs from that in pressure-volume-temperature(PVT)cells because it is influenced by porous media in the reservoir *** was used as a sample to investigate the influence of porous media on the phase behavior of the gas *** pore structure was first analyzed using computed tomography(CT)scanning,digital core technology,and a pore network *** sandstone core sample was then saturated with gas condensate for the pressure depletion *** each pressure-depletion state was stable,realtime CT scanning was performed on the *** scanning results of the sample were reconstructed into three-dimensional grayscale images,and the gas condensate and condensate liquid were segmented based on gray value discrepancy to dynamically characterize the phase behavior of the gas condensate in porous *** network models of the condensate liquid ganglia under different pressures were built to calculate the characteristic parameters,including the average radius,coordination number,and tortuosity,and to analyze the changing mechanism caused by the phase behavior change of the gas *** types of condensate liquid(clustered,branched,membranous,and droplet ganglia)were then classified by shape factor and Euler number to investigate their morphological changes dynamically and *** results show that the dew point pressure of the gas condensate in porous media is 12.7 MPa,which is 0.7 MPa higher than 12.0 MPa in PVT *** average radius,volume,and coordination number of the condensate liquid ganglia increased when the system pressure was between the dew point pressure(12.7 MPa)and the pressure for the maximum liquid dropout,Pmax(10.0 MPa),and decreased when it was below *** volume proportion of clustered ganglia was the highest,followed by branched,membranous,and droplet *** study provides crucial experimental evidence for the phase behavior chan

关键词： Gas condensate Pressure depletion Real-time micro-computed tomography scanning Distribution of condensate liquid

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Microstructural characterization and mechanical properties of(TiC+TiB)/TA15 composites prepared by an in-situ synthesis method

引用

China Foundry 2024年第2期21卷 168-174页

作者： Zhi-yong zhang Jiao-jiao Cheng Jia-qi Xie Shi-bing Liu Kun Shi jun Zhao Shenyang Research Institute of Foundry Co. Ltd.CAMShenyang 110022China National Key Laboratory of Advanced Casting Technologies Shenyang 110022China

Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high *** this study,the TA15-based composites reinforced with a volume fraction of 10% to 25%(TiB+TiC)were prepared using powder metallurgy and casting *** characterization and phase constitution were examined using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray diffraction(XRD).In addition,the microhardness,room temperature(RT)and high temperature(HT)tensile properties of the composites were *** revealed that the reinforcements are distributed uniformly even in the composites with a high volume of TiB and ***,as the volume fraction exceeds 15%,TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like *** increases gradually from 321.2 HV for the base alloy to a maximum of 473.3 HV as the reinforcement increases to 25vol.%.Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and yield strength at high temperatures,but it has an adverse effect on room temperature ***,if the reinforcement volume fraction is below 20%,it can improve high-temperature elongation when the temperature exceeds 600℃.

关键词： titanium matrix composites microstucture microhardness tensile properties in-situ synthesis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Distribution of natural killer cell receptors in HIV infected individuals

引用

Chinese Medical Journal 2007年第17期120卷 1544-1548页

作者： JIANG yong-jun zhang Zi-ning DIAO Ying-ying GENG Wen-qing DAI Di LIU Jing WANG Ya-nan zhang Min HAN Xiao-xu SHANG Hong Key Laboratory of AIDS Immunology of Ministry of Health FirstHosoital of China Medical University Shenvang 110001 China

Natural killer （NK） cells are bone marrow derived, large granular lymphocytes, comprising approximately 10% to 20% of the mononuclear cell fraction in normal peripheral blood. They form a part of the first line defense mechanism against tumoural and viral spreading^1-4 Unlike T and B cells, NK cells do not require gene rearrangement for assembly of their receptor genes; rather, NK cells discriminate potential target cells based on the levels of self major histocompatibility complex （MHC） class I expression on such cells^5.6 There are two kinds of NK cell receptors^2.7.8 Inhibitory receptors recognize MHC class I molecules and deliver a downregulatory signal that inactivates the lytic machinery of NK cells. Stimulatory receptors expressed by NK cells deliver an activation signal.

关键词： HIV infections NK cells NK cell receptors

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Recovery and in-situ reduction of precious metals by graphdiyne and graphdiyne oxide for antibacterial use

引用

Rare Metals 2024年第4期43卷 1747-1757页

作者： Ming-Ji Jiang Ya-Na zhang Ling-Shen Meng Jing Kang yong-jun Li Alideertu Dong College of Chemistry and Chemical Engineering Inner Mongolia UniversityHohhot010021China Engineering Research Center of Dairy Quality and Safety Control Technology Ministry of EducationInner Mongolia UniversityHohhot010021China Department of Chemistry University of ZurichCH-8057ZurichSwitzerland Laboratory of Organic Solids and Beijing National Laboratory for Molecular Sciences Institute of ChemistryChinese Academy of SciencesBeijing100190China

Based on the in-situ self-reduction and chemical stability,graphdiyne(GDY)and graphdiyne oxide(GDYO)are used as trapping agents to investigate the ability for recovering Au^(3+),Ag^+,and Pd^(2+)under different pH values and interfering *** strong acidity at pH=1,these two agents demonstrate high select recovery towards the three precious metal ions,which could be insitu reduced to nanoparticles(NPs).In addition,superparamagnetic Fe_(3)O_(4)NPs are deposited on the surfaces of GDY and *** magnetic responses enable GDYFe_(3)O_(4)to recover precious metals conveniently and efficiently by the aid of an external magnetic *** study also confirms the antibacterial activity of the as-recovered NPs deposited on GDY and GDYO against Escherichia coli and Staphylococcus aureus(1×10^(5)colony-forming unit(CFU)·mL^(-1)),and the antibacterial rates are 100%.This strategy of recovering precious metals and subsequently reusing to combat pathogens will be of great significance for environmental remediation and biomedical applications.

关键词： Graphdiyne In-situ reduction Recovery Precious metals Antibacterial

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Factors influencing the functional significance in intermediate coronary stenosis

引用

Journal of Geriatric Cardiology 2015年第2期12卷 107-112页

作者： Li-Jie SUN Gui-Song WANG Ming CUI Li-jun GUO yong-Zhen zhang Fu-Chun zhang Jie NIU Jiang-Li HAN Wei-Xian XU Dan ZHU Wei GAO Department of Cardiology Peking University Third Hospital 49 North Huayuan Road Haidian D&trict Beijingl O0191 China

Objective To analyze the influencing factors of the functional significance determined by fractional flow reserve （FFR） in interme- diate coronary artery stenosis. Methods The study enrolled 143 patients with 203 intermediate coronary lesions. Pressure-derived FFR of these lesions was gained at maximal hyperemia induced by intravenous adenosine infusion. An FFR 〈 0.80 was considered as abnormal functional significance. Anatomic parameters at the lesion sites were obtained by off-line quantitative coronary angiography analysis （QCA）. The predictive value of the demographic characteristics and anatomic parameters for FFR in these intermediate lesions was assessed using multiple linear and binary logistic regression analysis. Results Overall, FFR 〈 0.8 was found in 70 （34%） of the total 203 intermediate coronary lesions. FFR values were positively correlated with QCA-measured minimum lumen diameters （MLD, r = 0.372, P = 0.000） and the reference vessel diameters （RVD, r = 0.217, P〈 0.002） were negatively correlated with percent area stenosis （AS, r = -0.251, P = 0.000） and percent diameter stenosis （DS, r = -0.210, P = 0.000）. Age, MLD and the lesion location in different coronary arteries were the inde- pendent determinants of FFR 〈 0.8. Conclusions MLD can predict the functional significance of intermediate coronary stenosis, while age and the lesion location in different coronary arteries should be taken into account as important influencing factors of FFR values.

关键词： Fractional flow reserve Influencing factors Intermediate coronary lesion Quantitative coronary angiography

来源：

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

Identification of heat shock cognate protein 70 gene （Alhsc70） of Apolygus lucorum and its expression in response to different temperature and pesticide stresses

引用

Insect Science 2016年第1期23卷 37-49页

作者： Yang Sun Jing Zhao Yang Sheng Ying-Fang Xiao yong-jun zhang Li-Xin Bai yongan Tan Liu-Bin Xiao Guang-Chun Xu Institute of Plant Protection Jiangsu Academy of Agricultural Sciences Nanjing China Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant Protection Chinese Academy of Agricultural Sciences Beijing China Entomology and Nematology Mid-Florida Research and Education Center University of Florida Apopka Florida USA

Heat shock cognate protein 70 （Hsc70） is a very important stress-resistance protein of insects against environmental stresses. We employed fluorescent real-time quan- titative polymerase chain reaction and Western-blot techniques to analyze the transcrip- tional and translational expression profiles of AIHSC70 under extreme temperature （4℃ and 40℃） or 4 pesticide stresses in Apolygus lucorum. The results showed that the expres- sion of AIHSC70 were significantly induced by cyhalothrin or extremely high temperature （40℃） in both transcriptional and translational levels （P 〈 0.05）, while the transcriptional and translational level of AIHSC70 decreased significantly in treatments of chlorpyrifos or extreme cold temperature （4℃）（P 〈 0.05）. Moreover, afterApolygus lucorum treated by imidacloprid or emamectin benzoate, the expression of AIHSC70 was only up-regulated significantly at the transcriptional level （P 〈 0.05）, although obviously up-regulated at the translational level of AIHSC70. Therefore, this study confirmed that the Alhsc70 gene played important roles in response to both temperature and pesticide stresses, especially for cyhalothrin or extremely high temperature （40℃）. In addition, the significant polynomial regression correlations between temperature and the Alhsc70 expression level were shown in all the nymph and adult stages （P 〈 0.01）, indicating temperature was an important factor to affect the relative expression of Alhsc70.

关键词： Apolygus lucorum expression files extreme temperature hsc70 pesticide

来源：

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

Geometric Error Identification of Gantry-Type CNC Machine Tool Based on Multi-Station Synchronization Laser Tracers

引用

Chinese Journal of Mechanical Engineering 2024年第2期37卷 150-162页

作者： jun Zha Huijie zhang School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China Xi’an Jiaotong University Suzhou Academy Suzhou 215123China

Laser tracers are a three-dimensional coordinate measurement system that are widely used in industrial *** propose a geometric error identification method based on multi-station synchronization laser tracers to enable the rapid and high-precision measurement of geometric errors for gantry-type computer numerical control(CNC)machine *** method also improves on the existing measurement efficiency issues in the single-base station measurement method and multi-base station time-sharing measurement *** consider a three-axis gantry-type CNC machine tool,and the geometric error mathematical model is derived and established based on the combination of screw theory and a topological analysis of the machine kinematic *** four-station laser tracers position and measurement points are realized based on the multi-point positioning principle.A self-calibration algorithm is proposed for the coordinate calibration process of a laser tracer using the Levenberg-Marquardt nonlinear least squares method,and the geometric error is solved using Taylor’s first-order linearization *** experimental results show that the geometric error calculated based on this modeling method is comparable to the results from the Etalon laser *** a volume of 800 mm×1000 mm×350 mm,the maximum differences of the linear,angular,and spatial position errors were 2.0μm,2.7μrad,and 12.0μm,respectively,which verifies the accuracy of the proposed *** research proposes a modeling method for the precise measurement of errors in machine tools,and the applied nature of this study also makes it relevant both to researchers and those in the industrial sector.

关键词： Multi-point positioning Multi-station synchronization CNC machine tool Geometric error Error separation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

State of the art of lightweight aggregates used in lightweight refractories for working lining of high-temperature furnaces

引用

Journal of Iron and Steel Research International 2024年第6期31卷 1320-1343页

作者： Wei zhang Wen-yong Dai Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016LiaoningChina Research and Development Department AGC Plibrico(Dalian)Industries Inc.Dalian 116600LiaoningChina

Lightweight refractories for the working lining of high-temperature furnaces play an important role in the smelting of advanced steels and *** prepare lightweight refractories for the working lining of high-temperature furnaces,the synthesis of lightweight aggregates is the ***,the research on the synthesis of lightweight aggregates with high service temperature,low thermal conductivity,high strength,and good slag resistance has received widespread *** available literature on the synthesis of lightweight aggregates was summarized,including corundum,mullite,mullite-corundum,spinel,corundum-spinel,cordierite,cordierite-mullite,calcium hexaluminate,corundum-calcium hexaluminate,bauxite,magnesia,magnesia-based,and forsterite-based ***,the future development trend of lightweight aggregates was proposed.

关键词： Lightweight aggregate Lightweight refractory Working lining Apparent porosity Closed porosity Thermal conductivity Pore-forming approach

来源：

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

Deep Guided Attention Network for Joint Denoising and Demosaicing in Real Image

引用

Chinese Journal of Electronics 2024年第1期33卷 303-312页

作者： Tao zhang Ying FU jun zhang School of Computer Science and Technology Beijing Institute of Technology Advanced Reasearch Institute of Multidisciplinary Science Beijing Institute of Technology

Denoising(DN) and demosaicing(DM) are the first crucial stages in the image signal processing pipeline. Recently, researches pay more attention to solve DN and DM in a joint manner, which is an extremely undetermined inverse problem. Existing deep learning methods learn the desired prior on synthetic dataset, which limits the generalization of learned network to the real world data. Moreover, existing methods mainly focus on the raw data property of high green information sampling rate for DM, but occasionally exploit the high intensity and signalto-noise(SNR) of green channel. In this work, a deep guided attention network(DGAN) is presented for real image joint DN and DM(JDD), which considers both high SNR and high sampling rate of green information for DN and DM, respectively. To ease the training and fully exploit the data property of green channel, we first train DN and DM sub-networks sequentially and then learn them jointly, which can alleviate the error accumulation. Besides, in order to support the real image JDD, we collect paired raw clean RGB and noisy mosaic images to conduct a realistic dataset. The experimental results on real JDD dataset show the presented approach performs better than the state-of-the-art methods, in terms of both quantitative metrics and qualitative visualization.

关键词： Training Visualization Inverse problems Green products Noise reduction Pipelines Signal processing

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Simulation study on cuttings transport of the backreaming operation for long horizontal section wells

引用

Petroleum Science 2024年第2期21卷 1149-1170页

作者： Yu-Fei Chen Hui zhang Wen-Xin Wu jun Li yong Ouyang Zong-Yu Lu De-Xin Ma yong-Chuan Wu jun-Bo Liu Ke-Rou Liu Zhuo-Xin Dong China University of Petroleum(Beijing) Beijing102249China Beijing Normal University at Zhuhai Experimental and Practical Education Innovation CenterZhuhai519087GuangdongChina Oil&Gas Technology Research Institute of PetroChina Changqing Oilfield Company Xi'an710016ShaanxiChina PetroChina Xinjiang Oilfield Company Karamay834002XinjiangChina China Oilfield Services Ltd. Tianjin300459China

The backreaming operation plays a significant role in safe drilling for horizontal wellbores, while it may cause severe stuck pipe accidents. To lower the risk of the stuck pipe in backreaming operations, the mechanism of cuttings transport needs to be carefully investigated. In this research, a transient cuttings transport with multiple flow patterns model is developed to predict the evolution of cuttings transported in the annulus while backreaming. The established model can provide predictions of the distribution of cuttings bed along the wellbore considering the bulldozer effect caused by large-size drilling tools(LSDTs). The sensitivity analyses of the size of LSDTs, and backreaming operating parameters are conducted in Section 4. And a new theory is proposed to explain the mechanism of cuttings transport in the backreaming operation, in which both the bit and LSDTs have the “cleaning effect” and “plugging effect”.The results demonstrate that the cuttings bed in annuli is in a state of dynamic equilibrium, but the overall trend and the distribution pattern are obvious. First, larger diameters and longer drilling tools could lead to a higher risk of the stuck pipe. Second, we find that it is not the case that the higher flow rate is always better for hole cleaning, so three flow-rate intervals are discussed separately under the given conditions. When the “dangerous flow rate”(35 L/s in Case 4),the higher the flow rate, the better the cleaning effect of cuttings beds. Third, an interval of tripping velocity called “dangerous velocity” is proposed, in which the cuttings bed accumulation near the LSDTs is more serious than

关键词： Backreaming Stuck pipe Hole cleaning Transient solid transport Multiple flow patterns

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：