资源类型

期刊论文 192

会议视频 3

年份

2023 7

2022 12

2021 13

2020 9

2019 12

2018 15

2017 10

2016 5

2015 6

2014 7

2013 3

2012 7

2011 9

2010 15

2009 5

2008 12

2007 26

2006 9

2005 2

2004 3

展开 ︾

关键词

BNLAS 2

影响图 2

数值模拟 2

海上风电场 2

BIM 1

EFP 1

GIC 1

Howard正则型 1

LC4CS 铝合金 1

“专精特”小巨人 1

三维有限元 1

中央扣 1

中间桥塔 1

二维插值 1

互联网 1

京津冀 1

人体健康 1

人工神经网络 1

人类活动 1

展开 ︾

检索范围：

排序： 展示方式：

Analyses of the seismic responses of soil layers with deep deposits

LOU Menglin, LI Yuchun, LI Nansheng

《结构与土木工程前沿（英文）》 2007年 第1卷 第2期   页码 188-193 doi: 10.1007/s11709-007-0021-3

摘要： Several typical problems in the seismic response analysis of soil layers with deep deposits have been studied according to the seismic response analysis of the soil layer in the Shanghai region. The problems include the effect of the inclination of the bedrock under the soil layer on the seismic responses of the soil layer, the rationality of the artificial horizontal bedrock boundary in the soil layer, and the effect of the wave velocity of the bedrock and dynamic characteristics of the soil media on the seismic responses of the soil layer. Some results are obtained by numerical analysis. In the seismic response analysis, the effect of angle of inclination of the rock surface under the soil layer can be neglected if the angle is not more than two degrees. A significant error will be introduced in the calculation when the artificial horizontal rock surface is assumed in the soil layer according to the shear velocity of the soil media. The elasticity of the solid rock has little influence on the seismic response of the deep soil layer. The field investigation on the soil dynamic property should be paid more attention to.

关键词： little influence     layer     calculation     Shanghai     dynamic    

HTML PDF 收藏

“专精特”小巨人企业培育路径研究——以苏南地区为例

张睿,石晓鹏,陈英武

《中国工程科学》 2017年 第19卷 第5期   页码 97-102 doi: 10.15302/J-SSCAE-2017.05.017

摘要：

加快发展“专精特”小巨人企业是提升我国企业整体竞争力、走创新驱动与内生增长道路的重要载体和抓手，是一条符合中国实际、有利于制造业持续健康发展的必由之路，是提高全要素生产率、落实供给侧结构性改革要求的战略举措。本文对“专精特”小巨人企业的重要集聚区域——苏南地区展开专题研究，梳理省市两级政府长期以来培育小巨人企业的思路、政策和成果，为全国范围内“专精特”小巨人企业培育工作提供经验借鉴，为创新驱动和工业强基战略深入实施提供决策参考。

关键词： “专精特”小巨人     工业基础     政策体系    

HTML PDF 收藏

Identifying spreading influence nodes for social networks

《工程管理前沿（英文）》   页码 520-549 doi: 10.1007/s42524-022-0190-8

摘要： The identification of spreading influence nodes in social networks, which studies how to detect important individuals in human society, has attracted increasing attention from physical and computer science, social science and economics communities. The identification algorithms of spreading influence nodes can be used to evaluate the spreading influence, describe the node’s position, and identify interaction centralities. This review summarizes the recent progress about the identification algorithms of spreading influence nodes from the viewpoint of social networks, emphasizing the contributions from physical perspectives and approaches, including the microstructure-based algorithms, community structure-based algorithms, macrostructure-based algorithms, and machine learning-based algorithms. We introduce diffusion models and performance evaluation metrics, and outline future challenges of the identification of spreading influence nodes.

关键词： complex network     network science     spreading influence     machine learning    

HTML PDF 收藏

Immunohistochemical characterization of hepatic stem cell-related cells in developing human liver

XU Jun, HU Yong, WANG Jian, ZHANG Taiping, ZHOU Ji, YU Hongyu

《医学前沿（英文）》 2007年 第1卷 第3期   页码 264-268 doi: 10.1007/s11684-007-0050-2

摘要： Little is known about the expression characteristics of the various kinds of possible markers in hepatic stem cells (HSCs) and other HSC-related cells in human fetal liver in various developmental stages. It is significant to investigate the immunohistochemical expression for better understanding of the origin, differentiation and migration of HSCs in the developing human liver. H-E staining and immunohistochemical methods were used to observe the expression of hepatic/cholangiocellular differentiation markers (AFP, GST-, CK7, CK19) and hematopoietic stem cell markers (CD34 and c-kit) in several kinds of HSC-related cells in thirty cases of fetal liver samples (4–35 weeks after pregnancy). AFP expression appears in fetal hepatocytes at four weeks’ gestation. It peaks at 16–24 weeks’ gestation and decreases gradually afterwards. Finally, weak signals were only found in some ductal plate cells and a few limiting plate cells. GST- was detected in hepatic cord cells from the sixth week and in the ductal plate cells from the eighth week. Twenty-six weeks later, only some ductal plate cells and a few limiting plate cells show positive signals. CK19 expression peaks during the 6th–11th weeks in hepatic cord cells and decreases gradually afterwards, except for the ductal plates. CK7 expression was limited in the ductal plate cells and bile ducts cells from the 14th week. CD34 and c-kit were detected at the eighth week in some ductal plate cells and a few mononuclear cells in the hepatic cords/mesenchymal tissue of portal areas. After 21 weeks, CD34 and c-kit were found only in ductal plate cells and a few mononuclear cells in the hepatic mesenchymal tissue of portal areas. Fetal hepatocytes at 4–16 weeks’ gestation are mainly constituted by HSCs characterized with bi-potential differentiation capacity. At 16 weeks’ gestation, most hepatic cord cells begin to differentiate into hepatocytes and abundant HSCs remain in ductal plate (the origin site of Hering canals). It is also indicated that the hematopoietic stem cells may give rise to some HSCs in embryonic liver. These indirectly support the hypothesis about the location and origin of HSCs in liver valley hypothesis reported previously.

关键词： origin     Little     mesenchymal tissue     cords/mesenchymal tissue     CD34    

HTML PDF 收藏

Heterogeneous influence of individuals’ behavior on mask efficacy in gathering environments

《工程管理前沿（英文）》   页码 550-562 doi: 10.1007/s42524-022-0193-5

摘要： Wearing masks is an easy way to operate and popular measure for preventing epidemics. Although masks can slow down the spread of viruses, their efficacy in gathering environments involving heterogeneous person-to-person contacts remains unknown. Therefore, we aim to investigate the epidemic prevention effect of masks in different real-life gathering environments. This study uses four real interpersonal contact datasets to construct four empirical networks to represent four gathering environments. The transmission of COVID-19 is simulated using the Monte Carlo simulation method. The heterogeneity of individuals can cause mask efficacy in a specific gathering environment to be different from the baseline efficacy in general society. Furthermore, the heterogeneity of gathering environments causes the epidemic prevention effect of masks to differ. Wearing masks can greatly reduce the probability of clustered epidemics and the infection scale in primary schools, high schools, and hospitals. However, the use of masks alone in primary schools and hospitals cannot control outbreaks. In high schools with social distancing between classes and in workplaces where the interpersonal contact is relatively sparse, masks can meet the need for prevention. Given the heterogeneity of individual behavior, if individuals who are more active in terms of interpersonal contact are prioritized for mask-wearing, the epidemic prevention effect of masks can be improved. Finally, asymptomatic infection has varying effects on the prevention effect of masks in different environments. The effect can be weakened or eliminated by increasing the usage rate of masks in high schools and workplaces. However, the effect on primary schools and hospitals cannot be weakened. This study contributes to the accurate evaluation of mask efficacy in various gathering environments to provide scientific guidance for epidemic prevention.

关键词： COVID-19     masks     behavioral heterogeneity     asymptomatic infection    

HTML PDF 收藏

社会影响力分析——模型、方法和评价 Review

李侃, 张林, 黄河燕

《工程（英文）》 2018年 第4卷 第1期   页码 40-46 doi: 10.1016/j.eng.2018.02.004

摘要：

社会影响力分析（SIA）是一个广泛的研究领域，吸引了诸多研究者的兴趣。本文总结了SIA 相关的模型、方法和评价方面代表性的工作，并将SIA 模型归纳为两种类型：微观模型和宏观模型。微观模型考虑人与人之间的相互影响和影响的过程，而宏观模型认为每个人具有相同的传播概率和影响力。本文分析了包括影响最大化、影响最小化、影响流和个人影响力等的社会影响力分析方法；介绍了影响力评价指标，并分析了社会影响力评价模型。本文的目标是对社会影响力提供全面的分析，旨在辅助理解社会行为，为舆论影响提供理论基础，并揭示未来的研究方向和潜在的应用。

关键词： 社会影响力分析     在线社交网络     社会影响力分析模型     影响力评价    

HTML PDF 收藏

Conversion of polyethylene to gasoline: Influence of porosity and acidity of zeolites

《能源前沿（英文）》   页码 763-774 doi: 10.1007/s11708-023-0897-1

摘要： Plastic waste is causing serious environmental problems. Developing efficient, cheap and stable catalytic routes to convert plastic waste into valuable products is of great importance for sustainable development, but remains to be a challenging task. Zeolites are cheap and stable, but they are usually not efficient for plastic conversion at a low temperature. Herein a series of microporous and mesoporous zeolites were used to study the influence of porosity and acidity of zeolite on catalytic activity for plastics conversion. It was observed that H-Beta zeolite was an efficient catalyst for cracking high-density polyethylene to gasoline at 240 °C, and the products were almost C4–C12 alkanes. The effect of porosity and acidity on catalytic performance of zeolites was evaluated, which clearly visualized the good performance of H-Beta due to high surface area, large channel system, large amount accessible acidic sites. This study provides very useful information for designing zeolites for efficient conversion of plastics.

关键词： plastics conversion     polyethylene     zeolites     acidity     porosity    

HTML PDF 收藏

Theoretical insights into influence of additives on sulfamethoxazole crystal growth kinetics and mechanisms

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1503-1515 doi: 10.1007/s11705-022-2294-4

摘要： In this work, the influence of the initial chemical potential gradient, stirring speed, and polymer type on sulfamethoxazole (SMX) crystal growth kinetics was systematically investigated through density functional theory (DFT) calculations, experimental measurements and the two-step chemical potential gradient model. To investigate the influence of different conditions on the thermodynamic driving force of SMX crystal growth, SMX solubilities in different polymer solutions were studied. Four model polymers effectively improved SMX solubility. It was further found that polyvinylpyrrolidone (PVP) and hydroxypropyl methyl cellulose (HPMC) played a crucial role in inhibiting SMX crystal growth. However, polyethylene glycol (PEG) promoted SMX crystal growth. The effect of the polymer on the crystal growth mechanisms of SMX was further analyzed by the two-step chemical potential gradient model. In the system containing PEG 6000, crystal growth is dominated by the surface reaction. However, in the system containing PEG 20000, crystal growth is dominated by both the surface reaction and diffusion. In addition, DFT calculations results showed that HPMC and PVP could form strong and stable binding energies with SMX, indicating that PVP and HPMC had the potential ability to inhibit SMX crystal growth.

关键词： insoluble drugs     polymer     inhibition crystallization     crystal growth kinetics     DFT calculations    

HTML PDF 收藏

Transport of antibiotic resistance plasmids in porous media and the influence of surfactants

Peipei Chen, Chaoqi Chen, Xiqing Li

《环境科学与工程前沿（英文）》 2018年 第12卷 第2期 doi: 10.1007/s11783-017-0986-7

摘要： Transport of engineered antibiotic resistance plasmids in porous media has been reported to potentially cause significant spreading of antibiotic resistance in the environment. In this work, transport of an indigenous resistance plasmid pK5 in porous media was investigated through packed column experiments. At identical ionic strengths in CaCl solutions, the breakthroughs of pK5 from soil columns were very close to those from quartz sand columns, indicating that transport of pK5 in quartz sand and soil was similar. A similarity in transport behavior was also found between pK5 and an engineered plasmid pBR322 that has approximately the same number of base pairs as pK5. The influence of surfactants, a major group of constituents in soil solutions, was examined using an engineered plasmid pcDNA3.1(+)/myc-His A. The impact of an anionic surfactant, sodium dodecyl sulfate (SDS), was negligible at concentrations up to 200 mg·L . Cetyltrimethyl ammonium bromide (CTAB), a cationic surfactant, was found to significantly enhance plasmid adsorption at high concentrations. However, at environmentally relevant concentrations (<1 mg·L ), the effect of this surfactant was also minimal. The negligible impact of surfactants and the similarity between the transport of engineered and indigenous plasmids indicate that under environmentally relevant conditions, indigenous plasmids in soil also have the potential to transport over long distances and lead to the spreading of antibiotic resistance.

关键词： Indigenous plasmid     Transport     Porous media     Surfactants    

HTML PDF 收藏

Experimental study of the influence of acid wash on cellulose pyrolysis

WANG Shurong, LIU Qian, LUO Zhongyang, CEN Kefa, LIAO Yanfen

《化学科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 35-39 doi: 10.1007/s11705-007-0007-7

摘要： The analysis of microstructure and polymerization degree showed that acid wash altered the cellulose morphology and decreased the polymerization degree significantly. A series of experiments were done to study the effect of acid wash on cellulose rapid pyrolysis. Experimental results showed that under acid pretreatment, the yield of bio-oil decreased while the production of gas and char increased. With an increase in acid concentration, this trend would be further enhanced. Sulphuric acid limited the formation of bio-oil more effectively than hydrochloric acid and phosphoric acid. According to the GC-MS analysis of bio-oil, high-concentration acid wash restrained the formation of levoglucosan by catalyzing dehydration process and cross linking reaction.
HTML PDF 收藏

The influence of brain death on donor liver and the potential mechanisms of protective intervention

null

《医学前沿（英文）》 2011年 第5卷 第1期   页码 8-14 doi: 10.1007/s11684-011-0109-y

摘要：

Brain-dead donors have become one of the main sources of organs for transplantation in Western countries. The quality of donor organs is closely related to the outcome of the transplantation. Experimental studies have confirmed the inferior graft survival of livers from brain-dead donors compared with those from living donors. Studies conducted in the past 10 years have shown that brain death is associated with effects on the decreased donor organ quality. However, whether the decrease in the viability of donor organs is caused by brain death or by the events before and after brain death remains uncertain. The purpose of this review is to introduce the advances and controversies regarding the influence of brain death on the viability of donor livers and to summarize the mechanisms of the different protective interventions for donor livers.

关键词： brain death     donor liver    

HTML PDF 收藏

Experimental investigation of the influence on static and cyclic deformation of structural soft clay

CHEN Yunmin, CHEN Yingping, HUANG Bo

《结构与土木工程前沿（英文）》 2007年 第1卷 第4期   页码 422-429 doi: 10.1007/s11709-007-0057-4

摘要： This paper presents the experimental results performed to study the static and cyclic deformation behavior of undisturbed and remolded soft clays sampling from Xiaoshan. The consolidation tests indicated that the vertical strains of

关键词： consolidation     deformation     experimental     undisturbed    

HTML PDF 收藏

Analysis and prediction of the influence of energy utilization on air quality in Beijing

LI Lin, HAO Jiming, HU Jingnan

《环境科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 339-344 doi: 10.1007/s11783-007-0058-5

摘要： This work evaluates the influence of energy consumption on the future air quality in Beijing, using 2000 as the base year and 2008 as the target year. It establishes the emission inventory of primary PM, SO and NO related to energy utilization in eight areas of Beijing. The air quality model was adopted to simulate the temporal and spatial distribution of each pollutant concentration in the eight urban areas. Their emission, concentration distribution, and sectoral share responsibility rate were analyzed, and air quality in 2008 was predicted. The industrial sector contributed above 40% of primary PM and SO resulting from energy consumption, while vehicles accounted for about 65% of NO. According to the current policy and development trend, air quality in the eight urban areas could become better in 2008 when the average concentrations of primary PM, SO and NO related to energy utilization at each monitored site are predicted to be about 25, 50 and 51 μg/m, respectively.
HTML PDF 收藏

A filtering-based bridge weigh-in-motion system on a continuous multi-girder bridge considering the influence

Hanli WU, Hua ZHAO, Jenny LIU, Zhentao HU

《结构与土木工程前沿（英文）》 2020年 第14卷 第5期   页码 1232-1246 doi: 10.1007/s11709-020-0653-0

摘要： A real-time vehicle monitoring is crucial for effective bridge maintenance and traffic management because overloaded vehicles can cause damage to bridges, and in some extreme cases, it will directly lead to a bridge failure. Bridge weigh-in-motion (BWIM) system as a high performance and cost-effective technology has been extensively used to monitor vehicle speed and weight on highways. However, the dynamic effect and data noise may have an adverse impact on the bridge responses during and immediately following the vehicles pass the bridge. The fast Fourier transform (FFT) method, which can significantly purify the collected structural responses (dynamic strains) received from sensors or transducers, was used in axle counting, detection, and axle weighing technology in this study. To further improve the accuracy of the BWIM system, the field-calibrated influence lines (ILs) of a continuous multi-girder bridge were regarded as a reference to identify the vehicle weight based on the modified Moses algorithm and the least squares method. experimental results indicated that the signals treated with FFT filter were far better than the original ones, the efficiency and the accuracy of axle detection were significantly improved by introducing the FFT method to the BWIM system. Moreover, the lateral load distribution effect on bridges should be considered by using the calculated average ILs of the specific lane individually for vehicle weight calculation of this lane.

关键词： bridge weigh-in-motion     continuous bridge     fast Fourier transform     influence line     axle weight calculation    

HTML PDF 收藏

The formation mechanism and the influence factor of residual stress in machining

null

《机械工程前沿（英文）》 2014年 第9卷 第3期   页码 265-269 doi: 10.1007/s11465-014-0311-0

摘要：

Residual stresses generated in cutting process have important influences on workpiece performance. The paper presents a method of theoretical analysis in order to explicate the formation mechanism of residual stresses in cutting. An important conclusion is drawn that the accumulated plastic strain is the main factor which determines the nature and the magnitude of surface residual stresses in the workpiece. On the basis of the analytical model for residual stress, a series of simulations for residual stress prediction during cutting AISI 1045 steel are implemented in order to obtain the influences of cutting speed, depth of cut and tool edge radius on surface residual stress in the workpiece. And these influences are explained from the perspective of formation mechanism of residual stress in cutting. The conclusions have good applicability and can be used to guide the parameters selection in actual production.

关键词： residual stress     analytical model     strain     plastic     cutting parameter    

HTML PDF 收藏

标题 作者 时间 类型 操作

Analyses of the seismic responses of soil layers with deep deposits

LOU Menglin, LI Yuchun, LI Nansheng

期刊论文

“专精特”小巨人企业培育路径研究——以苏南地区为例

张睿,石晓鹏,陈英武

期刊论文

Identifying spreading influence nodes for social networks

期刊论文

Immunohistochemical characterization of hepatic stem cell-related cells in developing human liver

XU Jun, HU Yong, WANG Jian, ZHANG Taiping, ZHOU Ji, YU Hongyu

期刊论文

Heterogeneous influence of individuals’ behavior on mask efficacy in gathering environments

期刊论文

社会影响力分析——模型、方法和评价

李侃, 张林, 黄河燕

期刊论文

Conversion of polyethylene to gasoline: Influence of porosity and acidity of zeolites

期刊论文

Theoretical insights into influence of additives on sulfamethoxazole crystal growth kinetics and mechanisms

期刊论文

Transport of antibiotic resistance plasmids in porous media and the influence of surfactants

Peipei Chen, Chaoqi Chen, Xiqing Li

期刊论文

Experimental study of the influence of acid wash on cellulose pyrolysis

WANG Shurong, LIU Qian, LUO Zhongyang, CEN Kefa, LIAO Yanfen

期刊论文

The influence of brain death on donor liver and the potential mechanisms of protective intervention

null

期刊论文

Experimental investigation of the influence on static and cyclic deformation of structural soft clay

CHEN Yunmin, CHEN Yingping, HUANG Bo

期刊论文

Analysis and prediction of the influence of energy utilization on air quality in Beijing

LI Lin, HAO Jiming, HU Jingnan

期刊论文

A filtering-based bridge weigh-in-motion system on a continuous multi-girder bridge considering the influence

Hanli WU, Hua ZHAO, Jenny LIU, Zhentao HU

期刊论文

The formation mechanism and the influence factor of residual stress in machining

null

期刊论文