资源类型

期刊论文 194

会议视频 1

年份

2023 16

2022 16

2021 14

2020 14

2019 10

2018 2

2017 10

2016 9

2015 6

2014 8

2013 9

2012 8

2011 8

2010 5

2009 3

2008 8

2007 12

2006 4

2005 5

2004 7

展开 ︾

关键词

稳定性 11

安全系数 2

有限元法 2

700 MW级水电机组 1

GA-ANFIS模型 1

Lipschitz非线性系统；动态输出反馈控制；事件触发控制；全局渐近稳定 1

Mittag-Leffler稳定性；分数阶；四元数神经网络；脉冲 1

SARS 1

μ综合 1

“trade-off”效应 1

三峡大坝 1

三峡工程 1

上举力 1

不可还原性 1

不确定性 1

临界滑动场算法 1

乳化炸药 1

二维层状结构 1

展开 ︾

检索范围：

排序： 展示方式：

Being good or being known: International reputation of high-speed railway enterprises

《工程管理前沿（英文）》   页码 455-466 doi: 10.1007/s42524-023-0250-8

摘要： With fierce competition in the global high-speed railway (HSR) market, international reputation has become essential for enterprises to venture into overseas markets. However, few studies have been performed on the international reputation of HSR enterprises. This study aims to reveal the formation mechanism of HSR enterprises’ international reputation by developing a theoretical framework. The researchers identified five factors and proposed a hypothetical path model based on a comprehensive literature review. After the pilot study, questionnaires were distributed to practitioners in the international HSR industry for data collection. The path model was validated based on partial least-squares structural equation modeling. Eight of the nine paths are statistically supported. Researchers have structured a theoretical framework for the international reputation of HSR enterprises from two perspectives: Being good and being known. Subsequently, a strategic framework was developed to provide targeted promotion strategies for HSR enterprises. The findings of this study contribute to existing international reputation theories using the theoretical model and provide beneficial guidance for HSR enterprises to improve their international reputation through a strategic framework.

关键词： high-speed railway     international reputation     being good     being known     structural equation modeling    

HTML PDF 收藏

Enhanced electrocatalytic performance of ultrathin PtNi alloy nanowires for oxygen reduction reaction

Hongjie ZHANG, Yachao ZENG, Longsheng CAO, Limeng YANG, Dahui FANG, Baolian YI, Zhigang SHAO

《能源前沿（英文）》 2017年 第11卷 第3期   页码 260-267 doi: 10.1007/s11708-017-0499-x

摘要： In this paper, ultrathin Pt nanowires (Pt NWs) and PtNi alloy nanowires (PtNi NWs) supported on carbon were synthesized as electrocatalysts for oxygen reduction reaction (ORR). Pt and PtNi NWs catalysts composed of interconnected nanoparticles were prepared by using a soft template method with CTAB as the surface active agent. The physical characterization and electrocatalytic performance of Pt NWs and PtNi NWs catalysts for ORR were investigated and the results were compared with the commercial Pt/C catalyst. The atomic ratio of Pt and Ni in PtNi alloy was approximately 3 to 1. The results show that after alloying with Ni, the binding energy of Pt shifts to higher values, indicating the change of its electronic structure, and that Pt Ni NWs catalyst has a significantly higher electrocatalytic activity and good stability for ORR as compared to Pt NWs and even Pt/C catalyst. The enhanced electrocatalytic activity of Pt Ni NWs catalyst is mainly resulted from the downshifted-band center of Pt caused by the interaction between Pt and Ni in the alloy, which facilitates the desorption of oxygen containing species (O or OH ) and the release of active sites.

关键词： PtNi alloy     nanowires     oxygen reduction reaction     enhanced activity     good stability    

HTML PDF 收藏

构建二维层状结构的稠环含能材料——高能量与高稳定性的平衡 Article

冯永安, 邓沐聪, 宋思维, 陈思同, 张庆华, Jean’ne M. Shreeve

《工程（英文）》 2020年 第6卷 第9期   页码 1006-1012 doi: 10.1016/j.eng.2020.01.013

摘要：

制造具有良好机械感度的高性能含能材料在过去几十年里一直是一项重大挑战，因为这类蕴含巨大能量的材料存在内在的不稳定性。本文研究了一种极具潜力的稠环含能材料：4-硝基-7-叠氮基-吡唑-[3,4-d]-1,2,3-三嗪-2-氧（NAPTO）。这种物质具有不同寻常的二维（2D）层状结构，其绝对结构已经单晶X射线衍射证实。研究显示，这一结构新颖的含能物质具有惊人的能量[如爆速（D）高达9.12 km·s–1，爆压（P）为35.1 GPa]、优异的机械感度[撞击感度（IS）为18 J、摩擦感度（FS）为325 N、静电感度（EDS）为0.32 J]和良好的热分解温度（203.2 ℃），展示出高能量与低感度的双重优势。据我们所知，NAPTO是首个具有二维层状结构的稠环含能材料。与此同时，运用分子模拟分析了其在外界机械刺激下的稳定机制，结果表明，该含能材料超平的二维层状结构比其他结构更能有效地缓冲外界机械刺激，从而将作用在材料上的机械能转化为晶体的层间滑动与压缩。本研究从实验和理论两个方面揭示了稠环二维层状结构在制造先进含能材料方面的巨大潜力。

关键词： 含能材料     稠环杂环化合物     二维层状结构     高能量     稳定性     感度    

HTML PDF 收藏

Is sodium percarbonate a good choice in situ remediation of deltamethrin pollution?

Xu Zhang, Baigang Ren, Shangge Li, Xiaodi Qu, Huanhuan Yang, Shiguo Xu, Zongming Ren, Qiang Kong, Cheng Wang

《环境科学与工程前沿（英文）》 2017年 第11卷 第3期 doi: 10.1007/s11783-017-0931-9

摘要： In this research, the toxic effects of deltamethrin (DM) on the behavior responses of Zebra fish ( ) in the characteristic of behavior strength were investigated followed by an assessment of an in situ remediation of the DM pollution using sodium percarbonate. Behavior strength of was approximately 0.83 in the control group and was slightly higher than 0.83 in the sublethal treatment (0.1 TU (toxic unit)), which suggested that sublethal DM exposure could induce a stimulation effect in 48 h of exposure. In lower DM concentration treatments (0.5 and 1.0 TU), behavior strength could be inhibited significantly. Behavior responses of showed a gradually increased tendency when they were exposed to higher concentration of DM, and the declining amplitudes of behavior strength changed with the increase of DM concentrations. These results suggested that DM had evident acute toxicity effects on the behavior responses of with a good dose-effect relationship. The in situ remediation of the DM pollution using sodium percarbonate showed that the toxic effect of DM on behavior responses of could be eliminated even in the highest concentration of DM (5.0 TU). Meanwhile, the behavior response of in the treatment of sodium percarbonate was the same as in the control, which indicated that sodium percarbonate had no evident toxic effects on the behavior of in the current concentration. This study suggested that adding sodium percarbonate in situ might be a good way to eliminate the DM toxic effects.

关键词： Behavior strength     Sublethal treatment     Detoxification     Accidental pollution    

HTML PDF 收藏

水的良性社会循环与城市水资源

李圭白,李星

《中国工程科学》 2001年 第3卷 第6期   页码 37-40

摘要：

文章从水的社会循环全过程的角度，论述了城市水资源短缺危机的解决途径，指出进行城市污水和 工业废水的处理和回用，节约用水，进行饮用水除污染处理，以及进行水的优质优用，合理调配，开发雨水、 海水利用等，以及在充分论证基础上进行远距离调水，是缓解城市水资源危机的多种可能途径。

关键词： 城市水资源     水的良性社会循环     节水     污废水回用    

HTML PDF 收藏

Solvates and polymorphs of clindamycin phosphate: Structural, thermal stability and moisture stability

Junbo Gong, Dejiang Zhang, Yuanyuan Ran, Keke Zhang, Shichao Du

《化学科学与工程前沿（英文）》 2017年 第11卷 第2期   页码 220-230 doi: 10.1007/s11705-017-1624-4

摘要： Clindamycin phosphate (CP), an antibacterial agent, has been reported to form several solid-state forms. The crystal structures of two CP solvates, a dimethyl sulfoxide (DMSO) solvate and a methanol/water solvate (solvate V), have been determined by single crystal X-ray diffraction. The properties and transformations of these forms were characterized by powder X-ray diffraction, Single-crystal X-ray diffraction, differential scanning calorimetry, thermo gravimetric analysis, hot-stage microscopy, and dynamic vapor sorption. Very different hydrogen bonding networks exist among the host-host and host-solvent molecules in the two crystal structures, resulting in different moisture stabilities. The thermal stabilities of the two solvates upon heating and desolvation were also studied. When the temperature was above the boiling point of methanol, solvate V converted to a polymorphic phase after a one step desolvation process, whereas the desolvation temperature of the DMSO solvate was below the boiling point of DMSO. At the relative humidity above 43%, the DMSO solvate transformed to a hydrate at 25 °C. In contrast, solvate V did not transform at any of the humidities studied.

关键词： clindamycin phosphate     solvate     crystal structure     thermal stability     moisture stability    

HTML PDF 收藏

全面终止人用抗微生物药物在动物源性食品生产链中的使用 Views & Comments

Timothy R. Walsh

《工程（英文）》 2022年 第15卷 第8期   页码 9-10 doi: 10.1016/j.eng.2022.04.008

HTML PDF 收藏

早上好——工程师们警醒的信号 Views & Comments

Charles O. Holliday

《工程（英文）》 2016年 第2卷 第1期   页码 8-9 doi: 10.1016/J.ENG.2016.01.002

HTML PDF 收藏

Evaluation and prediction of slope stability using machine learning approaches

《结构与土木工程前沿（英文）》 2021年 第15卷 第4期   页码 821-833 doi: 10.1007/s11709-021-0742-8

摘要： In this paper, the machine learning (ML) model is built for slope stability evaluation and meets the high precision and rapidity requirements in slope engineering. Different ML methods for the factor of safety (FOS) prediction are studied and compared hoping to make the best use of the large variety of existing statistical and ML regression methods collected. The data set of this study includes six characteristics, namely unit weight, cohesion, internal friction angle, slope angle, slope height, and pore water pressure ratio. The whole ML model is primarily divided into data preprocessing, outlier processing, and model evaluation. In the data preprocessing, the duplicated data are first removed, then the outliers are filtered by the LocalOutlierFactor method and finally, the data are standardized. 11 ML methods are evaluated for their ability to learn the FOS based on different input parameter combinations. By analyzing the evaluation indicators R 2, MAE, and MSE of these methods, SVM, GBR, and Bagging are considered to be the best regression methods. The performance and reliability of the nonlinear regression method are slightly better than that of the linear regression method. Also, the SVM-poly method is used to analyze the susceptibility of slope parameters.

关键词： slope stability     factor of safety     regression     machine learning     repeated cross-validation    

HTML PDF 收藏

The psychology of organizational and social sustainability

Wei-Tau LEE, Hao ZHANG, Kenneth H. FUNK II

《工程管理前沿（英文）》 2019年 第6卷 第3期   页码 336-350 doi: 10.1007/s42524-019-0029-0

摘要： This paper presents 12 dimensions of work with the aim of providing further understanding of the relationship between work and the psychological well-being of workers. Previous research has indicated that these dimensions are significant in establishing such a relationship, which is essential to creating good work. These dimensions are also influential in their effect on the psychological state of workers and are translated specifically into actionable items in the workplace. A hypothetical system model is developed to relate these dimensions to one another, to workers, and to organizations. This set of dimensions also serves as a basis for further development of work design and evaluation tools.

关键词： work design     work dimensions     psychological factors     good work    

HTML PDF 收藏

Modified Bishop method for stability analysis of weakly sloped subgrade under centrifuge model test

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 727-741 doi: 10.1007/s11709-021-0730-z

摘要： The sliding forms of weak sloped and horizontal subgrades during the sliding process differ. In addition, the sliding form of weakly sloped subgrades exhibits considerable slippage and asymmetry. The accuracy of traditional slice methods for computing the stability safety factor of weakly sloped subgrades is insufficient for a subgrade design. In this study, a novel modified Bishop method was developed to improve the accuracy of the stability safety factor for different inclination angles. The instability mechanism of the weakly sloped subgrade was considered in the proposed method using the “influential force” and “additional force” concepts. The “additional force” reflected the weight effect of the embankment fill, whereas the “influential force” reflected the effect of the potential energy difference. Numerical simulations and experimental tests were conducted to evaluate the advantages of the proposed modified Bishop method. Compared with the traditional slice method, the error between the proposed method and the exact value is less than 32.3% in calculating the safety factor.

关键词： weakly sloped subgrade     stability analysis     additional force     influential force     modified Bishop method    

HTML PDF 收藏

Effect of cutterhead configuration on tunnel face stability during shield machine maintenance outages

《结构与土木工程前沿（英文）》 2023年 第17卷 第4期   页码 522-532 doi: 10.1007/s11709-023-0930-9

摘要： Owing to long-distance advancement or obstacles, shield tunneling machines are typically shut down for maintenance. Engineering safety during maintenance outages is determined by the stability of the tunnel face. Pressure maintenance openings are typically used under complicated hydrogeological conditions. The tunnel face is supported by a medium at the bottom of the excavation chamber and compressed air at the top. Owing to the high risk of face failure, the necessity of support pressure when cutterhead support is implemented and a method for determining the value of compressed air pressure using different support ratios must to be determined. In this study, a non-fully chamber supported rotational failure model considering cutterhead support is developed based on the upper-bound theorem of limit analysis. Numerical simulation is conducted to verify the accuracy of the proposed model. The results indicate that appropriately increasing the specific gravity of the supporting medium can reduce the risk of collapse. The required compressed air pressure increases significantly as the support ratio decreases. Disregarding the supporting effect of the cutterhead will result in a tunnel face with underestimated stability. To satisfy the requirement of chamber openings at atmospheric pressure, the stratum reinforcement strength and range at the shield end are provided based on different cutterhead aperture ratios.

关键词： tunnel face stability     cutterhead configuration     aperture ratio     pressure gradient     support ratio    

HTML PDF 收藏

On water security, sustainability, and the water-food-energy-climate nexus

Michael Bruce BECK, Rodrigo VILLARROEL WALKER

《环境科学与工程前沿（英文）》 2013年 第7卷 第5期   页码 626-639 doi: 10.1007/s11783-013-0548-6

摘要： The role of water security in sustainable development and in the nexus of water, food, energy and climate interactions is examined from the starting point of the definition of water security offered by Grey and Sadoff. Much about the notion of security has to do with the presumption of scarcity in the resources required to meet human needs. The treatment of scarcity in mainstream economics is in turn examined, therefore, in relation to how each of us as individuals reconciles means with ends, a procedure at the core of the idea of sustainable development. According to the Grey-Sadoff definition, attaining water security amounts to achieving basic, single-sector water development as a precursor of more general, self-sustaining, multi-sectoral development. This is consistent with the way in which water is treated as “first among equals”, i.e. privileged, in thinking about what is key in achieving security around the nexus of water, food, energy and climate. Cities, of course, are locations where demands for these multiple resource-energy flows are increasingly being generated. The paper discusses two important facets of security, i.e., diversity of access to resources and services (such as sanitation) and resilience in the behavior of coupled human-built-natural systems. Eight quasi-operational principles, by which to gauge nexus security with respect to city buildings and infrastructure, are developed.

关键词： cities as forces for good     diversity     energy and nutrient recovery     green economy     infrastructure failure     resilience    

HTML PDF 收藏

Effect of undercut on the lower bound stability of vertical rock escarpment using finite element and

Shuvankar DAS; Debarghya CHAKRABORTY

《结构与土木工程前沿（英文）》 2022年 第16卷 第8期   页码 1040-1055 doi: 10.1007/s11709-022-0841-1

摘要： In the present study, the stability of a vertical rock escarpment is determined by considering the influence of undercut. Lower bound finite element limit analysis in association with Power Cone Programming (PCP) is applied to incorporate the failure of rock mass with the help of the Generalized Hoek-Brown yield criterion. The change in stability due to the presence of undercut is expressed in terms of a non-dimensional stability number (σci/γH). The variations of the magnitude of σci/γH are presented as design charts by considering the different magnitudes of undercut offset (H/vu and wu/vu) from the vertical edge and different magnitudes of Hoek-Brown rock mass strength parameters (Geological Strength Index (GSI), rock parameter (mi,), Disturbance factor (D)). The obtained results indicate that undercut can cause a severe stability problem in rock mass having poor strength. With the help of regression analysis of the computed results, a simplified design equation is proposed for obtaining σci/γH. By performing sensitivity analysis for an undisturbed vertical rock escarpment, we have found that the undercut height ratio (H/vu) is the most sensitive parameter followed by GSI, undercut shape ratio (wu/vu), and mi. The developed design equation as well as design charts can be useful for practicing engineers to determine the stability of the vertical rock escarpment in the presence of undercut. Failure patterns are also presented to understand type of failure and extent of plastic state during collapse.

关键词： undercut     vertical escarpment     stability     Hoek-Brown yield criterion     PCP    

HTML PDF 收藏

Correction to: Effect of undercut on the lower bound stability of vertical rock escarpment using finite

《结构与土木工程前沿（英文）》 doi: 10.1007/s11709-023-0035-5

摘要： Correction to: Effect of undercut on the lower bound stability of vertical rock escarpment using finite element and power cone programming

关键词： finite element power     stability rock escarpment    

HTML PDF 收藏

标题 作者 时间 类型 操作

Being good or being known: International reputation of high-speed railway enterprises

期刊论文

Enhanced electrocatalytic performance of ultrathin PtNi alloy nanowires for oxygen reduction reaction

Hongjie ZHANG, Yachao ZENG, Longsheng CAO, Limeng YANG, Dahui FANG, Baolian YI, Zhigang SHAO

期刊论文

构建二维层状结构的稠环含能材料——高能量与高稳定性的平衡

冯永安, 邓沐聪, 宋思维, 陈思同, 张庆华, Jean’ne M. Shreeve

期刊论文

Is sodium percarbonate a good choice in situ remediation of deltamethrin pollution?

Xu Zhang, Baigang Ren, Shangge Li, Xiaodi Qu, Huanhuan Yang, Shiguo Xu, Zongming Ren, Qiang Kong, Cheng Wang

期刊论文

水的良性社会循环与城市水资源

李圭白,李星

期刊论文

Solvates and polymorphs of clindamycin phosphate: Structural, thermal stability and moisture stability

Junbo Gong, Dejiang Zhang, Yuanyuan Ran, Keke Zhang, Shichao Du

期刊论文

全面终止人用抗微生物药物在动物源性食品生产链中的使用

Timothy R. Walsh

期刊论文

早上好——工程师们警醒的信号

Charles O. Holliday

期刊论文

Evaluation and prediction of slope stability using machine learning approaches

期刊论文

The psychology of organizational and social sustainability

Wei-Tau LEE, Hao ZHANG, Kenneth H. FUNK II

期刊论文

Modified Bishop method for stability analysis of weakly sloped subgrade under centrifuge model test

期刊论文

Effect of cutterhead configuration on tunnel face stability during shield machine maintenance outages

期刊论文

On water security, sustainability, and the water-food-energy-climate nexus

Michael Bruce BECK, Rodrigo VILLARROEL WALKER

期刊论文

Effect of undercut on the lower bound stability of vertical rock escarpment using finite element and

Shuvankar DAS; Debarghya CHAKRABORTY

期刊论文

Correction to: Effect of undercut on the lower bound stability of vertical rock escarpment using finite

期刊论文