Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 816

会议视频 13

会议信息 1

年份

2023 61

2022 80

2021 66

2020 63

2019 55

2018 43

2017 36

2016 29

2015 34

2014 47

2013 35

2012 21

2011 37

2010 36

2009 29

2008 34

2007 39

2006 17

2005 17

2004 5

展开︾

关键词

动力特性 6

医学 5

动态规划 4

治疗 4

人工智能 3

力学性能 3

动力响应 3

绿色化工 3

SARS-CoV-2 2

前景 2

剖宫产瘢痕妊娠 2

动力学 2

动力气垫 2

动态特性 2

动态管理 2

反渗透 2

废水 2

扬矿管 2

模态 2

展开︾

检索范围：

排序：展示方式：

Recent development on statistical methods for personalized medicine discovery

null

《医学前沿（英文）》 2013年第7卷第1期页码 102-110 doi: 10.1007/s11684-013-0245-7

摘要：

It is well documented that patients can show significant heterogeneous responses to treatments so the best treatment strategies may require adaptation over individuals and time. Recently, a number of new statistical methods have been developed to tackle the important problem of estimating personalized treatment rules using single-stage or multiple-stage clinical data. In this paper, we provide an overview of these methods and list a number of challenges.

关键词： dynamic treatment regimes personalized medicine reinforcement learning Q-learning

HTML PDF 收藏

Development of combined coagulation-hydrolysis acidification-dynamic membrane bioreactor system for treatment

Xue Shen, Lei Lu, Baoyu Gao, Xing Xu, Qinyan Yue

《环境科学与工程前沿（英文）》 2019年第13卷第1期 doi: 10.1007/s11783-019-1093-8

摘要：

• We created a combined system for treating oilfield polymer-flooding wastewater.

• The system was composed of coagulation, hydrolysis acidification and DMBR.

• Coagulant integrated with demulsifier dominated the removal of crude oil.

• The DMBR proceed efficiently without serious membrane fouling.

关键词： Coagulation Hydrolysis acidification Dynamic membrane bioreactor Polymer flooding

HTML PDF 收藏

Direct acting antiviral-induced dynamic reduction of serum

Tung Huynh, Ke-Qin Hu

《医学前沿（英文）》 2019年第13卷第6期页码 658-666 doi: 10.1007/s11684-019-0707-7

摘要： Direct acting antiviral (DAA) treatments may reduce the elevated α fetoprotein (AFP), but data on how these treatments affect elevated AFP in patients with chronic hepatitis C (CHC) remain insufficient. In the present study, the frequency of baseline AFP elevations and their related factors, AFP dynamics during and after DAA treatment, and factors associated with AFP reduction was assessed. This retrospective study included 141 patients with CHC without hepatocellular carcinoma who received DAA and achieved sustained virological response. The details are as follows: mean post-treatment follow-up was 99 weeks (12–213); mean age, 57.8 years old; 52%, males; 79%, genotype (GT) 1; and 47%, cirrhosis. Pre-treatment AFP elevation (>5.5 ng/mL) was seen in 48.2% patients. On multivariate analysis, baseline AFP>5.5 was associated with the presence of cirrhosis ( =0.001), co-existing non-alcoholic steatohepatitis (NASH) ( = 0.035), and GT 1 ( = 0.029). AFP normalization was seen in 28.2% patients at treatment week 2, in 52% at the end of treatment, and in 73.4% at the end of follow-up. Post-treatment week 24 AFP normalization was associated with the absence of cirrhosis ( = 0.003), Child–Pugh score<6 ( = 0.015), and baseline AFP<10 ( = 0.015). AFP elevation is common in patients with CHC and independently associated with NASH, cirrhosis, and GT 1. DAA treatment resulted in AFP normalization as early as treatment week 2. Post-treatment week 24 AFP normalization is independently associated with the absence of cirrhosis, Child–Pugh score<6, and baseline AFP<10.

关键词： chronic hepatitis C α fetoprotein direct acting antiviral treatment cirrhosis

HTML PDF 收藏

黄幼麟：Dynamic Consumer Preferences for Electric Vehicles — A Longitudinal Analysis（2020年7月12日）

2022年06月10日

关键词：能源

Occurrence and migration of microplastics and plasticizers in different wastewater and sludge treatmentunits in municipal wastewater treatment plant

《环境科学与工程前沿（英文）》 2022年第16卷第11期 doi: 10.1007/s11783-022-1577-9

摘要：

● Reduce the quantifying MPs time by using Nile red staining.

关键词： Microplastics Municipal wastewater treatment plant Phthalate esters Thermal hydrolysis

HTML PDF 收藏

罗军：Treatment Selection in Prostate Cancer（2019年8月16日）

2021年04月22日

关键词：医学

Numerical analysis of nonlinear dynamic behavior of earth dams

Babak EBRAHIMIAN

《结构与土木工程前沿（英文）》 2011年第5卷第1期页码 24-40 doi: 10.1007/s11709-010-0082-6

摘要： A numerical study is conducted to investigate the dynamic behavior of earth dams. The numerical investigation employs a fully nonlinear dynamic finite difference analysis incorporating a simple elastic perfectly plastic constitutive model to describe the stress-strain response of the soil and the Rayleigh damping to increase the level of hysteretic damping. The extended Masing rules are implemented into the constitutive model to explain more accurately the soil response under general cyclic loading. The soil stiffness and hysteretic damping change with loading history. The procedures for calibrating the constructed numerical model with centrifuge test data and also a real case history are explained. For the latter, the Long Valley (LV) earth dam subjected to the 1980 Mammoth Lake earthquake as a real case-history is analyzed and the obtained numerical results are compared with the real measurements at the site in both the time and frequency domains. Relatively good agreement is observed between computed and measured quantities. It seems that the Masing rules combined with a simple elasto-plastic model gives reasonable numerical predictions. Afterwards, a comprehensive parametric study is carried out to identify the effects of dam height, input motion characteristics, soil behavior, strength of the shell materials and dam reservoir condition on the dynamic response of earth dams. Three real earthquake records with different levels and peak acceleration values (PGAs) are used as input motions. The results show that the crest acceleration decreases when the dam height increases and no amplification is observed. Further, more inelastic behavior and more earthquake energy absorption are observed in higher dams.

关键词： earth dam numerical nonlinear response dynamic analysis earthquake dam height

HTML PDF 收藏

Construction of interfacial dynamic bonds for high performance lignin/polymer biocomposites

《化学科学与工程前沿（英文）》 2023年第17卷第10期页码 1372-1388 doi: 10.1007/s11705-023-2302-3

摘要： Lignin is the largest natural aromatic biopolymer, but usually treated as industrial biomass waste. The development of lignin/polymer biocomposites can promote the high value utilization of lignin and the greening of polymers. However, the weak interfacial interaction between industrial lignin and polymer induces poor compatibility and serious agglomeration in polymer owing to the strong intermolecular force of lignin. As such, it is extremely difficult to prepare high performance lignin/polymer biocomposites. Recently, we proposed the strategy of in situ construction of interfacial dynamic bonds in lignin/polymer composites. By taking advantage of the abundant oxygen-containing polar groups of lignin, we inserted dynamic bonding connection such as hydrogen bonds and coordination bonds into the interphase between lignin and the polymer matrix to improve the interfacial interactions. Meanwhile, the natural amphiphilic structure characteristics of lignin were utilized to construct the hierarchical nanophase separation structure in lignin/polymer composites. The persistent problems of poor dispersity and interfacial compatibility of lignin in the polymer matrix were effectively solved. The lignin-modified polymer composites achieved simultaneously enhanced strength and toughness. This concise review systematically summarized the recent research progress of our group toward building high-performance lignin/polymer biocomposites through the design of interfacial dynamic bonds (hydrogen bonds, coordination bonds, and dynamic covalent bonds) between lignin and different polymer systems (polar plastics, rubber, polyurethane, hydrogels, and other polymers). Finally, the future development direction, main challenges, and potential solutions of lignin application in polymers were presented.

关键词： lignin polymer interfacial dynamic bonds

HTML PDF 收藏

Molecular size characterization of heavy oil fractions in vacuum and solution by molecular dynamic simulation

Wenpo REN, Honggang CHEN, Chaohe YANG, Honghong SHAN,

《化学科学与工程前沿（英文）》 2010年第4卷第3期页码 250-256 doi: 10.1007/s11705-009-0281-7

摘要： Two kinds of heavy oils were fractionated into eight fractions by Liquid-Solid Adsorption Chromatography, respectively, and samples were collected to measure properties. According to the elemental analysis, molecular weight and H-NMR data, average molecular structures of polycyclic aromatic and heavy resin were constructed with improved Brown-Ladner (B-L) method and several corrections. And then, the most stable conformations of polycyclic aromatic and heavy resin in vacuum and toluene solution were obtained by molecular dynamic simulation, and the molecular size was gotten via the radius of gyration analysis. The results showed that the radius of gyration of polycyclic aromatic and heavy resin was 0.55–0.70 nm in vacuum and 0.60–0.90 nm in toluene solution. With molecular weight increasing, the molecular size in vacuum and toluene solution also increased. Due to the swelling behavior of solvent, the alkyl side chains of heavy oil molecule in solution were more stretched. Thus, the molecular size in toluene solution was larger than that in vacuum.

关键词： dynamic simulation molecular dynamic behavior molecule Adsorption Chromatography

HTML PDF 收藏

动态设定型板形板厚自动控制系统

张进之,段春华

《中国工程科学》 2000年第2卷第6期页码 67-72

摘要：

文章介绍了应用解析板形方程推出板形最佳轧制规程和板形板厚协调控制新方法。该方法的主要特点：系统中采用了静、动态负荷分配，动态设定厚度自动控制系统（DAGC）完成了板形板厚的闭环控制，在算法中采用了贝尔曼动态规划。新方法将会改变目前轧机设计和控制思想：设计合理刚度，强调调度计划、配置轧辊凸度和优化轧制规程等方面的作用，实现信息控制。

关键词：动态负荷分配板形最佳规程动态规划动态设定

HTML PDF 收藏

Modelling of dynamic contact length in rail grinding process

null

《机械工程前沿（英文）》 2014年第9卷第3期页码 242-248 doi: 10.1007/s11465-014-0305-y

摘要：

Rails endure frequent dynamic loads from the passing trains for supporting trains and guiding wheels. The accumulated stress concentrations will cause the plastic deformation of rail towards generating corrugations, contact fatigue cracks and also other defects, resulting in more dangerous status even the derailment risks. So the rail grinding technology has been invented with rotating grinding stones pressed on the rail with defects removal. Such rail grinding works are directed by experiences rather than scientifically guidance, lacking of flexible and scientific operating methods. With grinding control unit holding the grinding stones, the rail grinding process has the characteristics not only the surface grinding but also the running railway vehicles. First of all, it’s important to analyze the contact length between the grinding stone and the rail, because the contact length is a critical parameter to measure the grinding capabilities of stones. Moreover, it’s needed to build up models of railway vehicle unit bonded with the grinding stone to represent the rail grinding car. Therefore the theoretical model for contact length is developed based on the geometrical analysis. And the calculating models are improved considering the grinding car’s dynamic behaviors during the grinding process. Eventually, results are obtained based on the models by taking both the operation parameters and the structure parameters into the calculation, which are suitable for revealing the process of rail grinding by combining the grinding mechanism and the railway vehicle systems.

关键词： rail grinding contact length dynamic model Hamiltonian system grinding stone rail grinding car

HTML PDF 收藏

A job-insertion heuristic for minimizing the mean flowtime in dynamic flowshops

Guang GUO, Bo WU, Shuzi YANG

《机械工程前沿（英文）》 2011年第6卷第2期页码 197-202 doi: 10.1007/s11465-011-0211-5

摘要：

A new adaptive job-insertion based heuristic is presented to minimize the mean flowtime in a dynamic flowshop consisting of machines. Job orders arrive to the system randomly, and the job arrival or release dates are not known in advance. The heuristic is derived by inserting new jobs into the scheduled sequence as needed when the machine becomes free. Computation results indicate that the proposed heuristic performs 2.7%–10.8% better than the SPT dispatching rule, which is currently one of the most effective methods for minimizing the mean flowtime in dynamic flowshops.

关键词： scheduling dynamic flowshops flowtime heuristic mean flowtime

HTML PDF 收藏

Seasonal and treatment-process variations in invertebrates in drinking water treatment plants

Zhiling Wu, Xianchun Tang, Hongbin Chen

《环境科学与工程前沿（英文）》 2021年第15卷第4期 doi: 10.1007/s11783-020-1354-6

摘要： Abstract • Seasonal and treatment-process variations in invertebrates in a DWTP were analyzed. • The propagation and leakage of invertebrates in BAC filter were the most serious. • Invertebrates can survive and reproduce in chlorine disinfected clear water tanks. • Proportions of endogenous invertebrates increased along the treatment process. Problems associated with excessive propagation and leakage of invertebrates in drinking water have received increasing attention in recent years. We performed a monthly survey of invertebrate abundance and taxa in the effluent of each treatment stage in a drinking water treatment plant between May 2015 and April 2016 and analyzed seasonal and treatment-process variations in invertebrates. The results showed that invertebrate abundances in raw water, effluent of the biological activated carbon (BAC) filter, and finished water significantly correlated with water temperature, whereas no correlation was observed between water temperature and invertebrate abundance in the effluents of the sedimentation tank and sand filter. The dominant taxa in the effluent of each treatment stage were rotifers, nematodes, and crustaceans. The sedimentation tank could efficiently remove invertebrates with an annual average removal rate of 92%. The propagation and leakage of invertebrates occurred in the sand and BAC filters but more seriously in the latter. The average reproduction rate in the BAC filter was 268.8% with rotifers as the taxon that leaked the most. Invertebrate survival and reproduction were also observed in the chlorine-disinfected clean water reservoir with an average reproduction rate of 41.9%. Owing to differences in chlorine resistance, the reproduction ability of the dominant taxa was in the order nematodes>crustaceans>rotifers. The proportion of endogenous invertebrates gradually increased along the treatment process. The average proportion of endogenous invertebrates in the finished water was higher than 79.0%. Our findings suggested that waterworks should pay more attention to endogenous invertebrate growth.

关键词： Invertebrates Drinking water Seasonal variations Treatment process

HTML PDF 收藏

Finding buckling points for nonlinear structures by dynamic relaxation scheme

Mohammad REZAIEE-PAJAND, Hossein ESTIRI

《结构与土木工程前沿（英文）》 2020年第14卷第1期页码 23-61 doi: 10.1007/s11709-019-0549-z

摘要： Dynamic Relaxation Method (DRM) is an explicit approach for solving the simultaneous systems of equations. In this tactic, the fictitious mass and damping are added to the static governing equations, and an artificial dynamic system is constructed. By using DRM for nonlinear analysis, the structural static equilibrium path is obtained. This outcome is extremely valuable, since it leads to the behavior of structures. Among the finding related to the structural static path are the critical and buckling points for nonlinear structures. In this paper, a new way for calculating the load factor is proposed by setting the external work zero. Mixing the dynamic relaxation scheme with external work technique has not been formulated so far. In all incremental-iterative methods, the load factor increment sign should be determinated by extra calculations. This sign leads to increase or decrease of the load increment. It is worth emphasizing that sign of the load factor increment changes at the load limit points. Therefore, the sign determinations are required in the common work control methods. These disadvantages are eliminated in the proposed algorithm. In fact, the suggested load factor depends only on the Dynamic Relaxation (DR) fictitious parameters. Besides, all DR calculations are performed via vector operation. Moreover, the load factor is calculated only by one formula, and it has the same relation in the all solution processes. In contrast to the arc length techniques, which requires the sign determined, the proposed scheme does not need any sign finding. It is shown that author’s technique is quicker than the other dynamic relaxation strategies. To prove the capability and efficiency of the presented scheme, several numerical tests are performed. The results indicate that the suggested approach can trace the complex structural static paths, even in the snap-back and snap-through parts.

关键词： load factor external work dynamic relaxation static equilibrium path large displacement