资源类型

期刊论文 232

会议视频 3

年份

2023 12

2022 14

2021 12

2020 17

2019 16

2018 11

2017 12

2016 15

2015 10

2014 16

2013 11

2012 9

2011 8

2010 10

2009 14

2008 16

2007 16

2006 3

2005 1

2004 1

展开 ︾

关键词

4D打印 2

三塔两跨悬索桥 2

增材制造 2

形状记忆聚合物 2

HEMTs）；栅槽；数字湿法腐蚀；选择性湿法腐蚀 1

HY-2 1

Inconel 718合金 1

Laves相 1

MIMO雷达；波形设计；谱分解；分式二次约束二次规划 1

Otway 1

SPH 1

X射线 1

“两山”理论 1

“单独二孩” 1

一致性 1

三塔双跨悬索桥 1

三塔悬索桥 1

上部结构施工 1

两个反应区 1

展开 ︾

检索范围：

排序： 展示方式：

Effect of counter current gas phase on liquid film

Shujuan LUO, Huaizhi LI, Weiyang FEI, Yundong WANG

《化学科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 135-137 doi: 10.1007/s11705-009-0129-1

摘要： Liquid film flow is very important in many industrial applications. However, there are few reports about its characteristics on structured packings. Therefore, in this paper, liquid film phenomena were investigated experimentally to exploit new approaches for intensifying the performance of the structured packings. All experiments were performed at room temperature. Water and air were the working fluids. The effect of counter current gas phase on the liquid film was taken into consideration. A high speed camera, a non-intrusive measurement technique, was used. It is shown that both liquid and gas phases have strong effects on film characteristics. In the present work, liquid film width increased by 57% because of increasing liquid flow rate, while it decreased by 25% resulting from the counter current gas phase.

关键词： counter current     liquid film     two phases     structured packings    

HTML PDF 收藏

Enhanced performance of oxygen vacancies on CO adsorption and activation over different phases of ZrO

《能源前沿（英文）》 2023年 第17卷 第4期   页码 545-554 doi: 10.1007/s11708-023-0867-7

摘要： The effect of oxygen vacancies on the adsorption and activation of CO2 on the surface of different phases of ZrO2 is investigated by density functional theory (DFT) calculations. The calculations show that the oxygen vacancies contribute greatly to both the adsorption and activation of CO2. The adsorption energy of CO2 on the c-ZrO2, t-ZrO2 and, m-ZrO2 surfaces is enhanced to 5, 4, and 3 folds with the help of oxygen vacancies, respectively. Moreover, the energy barrier of CO2 dissociation on the defective surfaces of c-ZrO2, t-ZrO2, and m-ZrO2 is reduced to 1/2, 1/4, and 1/5 of the perfect surface with the assistance of oxygen vacancies. Furthermore, the activation of CO2 on the ZrO2 surface where oxygen vacancies are present, and changes from an endothermic reaction to an exothermic reaction. This finding demonstrates that the presence of oxygen vacancies promotes the activation of CO2 both kinetically and thermodynamically. These results could provide guidance for the high-efficient utilization of CO2 at an atomic scale.

关键词： CO2 activation     oxygen vacancies     ZrO2     different phases    

HTML PDF 收藏

Optimising the oil phases of aluminium hydrogel-stabilised emulsions for stable, safe and efficient vaccine

《化学科学与工程前沿（英文）》 2022年 第16卷 第6期   页码 973-984 doi: 10.1007/s11705-021-2123-1

摘要： To increase antibody secretion and dose sparing, squalene-in-water aluminium hydrogel (alum)-stabilised emulsions (ASEs) have been developed, which offer increased surface areas and cellular interactions for higher antigen loading and enhanced immune responses. Nevertheless, the squalene (oil) in previous attempts suffered from limited oxidation resistance, thus, safety and stability were compromised. From a clinical translational perspective, it is imperative to screen the optimal oils for enhanced emulsion adjuvants. Here, because of the varying oleic to linoleic acid ratio, soybean oil, peanut oil, and olive oil were utilised as oil phases in the preparation of aluminium hydrogel-stabilised squalene-in-water emulsions, which were then screened for their stability and immunogenicity. Additionally, the underlying mechanisms of oil phases and emulsion stability were unravelled, which showed that a higher oleic to linoleic acid ratio increased anti-oxidative capabilities but reduced the long-term storage stability owing to the relatively low zeta potential of the prepared droplets. As a result, compared with squalene-in-water ASEs, soybean-in-water ASEs exhibited comparable immune responses and enhanced stability. By optimising the oil phase of the emulsion adjuvants, this work may offer an alternative strategy for safe, stable, and effective emulsion adjuvants.

关键词： pickering emulsion     vaccine adjuvant     alum-stabilised emulsion     oleic to linoleic acid ratio     stability    

HTML PDF 收藏

Toxic effects of wastewater from various phases of monosodium glutamate production on seed germination

LIU Rui, ZHOU Qixing, ZHANG Lanying, GUO Hao

《环境科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 114-119 doi: 10.1007/s11783-007-0021-5

摘要： To make a comprehensive assessment on monosodium glutamate (MSG) wastewater pollution, a pollution exposure experiment was carried out on the seed germination and root elongation of wheat, Chinese cabbage and tomato by using the wastewater discharged from different processing phases of MSG production. The results showed that there were significantly positive linear relationships between the inhibitory rates of wheat seed germination and root elongation and the COD of the mother liquor scraps. The toxicity of MSG wastewater to the test crops was in the order of tomato > Chinese cabbage > wheat, indicating that tomato was the most sensitive to the wastewater, and could be considered as an ideal toxic bioindicator. The half-effect concentrations (IC) based on the seed germination and root elongation of the test crops exposed to the wastewater discharged from various processing phases of MSG production was 22.0 32 432 and 17.3 3320 mg/L, respectively.

关键词： monosodium glutamate     different     inhibitory     pollution exposure     half-effect    

HTML PDF 收藏

insights into nitrogen and sulfur co-doped carbon nanotubes for effective desulfurization of liquid phases

《环境科学与工程前沿（英文）》 2021年 第15卷 第5期 doi: 10.1007/s11783-021-1397-3

摘要：

• Synthesis of NS-CNTS is used in a high desulfurization performance.

关键词： Dibenzothiophene (DBT)     Tertiary methyl mercaptan     Adsorption     Carbon nano tube (CNT)     Desulfurization     Doping    

HTML PDF 收藏

Dynamics of foot-and-mouth disease virus replication in cells at different phases of the cell-division

Claudia DOEL,Zhidong ZHANG,Lise MAZELET,Ryan WATERS,John BASHIRUDDIN

《农业科学与工程前沿（英文）》 2014年 第1卷 第3期   页码 250-257 doi: 10.15302/J-FASE-2014031

摘要： Foot-and-mouth-disease virus (FMDV) replicates in epithelial cells. The restriction of FMDV RNA to the basal cell layer of epithelia suggests a possible link between FMDV replication and the cell status. This paper describes studies in which FMDV infection was investigated in cells that were held at various cell division phases using cell cycle inhibitors. The results suggest that when cells were arrested at the G or G /S phase, high levels of viral RNA were detected by quantitative real-time reverse transcription PCR and viral protein synthesis was observed by specific labeling techniques. In contrast, when cells were arrested at the G /M phase, reduced or no viral RNA synthesis was detected.

关键词： foot-and-mouth disease virus     cell cycle     replication    

HTML PDF 收藏

Carbon dots-based fluorescence sensor for two-photon imaging of pH in diabetic mice

《化学科学与工程前沿（英文）》 2023年 第17卷 第3期   页码 298-306 doi: 10.1007/s11705-022-2212-9

摘要： Herein, a reversible pH fluorescent sensor was developed using caffeic acid as the precursor by one-step solvothermal synthesis method. The carbon dots-based sensor (CA-CDs) exhibited pH-dependent increase in fluorescence intensity and showed linear relationship in the range of pH 6.60 and 8.00. Notably, the fluorescence sensor has a reversible response to pH change. Finally, the CA-CDs has been successfully applied for two-photon imaging of the pH in liver and kidney of diabetic mice. Imaging results showed that the pH value in kidney of diabetic mice was lower than that of the normal mice, while the pH value in liver of diabetic mice was almost the same as that of the normal mice. The present study provides a simple analytical method for pH detection suitable for in vivo.

关键词： carbon dots     two-photon imaging     pH     diabetic mice    

HTML PDF 收藏

New medical risks affecting obstetrics after implementation of the two-child policy in China

null

《医学前沿（英文）》 2017年 第11卷 第4期   页码 570-575 doi: 10.1007/s11684-017-0552-5

摘要：

China recently instituted a two-child policy in response to its aging population, declining workforce and demographic dividend, and the need to develop asocial economy. Additionally, women generally delay having a second child because of the overwhelming pressure in their lives. With the improvements in assisted fertility technologies in recent years, the number of elderly women attempting to bear children has increased. The quality of woman’s eggs and a man’s sperm declined dramatically with increasing age, leading to an increased risk of pregnancy-related complications among older women. Therefore, the types of fertility problems experienced by elderly females must be provided with considerable attention by obstetricians. This commentary article focuses on the medical problems faced by older second-child pregnant women. This work discusses their increased rates of infertility, spontaneous abortion, fetal malformation, gestational diabetes, cesarean section, placenta previa, postpartum hemorrhage, postpartum depression, and hypertensive disorders, which complicate pregnancy.

关键词： two-child policy     birth defects     cesarean delivery     placenta previa    

HTML PDF 收藏

Extended two-fluid model applied to analysis of bubbly flow in multiphase rotodynamic pump impeller

Zhiyi YU, Guoyu WANG, Shuliang CAO

《机械工程前沿（英文）》 2009年 第4卷 第1期   页码 53-59 doi: 10.1007/s11465-009-0006-0

摘要： This paper presents an extended two-fluid model based on the Navier-Stokes equations and the standard turbulence model, to simulate the three-dimensional air-water bubbly flow in turbo machinery. In the governing equations, the drag force and added mass force are added and the additional source terms arising from fluctuations of gas volume fraction are considered. The discrete equations are solved using a developed two-phase semi-implicit method for pressure-linked equations, consistent (SIMPLEC) algorithm in body-fitted coordinates with a staggered grid system. Simulation is then carried out for the pure liquid flow and air-water two-phase flow with the inlet gas volume fraction being 15% in a multiphase rotodynamic pump impeller and the pump head performance is predicted. Comparison with experimental results shows the reliability and commonality of the numerical model.

关键词： two-fluid model     multiphase rotodynamic pump     SIMPLEC algorithm     numerical simulation    

HTML PDF 收藏

Feasible workspace regions for general two-revolute manipulator

Conghui LIANG, Marco CECCARELLI

《机械工程前沿（英文）》 2011年 第6卷 第4期   页码 397-408 doi: 10.1007/s11465-011-0228-9

摘要：

In this paper, a topology is presented for feasible workspace regions in general two-revolute manipulators. The design problem and concept of feasible workspace regions have been discussed as linked to each other. Design equations are formulated by arbitrarily prescribing four workspace boundary points. The so-called feasible workspace regions are the intersection of three different sub-regions, which are given by constraint curves as function of the relative positions of three workspace boundary points. By using a parametric study, all topologies for three sub-regions are figured out. Corresponding areas in cross section plane are determined for prescribing the position of a feasible workspace point as function of the topology for sub-regions. A classification has been proposed to determine and to characterize the combination of the topologies for those sub-regions. All topologies for feasible workspace regions are figured out and they are discussed as a design tool. Three general cases are analyzed in details to characterize workspace design capabilities for general two-revolute manipulators.

关键词： workspace     two-revolute manipulators     topology analysis     design    

HTML PDF 收藏

Offline motion planning and simulation of two-robot welding coordination

Tie ZHANG, Fan OUYANG

《机械工程前沿（英文）》 2012年 第7卷 第1期   页码 81-92 doi: 10.1007/s11465-012-0309-4

摘要：

This paper focuses on the two-robot welding coordination of complex curve seam which means one robot grasp the workpiece, the other hold the torch, the two robots work on the same workpiece simultaneously. This paper builds the dual-robot coordinate system at the beginning, and three point calibration method of two robots’ relative base coordinate system is presented. After that, the non master/slave scheme is chosen for the motion planning, the non master/slave scheme sets the poses versus time function of the point u on the workpiece, and calculates the two robot end effecter trajectories through the constrained relationship matrix automatically. Moreover, downhand welding is employed which can guarantee the torch and the seam keep in good contact condition all the time during the welding. Finally, a Solidworks-SimMechanics simulation platform is established, and a simulation of curved steel pipe welding is conducted. The results of the simulation illustrate the welding process can meet the requirements of downhand welding, the joint displacement curves are smooth and continuous and no joint velocities are out of working scope.

关键词： complex curve seam     two robots     coordinated welding     motion planning    

HTML PDF 收藏

Simulation of heterogeneous two-phase media using random fields and level sets

George STEFANOU

《结构与土木工程前沿（英文）》 2015年 第9卷 第2期   页码 114-120 doi: 10.1007/s11709-014-0267-5

摘要： The accurate and efficient simulation of random heterogeneous media is important in the framework of modeling and design of complex materials across multiple length scales. It is usually assumed that the morphology of a random microstructure can be described as a non-Gaussian random field that is completely defined by its multivariate distribution. A particular kind of non-Gaussian random fields with great practical importance is that of translation fields resulting from a simple memory-less transformation of an underlying Gaussian field with known second-order statistics. This paper provides a critical examination of existing random field models of heterogeneous two-phase media with emphasis on level-cut random fields which are a special case of translation fields. The case of random level sets, often used to represent the geometry of physical systems, is also examined. Two numerical examples are provided to illustrate the basic features of the different approaches.

关键词： microstructure     random fields     level sets     shape recovery     two-phase media    

HTML PDF 收藏

Modified landfill gas generation rate model of first-order kinetics and two-stage reaction

Jiajun CHEN , Hao WANG , Na ZHANG ,

《环境科学与工程前沿（英文）》 2009年 第3卷 第3期   页码 313-319 doi: 10.1007/s11783-009-0025-4

摘要： This investigation was carried out to establish a new domestic landfill gas (LFG) generation rate model that takes into account the impact of leachate recirculation. The first-order kinetics and two-stage reaction (FKTSR) model of the LFG generation rate includes mechanisms of the nutrient balance for biochemical reaction in two main stages. In this study, the FKTSR model was modified by the introduction of the outflow function and the organic acid conversion coefficient in order to represent the in-situ condition of nutrient loss through leachate. Laboratory experiments were carried out to simulate the impact of leachate recirculation and verify the modified FKTSR model. The model calibration was then calculated by using the experimental data. The results suggested that the new model was in line with the experimental data. The main parameters of the modified FKTSR model, including the LFG production potential (), the reaction rate constant in the first stage (), and the reaction rate constant in the second stage () of 64.746 L, 0.202 d, and 0.338 d, respectively, were comparable to the old ones of 42.069 L, 0.231 d, and 0.231 d. The new model is better able to explain the mechanisms involved in LFG generation.

关键词： landfill gas (LFG)     generation rate model     first-order kinetics     two-stage reaction     outflow function    

HTML PDF 收藏

Study of two-phase flow regime identification in horizontal tube bundles under vertical upward cross-flow

HUANG Xinghua, WANG Li, JIA Feng

《能源前沿（英文）》 2008年 第2卷 第3期   页码 333-338 doi: 10.1007/s11708-008-0043-0

摘要： A wavelet-transform based approach for flow regime identification in horizontal tube bundles under vertical upward cross-flow condition was presented. Tests on two-phase flow pattern of R134a were conducted under low mass velocity and flow boiling conditions over ranges of mass flux 4–25 kg/ms, vapor quality 0.02–0.90. Time series of differential pressure fluctuations were measured and analyzed with discrete wavelet transform. Different time-scale characteristics in bubbly flow, churn flow and annular flow were analyzed. The wavelet energy distributions over scales were found to be appropriate for flow regime identification. Based on the wavelet energy distribution over characteristic scales, a criterion of flow regime identification was proposed. The comparison with experiment results show that it is feasible to use the discrete wavelet transform as the tool of flow regime identification in horizontal tube bundles under vertical upward cross-flow condition.

关键词： two-phase     discrete     appropriate     wavelet-transform     criterion    

HTML PDF 收藏

Compressor performance of two-stage turbocharging system

HE Yituan, MA Chaochen, WEI Mingshan, ZHU Zhifu, HE Yituan

《机械工程前沿（英文）》 2008年 第3卷 第2期   页码 218-221 doi: 10.1007/s11465-008-0027-0

摘要： To study the performance of high and low stage compressors and that of the system as a whole, a two-stage turbocharging system was matched, and a special two-stage turbocharging system test bench was built. For each test curve, the speeds of the two stage turbochargers were adjusted to the fixed data, and a compressor performance experiment was performed. The results showed many differences between the corrected mass flow and the actual mass flow of the high pressure (HP) stage compressor. To find out the actual supercharging effect of the two-stage turbocharging system, it is better to adopt the actual mass flow. The two-stage turbocharging system in this paper has much higher efficiency under most operating conditions if the pressure ratio assignment is 1:1. The system can get very high supercharging pressure when the speeds of the two stage turbochargers are rather low, which ensures the system’s security and reliability.

关键词： special two-stage     HP     performance experiment     reliability     actual supercharging    

HTML PDF 收藏

标题 作者 时间 类型 操作

Effect of counter current gas phase on liquid film

Shujuan LUO, Huaizhi LI, Weiyang FEI, Yundong WANG

期刊论文

Enhanced performance of oxygen vacancies on CO adsorption and activation over different phases of ZrO

期刊论文

Optimising the oil phases of aluminium hydrogel-stabilised emulsions for stable, safe and efficient vaccine

期刊论文

Toxic effects of wastewater from various phases of monosodium glutamate production on seed germination

LIU Rui, ZHOU Qixing, ZHANG Lanying, GUO Hao

期刊论文

insights into nitrogen and sulfur co-doped carbon nanotubes for effective desulfurization of liquid phases

期刊论文

Dynamics of foot-and-mouth disease virus replication in cells at different phases of the cell-division

Claudia DOEL,Zhidong ZHANG,Lise MAZELET,Ryan WATERS,John BASHIRUDDIN

期刊论文

Carbon dots-based fluorescence sensor for two-photon imaging of pH in diabetic mice

期刊论文

New medical risks affecting obstetrics after implementation of the two-child policy in China

null

期刊论文

Extended two-fluid model applied to analysis of bubbly flow in multiphase rotodynamic pump impeller

Zhiyi YU, Guoyu WANG, Shuliang CAO

期刊论文

Feasible workspace regions for general two-revolute manipulator

Conghui LIANG, Marco CECCARELLI

期刊论文

Offline motion planning and simulation of two-robot welding coordination

Tie ZHANG, Fan OUYANG

期刊论文

Simulation of heterogeneous two-phase media using random fields and level sets

George STEFANOU

期刊论文

Modified landfill gas generation rate model of first-order kinetics and two-stage reaction

Jiajun CHEN , Hao WANG , Na ZHANG ,

期刊论文

Study of two-phase flow regime identification in horizontal tube bundles under vertical upward cross-flow

HUANG Xinghua, WANG Li, JIA Feng

期刊论文

Compressor performance of two-stage turbocharging system

HE Yituan, MA Chaochen, WEI Mingshan, ZHU Zhifu, HE Yituan

期刊论文