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 158

年份

2023 6

2022 7

2021 5

2020 4

2019 7

2018 5

2017 9

2016 2

2015 5

2014 5

2013 5

2012 4

2011 7

2010 13

2009 17

2008 16

2007 8

2006 5

2005 6

2004 2

展开︾

关键词

优化 2

建模 2

跨海大桥 2

CFD 1

CP）；符号间干扰（inter symbol interference， ISI）；载波间干扰（inter carrier interference 1

GC-Q-TOFMS 1

HY-2卫星 1

ICI）；最大似然估计（maximum likelihood estimation 1

KD技术标准 1

KD挑战性问题 1

KD核心问题 1

KD猜想 1

K平均聚类 1

LC-Q-TOFMS 1

MCDB 1

MLE） 1

NURBS技术 1

OFDM）；快速傅立叶变换（Fast Fourier transform， FFT）；循环前缀（cyclic prefix 1

PBO纤维片材 1

展开︾

检索范围：

排序：展示方式：

Fabrication of high-capacity cation-exchangers for protein adsorption: Comparison of grafting-from andgrafting-to approaches

Ming Zhao, Run Liu, Jian Luo, Yan Sun, Qinghong Shi

《化学科学与工程前沿（英文）》 2019年第13卷第1期页码 120-132 doi: 10.1007/s11705-018-1730-y

摘要： In this work, we have synthesized two polymer-grafted cation exchangers: one via the grafting-from approach, in which sulfopropyl methacrylate (SPM) is grafted through atom transfer radical polymerization onto Sepharose FF (the thus resulting exchanger is referred as Sep- -SPM), and another via the grafting-to approach, in which the polymer of SPM is directly coupled onto Sepharose FF (the thus resulting exchanger is called as Sep- SPM). Protein adsorption on these two cation exchangers have been also investigated. At the same ligand density, Sep- -SPM has a larger accessible pore radius and a smaller depth of polymer layer than Sep- SPM, due to the controllable introduction of polymer chains with the regular distribution of the ligand. Therefore, high-capacity adsorption of lysozyme and -globulin could be achieved simultaneously in Sep- -SPM with an ionic capacity (IC) of 308 mmol·L . However, Sep- SPM has an irregular chain distribution and different architecture of polymer layer, which lead to more serious repulsive interaction to proteins, and thus Sep- SPM has a lower adsorption capacity for -globulin than Sep- -SPM with the similar IC. Moreover, the results from protein uptake experiments indicate that the facilitated transport of adsorbed -globulin occurs only in Sep- SPM and depends on the architecture of polymer layers. Our research provides a clear clue for the development of high-performance protein chromatography.

关键词： polymer-grafted ionic exchanger grafting technique protein adsorption atom transfer radical polymerization γ-globulin

HTML PDF 收藏

Liver cell therapies: cellular sources and grafting strategies

《医学前沿（英文）》 2023年第17卷第3期页码 432-457 doi: 10.1007/s11684-023-1002-1

摘要： The liver has a complex cellular composition and a remarkable regenerative capacity. The primary cell types in the liver are two parenchymal cell populations, hepatocytes and cholangiocytes, that perform most of the functions of the liver and that are helped through interactions with non-parenchymal cell types comprising stellate cells, endothelia and various hemopoietic cell populations. The regulation of the cells in the liver is mediated by an insoluble complex of proteins and carbohydrates, the extracellular matrix, working synergistically with soluble paracrine and systemic signals. In recent years, with the rapid development of genetic sequencing technologies, research on the liver’s cellular composition and its regulatory mechanisms during various conditions has been extensively explored. Meanwhile breakthroughs in strategies for cell transplantation are enabling a future in which there can be a rescue of patients with end-stage liver diseases, offering potential solutions to the chronic shortage of livers and alternatives to liver transplantation. This review will focus on the cellular mechanisms of liver homeostasis and how to select ideal sources of cells to be transplanted to achieve liver regeneration and repair. Recent advances are summarized for promoting the treatment of end-stage liver diseases by forms of cell transplantation that now include grafting strategies.

关键词： liver regeneration hepatocytes cholangiocytes stem cells organoids regulatory mechanisms transplantation/grafting strategies

HTML PDF 收藏

Trihydrazinotriazine-grafting Fe

Jamal Rahimi, Seyedeh Shadi Mirmohammadi, Ali Maleki

《化学科学与工程前沿（英文）》 2021年第15卷第4期页码 1008-1020 doi: 10.1007/s11705-020-1996-8

摘要： This study focuses on the synthesis and characterization of a novel magnetic nanocomposite 2,4,6-trihydrazino-1,3,5-triazine (THDT)-functionalized with silica-coated iron oxide magnetic nanoparticles (MNPs). This nanocomposite has porous morphology decorated with the spherical MNPs. Through co-precipitation of iron salts, MNPs were obtained. The prepared THDT was placed on the chlorine surface-modified MNPs. The present environment-friendly nanocatalyst intensely accelerated the synthesis of highly functionalized tetrahydrobenzo[ ]pyran derivatives as well as reduced the reaction times and increased yields of the products.

关键词： trihydrazino-triazine porous magnetic nanocatalyst green chemistry tetrahydrobenzo[b]pyrans

HTML PDF 收藏

SinoSCORE: a logistically derived additive prediction model for post-coronary artery bypass grafting

null

《医学前沿（英文）》 2013年第7卷第4期页码 477-485 doi: 10.1007/s11684-013-0284-0

摘要：

This study aims to construct a logistically derived additive score for predicting in-hospital mortality risk in Chinese patients undergoing coronary artery bypass surgery (CABG). Data from 9839 consecutive CABG patients in 43 Chinese centers were collected between 2007 and 2008 from the Chinese Coronary Artery Bypass Grafting Registry. This database was randomly divided into developmental and validation subsets (9:1). The data in the developmental dataset were used to develop the model using logistic regression. Calibration and discrimination characteristics were assessed using the validation dataset. Thresholds were defined for each model to distinguish different risk groups. After excluding 275 patients with incomplete information, the overall mortality rate of the remaining 9564 patients was 2.5%. The SinoSCORE model was constructed based on 11 variables: age, preoperative NYHA stage III or IV, chronic renal failure, extracardiac arteriopathy, chronic obstructive pulmonary disease, preoperative atrial fibrillation or flutter (within 2βweeks), left ventricular ejection fraction, other elective surgery, combined valve procedures, preoperative critical state, and BMI. In the developmental dataset, calibration using a Hosmer-Lemeshow (HL) test was at =β0.44 and discrimination based on the area under the receiver operating characteristic curve (ROC) was 0.80. In the validation dataset, the HL test was at =β0.34 and the area under the ROC (AUC) was 0.78. A logistically derived additive model for predicting in-hospital mortality among Chinese patients undergoing CABG was developed based on the most up-to-date multi-center data from China.

关键词： coronary artery bypass grafting risk stratification in-hospital mortality

HTML PDF 收藏

Enhanced permeability and biofouling mitigation of forward osmosis membranes via grafting graphene quantum

《化学科学与工程前沿（英文）》 2023年第17卷第10期页码 1470-1483 doi: 10.1007/s11705-023-2329-5

摘要： In this paper, graphene oxide quantum dots with amino groups (NH₂-GOQDs) were tailored to the surface of a thin-film composite (TFC) membrane surface for optimizing forward osmosis (FO) membrane performance using the amide coupling reaction. The results jointly demonstrated hydrophilicity and surface roughness of the membrane enhanced after grafting NH₂-GOQDs, leading to the optimized affinity and the contact area between the membrane and water molecules. Therefore, grafting of the membrane with a concentration of 100 ppm (TFC-100) exhibited excellent permeability performance (58.32 L·m^–2·h^–1) compared with TFC membrane (16.94 L·m^–2·h^–1). In the evaluation of static antibacterial properties of membranes, TFC-100 membrane destroyed the cell morphology of Escherichia coli (E. coli) and reduced the degree of bacterial adsorption. In the dynamic biofouling experiment, TFC-100 membrane showed a lower flux decline than TFC membrane. After the physical cleaning, the flux of TFC-100 membrane could recover to 96% of the initial flux, which was notably better than that of TFC membrane (63%). Additionally, the extended Derjaguin–Landau–Verwey–Overbeek analysis of the affinity between pollutants and membrane surface verified that NH₂-GOQDs alleviates E. coli contamination of membrane. This work highlights the potential applications of NH₂-GOQDs for optimizing permeability and biofouling mitigation of FO membranes.

关键词： forward osmosis membrane graphene oxide quantum dots graft modification anti-fouling membrane XDLVO theory

HTML PDF 收藏

Synthesis and characterization of well-defined comb-like branched polymers

LI Aixiang, LU Zaijun, LÜ Zijian

《化学科学与工程前沿（英文）》 2008年第2卷第4期页码 407-411 doi: 10.1007/s11705-008-0064-6

摘要： Well-defined comb-like branched polymers having one branch in each repeating unit have been successfully synthesized by the coupling reaction of living polystyrene (PS) and polyisoprene (PI) anions with 1, 1-diphenylethenyl (DPE) groups along PS backbone prepared via atom transfer radical polymerization (ATRP) of 4-vinylbenzyloxy benzophenone (Sc) followed by Wittig reaction. The resulting comb-like branched polymers were characterized by IR, H-NMR, gel permeation chromatography (GPC) and static light scattering (SLS) in detail. The effect of living chains and DPE group molar ratio on grafting efficiency was discussed. The results show the coupling reaction of living chains and DPE groups was highly effective, and the coupling efficiency can be controlled via the feed molar ratios of living chains and DPE groups. Moreover, the effect of molecular weights of backbone (PSe) and PSLi or PILi on grafting efficiency was also discussed. The results show that when excess living polymers were used, the almost quantitative grafting efficiency could be achieved.

关键词： grafting efficiency polyisoprene quantitative grafting effective molecular

HTML PDF 收藏

General modeling and optimization technique for real-world earth observation satellite scheduling

《工程管理前沿（英文）》页码 695-709 doi: 10.1007/s42524-023-0263-3

摘要： Over the last two decades, many modeling and optimization techniques have been developed for earth observation satellite (EOS) scheduling problems, but few of them show good generality to be engineered in real-world applications. This study proposes a general modeling and optimization technique for common and real-world EOS scheduling cases; it includes a decoupled framework, a general modeling method, and an easy-to-use algorithm library. In this technique, a framework that decouples the modeling, constraints, and optimization of EOS scheduling problems is built. With this framework, the EOS scheduling problems are appropriately modeled in a general manner, where the executable opportunity, another format of the well-known visible time window per EOS operation, is viewed as a selectable resource to be optimized. On this basis, 10 types of optimization algorithms, such as Tabu search and genetic algorithm, and a parallel competitive memetic algorithm, are developed. For simplified EOS scheduling problems, the proposed technique shows better performance in applicability and effectiveness than the state-of-the-art algorithms. In addition, a complicatedly constrained real-world benchmark exampled by a four-EOS Chinese commercial constellation is provided, and the technique is qualified and outperforms the in-use scheduling system by more than 50%.

关键词： earth observation satellite scheduling general technique optimization algorithm commercial constellation real-world benchmark

HTML PDF 收藏

Contemporary coronary artery bypass grafting

null

《医学前沿（英文）》 2014年第8卷第4期页码 395-398 doi: 10.1007/s11684-014-0374-7

摘要：

Current evidence clearly demonstrates that coronary artery bypass grafting (CABG) remains the “gold standard” treatment for most patients with multivessel and left main stem disease. This article summarizes the relevant evidence basis demonstrating that CABG, in comparison to stenting, reduces mortality and subsequent myocardial infarction and the need for repeat revascularization. The article also describes the evidence basis to support the use of more arterial grafts during CABG and the current role of off-pump CABG.

关键词： coronary artery bypass grafting (CABG) coronary artery disease left main arterial grafts internal mammary artery off-pump CABG

HTML PDF 收藏

Preparation of reverse osmosis membrane with high permselectivity and anti-biofouling properties for desalination

《环境科学与工程前沿（英文）》 2022年第16卷第7期 doi: 10.1007/s11783-021-1497-0

摘要：

• Nanoparticle incorporation and anti-biofouling grafting were integrated.

关键词： Anti-biofouling grafting Nanoparticle incorporation Sterilization rates Water flux Water flux recovery

HTML PDF 收藏

构建我国农业信息化技术支持体系的探讨

郭书普,张立平,沈基长,董伟

《中国工程科学》 2005年第7卷第9期页码 89-94

摘要：

阐述了农业信息化的基本特征，介绍了农业信息化技术支持体系的发展现状，分析了存在的问题，指出现阶段加快农业信息技术体系建设应当重点抓好农业信息贮藏技术的研究、农业信息应用技术的开发、农业信息传播网络的建设。

关键词：农业信息化技术支持体系信息贮藏技术信息应用技术信息传播网络

HTML PDF 收藏

Grafting of PEG400 onto the surface of LLDPE/SMA film

CHEN Gufeng, ZHANG Yi, XU Jiarui, ZHU Yafei

《化学科学与工程前沿（英文）》 2007年第1卷第2期页码 128-131 doi: 10.1007/s11705-007-0024-6

摘要： Linear low-density polyethylene (LLDPE) was melt and blended with styrene-maleic anhydride copolymer (SMA). The blending films were then immersed in poly(ethylene glycol)400 (PEG400) at room temperature. The surface composition of the blend films was determined by Fourier transform infra-red spectroscopy coupled with a variable incidence angle attenuated total reflection accessory (ATR-FTIR). Results show that PEG400 can be grafted onto the surface of the films via esterification with SMA. The immersion of PEG promotes the enrichment of SMA onto the surface of the films. The water contact angle data show that grafting of PEG400 onto PE can greatly improve the hydrophilicity of the PE surface. These experiments show that surface functionalization of polyethylene films by blending SMA and then surface grafting of PEG is feasible, which suggest an effective and simple route for PE surface modification via blending and grafting.

关键词： hydrophilicity temperature effective immersion reflection accessory

HTML PDF 收藏

The electrostatic-alloy bonding technique used in MEMS

WANG Wei, CHEN Wei-ping

《机械工程前沿（英文）》 2006年第1卷第2期页码 238-241 doi: 10.1007/s11465-006-0011-5

摘要： Electrostatic-alloy bonding of silicon wafer with glass deposited by Au to form Si/Au-glass water, and bonding of Si/Au-glass with silicon wafer were researched during fabrication of pressure sensors. The silicon wafer and glass wafer with an Au film resistor were bonded by electrostatic bonding, and then Si-Au alloy bonding was formed by annealing at 400vH for 2 h. The air sealability of the cavity after bonding was finally tested using the N filling method. The results indicate that large bond strength was obtained at the bonding interface. This process was used in fabricating a pressure sensor with a sandwich structure. The results indicate that the sensor presented better performances and that the bonding techniques can be used in MEMS packaging.

关键词： Si/Au-glass strength MEMS packaging process sandwich structure

HTML PDF 收藏

Seismic safety evaluation methodology for masonry building and retrofitting using splint and bandage technique

Pravin Kumar Venkat Rao PADALU; Yogendra SINGH

《结构与土木工程前沿（英文）》 2022年第16卷第4期页码 478-505 doi: 10.1007/s11709-022-0817-1

摘要： The paper presents a seismic safety assessment of unreinforced masonry (URM) building using two approaches. The first approach uses the ‘Pier Analysis’ method, based on the concept of equivalent lateral stiffness, where in-plane and out-of-plane actions are considered independently. The second approach is developed with the program SAP2000, where the linear response is evaluated using continuum ‘finite element modelling’ (FEM). Both methods are compared to evaluate the safety of wall piers and the differences in the outcomes under combined gravitational and lateral seismic forces. The analysis results showed that few wall elements are unsafe in in-plane and out-of-plane tension. It is also observed that the pier analysis method is conservative compared to FEM, but can be used as a simplified and quick tool in design offices for safety assessment, with reasonable accuracy. To safeguard the URM wall piers under lateral loads, a retrofitting technique is adopted by providing vertical and horizontal belts called splints and bandages, respectively, using welded wire mesh (WWM) reinforcement. The study using the ‘Pier Analysis’ shows that the lateral load capacity of unsafe URM piers can be enhanced up to 3.67 times and made safe using the applied retrofitting technique. Further, the retrofitting design methodology and recommendations for application procedures to on-site URM buildings are discussed in detail.

关键词： unreinforced masonry seismic in-plane and out-of-plane forces pier analysis finite element modelling splint and bandage technique with wire mesh

HTML PDF 收藏

Significance of using isolated footing technique for residential construction on expansive soils

Harry FAR,Deacon FLINT

《结构与土木工程前沿（英文）》 2017年第11卷第1期页码 123-129 doi: 10.1007/s11709-016-0372-8

摘要： Expansive soils cause problems with the founding of lightly loaded structures in many parts of the world. Foundation design for expansive soils is one of the most discussed and problematic issues in Australia as expansive soils were responsible for billions of dollars’ worth of damage to man-made structures such as buildings and roads. Several studies and reports indicate that one of the most common and least recognized problems causing severe structural damage to houses lies in expansive soils. In this study, a critical review has been carried out on the current Australian standards for building on expansive soils and they are compared with some techniques that are not included in the current Australian standards for residential slabs and footings. Based on the results of this review, the most effective and economical method has been proposed for construction of footings on all site classifications without restriction to 75mm of characteristic movement. In addition, it has become apparent that as design procedures for footings resting on sites with extreme characteristic movements are not included in the current Australian standards, there is a strong need for well-developed and simplified standard design procedures for characteristic soil movement of greater than 75mm to be included into the Australian Standards.

关键词： expansive soils residential slabs isolated footings Australian Standards

HTML PDF 收藏

Knife-edge technique for laser cooling

WANG Zhanshan, MA Shanshan, MA Yan, ZHAO Min, LIU Hengbiao

《机械工程前沿（英文）》 2007年第2卷第4期页码 468-473 doi: 10.1007/s11465-007-0081-z

摘要： The transfer characteristics of an atomic beam and the effect of laser were investigated in this paper. In the application of knife-edge technique, the temperature of atoms through laser cooling was measured. Results indicate that, after atoms are emitted from an atomic oven, the longer the atoms move, the worse the distribution of the atomic beam shows, regardless the laser cooling is taken or not. Laser cooling can reduce the transverse velocity of the atomic beam to several orders of magnitude and also increase the uniformity of an atomic beam. Knife-edge technique can measure the temperature of an atomic beam through laser cooling. The measurement accuracy depends on the pixel size of the charge coupled device (CCD), which is used for the fluorescent imaging of the atomic beam. The results are very important for the future experiments of laser cooling.

关键词： knife-edge technique uniformity coupled transfer fluorescent