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 100

会议信息 1

年份

2023 2

2022 5

2021 10

2020 7

2019 13

2018 9

2017 6

2016 5

2015 10

2014 5

2013 4

2012 8

2011 4

2010 3

2009 3

2008 2

2007 2

2004 1

展开︾

关键词

人工智能 2

岩爆 2

机器学习 2

/III-V界面 1

Biological Rhythms 1

Chord图 1

Chronobiology 1

HuMiX 1

Klee图 1

LM331型电压-频率转换器 1

Ni–Ti–Cu–V合金 1

Skyline图 1

Ti-V微合金钢 1

V-W-Mo-Cu催化剂 1

Visual Basic 6.0 1

V形坑 1

academic exchange 1

“五维”拥堵指数 1

个体患者通风隔离罩 1

展开︾

检索范围：

排序：展示方式：

Autoimmunity in acute ischemic stroke and the role of blood—brain barrier: the dark side or the light one?

Nikolay V. Tsygan, Alexandr P. Trashkov, Igor V. Litvinenko, Viktoriya A. Yakovleva, Alexandr V.

《医学前沿（英文）》 2019年第13卷第4期页码 420-426 doi: 10.1007/s11684-019-0688-6

摘要： This article presents a synopsis of the current data on the mechanisms of blood—brain barrier (BBB) alteration and autoimmune response in acute ischemic stroke. Most researchers confirm the relationship between the severity of immunobiochemical changes and clinical outcome of acute ischemic stroke. Ischemic stroke is accompanied by aseptic inflammation, which alters the brain tissue and exposes the co-stimulatory molecules of the immune system and the neuronal antigens. To date, BBB is not considered the border between the immune system and central nervous system, and the local immune subsystems are found within and behind the BBB. BBB disruption contributes to the leakage of brain autoantigens and induction of secondary autoimmune response to neuronal antigens and long-term inflammation. Glymphatic system function is altered and jeopardized both in hemorrhagic and ischemic stroke types. The receptors of innate immunity (toll-like receptor-2 and toll-like receptor-4) are also involved in acute ischemia—reperfusion injury. Immune response is related to the key processes of blood clotting and fibrinolysis. At the same time, the stroke-induced immune activation may promote reparation phenomena in the brain. Subsequent research on the reduction of the acute ischemic brain injury through the target regulation of the immune response is promising.

关键词： stroke blood–brain barrier autoimmunity innate immunity inflammation cell death

HTML PDF 收藏

Emulsification for castor biomass oil

Dongxiang ZHANG, Yuanping LIN, Anmei LI, V. V. TARASOV

《化学科学与工程前沿（英文）》 2011年第5卷第1期页码 96-101 doi: 10.1007/s11705-010-0553-2

摘要： The effect of the emulsifier formula on the stability of castor oil-water system was studied through compounding three groups of emulsifiers from the aspects of stability factor of absorbance, centrifuge stability, demulsification time in quiescence, appearance of the droplets, and viscosity. The best emulsifier formula for castor biomass oil was the composite formula of sorbitan monooleate and polyoxyethylene sorbitan monostearate. Correlation exists between the stability of emulsion and the viscosity/particle size of the droplets, with better stability in the case of greater viscosity or narrower distribution of particle size in the emulsion of castor oil-water system. Methanol added to the castor oil-water system may decrease the viscosity of the emulsion. Comparing the castor oil-water emulsion with methanol-castor oil-water emulsion, the optimal hydrophilic and lipophilic balance (HLB) value based on castor oil-water system was acquired between 6.6 and 7.5, while the optimal HLB value based on the methanol-castor oil-water system was between 5.5 and 6.0. The optimal HLB value of methanol-castor oil-water system gradually moved to that of castor oil-water emulsion with adding more water.

关键词： castor oil biomass oil emulsification stability viscosity corrosivity

HTML PDF 收藏

Synergistic effect of V and Fe in Ni/Fe/V ternary layered double hydroxides for efficient and durable

《化学科学与工程前沿（英文）》 2023年第17卷第1期页码 102-115 doi: 10.1007/s11705-022-2179-6

摘要： High-performance and stable electrocatalysts are vital for the oxygen evolution reaction (OER). Herein, via a one-pot hydrothermal method, Ni/Fe/V ternary layered double hydroxides (NiFeV-LDH) derived from Ni foam are fabricated to work as highly active and durable electrocatalysts for OER. By changing the feeding ratio of Fe and V salts, the prepared ternary hydroxides were optimized. At an Fe:V ratio of 0.5:0.5, NiFeV-LDH exhibits outstanding OER activity superior to that of the binary hydroxides, requiring overpotentials of 269 and 274 mV at 50 mA·cm^–2 in the linear sweep voltammetry and sampled current voltammetry measurements, respectively. Importantly, NiFeV-LDH shows extraordinary long-term stability (≥ 75 h) at an extremely high current density of 200 mA·cm^–2. In contrast, the binary hydroxides present quick decay at 200 mA·cm^–2 or even reduced current densities (150 and 100 mA·cm^–2). The outstanding OER performance of NiFeV-LDH benefits from the synergistic effect of V and Fe while doping the third metal into bimetallic hydroxide layers: (a) Fe plays a crucial role as the active site; (b) electron-withdrawing V stabilizes the high valence state of Fe, thus accelerating the OER process; (c) V further offers great stabilization for the formed intermediate of FeOOH, thus achieving superior durability.

关键词： oxygen evolution reaction electrocatalysts ternary layered double hydroxides long-term stability

HTML PDF 收藏

Association between ICU quality and in-hospital mortality of V-V ECMO-supported patients—the ECMO quality

《医学前沿（英文）》 doi: 10.1007/s11684-023-1014-x

摘要： This cohort study was performed to explore the influence of intensive care unit (ICU) quality on in-hospital mortality of veno-venous (V-V) extracorporeal membrane oxygenation (ECMO)-supported patients in China. The study involved all V-V ECMO-supported patients in 318 of 1700 tertiary hospitals from 2017 to 2019, using data from the National Clinical Improvement System and China National Critical Care Quality Control Center. ICU quality was assessed by quality control indicators and capacity parameters. Among the 2563 V-V ECMO-supported patients in 318 hospitals, a significant correlation was found between ECMO-related complications and prognosis. The reintubation rate within 48 hours after extubation and the total ICU mortality rate were independent risk factors for higher in-hospital mortality of V-V ECMO-supported patients (cutoff: 1.5% and 7.0%; 95% confidence interval: 1.05–1.48 and 1.04–1.45; odds ratios: 1.25 and 1.23; P = 0.012 and P = 0.015, respectively). Meanwhile, the V-V ECMO center volume was a protective factor (cutoff of ≥ 50 cases within the 3-year study period; 95% confidence interval: 0.57–0.83, odds ratio: 0.69, P = 0.0001). The subgroup analysis of 864 patients in 11 high-volume centers further strengthened these findings. Thus, ICU quality may play an important role in improving the prognosis of V-V ECMO-supported patients.

关键词： veno-venous extracorporeal membrane oxygenation in-hospital mortality high-volume centers quality control intensive care unit capacity parameters

HTML PDF 收藏

A concise review about fracture assessments of brittle solids with V-notches

Hsien-Yang YEH, Bin YANG

《结构与土木工程前沿（英文）》 2019年第13卷第2期页码 478-485 doi: 10.1007/s11709-019-0520-z

摘要：

A concise review of recent studies about the fracture assessments of elastic brittle solid materials containing V-notches is presented. In this preliminary and brief survey, elastic stress distributions in V-notched solids are discussed first. The concept of notch stress intensity factor is introduced. Combine the digital image correlation method with numerical computation techniques to analyze the stress distribution near the notches. Fracture criteria such as strain energy density, J-integral, theory of critical distance are used.

关键词： fracture assessment brittle solids V-notches review

HTML PDF 收藏

V-shaped substrate for surface and volume enhanced Raman spectroscopic analysis of microplastics

《环境科学与工程前沿（英文）》 2022年第16卷第11期 doi: 10.1007/s11783-022-1578-8

摘要：

● V-shaped substrate was obtained for SERS analysis of microplastics (diameter ≈ 1 μm).

关键词： SERS V-shaped AAO Microplastic Atmospheric aerosol

HTML PDF 收藏

V/STOL飞机建模与仿真分析

范勇,朱纪洪,孟宪宇,刘凯,杨喜立

《中国工程科学》 2011年第13卷第3期页码 107-112

摘要：

以原理验证机为背景，建立了无尾布局垂直/短距起降飞行器的数学模型，并通过智能自适应方法对其进行了闭环飞行控制，控制量通过控制分配合理的协调各操纵面，最后在MATLAB7.0/Simulink环境下通过数值仿真进行了验证。结果显示，该平台具备垂直/短距起降能力和较好的飞行性能。

关键词：无尾布局飞行器垂直/短距起降飞行器（V/STOL）动力学建模飞行控制

HTML PDF 收藏

Observation of a higher JAK2 V617F homozygous mutated clone in polycythemia vera compared to essential

LIU Hongxing, TONG Chunrong, CAI Peng, GU Jiangying, LIN Yuehui, TENG Wen, WANG He, ZHANG Ying, ZHU Ping

《医学前沿（英文）》 2008年第2卷第3期页码 309-313 doi: 10.1007/s11684-008-0059-1

摘要： Single-tube bi-directional allele specific amplification (SB-ASA) and real-time quantitative polymerase chain reaction (RQ-PCR) assays were developed and performed for JAK2V617F detection on 40 polycythemia vera (PV) samples, 31 essential thrombocythemia (ET) samples, 40 acute leukemia samples, and 40 healthy control samples. Differences between detect limitations of the two assays and their influence on the mutation detection rate were analyzed. The results showed that in some samples, the JAK2V617F burden was as low as nearly 1%, and thus more JAK2V617F-positive samples were detected by RQ-PCR than by SB-ASA assay due to the former higher detect limitation. Mutation allele ratios in PV and ET samples and their relevance to biological characteristics were also analyzed. The results showed that the mutation allele ratio was 0.436 ± 0.261 in PV, higher than the 0.216 ± 0.207 in ET; percentage of certainly homozygous mutation carriers in PV was 40.54%, higher than the 10% in ET. However, statistical analysis showed no relevance between mutation allele burden and sex or age. Our result shows that the pathogenesis of PV and ET may be related to the mutation allele burden of JAK2V617F.

关键词： specific amplification essential thrombocythemia Single-tube bi-directional JAK2V617F-positive JAK2V617F detection

HTML PDF 收藏

Mortarless structures based on topological interlocking

Arcady V. DYSKIN, Elena PASTERNAK, Yuri ESTRIN

《结构与土木工程前沿（英文）》 2012年第6卷第2期页码 188-197 doi: 10.1007/s11709-012-0156-8

摘要： We review the principle of topological interlocking and analyze the properties of the mortarless structures whose design is based on this principle. We concentrate on structures built of osteomorphic blocks – the blocks possessing specially engineered contact surfaces allowing assembling various 2D and 3D structures. These structures are easy to build and can be made demountable. They are flexible, resistant to macroscopic fractures and tolerant to missing blocks. The blocks are kept in place without keys or connectors that are the weakest elements of the conventional interlocking structures. The overall structural integrity of these structures depends on the force imposed by peripheral constraint. The peripheral constraint can be provided in various ways: by an external frame or features of site topography, internal pre-stressed cables/tendons, or self-weight and is a necessary auxiliary element of the structure. The constraining force also determines the degree of delamination developing between the blocks due to bending and thus controls the overall flexibility of the structure thus becoming a new design parameter.

关键词： topological interlocking fragmented structures segmented structures constraint delamination bending stiffness

HTML PDF 收藏

Effect of exhaust gas recirculation and ethyl hexyl nitrate additive on biodiesel fuelled diesel engine for the reduction of NO

R MURTHY, V. V. SUBBARAO, K. Vijaya KUMAR

《能源前沿（英文）》 2012年第6卷第3期页码 304-310 doi: 10.1007/s11708-012-0195-9

摘要： Cetane improvers reduce the ignition delay, which in turn reduces the combustion temperatures thereby reduce NO emissions. Exhaust gas recirculation (EGR) proved to be an effective way to reduce the NO emissions. In this present experimental work, a combination of exhaust gas recirculation and cetane improver ethyl hexyl nitrate (EHN) is used to investigate the performance and exhaust emissions of a single cylinder four stroke naturally aspirated direct injection and air cooled diesel engine. Test results show that the brake thermal efficiency increases with the increase in the percentage of EGR which is accompanied by a reduction in brake specific fuel consumption and exhaust gas temperatures, and that bio-diesel with cetane improver under 20% EGR reduces NO emissions by 33% when compared to baseline fuel without EGR. However carbon monoxide (CO), hydro carbon (HC) and smoke emissions increase with an increase in percentage of EGR.

关键词： additive exhaust gas recirculation (EGR) emissions ethyl hexyl nitrate (EHN) performance

HTML PDF 收藏

Processing of high-precision ceramic balls with a spiral V-groove plate

Ming FENG,Yongbo WU,Julong YUAN,Zhao PING

《机械工程前沿（英文）》 2017年第12卷第1期页码 132-142 doi: 10.1007/s11465-017-0436-z

摘要：

As the demand for high-performance bearings gradually increases, ceramic balls with excellent properties, such as high accuracy, high reliability, and high chemical durability used, are extensively used for high-performance bearings. In this study, a spiral V-groove plate method is employed in processing high-precision ceramic balls. After the kinematic analysis of the ball-spin angle and enveloped lapping trajectories, an experimental rig is constructed and experiments are conducted to confirm the feasibility of this method. Kinematic analysis results indicate that the method not only allows for the control of the ball-spin angle but also uniformly distributes the enveloped lapping trajectories over the entire ball surface. Experimental results demonstrate that the novel spiral V-groove plate method performs better than the conventional concentric V-groove plate method in terms of roundness, surface roughness, diameter difference, and diameter decrease rate. Ceramic balls with a G3-level accuracy are achieved, and their typical roundness, minimum surface roughness, and diameter difference are 0.05, 0.0045, and 0.105 mm, respectively. These findings confirm that the proposed method can be applied to high-accuracy and high-consistency ceramic ball processing.

关键词： bearing ceramic ball spiral V-groove kinematic analysis trajectory

HTML PDF 收藏

A MYB-INDUCED MECHANISM FOR ENHANCED ASCORBATE IN RED-FLESHED APPLES

Richard V. ESPLEY, Kuilin WANG

《农业科学与工程前沿（英文）》页码 356-357 doi: 10.15302/J-FASE-2021381

摘要： The results presented in “The anthocyanin biosynthetic regulator MdMYB1 positively regulates ascorbic acid biosynthesis in apple” (An et al., this issue) provide evidence for a new mechanism for the elevation of ascorbate concentration in apple. Using a red-fleshed apple breeding population, the authors show how the anthocyanin-regulating MYB transcription factor, MdMYB1, also increases ascorbate concentrations by directly activating transcription of the dehydroascorbate reductase gene . This gene recycles oxidized ascorbate back to ascorbate, leading to elevated concentrations of vitamin C. These red-fleshed apples have enhanced concentrations of both anthocyanins and ascorbate, both of which are appealing traits for the development of healthier apples.

HTML PDF 收藏

跨维数线性连续系统的解和稳定性

张庆乐,王彪,冯俊娥

《信息与电子工程前沿（英文）》 2021年第22卷第2期页码 141-286 doi: 10.1631/FITEE.1900504

摘要：利用V-加法和V-乘法研究了维数有界的跨维数线性连续系统（CCDLSs）的解和稳定性。使用积分迭代法，得到CCDLSs的解。

关键词：跨维数；V-加法；V-乘法；渐进稳定性；镇定性

HTML PDF 收藏

V-W-Mo-Cu催化剂作用下生物质醇解重油加氢精制研究

邹献武,秦特夫,李改云,黄洛华

《中国工程科学》 2014年第16卷第4期页码 69-73

摘要：为此，本文考察了V-W-Mo-Cu 催化剂作用下重油的加氢精制。结果表明，在330 ℃以上该催化剂才表现出加氢反应活性，在450 ℃时轻油产率最高可到93 %。

关键词：生物质醇解重油加氢 V-W-Mo-Cu催化剂图像处理

HTML PDF 收藏

State of Practice of Construction Site Safety in the USA

Fei Dai,Yoojung Yoon,Hota V. GangaRao

《工程管理前沿（英文）》 2016年第3卷第3期页码 275-282 doi: 10.15302/J-FEM-2016035

摘要： The construction industry has long been plagued with a high number of fatalities in the USA. Much safety improvements have been made after the USA Congress passed the Occupational Safety and Health Act in 1970. However, this industry still suffers from a disproportionately high rate of work-related fatalities in comparison to other industries. To provide a holistic view of current construction safety practices and corresponding performance, this paper reviews statistics of construction fatalities and their causes. It then presents efforts led to prevent work-related accidents and injuries by the federal safety agencies and the industry. Additionally, advantages and limitations of current practices in terms of construction safety have been discussed along with promotion of aspects in construction work environment.

关键词： workplace safety construction industry safety strategy accident prevention review work