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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    

扩容角对圆形巷道岩爆过程的影响

王学滨,潘一山,张智慧

《中国工程科学》 2010年 第12卷 第2期   页码 40-46

摘要:

利用FLAC模拟了不同扩容角时圆形巷道的岩爆过程。为了模拟巷道开挖,利用编写的FISH函数删除巷道内部的单元。岩石服从莫尔库仑剪破坏与拉破坏复合的破坏准则,破坏之后呈现应变软化—理想塑性行为。文章的模拟分为3步:首先,将静水压力施加在模型上,直到达到静力平衡状态;然后,利用编写的FISH函数,开挖巷道;最后,计算重新开始,直到达到静力平衡状态。模拟结果表明,随着扩容角的增加,剪切带变宽,岩爆坑变深,破坏单元数目增多,破坏区变大。当扩容角较低时,高剪切应变集中于“狗耳”形岩爆坑位置,剪切带与巷道周边切线之间的夹角较大;当扩容角较高时,高剪切应变集中于巷道周边的一些位置上,剪切带与巷道周边切线之间的夹角较小。该研究结果与Roscoe,Arthur理论相符。

关键词: 扩容角     圆形巷道     岩爆     剪切带     V形坑     剪切应变     体积应变    

A novel flow electrode capacitive deionization device with spindle-shaped desalting chamber

《环境科学与工程前沿(英文)》 2023年 第18卷 第4期 doi: 10.1007/s11783-024-1800-y

摘要:

● A spindle-shaped influent chamber was designed and equipped in FCDI system.

关键词: Spindle-shaped chamber     Desalination performance     Flow electrode capacitive deionization    

Bending performance of composite bridge deck with T-shaped ribs

Qingtian SU, Changyuan DAI, Xu JIANG

《结构与土木工程前沿(英文)》 2019年 第13卷 第4期   页码 990-997 doi: 10.1007/s11709-019-0532-8

摘要: This paper proposes a new type of steel-concrete composite deck, which is composed of orthotropic steel deck (OSD) with T-shaped ribs, concrete plate and studs connecting OSD and concrete plate. The OSD can act as framework for concrete plate and contribute to load bearing capacity at the same time, which could save construction time. Compared with conventional OSD system, this new type of composite bridge deck can also improve fatigue performance. Considering that this type of composite deck is not yet applied in practical engineering and its mechanical performance is not revealed in previous literatures, two full-scale specimens were designed and manufactured in this research. The mechanical performance, particularly, bending capacity in positive and negative region was carefully tested and analyzed. The load-deflection curve, load-slip relation, strain distribution in concrete and steel were obtained. The test results showed that the plastic performance of this kind of composite bridge deck was satisfying and the bending capacity was high.

关键词: bending performance     composite bridge deck     T-shaped steel ribs    

Performance of vertical axis water turbine with eye-shaped baffle for pico hydropower

Zhuohuan HU, Dongcheng WANG, Wei LU, Jian CHEN, Yuwen ZHANG

《能源前沿(英文)》 2022年 第16卷 第4期   页码 683-696 doi: 10.1007/s11708-020-0689-9

摘要: A series of inline pico hydropower systems, which could be used in confined space, especially for water distribution networks (WDNs), was designed and investigated. The turbine with an eye-shaped vertical water baffle was developed to evaluate the hydraulic performance. A three-dimensional dynamic mesh was employed and the inlet velocity was considered as the inlet boundary condition, whereas the outlet boundary was set as the outflow. Then, numerical simulations were conducted and the standard turbulence model was found to be the best capable of predicting flow features through the comparison with the experimental results. The effects of the opening diameter of the water baffle and installation angle of the rotor on the flow field in the turbine were investigated. The results suggested that the water baffle opening at = 30 mm and the rotor at a 52° angle could achieve the highest efficiency of 5.93%. The proper eye-shaped baffle not only accelerates the fluid flow and generates positive hydrodynamic torque, but also eliminates the flow separation. The scheme proposed in this paper can be exploited for practical applications in the water pipelines at various conditions and power requirements.

关键词: vertical axis water turbine     eye-shaped     vertical water baffle     pico hydropower    

Parametric computational study on butterfly-shaped hysteretic dampers

Ali Reza FARZAMPOUR, Matthew Roy EATHERTON

《结构与土木工程前沿(英文)》 2019年 第13卷 第5期   页码 1214-1226 doi: 10.1007/s11709-019-0550-6

摘要: A parametric computational study is conducted to investigate the shear yielding, flexural yielding, and lateral torsional buckling limit states for butterfly-shaped links. After validating the accuracy of the finite element (FE) modeling approach against previous experiments, 112 computational models with different geometrical properties were constructed and analyzed including consideration of initial imperfections. The resulting yielding moment, corresponding critical shear force, the accumulation of plastic strains through the length of links as well as the amount of energy dissipated are investigated. The results indicate that as the shape of the butterfly-shaped links become too straight or conversely too narrow in the middle, peak accumulated plastic strains increase. The significant effect of plate thickness on the buckling limit state is examined in this study. Results show that overstrength for these links (peak force divided by yield force) is between 1.2 and 4.5, with straight links producing larger overstrength. Additionally, proportioning the links to delay buckling, and designing the links to yield in the flexural mode are shown to improve energy dissipation.

关键词: structural fuse     hysteretic damper     finite element analysis     energy dissipation     initial imperfection     butterfly-shaped links    

Seismic behavior experimental study of frame joints with special-shaped column and dispersed steel bar

Shuchun LI, Bo DIAO, Youpo SU,

《结构与土木工程前沿(英文)》 2009年 第3卷 第4期   页码 378-383 doi: 10.1007/s11709-009-0064-8

摘要: To overcome the problem that steel bars are put too close at a flame joint with special-shaped beam and column, mechanical performance of three groups of six RC flame joints with special-shaped (L, T and+) column and dispersed-steel bars-beam on the top floor under cyclic loads were studied. Experimental comparison was conducted between special-shaped (L, T and+) column and normal beams. The cracking load, yielding load, ultimate bearing capacity, failure patterns, and hysteretic properties at joint core area were investigated. The seismic behaviors of the joints with different proportions of dispersed-steel-bar beams were analyzed. The results of experimental analysis indicate that the mechanical and seismic behaviors of frame joints with T-shaped and+-shaped column are nearly not changed when suitable proportion steel bars are dispersed to flange plane. Stiffness degeneration of flame joint with L-shaped column is rather serious due to concrete damage stiffness. Theoretical result indicates that distributing area of the dispersed steel-bar beams in the flange plate should be strictly controlled to avoid anchor destroy.

关键词: beam with dispersed steel bar     flame joints with special-shaped beam and column     seismic behavior     scale of dispersed steel bars    

一种新型聚能破甲战斗部及其发展趋势探讨

安二峰,沈兆武,周听清,王德润

《中国工程科学》 2004年 第6卷 第6期   页码 85-90

摘要:

针对当前以单罩聚能效应为主的聚能破甲战斗部,提出一种新型多罩复合聚能装药结构,探讨了其成型机理和联合破甲原理,系统研究了主要装药结构参数对破甲效果的影响。实验结果表明,该聚能装药结构比EFP装药结构,在保持穿孔孔径相当和同等装药条件下,可以提高穿深50%左右。在此基础上,进一步提出反反应装甲目标新型聚能装药结构,深化了聚能效应的内涵,丰富了打击目标的手段。

关键词: 聚能战斗部     爆炸成型弹丸     聚能射流     反应装甲     侵彻    

Soil arching effect of Lattice-Shaped Diaphragm Wall as bridge foundation

Jiujiang WU, Lingjuan WANG, Qiangong CHENG

《结构与土木工程前沿(英文)》 2017年 第11卷 第4期   页码 446-454 doi: 10.1007/s11709-017-0397-7

摘要: As a new type of bridge foundation, Lattice-Shaped Diaphragm Wall (hereinafter for LSDW) is highly concerned in relevant construction area but its research is far from achievement. Based on PFC , the soil arching effect of LSDWs is studied thoroughly in this paper and the special attention is given to its influencing factors. It turns out to be that a differential wall-soil settlement can be found at the lower location of soil core of an LSDW which is one of the trigger factors of soil arching; meanwhile, the differential settlement degree can reflect the exertion degree of soil arching; the shape of soil arching is basically a hemisphere which can be explained by the theory proposed by Hewlett and Randolph; normally, the chamber number is a negative factor for the development of soil arching; the soil arching effect is significantly influenced by the distance of two adjacent wall elements and the foundation depth, and a relatively large or small value of these factors is disadvantageous to the exertion of soil arching; in addition, the soil arching effect increase with the growth of stiffness and friction coefficient of particles and the friction coefficient of particles has insignificant influence on the development of soil arching effect compared with particle stiffness.

关键词: LSDW     soil arching     PFC2D     shape of soil arching     influencing factors    

Modal disturbance investigation of rod-shaped ultrasonic motor using bending vibrations

ZHANG Jiantao, ZHU Hua, ZHAO Chunsheng

《机械工程前沿(英文)》 2008年 第3卷 第3期   页码 343-347 doi: 10.1007/s11465-008-0058-6

摘要: Modal disturbance of a rod-shaped ultrasonic motor using bending vibrations can cause problems such as low motor efficiency, instability, and poor control. In this paper, a dynamic analysis model of a stator is created on the basis of the finite element method (FEM) and Hamilton principle. The modal frequency sensitivities of the stator to the structure parameters are investigated by modal analysis. Accordingly, the structure parameters of the stator are modified to separate working modes from disturbance modes. A rod-shaped ultrasonic motor stator is fabricated, and the experimental results of its amplitude frequency response characteristics show that the purpose of modal separation is achieved. The frequency separation between working modes and disturbance modes is more than 2 kHz. The validity of the method is verified.

关键词: Hamilton principle     disturbance     separation     frequency separation     dynamic analysis    

On subsurface box-shaped lined tunnel under incident SH-wave propagation

《结构与土木工程前沿(英文)》 2021年 第15卷 第4期   页码 948-960 doi: 10.1007/s11709-021-0740-x

摘要: In this paper, a half-plane time-domain boundary element method is applied to obtain the seismic ground response, including a subsurface box-shaped lined tunnel deployed in a linear homogenous elastic medium exposed to obliquely incident SH-waves. Only the boundary around the tunnel is required to be discretized. To prepare an appropriate model by quadratic elements, a double-node procedure is used to receive dual boundary fields at corners as well as change the direction of the normal vector. After encoding the method in a previously confirmed computer program, a numerical study is carried out to sensitize some effective parameters, including frequency content and incident wave angle for obtaining a surface response. The depth and impedance ratio of the lining are assumed to be unvaried. The responses are illustrated in the time and frequency domains as two/three-dimensional graphs. The results showed that subsurface openings with sharp corners distorted the propagation path of the anti-plane waves to achieve the critical states on the ground surface. The present approach can be proposed to civil engineers for preparing simple underground box-shaped models with angular boundaries.

关键词: box-lined tunnel     half-plane BEM     surface response     SH-wave     time-domain    

Novel piezoelectric pump with “E”-shaped valve found from sub-experiments

Jianhui ZHANG, Jun HUANG, Xiaoqi HU, Qixiao XI,

《机械工程前沿(英文)》 2010年 第5卷 第2期   页码 212-218 doi: 10.1007/s11465-010-0009-x

摘要: Increasing the driving frequency of a piezoelectric vibrator can resolve the bottleneck of low flow in a valve piezoelectric pump. However, a piezoelectric pump of a traditional valve body presents the hysteretic nature of the valve, and macroscopic performance is up-frequency to flow-sharply. This research is to settle the bottleneck mentioned above. First, through the sub-experiment on various parameters of the plate valve of a piezoelectric pump, the reasons why a valve body itself can influence “up-frequency to flow-sharply”, which causes the hysteretic nature of the valve, were discovered. Second, an “E”-shaped valve and piezoelectric pump with an “E”-shaped valve (PPEV) were invented. Finally, the efficiency of PPEV has been proved helpful to reduce hysteretic nature in experiments. Under the similar conditions, compared with traditional pumps, the driving frequency of novel PPEV can be more than 10 times high, and the flow rate also can be several times high.

关键词: piezoelectricity     valve     pump     experiment         E”     -shaped valve    

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    

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    

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    

标题 作者 时间 类型 操作

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

期刊论文

扩容角对圆形巷道岩爆过程的影响

王学滨,潘一山,张智慧

期刊论文

A novel flow electrode capacitive deionization device with spindle-shaped desalting chamber

期刊论文

Bending performance of composite bridge deck with T-shaped ribs

Qingtian SU, Changyuan DAI, Xu JIANG

期刊论文

Performance of vertical axis water turbine with eye-shaped baffle for pico hydropower

Zhuohuan HU, Dongcheng WANG, Wei LU, Jian CHEN, Yuwen ZHANG

期刊论文

Parametric computational study on butterfly-shaped hysteretic dampers

Ali Reza FARZAMPOUR, Matthew Roy EATHERTON

期刊论文

Seismic behavior experimental study of frame joints with special-shaped column and dispersed steel bar

Shuchun LI, Bo DIAO, Youpo SU,

期刊论文

一种新型聚能破甲战斗部及其发展趋势探讨

安二峰,沈兆武,周听清,王德润

期刊论文

Soil arching effect of Lattice-Shaped Diaphragm Wall as bridge foundation

Jiujiang WU, Lingjuan WANG, Qiangong CHENG

期刊论文

Modal disturbance investigation of rod-shaped ultrasonic motor using bending vibrations

ZHANG Jiantao, ZHU Hua, ZHAO Chunsheng

期刊论文

On subsurface box-shaped lined tunnel under incident SH-wave propagation

期刊论文

Novel piezoelectric pump with “E”-shaped valve found from sub-experiments

Jianhui ZHANG, Jun HUANG, Xiaoqi HU, Qixiao XI,

期刊论文

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.

期刊论文

Emulsification for castor biomass oil

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

期刊论文

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

期刊论文