资源类型

期刊论文 517

会议视频 6

年份

2024 1

2023 41

2022 40

2021 44

2020 20

2019 41

2018 27

2017 26

2016 20

2015 26

2014 22

2013 15

2012 24

2011 23

2010 25

2009 28

2008 29

2007 25

2006 5

2005 5

展开 ︾

关键词

能源 3

COVID-19 2

三十烷醇 2

内禀尺度 2

冷凝水闪蒸 2

动力气垫 2

地效翼船 2

尺寸效应 2

水稻 2

32 m箱梁 1

ADV 1

ANSYS/LS-DYNA 1

Casimir效应 1

Cu(Inx 1

DQP漂白 1

Dirac理论 1

FDS数值模拟 1

Fe、Co、Ru 碳化物 1

Ga1–x)Se2 1

展开 ︾

检索范围:

排序: 展示方式:

Synthesis and ultraviolet/aggregation-induced emission investigation of novel tetraphenylvinyl hydrazone

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 2061-2073 doi: 10.1007/s11705-023-2366-0

摘要: Herein, three novel tetraphenylethylene hydrazone chemosensors TC12, SC16, and TC16 are prepared for the selective detection of F. Two NH and one C=N units are incorporated into the sensors for better colorimetric responses, whereas the tetraphenyl unit is in charge of the aggregation-induced emission effect. Among them, compounds SC16 and TC16 form stable gels with some organic solvents. All the tetrahydrofuran/H2O solutions of the three compounds exhibit aggregation-induced emission effect, whereby the fluorescence emission increases by varying degrees with the volume of poor solvent water. Moreover, good aggregation-induced emission effects are observed in the self-assembly of SC16 and TC16. As a sample chemosensor, TC12 in tetrahydrofuran responds to F selectively with high sensitivity, with the colorimetric and fluorometric detection limits of 8.25 × 10−7 mol·L–1 and 2.69 × 10−7 mol·L–1, respectively. The reversible gel-sol-gel phase transition and color changes indicate that both SC16-dimethyl sulfoxide and TC16-ethyl acetate gels specifically respond to F with good sensitivity. The detection results are well supported by ultraviolet-visible spectroscopy, fluorescent spectroscopy, and 1H nuclear magnetic resonance. More importantly, the driving forces of gelation are visually clarified through the single crystal X-ray analysis of compound TOMe.

关键词: organogelator     tetraphenylvinyldrazone     single crystal     aggregation-induced emission effect     ion sensing    

Autogenous healing mechanism of cement-based materials

《结构与土木工程前沿(英文)》   页码 948-963 doi: 10.1007/s11709-023-0960-3

摘要: Autogenous self-healing is the innate and fundamental repair capability of cement-based materials for healing cracks. Many researchers have investigated factors that influence autogenous healing. However, systematic research on the autogenous healing mechanism of cement-based materials is lacking. The healing process mainly involves a chemical process, including further hydration of unhydrated cement and carbonation of calcium oxide and calcium hydroxide. Hence, the autogenous healing process is influenced by the material constituents of the cement composite and the ambient environment. In this study, different factors influencing the healing process of cement-based materials were investigated. Scanning electron microscopy and optical microscopy were used to examine the autogenous healing mechanism, and the maximum healing capacity was assessed. Furthermore, detailed theoretical analysis and quantitative detection of autogenous healing were conducted. This study provides a valuable reference for developing an improved healing technique for cement-based composites.

关键词: autogenous healing     cement-based materials     healing mechanism     aggregation effect    

Effects of humic acid and surfactants on the aggregation kinetics of manganese dioxide colloids

Xiaoliu HUANGFU,Yaan WANG,Yongze LIU,Xixin LU,Xiang ZHANG,Haijun CHENG,Jin JIANG,Jun MA

《环境科学与工程前沿(英文)》 2015年 第9卷 第1期   页码 105-111 doi: 10.1007/s11783-014-0726-1

摘要: The aggregation of common manganese dioxide (MnO ) colloids has great impact on their surface reactivity and therefore on their fates as well as associated natural and synthetic contaminants in engineered (e.g. water treatment) and natural aquatic environments. Nevertheless, little is known about the aggregation kinetics of MnO colloids and the effect of humic acid (HA) and surfactants on these. In this study, the early stage aggregation kinetics of MnO nanoparticles in NaNO and Ca(NO ) solutions in the presence of HA and surfactants (i.e., sodium dodecyl sulfate (SDS), and polyvinylpyrrolidone (PVP)) were modeled through time-resolved dynamic light scattering. In the presence of HA, MnO colloids were significantly stabilized with a critical coagulation concentration (CCC) of ~300 mmol·L NaNO and 4 mmol·L Ca(NO ) . Electrophoretic mobility (EPM) measurements confirmed that steric hindrance may be primarily responsible for increasing colloidal stability in the presence of HA. Moreover, the molecular and/or chemical properties of HA might impact its stabilizing efficiency. In the case of PVP, only a slight increase of aggregation kinetics was observed, due to steric reactions originating from adsorbed layers of PVP on the MnO surface. Consequently, higher CCC values were obtained in the presence of PVP. However, there was a negligible reduction in MnO colloidal stability in the presence of 20 mg·L SDS.

关键词: humic acid     surfactant     aggregation kinetics     drinking water     manganese dioxide colloids    

cyclization of a heptapeptide eliminates its cytotoxicity and significantly increases its inhibition effect

Shuai Ma, Huan Zhang, Xiaoyan Dong, Linling Yu, Jie Zheng, Yan Sun

《化学科学与工程前沿(英文)》 2018年 第12卷 第2期   页码 283-295 doi: 10.1007/s11705-017-1687-2

摘要: Amyloid- (A ) protein aggregation is the main hallmark of Alzheimer’s disease (AD). Inhibition of A fibrillation is thus a promising therapeutic approach to the prevention and treatment of AD. Recently, we designed a heptapeptide inhibitor, LVFFARK (LK7). LK7 shows a promising inhibitory capability on A fibrillation, but is prone to self-assembling and displays high cytotoxicity, which would hinder its practical application. Herein, we modified LK7 by a head-to-tail cyclization and obtained a cyclic LK7 (cLK7). cLK7 exhibits a different self-assembly behavior from LK7, and has higher stability against proteolysis than LK7 and little cytotoxicity to SH-SY5Y cells. Thermodynamic analysis revealed that both LK7 and cLK7 could bind to A by electrostatic interactions, hydrogen bonding and hydrophobic interactions, but the binding affinity of cLK7 for A ( = 4.96 µmol/L) is six times higher than that of LK7 ( = 32.2 µmol/L). The strong binding enables cLK7 to stabilize the secondary structure of A and potently inhibit its nucleation, fibrillation and cytotoxicity at extensive concentration range, whereas LK7 could only moderately inhibit A fibrillation and cytotoxicity at low concentrations. The findings indicate that the peptide cyclization is a promising approach to enhance the performance of peptide-based amyloid inhibitors.

关键词: Alzheimer’s disease     amyloid β-protein     cyclic peptide     inhibition     protein aggregation    

Influence of extracellular polymeric substances from activated sludge on the aggregation kinetics of

《环境科学与工程前沿(英文)》 2022年 第16卷 第2期 doi: 10.1007/s11783-021-1450-2

摘要:

• The NPs aggregation in the electrolyte solution is consistent with the DLVO theory.

关键词: Silver nanoparticles     Silver sulfide nanoparticles     Extracellular polymeric substances     Aggregation kinetics     Influence mechanisms    

Trapezoidal Intuitionistic Fuzzy Aggregation Operator Based on Choquet Integral and Its Application to

Xi-hua Li,Xiao-hong Chen

《工程管理前沿(英文)》 2015年 第2卷 第3期   页码 266-276 doi: 10.15302/J-FEM-2015048

摘要: The Choquet integral can serve as a useful tool to aggregate interacting criteria in an uncertain environment. In this paper, a trapezoidal intuitionistic fuzzy aggregation operator based on the Choquet integral is proposed for multi-criteria decision-making problems. The decision information takes the form of trapezoidal intuitionistic fuzzy numbers and both the importance and the interaction information among decision-making criteria are considered. On the basis of the introduction of trapezoidal intuitionistic fuzzy numbers, its operational laws and expected value are defined. A trapezoidal intuitionistic fuzzy aggregation operator based on the Choquet integral is then defined and some of its properties are investigated. A new multi-criteria decision-making method based on a trapezoidal intuitionistic fuzzy Choquet integral operator is proposed. Finally, an illustrative example is used to show the feasibility and availability of the proposed method.

关键词: multi-criteria decision making     trapezoidal intuitionistic fuzzy numbers     Choquet integral     fuzzy measure     aggregation operator    

Controlling interstory drift ratio profiles via topology optimization strategies

《结构与土木工程前沿(英文)》 2023年 第17卷 第2期   页码 165-178 doi: 10.1007/s11709-022-0892-3

摘要: An approach to control the profiles of interstory drift ratios along the height of building structures via topology optimization is proposed herein. The theoretical foundation of the proposed approach involves solving a min–max optimization problem to suppress the maximum interstory drift ratio among all stories. Two formulations are suggested: one inherits the bound formulation and the other utilizes a p-norm function to aggregate all individual interstory drift ratios. The proposed methodology can shape the interstory drift ratio profiles into inverted triangular or quadratic patterns because it realizes profile control using a group of shape weight coefficients. The proposed formulations are validated via a series of numerical examples. The disparity between the two formulations is clear. The optimization results show the optimal structural features for controlling the interstory drift ratios under different requirements.

关键词: interstory drift ratio     aggregation function     bound formulation     min–max problem     topology optimization    

Protein aggregation in association with delayed neuronal death in rat model of brain ischemia

GE Pengfei, FU Shuanglin, LI Wenchen, WANG Chonghao, ZHOU Chuibing, LUO Yinan, LUO Tianfei

《医学前沿(英文)》 2008年 第2卷 第1期   页码 70-74 doi: 10.1007/s11684-008-0013-2

摘要: To investigate the relationship between protein aggregation and delayed neuronal death, we adopted rat models of 20 min ischemia. Brain ischemia was produced using the 2-vessel occlusion (2VO) model in rats Light microscopy, transmission electronic microscopy and Western blot analysis were performed for morphological analysis of neurons, and protein detection. The results showed delayed neuronal death took place at 72 h after ischemia-reperfusion, protein aggregates formed at 4 h after reperfusion and reached the peak at 24 h after reperfusion, and Western blot analysis was consistent with transmission electronic microscopy. We conclude that protein aggregation is one of the important factors leading to delayed neuronal death.

Novel approach to control adsorbent aggregation: iron fixed bentonite-fly ash for Lead (Pb) and Cadmium

Teza Mwamulima, Xiaolin Zhang, Yongmei Wang, Shaoxian Song, Changsheng Peng

《环境科学与工程前沿(英文)》 2018年 第12卷 第2期 doi: 10.1007/s11783-017-0979-6

摘要: In the present study, a novel approach was used to control zero valent iron aggregation and separation problems by fixing zero valent iron (ZVI) on bentonite-fly ash pellets. For this purpose, porous low cost bentonite-fly ash (BFA) pellets with size of 2.00 cm in length and 0.35 cm in diameter were prepared and fixed with ZVI to manufacture zero valent iron bentonite-fly ash (ZVI-BFA) pellets. Importantly, unlike powdered adsorbents, ZVI-BFA can easily be separated from final effluents when exhausted without any disintegration. The performance of the developed novel adsorbent was investigated for the removal of Pb and Cd from aqueous media. At 100 mg·L and 1 g adsorbent, a maximum of 89.5% of Cd and 95.6% of Pb was removed by ZVI-BFA as compared to 56% and 95% removal by BFA. At 200 mg·L , Cd and Pb removal by ZVI-BFA was 56% and 99.8% respectively as compared to only 28% and 96% by BFA. Further, the removal kinetics was best fitted for pseudo-second order model. The study provides the basis for improving the removal capacity of porous materials by iron fixation while taking separation ability into consideration.

关键词: Zero valent iron     Bentonite     Fly ash     Heavy metals removal     Synthesis    

Molecular dynamics simulations of initial Pd and PdO nanocluster growth in a magnetron gas aggregation

Pascal Brault, William Chamorro-Coral, Sotheara Chuon, Amaël Caillard, Jean-Marc Bauchire, Stève Baranton, Christophe Coutanceau, Erik Neyts

《化学科学与工程前沿(英文)》 2019年 第13卷 第2期   页码 324-329 doi: 10.1007/s11705-019-1792-5

摘要: Molecular dynamics simulations are carried out for describing growth of Pd and PdO nanoclusters using the ReaxFF force field. The resulting nanocluster structures are successfully compared to those of nanoclusters experimentally grown in a gas aggregation source. The PdO structure is quasi-crystalline as revealed by high resolution transmission microscope analysis for experimental PdO nanoclusters. The role of the nanocluster temperature in the molecular dynamics simulated growth is highlighted.

关键词: molecular dynamics     cluster growth     plasma sputtering     nanocatalyst    

Methods and applications of DEA cross-efficiency: Review and future perspectives

Jie WU, Jiasen SUN, Liang LIANG

《工程管理前沿(英文)》 2021年 第8卷 第2期   页码 199-211 doi: 10.1007/s42524-020-0133-1

摘要: The field of engineering management usually involves evaluation issues, such as program selection, team performance evaluation, technology selection, and supplier evaluation. The traditional self-evaluation data envelopment analysis (DEA) method usually exaggerates the effects of several inputs or outputs of the evaluated decision-making unit (DMU), resulting in unrealistic results. To address this problem, scholars have proposed the cross-efficiency evaluation (CREE) method. Compared with the DEA method, CREE can rank DMUs more completely by using reasonable weights. With the extensive application of this technique, several problems, such as non-unique weights and non-Pareto optimal results, have arisen in CREE methods. Therefore, the improvement of CREE has attracted the attention of many scholars. This paper reviews the theory and applications of CREE, including the non-uniqueness problem, the aggregation of cross-efficiency data, and applications in engineering management. It also discusses the directions for future research on CREE.

关键词: cross-efficiency evaluation     efficiency     secondary goal model     aggregation     review    

Topology optimization of transient problem with maximum dynamic response constraint using SOAR scheme

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 593-606 doi: 10.1007/s11465-021-0636-4

摘要: This paper proposes a novel method for the continuum topology optimization of transient vibration problem with maximum dynamic response constraint. An aggregated index in the form of an integral function is presented to cope with the maximum response constraint in the time domain. The density filter solid isotropic material with penalization method combined with threshold projection is developed. The sensitivities of the proposed index with respect to design variables are conducted. To reduce computational cost, the second-order Arnoldi reduction (SOAR) scheme is employed in transient analysis. Influences of aggregate parameter, duration of loading period, interval time, and number of basis vectors in the SOAR scheme on the final designs are discussed through typical examples while unambiguous configuration can be achieved. Through comparison with the corresponding static response from the final designs, the optimized results clearly demonstrate that the transient effects cannot be ignored in structural topology optimization.

关键词: topology optimization     solid isotropic material with penalization     transient response     aggregation function     second-order Arnoldi reduction    

Monte Carlo simulation of the diffusion-limited aggregating process of particle suspension systems

Jiajing XU, Lin ZHANG, Yongjian TANG, Wei DAI, Wenwen SHAN,

《化学科学与工程前沿(英文)》 2010年 第4卷 第3期   页码 270-274 doi: 10.1007/s11705-009-0273-7

摘要: The aggregating process of particle suspension systems is a very universal phenomena and crucial for various processes both in nature and in industry. In this paper, the aggregating process was simulated with off-lattice diffusion-limited cluster-cluster aggregation (DLCA) Monte Carlo programs. The self-similar fractal structures of aggregates have been clearly demonstrated by the statistical analysis of gyration radius distribution and the existence of a scaling distribution of the reduced cluster size. The fractal dimension determined from the relationship between mass and gyration radius of aggregates was 1.80 or so. The fractal dimension of the aggregates drawn from the radial distribution function and structure factor of a single aggregate is about 1.90–2.10. It was also showed that, along with the increasing of particle volume fraction, the fractal dimension will increase in a nearly square root manner, and the spatial range of the fractal structure appearing becomes narrower. Also, the gelation transition can only occur in a particle suspension system where the particle volume fraction is greater than a critical value.

关键词: cluster-cluster aggregation     distribution function     relationship     process     universal    

Analysis of effect of different construction methods of piles on the end effect on skin friction of piles

ZHOU Hongbo, CHEN Zhuchang

《结构与土木工程前沿(英文)》 2007年 第1卷 第4期   页码 458-463 doi: 10.1007/s11709-007-0062-7

摘要: Based on the comparative analysis of end effect on skin friction of displacement-pile (driven pile), the end effect on skin friction of bored pile is studied. The end effect on skin friction between driven pile and bored pile is different and the end effect on skin friction of bored pile is reduce of skin friction in the soil layer adjacent to the pile end. The degradation degree of skin friction is deduced with the increase of the distance from pile end. The concept of additional mud cake formed by the effect of cushion at the bottom of borehole during pouring concrete is introduced to explain the mechanism of end effect on skin friction of the bored pile. The test results of post-grouting piles indicate that the post-grouting technique is an effective way to improve the end effect on skin friction of bored pile.

关键词: distance     different     concept     additional     bottom    

标题 作者 时间 类型 操作

Synthesis and ultraviolet/aggregation-induced emission investigation of novel tetraphenylvinyl hydrazone

期刊论文

Autogenous healing mechanism of cement-based materials

期刊论文

Effects of humic acid and surfactants on the aggregation kinetics of manganese dioxide colloids

Xiaoliu HUANGFU,Yaan WANG,Yongze LIU,Xixin LU,Xiang ZHANG,Haijun CHENG,Jin JIANG,Jun MA

期刊论文

cyclization of a heptapeptide eliminates its cytotoxicity and significantly increases its inhibition effect

Shuai Ma, Huan Zhang, Xiaoyan Dong, Linling Yu, Jie Zheng, Yan Sun

期刊论文

Influence of extracellular polymeric substances from activated sludge on the aggregation kinetics of

期刊论文

Trapezoidal Intuitionistic Fuzzy Aggregation Operator Based on Choquet Integral and Its Application to

Xi-hua Li,Xiao-hong Chen

期刊论文

Controlling interstory drift ratio profiles via topology optimization strategies

期刊论文

Protein aggregation in association with delayed neuronal death in rat model of brain ischemia

GE Pengfei, FU Shuanglin, LI Wenchen, WANG Chonghao, ZHOU Chuibing, LUO Yinan, LUO Tianfei

期刊论文

Novel approach to control adsorbent aggregation: iron fixed bentonite-fly ash for Lead (Pb) and Cadmium

Teza Mwamulima, Xiaolin Zhang, Yongmei Wang, Shaoxian Song, Changsheng Peng

期刊论文

Molecular dynamics simulations of initial Pd and PdO nanocluster growth in a magnetron gas aggregation

Pascal Brault, William Chamorro-Coral, Sotheara Chuon, Amaël Caillard, Jean-Marc Bauchire, Stève Baranton, Christophe Coutanceau, Erik Neyts

期刊论文

Methods and applications of DEA cross-efficiency: Review and future perspectives

Jie WU, Jiasen SUN, Liang LIANG

期刊论文

Topology optimization of transient problem with maximum dynamic response constraint using SOAR scheme

期刊论文

Monte Carlo simulation of the diffusion-limited aggregating process of particle suspension systems

Jiajing XU, Lin ZHANG, Yongjian TANG, Wei DAI, Wenwen SHAN,

期刊论文

李浩然:基于同伴效应与网络效应的“气代煤〞改造决策研究(2020年7月11日)

2022年05月19日

会议视频

Analysis of effect of different construction methods of piles on the end effect on skin friction of piles

ZHOU Hongbo, CHEN Zhuchang

期刊论文