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Development of rocking constraint device with vertical damping capacity for three-dimensional base-isolated

《结构与土木工程前沿（英文）》 2023年 第17卷 第3期   页码 350-367 doi: 10.1007/s11709-022-0923-0

摘要： A new rocking constraint device (RCD) is developed for three-dimensional (3D) base-isolated frame structures by connecting a custom-designed cylinder pair to provide vertical damping with replaceable damping components installed outside the cylinders when the superstructure undergoes translational motion, and rocking constraint capacity when the superstructure is susceptible to rocking. Theoretical formulas for calculating the damping and rocking constraint stiffness of the RCD are proposed. Two series of sinusoidal loading tests are conducted at different loading frequencies and amplitudes to verify the damping and rocking constraint performance of the RCD. The test results show that the cylinder without orifices on its piston can provide the desired damping with a replaceable damping component, and that the RCD can effectively suppress rocking. Although the vertical stiffness of an individual cylinder is affected by the location of the replaceable damping component and loading frequency, the average vertical stiffness of the two cylinders, which determines the rocking constraint stiffness of the RCD, is independent of the two factors. Comparisons of the test and theoretical results indicate that the errors of the proposed formulas for calculating the damping and rocking constraint stiffness of the RCD do not exceed 12.9% and 11.0%, respectively.

关键词： three-dimensional isolation     rocking behavior     rocking constraint device     replaceable damping component     sinusoidal test    

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Design and analyses of open-ended pipe piles in cohesionless soils

Yuan GUO,Xiong (Bill) YU

《结构与土木工程前沿（英文）》 2016年 第10卷 第1期   页码 22-29 doi: 10.1007/s11709-016-0314-5

摘要： Large open-ended pipe pile has been found to be advantageous for use in transportation projects. The current design method, however, is not adequately developed. To close this practice gap, this paper first summarized different design methods for open-ended pipe piles in sandy soils. A major factor for all the design codes is to properly account for the formation and effects of soil plug. The comparison indicates that there is a large variation in the base capacity evaluation among different methods due to the complex behaviors of soil plug. To close the knowledge gap, discrete element method (DEM) was used to simulate the soil plugging process and provide insight on the plugging mechanism. The simulation results show that the arching effect significantly increases the internal unit shear resistance along pipe piles. The porosity distribution and particle contact force distribution from DEM model indicate a large stress concentration occurs at the bottom of the soil plug. Besides, nearly 90% of the plug resistance is provided by the bottom half portion of the soil column. The soil-pile friction coefficient has a significant effect on the magnitude of plug resistance, with the major transition occurred for friction coefficient between 0.3 and 0.4.

关键词： open-ended pipe pile     soil plug     DEM     base capacity    

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Study of base friction simulation tests based on a complicated engineered bridge slope

Liu HE, Guang WU, Hua WANG

《结构与土木工程前沿（英文）》 2012年 第6卷 第4期   页码 393-397 doi: 10.1007/s11709-012-0174-6

摘要： In this paper, a physical base friction test model of a slope is established. The model is based on similarity principles and the geological conditions of a complicated bridge slope during construction, deformation and failure. The behavior of the slope in both its natural state and during excavation loading is qualitatively analyzed through base friction tests. The base friction test results are then subjected to comparison and analysis using finite element numerical simulation. The findings show that the whole engineered slope tends to stabilize in its natural state, whereas instabilities will arise at faulted rock masses located near bridge piers during excavation loading. Therefore, to ensure normal construction operation of bridge works, it is suggested that pre-reinforcement of faulted rock masses be performed.

关键词： base friction test     slope stability evaluation     bridge slope    

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Base editors: development and applications in biomedicine

《医学前沿（英文）》 2023年 第17卷 第3期   页码 359-387 doi: 10.1007/s11684-023-1013-y

摘要： Base editor (BE) is a gene-editing tool developed by combining the CRISPR/Cas system with an individual deaminase, enabling precise single-base substitution in DNA or RNA without generating a DNA double-strand break (DSB) or requiring donor DNA templates in living cells. Base editors offer more precise and secure genome-editing effects than other conventional artificial nuclease systems, such as CRISPR/Cas9, as the DSB induced by Cas9 will cause severe damage to the genome. Thus, base editors have important applications in the field of biomedicine, including gene function investigation, directed protein evolution, genetic lineage tracing, disease modeling, and gene therapy. Since the development of the two main base editors, cytosine base editors (CBEs) and adenine base editors (ABEs), scientists have developed more than 100 optimized base editors with improved editing efficiency, precision, specificity, targeting scope, and capacity to be delivered in vivo, greatly enhancing their application potential in biomedicine. Here, we review the recent development of base editors, summarize their applications in the biomedical field, and discuss future perspectives and challenges for therapeutic applications.

关键词： base editing     CBE     ABE     ADAR     DdCBE     disease model     therapeutic application    

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Multistage-batch bipolar membrane electrodialysis for base production from high-salinity wastewater

《化学科学与工程前沿（英文）》 2022年 第16卷 第5期   页码 764-773 doi: 10.1007/s11705-021-2114-2

摘要： Bipolar membrane electrodialysis (BMED) is considered a state-of-the-art technology for the conversion of salts into acids and bases. However, the low concentration of base generated from a traditional BMED process may limit the viability of this technology for a large-scale application. Herein, we report an especially designed multistage-batch (two/three-stage-batch) BMED process to increase the base concentration by adjusting different volume ratios in the acid (Vacid), base (Vbase), and salt compartments (Vsalt). The findings indicated that performance of the two-stage-batch with a volume ratio of Vacid:Vbase:Vsalt = 1:1:5 was superior in comparison to the three-stage-batch with a volume ratio of Vacid:Vbase:Vsalt = 1:1:2. Besides, the base concentration could be further increased by exchanging the acid produced in the acid compartment with fresh water in the second stage-batch process. With the two-stage-batch BMED, the maximum concentration of the base can be obtained up to 3.40 mol∙L–1, which was higher than the most reported base production by BMED. The low energy consumption and high current efficiency further authenticate that the designed process is reliable, cost-effective, and more productive to convert saline water into valuable industrial commodities.

关键词： bipolar membrane electrodialysis     multistage-batch     base production     high-salinity wastewater    

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Enzyme@bismuth-ellagic acid: a versatile platform for enzyme immobilization with enhanced acid-base stability

《化学科学与工程前沿（英文）》 2023年 第17卷 第6期   页码 784-794 doi: 10.1007/s11705-022-2278-4

摘要： In situ encapsulation is an effective way to synthesize enzyme@metal–organic framework biocatalysts; however, it is limited by the conditions of metal–organic framework synthesis and its acid-base stability. Herein, a biocatalytic platform with improved acid-base stability was constructed via a one-pot method using bismuth-ellagic acid as the carrier. Bismuth-ellagic acid is a green phenol-based metal–organic framework whose organic precursor is extracted from natural plants. After encapsulation, the stability, especially the acid-base stability, of amyloglucosidases@bismuth-ellagic acid was enhanced, which remained stable over a wide pH range (2–12) and achieved multiple recycling. By selecting a suitable buffer, bismuth-ellagic acid can encapsulate different types of enzymes and enable interactions between the encapsulated enzymes and cofactors, as well as between multiple enzymes. The green precursor, simple and convenient preparation process provided a versatile strategy for enzymes encapsulation.

关键词： bismuth-ellagic acid     in situ encapsulation     enzyme@MOF biocomposites    

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Application of Cu nanoparticles as N32 base oil additives

Qiang HE, Jun YE, Hongzhao LIU, Jinling LI,

《机械工程前沿（英文）》 2010年 第5卷 第1期   页码 93-97 doi: 10.1007/s11465-009-0083-0

摘要： Cu nanoparticles as N32 base oil additives are studied in the paper and their structure is characterized by transmission electron microscopy (TEM) and X-ray powder diffraction spectroscopy (XRD). The widely used steel-steel friction system is chosen to test the feasibility and practicality of Cu nanoparticles as bearing lubricant additives. The results show that N32 base oil with 0.5% Cu nanoparticle can improve the test sample contact fatigue life than pure N32 base oil.

关键词： Cu nanoparticle     tribological property     contact fatigue     weibull distribution    

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Thermoresponsive block copolymer supported Pt nanocatalysts for base-free aerobic oxidation of 5-hydroxymethyl

《化学科学与工程前沿（英文）》 2021年 第15卷 第6期   页码 1514-1523 doi: 10.1007/s11705-021-2092-4

摘要： A base-free catalytic system for the aerobic oxidation of 5-hydroxymethyl-2-furfural was exploited by using Pt nanoparticles immobilized onto a thermoresponsive poly(acrylamide-co-acrylonitrile)-b-poly(N-vinylimidazole) block copolymer, with an upper critical solution temperature of about 45 °C. The Pt nanocatalysts were well-dispersed and highly active for the base-free oxidation of 5-hydroxymethyl-2-furfural by molecular oxygen in water, affording high yields of 2,5-furandicarboxylic acid (up to>99.9%). The imidazole groups in the block copolymer were conducive to the improvement of catalytic performance. Moreover, the catalysts could be easily separated and recovered based on their thermosensitivity by cooling the reaction system below the upper critical solution temperature. Good stability and reusability were observed over these copolymer-immobilized catalysts with no obvious decrease in catalytic activity in the five consecutive cycles.

关键词： aerobic oxidation     base-free     5-hydroxymethyl-2-furfural     Pt nanoparticle     thermoresponsive block copolymer    

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可拓知识库系统及其应用

李立希,李嘉

《中国工程科学》 2001年 第3卷 第3期   页码 61-64

摘要：

知识库系统是一种专门存储、管理大量知识的机构。文章以可拓学的理论和方法为指导，提出可拓知识表示法和可拓知识库系统的特点与构架。给出了可拓知识表示的形式化语义，其基本单元是知识物元；阐述了矛盾问题求解的形式表示，其核心是问题的物元模型，通过可拓算子把不相容问题转化为相容问题；相关方式推理是可拓知识库系统推理机的特点，是传统规则推理的推广。可拓知识库采用可拓知识表示方法，是传统知识库的一个超集；可拓知识库系统由目标库、条件库、公用知识库、分类知识库、推理机与知识库管理系统组成。

关键词： 可拓论     不相容     知识库    

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Process study on adsorption of glycerin from saline wastewater by strong base anion resin

Haitao ZHANG, Xiaoqing MA, Xian QU, Jeanpierre Arcangeli

《化学科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 113-116 doi: 10.1007/s11705-010-0547-0

摘要： A physicochemical method was used to adsorb glycerin in saline wastewater by strong base anion resin (D201). Boric acid, a kind of weak acid, can combine with glycerin, and a specific complex can be produced, which possess bigger molecule than glycerin. Then, this specific complex could be adsorbed by strong base anion resin. Via the experiment, the equation of adsorption isotherm with D201 at 20°C can be shown by lg / = 1.74lg - 5.72; for column test with simulative glycerin wastewater, the treatment capability was more than nine bed volumes, and 39.77 mg glycerin could be removed by per gram resin. When the NaCl concentration was 10 g/L, five bed volumes of simulative wastewater could be treated, and the adsorb mass was 29.09 mg/g. When the NaCl concentration was 30 g/L, only three bed volumes of simulative wastewater could be treated, and the adsorb mass was 14.83 mg/g.

关键词： glycerin     anion resin     boric acid     wastewater     NaCl    

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Efficient acetylene/carbon dioxide separation with excellent dynamic capacity and low regeneration energy

《化学科学与工程前沿（英文）》   页码 1616-1622 doi: 10.1007/s11705-022-2183-x

摘要： Adsorptive separation of acetylene/carbon dioxide mixtures by porous materials is an important and challenging task due to their similar sizes and physical properties. Here, remarkable acetylene/carbon dioxide separation featuring a high dynamic breakthrough capacity for acetylene (4.3 mmol·g–1) as well as an ultralow acetylene regeneration energy (29.5 kJ·mol–1) was achieved with the novel TiF62–-pillared material ZU-100 (TIFSIX-bpy-Ni). Construction of a pore structure with abundant TiF62– anion sites and pores with appropriate sizes enabled formation of acetylene clusters through hydrogen bonds and intermolecular interactions, which afforded a high acetylene capacity (8.3 mmol·g–1) and high acetylene/carbon dioxide uptake ratio (1.9) at 298 K and 1 bar. Moreover, the NbO52– anion-pillared material ZU-61 investigated for separation of acetylene/carbon dioxide. In addition, breakthrough experiments were also conducted to further confirm the excellent dynamic acetylene/carbon dioxide separation performance of ZU-100.

关键词： adsorption     acetylene/carbon dioxide separation     dynamic capacity     anion-pillared hybrid material    

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Heat-spreading analysis of a heat sink base embedded with a heat pipe

B. V. BORGMEYER, H. B. MA,

《能源前沿（英文）》 2010年 第4卷 第2期   页码 143-148 doi: 10.1007/s11708-010-0013-1

摘要： A simplified model predicting the heat transfer performance of a heat sink base with a high thermal conductivity was developed. Numerical analysis was performed using the commercial software FLUENT. The investigation indicates that for heat sink bases with a high effective thermal conductivity, such as the base embedded with a typical heat pipe, the entire heat sink can be modeled as a flat plate with a uniform temperature and an effective convection heat transfer coefficient. This simplified model can be used to determine the heat transfer performance of a heat sink embedded with a typical heat pipe or vapor chamber.

关键词： heat pipe     heat sink     microprocessor heat removal    

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Buffer capacity of granular matter to impact of spherical projectile based on discrete element method

Ying YAN, Pengfei LI, Shunying JI

《结构与土木工程前沿（英文）》 2013年 第7卷 第1期   页码 50-54 doi: 10.1007/s11709-013-0186-x

摘要： Granular matter possesses impact-absorbing property due to its energy dissipation character. To investigate the impact-absorbing capacity of granular matter, the discrete element method (DEM) is adopted to simulate the impact of a spherical projectile on to a granular bed. The dynamic responses of the projectile are obtained for both thin and thick granular bed. The penetration depth of the projectile and the first impact peak are investigated with different bed thicknesses and impact velocities. Determining a suitable bed thickness is crucial to the buffering effect of granular matter. The first impact peak is independent of bed thickness when the thickness is larger than the critical thickness.

关键词： granular matter     impact peak     buffer capacity     discrete element method     critical thickness    

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Base editing in pigs for precision breeding

Ruigao SONG, Yu WANG, Yanfang WANG, Jianguo ZHAO

《农业科学与工程前沿（英文）》 2020年 第7卷 第2期   页码 161-170 doi: 10.15302/J-FASE-2019308

摘要：

Pigs are one of the most important domesticated animals and have great value in agriculture and biomedicine. Single nucleotide polymorphisms (SNPs) are a dominant type of genetic variation among individual pigs and contribute to the formation of traits. Precision single base substitution provides a strategy for accurate genetic improvement in pig production with the characterization of functional SNPs and genetic variants in pigs. Base editing has recently been developed as the latest gene-editing tool that can directly make changes in single nucleotides without introducing double-stranded DNA breaks (DSBs), providing a promising solution for precise genetic modification in large animals. This review summarizes gene-editing developments and highlights recent genetic dissection related to SNPs in major economic traits which may have the potential to be modified using SNP-editing applications. In addition, limitations and future directions of base editing in pig breeding are discussed.

关键词： base editing     genetic improvement     pigs     single nucleotide polymorphisms    

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recognition of 1,1′-binaphthol through enantioselective collapse of gel based on an amphiphilic Schiff-base

Xuhong Zhang, Haimiao Li, Xin Zhang, Meng An, Weiwei Fang, Haitao Yu

《化学科学与工程前沿（英文）》 2017年 第11卷 第2期   页码 231-237 doi: 10.1007/s11705-017-1633-3

摘要： A novel gelator that contained both Schiff base and L-lysine moieties was synthesized and its gelation behavior was tested. This gelator can form gels in various organic solvents. The resulting gel can be applied as a fascinating platform for visual recognition of enantiomeric 1-(2-hydroxynaphthalen-1-yl)naphthalen-2-ol (BINOL) through selective gel collapse. In addition, the mechanism for the reaction of the gel with chiral BINOL was investigated by scanning electron microscope and H nuclear magnetic resonance.

关键词： gelator     Schiff base     chiral recognition     gel formation     gel collapse    

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标题 作者 时间 类型 操作

Development of rocking constraint device with vertical damping capacity for three-dimensional base-isolated

期刊论文

Design and analyses of open-ended pipe piles in cohesionless soils

Yuan GUO,Xiong (Bill) YU

期刊论文

Study of base friction simulation tests based on a complicated engineered bridge slope

Liu HE, Guang WU, Hua WANG

期刊论文

Base editors: development and applications in biomedicine

期刊论文

Multistage-batch bipolar membrane electrodialysis for base production from high-salinity wastewater

期刊论文

Enzyme@bismuth-ellagic acid: a versatile platform for enzyme immobilization with enhanced acid-base stability

期刊论文

Application of Cu nanoparticles as N32 base oil additives

Qiang HE, Jun YE, Hongzhao LIU, Jinling LI,

期刊论文

Thermoresponsive block copolymer supported Pt nanocatalysts for base-free aerobic oxidation of 5-hydroxymethyl

期刊论文

可拓知识库系统及其应用

李立希,李嘉

期刊论文

Process study on adsorption of glycerin from saline wastewater by strong base anion resin

Haitao ZHANG, Xiaoqing MA, Xian QU, Jeanpierre Arcangeli

期刊论文

Efficient acetylene/carbon dioxide separation with excellent dynamic capacity and low regeneration energy

期刊论文

Heat-spreading analysis of a heat sink base embedded with a heat pipe

B. V. BORGMEYER, H. B. MA,

期刊论文

Buffer capacity of granular matter to impact of spherical projectile based on discrete element method

Ying YAN, Pengfei LI, Shunying JI

期刊论文

Base editing in pigs for precision breeding

Ruigao SONG, Yu WANG, Yanfang WANG, Jianguo ZHAO

期刊论文

recognition of 1,1′-binaphthol through enantioselective collapse of gel based on an amphiphilic Schiff-base

Xuhong Zhang, Haimiao Li, Xin Zhang, Meng An, Weiwei Fang, Haitao Yu

期刊论文