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Theoretical study on Janus graphene oxide membrane for water transport

Quan Liu, Mingqiang Chen, Yangyang Mao, Gongping Liu

《化学科学与工程前沿（英文）》 2021年 第15卷 第4期   页码 913-921 doi: 10.1007/s11705-020-1954-5

摘要： Graphene oxide (GO) membranes have received considerable attention owing to their outstanding water-permeation properties; however, the effect of the membrane’s microstructures (such as the distribution of oxidized and pristine regions) on the transport mechanism remains unclear. In this study, we performed molecular simulations to explore the permeation of a water–ethanol mixture using a new type of Janus GO membranes with different orientations of oxidized and pristine surfaces. The results indicate that the oxidized upper surface endows the GO membrane with considerable water-capture capability and the in-built oxidized interlayer promotes the effective vertical diffusion of water molecules. Consequently, using the optimized Janus GO membrane, infinite water selectivity and outstanding water flux (~40.9 kg⋅m ⋅h ) were achieved. This study contributes to explaining the role of oxidized regions in water permeation via GO membranes and suggests that Janus GO membranes could be used as potential candidates for water–ethanol separation.

关键词： graphene oxide membrane     molecular dynamics simulation     water permeation     water-ethanol separation     oxidized and pristine regions    

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Determination of aniline derivatives in water samples after preconcentration with oxidized multiwalled

Hideyuki KATSUMATA, Yuta ODA, Satoshi KANECO, Tohru SUZUKI, Kiyohisa OHTA

《化学科学与工程前沿（英文）》 2012年 第6卷 第3期   页码 270-275 doi: 10.1007/s11705-012-1298-x

摘要： A sensitive and selective preconcentration method using solid-phase extraction (SPE) disk made from oxidized multiwalled carbon nanotubes (OMWCNTs), has been developed for the determination of aniline derivatives, such as 2-nitroaniline (2-NA), 4-nitroaniline (4-NA), and 2,4-dichloroaniline (2,4-DCA) in water samples. Anilines were extracted onto OMWCNT disk and then determined by high performance liquid chromatography (HPLC) with UV detector. Several parameters on the recovery of the analytes were investigated. The experimental results showed that it was possible to obtain quantitative analysis when the solution pH was 8 using 200 mL of validation solution containing 2 μg of anilines and 10 mL of acetonitrile/ethanol (8/2, v/v) as an eluent. Relative standard deviations for five determinations were 7.5% (2-NA), 6.5% (4-NA) and 3.8% (2,4-DCA) under optimum conditions. The linear range of calibration curves were 0.5 ng·mL to 15 ng·mL for each analyte with good correlation coefficients. The detection limits (3S/N) of 2-NA, 4-NA and 2,4-DCA were 30 pg·mL , 31 pg·mL and 26 pg·mL , respectively. Our method was successfully applied to the determination of aniline compounds in river water sample with high precision and accuracy.

关键词： aniline determination     solid-phase extraction     oxidized multiwalled carbon nanotubes     water sample     HPLC-UV    

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Mechanical responses of pristine and defective hexagonal boron-nitride nanosheets: A molecular dynamics

Mohammad SALAVATI, Arvin MOJAHEDIN, Ali Hossein Nezhad SHIRAZI

《结构与土木工程前沿（英文）》 2020年 第14卷 第3期   页码 623-631 doi: 10.1007/s11709-020-0616-5

摘要： In this work we conducted classical molecular dynamics (MD) simulation to investigate the mechanical characteristics and failure mechanism of hexagonal boron-nitride (h-BN) nanosheets. Pristine and defective structure of h-BN nanosheets were considered under the uniaxial tensile loadings at various temperatures. The defective structure contains three types of the most common initial defects in engineering materials that are known as cracks, notches (with various length/size), and point vacancy defects (with a wide range of concentration). MD simulation results demonstrate a high load-bearing capacity of extremely defective (amorphized) h-BN nanosheets. Our results also reveal that the tensile strength decline by increasing the defect content and temperature as well. Our MD results provide a comprehensive and useful vision concerning the mechanical properties of h-BN nanosheets with/without defects, which is very critical for the designing of nanodevices exploiting the exceptional physics of h-BN.

关键词： hexagonal boron-nitride     mechanical properties     crack     notch     point defects     molecular dynamics    

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Preparation and characteristics of TEMPO-oxidized cellulose nanofibrils from bamboo pulp and their oxygen-barrier

Bozhen Wu, Biyao Geng, Yufei Chen, Hongzhi Liu, Guangyao Li, Qiang Wu

《化学科学与工程前沿（英文）》 2017年 第11卷 第4期   页码 554-563 doi: 10.1007/s11705-017-1673-8

摘要： Bleached bamboo kraft pulp was pretreated by 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO)-mediated oxidation using a TEMPO/NaBr/NaClO system at pH= 10 in water to facilitate mechanical disintegration into TEMPO-oxidized cellulose nanofibrils (TO-CNs). A series of TO-CNs with different carboxylate contents were obtained by varying amounts of added NaClO. An increase in carboxylate contents results in aqueous TO-CN dispersions with higher yield, zeta potential values, and optical transparency. When carboxylate groups are introduced, the DP value of the TO-CNs remarkably decreases and then levels off. And the presence of hemicellulose in the pulp is favorable to TEMPO oxidization. After the oxidization, the native cellulose I crystalline structure and crystal size of bamboo pulp are almost maintained. TEM micrographs revealed that the degree of nanofibrillation is directly proportional to the carboxylate contents. With increasing carboxylate contents, the free-standing TO-CN films becomes more transparent and mechanically stronger. The oxygen permeability of PLA films drastically decreases from 355 for neat PLA to 8.4 mL·m ·d after coating a thin layer of TO-CN with a carboxylate content of 1.8 mmol·g . Therefore, inexpensive and abundant bamboo pulp would be a promising starting material to isolate cellulose nanfibrils for oxygen-barrier applications.

关键词： bamboo     TEMPO     cellulose nanofibrils     oxygen barrier    

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Repeats in the transcribed regions: comprehensive characterization and comparison of

Manosh Kumar BISWAS, Christoph MAYER, Xiuxin DENG

《农业科学与工程前沿（英文）》 2017年 第4卷 第4期   页码 421-432 doi: 10.15302/J-FASE-2017160

摘要： A large number of expressed sequences tags are available for spp., which provides an opportunity to understand genomic organization of the transcribed regions. Here, we report a detailed analysis of repetitive elements including tandem repeats (TRs) and transposable elements (TEs) in the transcribed region of the spp. On average, 22% of the expressed sequence tags (ESTs) contain TRs. The relative density of TR classes is highly taxon-specific. For instance, has a high relative density of mononucleotide repeats, whereas dinucleotide repeats are rare. The proportions of 2–6, 7–30 and 31–50 bp repeats were almost identical in all studied species except for and . We found that<1% of the citrus ESTs have a similarity with transposable elements. Transcriptional activity of transposable element families varied even within the same class of elements. A high proportion of transcriptional activity was observed for -like TEs compare to other TE classes. While TEs are relatively rare, TRs are abundant elements in ESTs of citrus. The high proportion of TRs that have a unit size longer than 6 bp raises the question about a possible functional or evolutionary role of these elements.

关键词： Citrus spp.     tandem repeats     transcribed region     transposable elements    

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Genomic regions under selection for important traits in domestic horse breeds

Xuexue LIU, Yuehui MA, Lin JIANG

《农业科学与工程前沿（英文）》 2017年 第4卷 第3期   页码 289-294 doi: 10.15302/J-FASE-2017155

摘要： Horses were domesticated 5500 years ago, thousands of years later than other domestic animals; however, in this relatively short period, domestic horses have had a great impact on human history by accelerating civilization, revolutionizing warfare and advancing agricultural production. Modern breeding using marker-assisted selection has greatly accelerated breeding progress. Therefore, identification of genetic markers underlying the traits of interest in domestic horses is the basis for the modern breeding system. In this review, we present an overview of genetic mapping studies and genome wide analyses to identify the genomic regions targeted by positive selection for four important aspects of horses, coat color, racing performance, gait and height at withers. The locus, for example, has been shown to be the main gene responsible for chestnut color, and the locus has been shown to control the muscle fiber growth in racing breeds. The missense mutation in is the causal mutation for the alternate gaits in horses. Height at withers, a quantitative trait, was mapped to four major loci (3:105547002, 6:81481064, 9:75550059 and 11:232597 32) that can explain 83% of the height variations in domestic horses.

关键词： horse     coat color     racing performance     gait     height    

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Adsorption of toluene, ethylbenzene and xylene isomers on multi-walled carbon nanotubes oxidized by different

Fei YU, Jie MA, Yanqing WU

《环境科学与工程前沿（英文）》 2012年 第6卷 第3期   页码 320-329 doi: 10.1007/s11783-011-0340-4

摘要： Multi-walled carbon nanotubes (MWCNTs) were fabricated and oxidized by different concentrations of sodium hypochlorite (NaOCl) solutions. The untreated MWCNTs and modified MWCNTs were employed as adsorbents to study their characterizations and adsorption performance of toluene, ethylbenzene and xylene isomers (TEX) in an aqueous solution. The physicochemical properties of MWCNTs were greatly affected after oxidation, which influences TEX adsorption capacity. The 3% NaOCl-oxidized MWCNTs shows the greatest enhancement in TEX adsorption, followed by the 30% NaOCl. More interestingly, the 15% NaOCl-oxidized MWCNTs has lower adsorption capacities than untreated MWCNTs. The adsorption mechanism of TEX on treated MWCNTs is attributed to the combined action of hydrophobic interaction, π-π bonding interaction between the aromatic ring of TEX and the oxygen-containing functional groups of MWCNTs and electrostatic interaction. 3% NaOCl solution could not only introduce much oxygen-containing functional groups on MWCNTs, but also lead to less damage for the pore structure. This suggests that the CNTs-3% NaOCl is efficient adsorbent for TEX and that they may possess good potential for TEX removal in wastewater treatment.

关键词： adsorption     toluene     ethylbenzene and xylene isomers (TEX)     multi-walled carbon nanotube     surface oxidation    

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Feasible workspace regions for general two-revolute manipulator

Conghui LIANG, Marco CECCARELLI

《机械工程前沿（英文）》 2011年 第6卷 第4期   页码 397-408 doi: 10.1007/s11465-011-0228-9

摘要：

In this paper, a topology is presented for feasible workspace regions in general two-revolute manipulators. The design problem and concept of feasible workspace regions have been discussed as linked to each other. Design equations are formulated by arbitrarily prescribing four workspace boundary points. The so-called feasible workspace regions are the intersection of three different sub-regions, which are given by constraint curves as function of the relative positions of three workspace boundary points. By using a parametric study, all topologies for three sub-regions are figured out. Corresponding areas in cross section plane are determined for prescribing the position of a feasible workspace point as function of the topology for sub-regions. A classification has been proposed to determine and to characterize the combination of the topologies for those sub-regions. All topologies for feasible workspace regions are figured out and they are discussed as a design tool. Three general cases are analyzed in details to characterize workspace design capabilities for general two-revolute manipulators.

关键词： workspace     two-revolute manipulators     topology analysis     design    

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selective adsorption of uranyl ions by porous polyethylenimine-functionalized carboxylated chitosan/oxidized

Juan Shen, Fang Cao, Siqi Liu, Congjun Wang, Rigui Chen, Ke Chen

《化学科学与工程前沿（英文）》 2022年 第16卷 第3期   页码 408-419 doi: 10.1007/s11705-021-2054-x

摘要： Composite materials have elicited much interest because of their superior performance in the removal of toxic and radioactive uranyl ions from aqueous solutions. With polyethyleneimine as a functional group, carboxylated chitosan as a matrix, and oxidizing activated carbon as a nanofiller, this study synthesized a novel environment-friendly polyethylenimine-functionalized carboxylated chitosan/oxidized activated charcoal (PCO) biocomposite with a unique three-dimensional porous structure. PCO was synthesized through an easy chemical cross-linking method. Detailed characterization certified the formation of the unique three-dimensional porous structure. The obtained PCO was used to remove uranyl ions from an aqueous solution, demonstrating the maximum adsorption capacity of 450 mg·g . The adsorption capacity of PCO decreased by less than 7.51% after five adsorption-desorption cycles. PCO exhibited good adsorption selectivity ( = 3.45 × 10 mL·g ) for uranyl ions. The adsorption mechanism of PCO was also discussed. The material showed good potential for application in the treatment of wastewater containing uranyl ions.

关键词： polyethylenimine     carboxylated chitosan     activated charcoal     uranyl ion     adsorption    

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Comparison and analysis of energy consumption of energy-efficient office buildings in different climate regions

Ke ZHANG, Neng ZHU

《能源前沿（英文）》 2013年 第7卷 第3期   页码 399-405 doi: 10.1007/s11708-013-0260-z

摘要： The purpose of this paper is to analyze the energy consumption (EC) and find out the determining factors of energy-efficient office building cases according to specific case studies in typical cities of different climate zones in China. The investigated building cases were located in four cities (Beijing, Ningbo, Nanjing and Shenzhen) of three architecture thermotechnical design zones (cold zone, hot summer and cold winter zone, hot summer and warm winter zone). The analysis indicates that the energy consumption index (ECI) of these four cases ranges from 41.06 to 74.23 kW·h/(m ·a). Besides, the outdoor climate can change the EC of air conditioning/heating systems, and further determine the monthly volatility of the total EC of the whole building.

关键词： energy-efficient building     breakdown energy consumption (EC)     energy consumption index (ECI)     different climate zone    

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Genomic regions associated with the sex-linked inhibitor of dermal melanin in Silkie chicken

Ming TIAN,Rui HAO,Suyun FANG,Yanqiang WANG,Xiaorong GU,Chungang FENG,Xiaoxiang HU,Ning LI

《农业科学与工程前沿（英文）》 2014年 第1卷 第3期   页码 242-249 doi: 10.15302/J-FASE-2014018

摘要： A unique characteristic of the Silkie chicken is its fibromelanosis phenotype. The dermal layer of its skin, its connective tissue and shank dermis are hyperpigmented. This dermal hyperpigmentation phenotype is controlled by the sex-linked inhibitor of dermal melanin gene ( ) and the dominant fibromelanosis allele. This study attempted to confirm the genomic region associated with . By genotyping, was found to be closely linked to the region between GGA_rs16127903 and GGA_rs14685542 (8406919 bp) on chromosome Z, which contains ten functional genes. The expression of these genes was characterized in the embryo and 4 days after hatching and it was concluded that , encoding methylthioadenosinephosphorylase, would be the most likely candidate gene. Finally, target DNA capture and sequence analysis was performed, but no specific SNP(s) was found in the targeted region of the Silkie genome. Further work is necessary to identify the causal mutation located on chromosome Z.

关键词： sex-linked inhibitor of dermal melanin (Id)     Silkie     chromosome Z    

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Identification of genome regions and important variations associated with expression level of

Ye HOU,Lu JING,Yunxia ZHAO,Sheng WANG,An LIU,Shuhong ZHAO,Xinyun LI

《农业科学与工程前沿（英文）》 2015年 第2卷 第3期   页码 237-241 doi: 10.15302/J-FASE-2015057

摘要： Meat quality is one of the most important economic traits in pig breeding. It has been reported that the composition of type II muscle fibers is correlated with meat quality in pigs. Type II muscle fibers contain three isoforms, IIa, IIb and IIx, which contain specific myofibrillar proteins MYH2, MYH4 and MYH1, respectively. In this study, the expression levels of , , and genes in the Longissimus thoracis (LT) muscle were measured in 114 Yorkshire pigs. Further, the correlations between the expression level of genes and the meat quality traits of intramuscular fat, drip loss, water-holding capacity and postmortem pH values were analyzed. The results showed that the expression level of was positively correlated with the intramuscular fat ( = 0.20, <0.05). The expression levels of and were negatively correlated with the pH at 24 h post mortem (pH ; = －0.28, <0.01; = －0.25, <0.01, respectively). Besides, the 60K SNP chip was used for genotyping the individuals. Genome wide association analysis indicated that 15 SNPs were significantly associated with the expression levels of these three genes. The results indicated the expression levels of , and genes could be useful markers for improvement of meat quality in pigs.

关键词： pig     IMF     pH     MYH1     MYH2     MYH4    

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Investigation of electrochemical degradation and application of e-paper dyes in organic solvents

Luhai LI, Ming WANG, Yi FANG, Shunan QIAO

《化学科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 182-185 doi: 10.1007/s11705-009-0062-3

摘要： To avoid environmental pollution due to organic dye solutions, the electrophoresis and degradation of dye in organic solvents such as alcohol were investigated. Many dyes were tested in the Indium tin oxide (ITO) electrode driving cell, and about 15 dyes moved under voltage driving. Both the curves of ultraviolet-visible (UV-Vis) and infrared (IR) spectra of the electrophoresis samples showed that the metal complexes Red 04 and Acid Black 1 were degradable in alcohol solution by electrochemical reaction. The cyclic volt-ampere curves of the samples from the electrochemical working station proved that electrochemical reactions took place. Based on the analysis of UV-Vis and IR spectra, the electrochemical degradation products of azo and metal complex azo dyes at lower voltage driving (1-5 V) in organic solvents are oxidized azobenzene, not hydrazine, which was found in the electrochemical degradation of dye water solutions. When the ITO electrode is modified by a polyimide (PI) film to a thickness less than 4 μm, the electrochemical degradation of the dye in alcohol solution will not appear in the cyclic volt-ampere curves. A dye electrophoresis in organic solution flexible prototype e-paper display was formed and the display picture is shown.

关键词： electrochemical degradation     electrophoresis     e-paper     oxidized azobenzene group    

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复杂结构中异常区域对波速成像影响的量化研究 Article

董陇军, 童小洁, 马举

《工程（英文）》 2021年 第7卷 第7期   页码 1011-1022 doi: 10.1016/j.eng.2020.06.021

摘要：

复杂结构中异常区域的探测是地下空间开发急需解决的技术瓶颈。人工开挖和天然因素导致的地质结构变化大大降低了传统勘探方法的效率。随着实时监测技术的出现，波速场精确成像使异常区域精准探测成为可能。但成像结果易受到多种因素的影响，尤其在小尺度上应用时。为此，我们采用被动声发射监测和主动超声波探测相结合的增强型三维成像技术，对包括初始速度模型、传感器排布、路径覆盖范围、事件的空间分布和定位误差等因素进行研究，共开展相关测试37组，获得了不同因素对成像精度的量化影响。测试结果表明该成像技术可有效应对复杂结构中的异常区域的精准探测，且在初始迭代参数优化后，异常区域的探测精度显著提高。

关键词： 异常区域探测     成像作用     波速     路径    

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Analysis of driving forces behind diversified carbon dioxide emission patterns in regions of the mainland

Xin TIAN, Hidefumi IMURA, Miao CHANG, Feng SHI, Hiroki TANIKAWA

《环境科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 445-458 doi: 10.1007/s11783-011-0330-6

摘要： China has large regional disparities in carbon dioxide CO emissions with economic development among its 31 provincial mainland regions. This paper investigates these disparities in CO emission patterns and identifies the factors underlying the differences. Results show that the 30 study China's mainland provinces (Tibet not included) can be divided into seven groups with three typical CO emission patterns. Index decomposition results indicate that changes in economic development, the industrial sector, and technology contribute far more to increased CO emissions than do population, energy structure, and other sectors. Close inspection reveals that different industry structures and technology contribute greatly to the differences observed in CO emissions between provinces with similar economic output. This study highlights the importance of region-specific industrial structure adjustment policies, especially for regions transitioning to heavy industry and for those still in the primary stages of industrialization. The potential application of a domestic carbon emissions trading system, to encourage regional investment in updated technology, is also discussed.

关键词： carbon dioxide emission patterns     China     economic development     index decomposition analysis     industrialization    

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标题 作者 时间 类型 操作

Theoretical study on Janus graphene oxide membrane for water transport

Quan Liu, Mingqiang Chen, Yangyang Mao, Gongping Liu

期刊论文

Determination of aniline derivatives in water samples after preconcentration with oxidized multiwalled

Hideyuki KATSUMATA, Yuta ODA, Satoshi KANECO, Tohru SUZUKI, Kiyohisa OHTA

期刊论文

Mechanical responses of pristine and defective hexagonal boron-nitride nanosheets: A molecular dynamics

Mohammad SALAVATI, Arvin MOJAHEDIN, Ali Hossein Nezhad SHIRAZI

期刊论文

Preparation and characteristics of TEMPO-oxidized cellulose nanofibrils from bamboo pulp and their oxygen-barrier

Bozhen Wu, Biyao Geng, Yufei Chen, Hongzhi Liu, Guangyao Li, Qiang Wu

期刊论文

Repeats in the transcribed regions: comprehensive characterization and comparison of

Manosh Kumar BISWAS, Christoph MAYER, Xiuxin DENG

期刊论文

Genomic regions under selection for important traits in domestic horse breeds

Xuexue LIU, Yuehui MA, Lin JIANG

期刊论文

Adsorption of toluene, ethylbenzene and xylene isomers on multi-walled carbon nanotubes oxidized by different

Fei YU, Jie MA, Yanqing WU

期刊论文

Feasible workspace regions for general two-revolute manipulator

Conghui LIANG, Marco CECCARELLI

期刊论文

selective adsorption of uranyl ions by porous polyethylenimine-functionalized carboxylated chitosan/oxidized

Juan Shen, Fang Cao, Siqi Liu, Congjun Wang, Rigui Chen, Ke Chen

期刊论文

Comparison and analysis of energy consumption of energy-efficient office buildings in different climate regions

Ke ZHANG, Neng ZHU

期刊论文

Genomic regions associated with the sex-linked inhibitor of dermal melanin in Silkie chicken

Ming TIAN,Rui HAO,Suyun FANG,Yanqiang WANG,Xiaorong GU,Chungang FENG,Xiaoxiang HU,Ning LI

期刊论文

Identification of genome regions and important variations associated with expression level of

Ye HOU,Lu JING,Yunxia ZHAO,Sheng WANG,An LIU,Shuhong ZHAO,Xinyun LI

期刊论文

Investigation of electrochemical degradation and application of e-paper dyes in organic solvents

Luhai LI, Ming WANG, Yi FANG, Shunan QIAO

期刊论文

复杂结构中异常区域对波速成像影响的量化研究

董陇军, 童小洁, 马举

期刊论文

Analysis of driving forces behind diversified carbon dioxide emission patterns in regions of the mainland

Xin TIAN, Hidefumi IMURA, Miao CHANG, Feng SHI, Hiroki TANIKAWA

期刊论文