资源类型

期刊论文 197

年份

2023 22

2022 21

2021 16

2020 14

2019 6

2018 8

2017 10

2016 10

2015 12

2014 8

2013 10

2012 9

2011 7

2010 10

2009 9

2008 8

2007 5

2006 2

2005 4

2004 2

展开 ︾

关键词

产业 2

3-酰基硫代四酸 1

Anderson 模型 1

DNA信息存储 1

DNA活字存储系统 1

DNA结构 1

IEEE80216 1

LK算法 1

LS算法 1

Mesh 1

PV/T 1

Reed-Solomon码；步进式译码算法；超宽带；流水线架构 1

SAHP 1

ST34 1

中国谱系 1

二阶矩模型 1

井壁稳定 1

亚麻屑纤维素 1

产出水处理 1

展开 ︾

检索范围：

排序： 展示方式：

Removal of clofibric acid from aqueous solution by polyethylenimine-modified chitosan beads

Yao NIE,Shubo DENG,Bin WANG,Jun HUANG,Gang YU

《环境科学与工程前沿（英文）》 2014年 第8卷 第5期   页码 675-682 doi: 10.1007/s11783-013-0622-0

摘要： Polyethylenimine (PEI)-modified chitosan was prepared and used to remove clofibric acid (CA) from aqueous solution. PEI was chemically grafted on the porous chitosan through a crosslinking reaction, and the effects of PEI concentration and reaction time in the preparation on the adsorption of clofibric acid were optimized. Scanning electron microscopy (SEM) showed that PEI macromolecules were uniformly grafted on the porous chitosan, and the analysis of pore size distribution indicated that more mesopores were formed due to the crosslinking of PEI molecules in the macropores of chitosan. The PEI-modified chitosan had fast adsorption for CA within the initial 5 h, while this adsorbent exhibited an adsorption capacity of 349 mg·g for CA at pH 5.0 according to the Langmuir fitting, higher than 213 mg·g on the porous chitosan. The CA adsorption on the PEI-modified chitosan was pH-dependent, and the maximum adsorption was achieved at pH 4.0. Based on the surface charge analysis and comparison of different pharmaceuticals adsorption, electrostatic interaction dominated the sorption of CA on the PEI-modified chitosan. The PEI-modified chitosan has a potential application for the removal of some anionic micropollutants from water or wastewater.

关键词： clofibric acid     PEI-modified chitosan     adsorption capacity     adsorption mechanism     electrostatic interaction    

HTML PDF 收藏

Removal of copper by modified chitosan adsorptive membrane

Xiaoshuai LIU, Zihong CHENG, Wei MA

《化学科学与工程前沿（英文）》 2009年 第3卷 第1期   页码 102-106 doi: 10.1007/s11705-009-0123-7

摘要： In this study, a novel adsorptive membrane was prepared from chitosan as the functional polymer and some additive blend solutions by solution casting method. The modified chitosan membrane was characterized by FTIR and its Water Swelling Ratio (WSR). The adsorption of copper ions on the adsorptive membrane was investigated in batch experiments. The results obtained from the experiments indicated that the membrane had a good adsorption capacity for copper ions, the optimal ionic strength and pH were 0.1 and 5-6, respectively. Compared with the Langmuir isotherm model, the experimental data were found to be following the Freundlich model.

关键词： chitosan     adsorptive membrane     copper removal     environmental engineering     heavy metal     isotherm model    

HTML PDF 收藏

An antifouling catechol/chitosan-modified polyvinylidene fluoride membrane for sustainable oil-in-water

Shanshan Zhao, Zhu Tao, Liwei Chen, Muqiao Han, Bin Zhao, Xuelin Tian, Liang Wang, Fangang Meng

《环境科学与工程前沿（英文）》 2021年 第15卷 第4期 doi: 10.1007/s11783-020-1355-5

摘要： Abstract • Underwater superoleophobic membrane was fabricated by deposition of catechol/chitosan. • The membrane had ultrahigh pure water flux and was stable under harsh pH conditions. • The membrane exhibited remarkable antifouling property in O/W emulsion separation. • The hydration layer on the membrane surface prevented oil droplets adhesion. Low-pressure membrane filtrations are considered as effective technologies for sustainable oil/water separation. However, conventional membranes usually suffer from severe pore clogging and surface fouling, and thus, novel membranes with superior wettability and antifouling features are urgently required. Herein, we report a facile green approach for the development of an underwater superoleophobic microfiltration membrane via one-step oxidant-induced ultrafast co-deposition of naturally available catechol/chitosan on a porous polyvinylidene fluoride (PVDF) substrate. Membrane morphology and surface chemistry were studied using a series of characterization techniques. The as-prepared membrane retained the original pore structure due to the ultrathin and uniform catechol/chitosan coating. It exhibited ultrahigh pure water permeability and robust chemical stability under harsh pH conditions. Moreover, the catechol/chitosan hydrophilic coating on the membrane surface acting as an energetic barrier for oil droplets could minimize oil adhesion on the surface, which endowed the membrane with remarkable antifouling property and reusability in a cyclic oil-in-water (O/W) emulsion separation. The modified membrane exhibited a competitive flux of ~428 L/(m2·h·bar) after three filtration cycles, which was 70% higher than that of the pristine PVDF membrane. These results suggest that the novel underwater superoleophobic membrane can potentially be used for sustainable O/W emulsions separation, and the proposed green facile modification approach can also be applied to other water-remediation materials considering its low cost and simplicity.

关键词： Antifouling     Catechol/chitosan co-deposition     Oil-in-water emulsions separation     Underwater superoleophobic    

HTML PDF 收藏

Removing phosphorus from aqueous solutions by using iron-modified corn straw biochar

Fenglin LIU,Jiane ZUO,Tong CHI,Pei WANG,Bo YANG

《环境科学与工程前沿（英文）》 2015年 第9卷 第6期   页码 1066-1075 doi: 10.1007/s11783-015-0769-y

摘要： Iron-modified corn straw biochar was used as an adsorbent to remove phosphorus from agricultural runoff. When agricultural runoffs with a total phosphorus (TP) concentration of 1.86 mg·L to 2.47 mg·L were filtered at a hydraulic retention time of 2 h through a filtration column packed with the modified biochar, a TP removal efficiency of over 99% and an effluent TP concentration of less than 0.02 mg·L were achieved. The isotherms of the phosphorus adsorption by the modified biochar fitted the Freundlich equation better than the Langmuir equation. The mechanism of the phosphorus adsorbed by the modified biochar was analyzed by using various technologies, i.e. scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). The results indicated that the surface of the modified biochar was covered by small iron granules, which were identified as Fe O . The results also showed that new iron oxides were formed on the surface of the modified biochar after the adsorption of phosphorus. Moreover, new bonds of Fe-O-P and P-C were found, which suggested that the new iron oxides tend to be Fe (PO ) (OH) . Aside from removing phosphorus, adding the modified biochar into soil also improved soil productivity. When the modified biochar-to-soil rate was 5%, the stem, root, and bean of broad bean plants demonstrated increased growth rates of 91%, 64%, and 165%, respectively.

关键词： iron-modified biochar     phosphorus removal     agricultural waste     agricultural runoff    

HTML PDF 收藏

Fertility outcome analysis after modified laparoscopic microsurgical tubal anastomosis

null

《医学前沿（英文）》 2011年 第5卷 第3期   页码 310-314 doi: 10.1007/s11684-011-0152-8

摘要：

Modified laparoscopic microsurgical tubal anastomosis is an alternative for microsurgical anastomosis via laparotomy to reverse sterilization in women with renewed child wish. The current study aims to evaluate the fertility outcome after modified laparoscopic microsurgical tubal anastomosis. A retrospective study was performed. Fifty-eight women who underwent modified laparoscopic microsurgical tubal anastomosis were monitored to investigate the fertility outcome and characteristics of this new technology. Of the 58 patients, the cumulative pregnancy rate (PR) in the 42 patients with follow-up data was 23.8% (10/42), 57.1% (24/42), 66.7% (28/42), and 73.8% (31/42) within 6, 12, 24, and 36 months after surgery, respectively. The intrauterine PR was 69.0% (29/42). Two patients (4.8%) had ectopic pregnancies that occurred within 24 months of surgery; three cases ended in spontaneous abortion. The delivery rate was 83.9% (26/31). The length of operating time was 1.2±0.3 h, with a range of 1.0–2.5 h (60–145 min), and the mean time was approximately 75 min. The blood loss was relatively small, between 10 and 50 ml with an average amount of 22 ml. Thus, the modified laparoscopic tubal anastomosis is a highly successful procedure and a viable alternative to open abdominal microsurgical approaches. Compared with the traditional laparoscopic tubal sterilization reversal, this modified approach has three advantages: (1) less invasive approach via a trocar reduction; (2) remodeling of tube is better performing tied together after 3–4 sutures; and (3) faster operating time.

关键词： modified laparoscopy     tubal anastomosis     microsurgery    

HTML PDF 收藏

Using thermodynamic parameters to study self-healing and interface properties of crumb rubber modified

Dongliang HU, Jianzhong PEI, Rui LI, Jiupeng ZHANG, Yanshun JIA, Zepeng FAN

《结构与土木工程前沿（英文）》 2020年 第14卷 第1期   页码 109-122 doi: 10.1007/s11709-019-0579-6

摘要： The thermodynamic property of asphalt binder is changed by the addition of crumb rubber, which in turn influences the self-healing property as well as the cohesion and adhesion within the asphalt-aggregate system. This study investigated the self-healing and interface properties of crumb rubber modified asphalt (CRMA) using thermodynamic parameters based on the molecular simulation approach. The molecular models of CRMA were built with representative structures of the virgin asphalt and the crumb rubber. The aggregate was represented by SiO and Al O crystals. The self-healing capability was evaluated with the thermodynamic parameter wetting time, work of cohesion and diffusivity. The interface properties were evaluated by characterizing the adhesion capability, the debonding potential and the moisture susceptibility of the asphalt-aggregate interface. The self-healing capability of CRMA is found to decrease as the rubber content increases. The asphalt-Al O interface with higher rubber content has stronger adhesion and moisture stability. But the influence of crumb rubber on the interfacial properties of asphalt-SiO interface has no statistical significance. Comparing with the interfacial properties of the asphalt-SiO interface, the asphalt-Al O interface is found to have a stronger adhesion but a worse moisture susceptibility for its enormous thermodynamic potential for water to displace the asphalt binder.

关键词： crumb rubber modified asphalt     surface free energy     self-healing     interface properties     molecular dynamics simulation    

HTML PDF 收藏

Dialdehyde cellulose nanocrystal cross-linked chitosan foam with high adsorption capacity for removal

《化学科学与工程前沿（英文）》 2023年 第17卷 第7期   页码 853-866 doi: 10.1007/s11705-022-2256-x

摘要： The discharge of large amounts of dye-containing wastewater seriously threats the environment. Adsorbents have been adopted to remove these dyes present in the wastewater. However, the high adsorption capacity, predominant pH-responsibility, and excellent recyclability are three challenges to the development of efficient adsorbents. The poly(acryloxyethyl trimethylammonium chloride)-graft-dialdehyde cellulose nanocrystals were synthesized in our work. Subsequently, the cationic dialdehyde cellulose nanocrystal cross-linked chitosan nanocomposite foam was fabricated via freeze-drying of the hydrogel. Under the optimal ratio of the cationic dialdehyde cellulose nanocrystal/chitosan (w/w) of 12/100, the resultant foam (Foam-12) possesses excellent absorption properties, such as high porosity, high content of active sites, strong acid resistance, and high amorphous region. Then, Foam-12 was applied as an eco-friendly adsorbent to remove acid red 134 (a representative of anionic dyes) from aqueous solutions. The maximum dye adsorption capacity of 1238.1 mg∙g‒1 is achieved under the conditions of 20 mg∙L‒1 adsorbents, 100 mg∙L‒1 dye, pH 3.5, 24 h, and 25 °C. The dominant adsorption mechanism for the anionic dye adsorption is electrostatic attraction, and Foam-12 can effectively adsorb acid red 134 at pH 2.5–5.5 and be desorbed at pH 8. Its easy recovery and good reusability are verified by the repeated acid adsorption–alkaline desorption experiments.

关键词： chitosan foam     cellulose nanocrystals     acid red 134     adsorption    

HTML PDF 收藏

Correction to: Highly degradable chitosan-montmorillonite (MMT) nanocomposite hydrogel for controlled

《环境科学与工程前沿（英文）》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1704-2

HTML PDF 收藏

Solvent-free mechanochemical mild oxidation method to enhance adsorption properties of chitosan

《环境科学与工程前沿（英文）》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1416-4

摘要：

• Solvent-free chitosan oxidation is obtained by rapid mechanochemical reaction.

关键词： Chitosan     High energy ball milling     Mechanochemistry     Oxidation    

HTML PDF 收藏

Anthocyanins/chitosan films doped by nano zinc oxide for active and intelligent packaging: comparison

《化学科学与工程前沿（英文）》 2023年 第17卷 第6期   页码 704-715 doi: 10.1007/s11705-022-2270-z

摘要： The multifunctional films was prepared by blending chitosan and nano-ZnO with purple tomato anthocyanins or black wolfberry anthocyanins. The properties of films functioned by anthocyanins source and nano-ZnO content were studied. It was found purple tomato anthocyanins showed more significant color change against pH than black wolfberry anthocyanins. The nano-ZnO were widely dispersed in matrix and enhanced the compatibility of anthocyanins with chitosan. However, the anthocyanins source influenced the properties of the films more slightly than nano-ZnO addition. The tensile strength, antioxidant and antibacterial effects of the chitosan films dramatically increased after cooperated by nano-ZnO and anthocyanins, which also enhanced with increase of nano-ZnO content, whereas the elongation at break of the composite films decreased. Especially, the anthocyanin and nano-ZnO promoted the antibacterial activity of films synergistically. Composite films made from black wolfberry anthocyanins exhibited higher mechanical performance than those made from purple tomato anthocyanins but weaker antibacterial effects. The purple tomato anthocyanins/chitosan and nano-ZnO/purple tomato anthocyanins/chitosan films effectively reflected pork spoilage, changing their colors from dark green to brown, indicating the potential for applications in active and intelligent food packaging.

关键词： bio-based     multifunction     colorimetric indicator     active and intelligent packaging    

HTML PDF 收藏

Nano-hydroxyapatite formation via co-precipitation with chitosan-g-poly(

Yang YU, Hong ZHANG, Hong SUN, Dandan XING, Fanglian YAO

《化学科学与工程前沿（英文）》 2013年 第7卷 第4期   页码 388-400 doi: 10.1007/s11705-013-1355-0

摘要： With the excellent biocompatibility and osteoconductivity, nano-hydroxyapatite (nHA) has shown significant prospect in the biomedical applications. Controlling the size, crystallinity and surface properties of nHA crystals is a critical challenge in the design of HA based biomaterials. With the graft copolymer of chitosan and poly( -isopropylacrylamide) in coil and globule states as a template respectively, a novel composite from chitosan-g-poly( -isopropylacrylamide) and nano-hydroxyapatite (CS-g-PNIPAM/nHA) was prepared via co-precipitation. Zeta potential analysis, thermogravimetric analysis and X-ray diffraction were used to identify the formation mechanism of the CS-g-PNIPAM/nHA composite and its morphology was observed by transmission electron microscopy. The results suggested that the physical aggregation states of the template polymer could induce or control the size, crystallinity and morphology of HA crystals in the CS-g-PNIPAM/nHA composite. The CS-g-PNIPAM/nHA composite was then introduced to chitosan-gelatin (CS-Gel) polyelectronic complex and the cytocompatibility of the resulting CS-Gel/composite hybrid film was evaluated. This hybrid film was proved to be favorable for the proliferation of MC 3T3-E1 cells. Therefore, the CS-g-PNIPAM/nHA composite is a potential biomaterial in bone tissue engineering.

关键词： chitosan     poly(N-isopropylacrylamide)     hydroxyapatite     coil     globule     bone tissue engineering    

HTML PDF 收藏

Chitosan/polyethylene glycol impregnated activated carbons: Synthesis, characterization and adsorption

Ehsan Salehi, Fereshteh Soroush, Maryam Momeni, Aboulfazl Barati, Ali Khakpour

《化学科学与工程前沿（英文）》 2017年 第11卷 第4期   页码 575-585 doi: 10.1007/s11705-017-1650-2

摘要： Novel modified activated carbons (ACs) with enhanced adsorptive properties were obtained coating by chitosan (CS), polyethylene glycol (PEG) and blends of the two polymers (0:1, 1:0, 1:1, 1:2 and 2:1 wt/wt) on ACs by an impregnation technique. The adsorption performances of the pristine, acidified and polymer-impregnated ACs were studied using methylene blue as a model adsorbate. The adsorbents were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy and abrasion hardness tests. The average coating thicknesses were between 10 to 23 microns. The pore sizes, pore densities and pore capacities of the activated carbons increased as the wt-% PEG in the coating increased. The highest adsorption capacity (424.7 mg/g) was obtained for the chitosan-coated ACs and this adsorption was well described by the Langmuir isotherm model. The kinetic results were best described by the pseudo-second-order kinetic model. The highest rate constant was obtained with the ACs modified with the CS:PEG (2:1) coating and this result was almost 2.6 times greater than that of the unmodified ACs. The CS/PEG impregnated ACs also displayed superior hardness (~90%), compared to unmodified ACs (~85%). Overall the chitosan had a greater effect on improving adsorption capacity whereas the polyethylene glycol enhanced the adsorption rate.

关键词： carbon biocomposites     impregnation     chitosan     polyethylene glycol     image processing    

HTML PDF 收藏

Effective and selective adsorption of uranyl ions by porous polyethylenimine-functionalized carboxylated chitosan

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    

HTML PDF 收藏

Synthesis of graphene oxide nanoribbons/chitosan composite membranes for the removal of uranium from

Xuewen Hu, Yun Wang, Jinbo Ou Yang,Yang Li, Peng Wu, Hengju Zhang, Dingzhong Yuan, Yan Liu, Zhenyu Wu, Zhirong Liu

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 1029-1038 doi: 10.1007/s11705-019-1898-9

HTML PDF 收藏

Regulatory issues for genetically modified animals

Perry Bradbury HACKETT

《农业科学与工程前沿（英文）》 2020年 第7卷 第2期   页码 188-203 doi: 10.15302/J-FASE-2019307

摘要：

Precision genetics and breeding have the potential to meet the agricultural needs and goals of the world in the 21st century. These needs include increasing the efficiency of production of animals and improving their products with minimal impact on the environment. The USA is the major innovator in genomic science and the acknowledged leader in formulating policies to regulate genetic applications in medicine and agriculture. However, governments worldwide have been exceedingly reluctant to support the introduction of genetically modified (GM) animals into agriculture. Regulatory policies have stagnated due to legal guidelines that could not anticipate the needs and solutions that are evident today. This must change if we are to maintain planetary integrity. I propose a new, market-based regulatory model for GM livestock that has both a strong scientific foundation and has worked for 10000 years. The model is similar to that for information technology in which specific algorithms drive computer and cell phone applications. Genome engineers write genetic algorithms that drive the traits in biological organisms. Accordingly, GM products should be viewed in terms of their use and public benefit rather than by limitations to the genetic programing coming from a few highly vocal groups. Genetic algorithms (Genapps) of the 21st century will include not only introduction of synthetic genes, but also complete natural and synthetic biochemical pathways to produce agricultural products that are maximally efficient, healthy to humans and animals, and sustainable in an era of changing climates while avoiding environmental degradation.

关键词： algorithms     editing     FDA     GMO     recombinant DNA     USDA    

HTML PDF 收藏

标题 作者 时间 类型 操作

Removal of clofibric acid from aqueous solution by polyethylenimine-modified chitosan beads

Yao NIE,Shubo DENG,Bin WANG,Jun HUANG,Gang YU

期刊论文

Removal of copper by modified chitosan adsorptive membrane

Xiaoshuai LIU, Zihong CHENG, Wei MA

期刊论文

An antifouling catechol/chitosan-modified polyvinylidene fluoride membrane for sustainable oil-in-water

Shanshan Zhao, Zhu Tao, Liwei Chen, Muqiao Han, Bin Zhao, Xuelin Tian, Liang Wang, Fangang Meng

期刊论文

Removing phosphorus from aqueous solutions by using iron-modified corn straw biochar

Fenglin LIU,Jiane ZUO,Tong CHI,Pei WANG,Bo YANG

期刊论文

Fertility outcome analysis after modified laparoscopic microsurgical tubal anastomosis

null

期刊论文

Using thermodynamic parameters to study self-healing and interface properties of crumb rubber modified

Dongliang HU, Jianzhong PEI, Rui LI, Jiupeng ZHANG, Yanshun JIA, Zepeng FAN

期刊论文

Dialdehyde cellulose nanocrystal cross-linked chitosan foam with high adsorption capacity for removal

期刊论文

Correction to: Highly degradable chitosan-montmorillonite (MMT) nanocomposite hydrogel for controlled

期刊论文

Solvent-free mechanochemical mild oxidation method to enhance adsorption properties of chitosan

期刊论文

Anthocyanins/chitosan films doped by nano zinc oxide for active and intelligent packaging: comparison

期刊论文

Nano-hydroxyapatite formation via co-precipitation with chitosan-g-poly(

Yang YU, Hong ZHANG, Hong SUN, Dandan XING, Fanglian YAO

期刊论文

Chitosan/polyethylene glycol impregnated activated carbons: Synthesis, characterization and adsorption

Ehsan Salehi, Fereshteh Soroush, Maryam Momeni, Aboulfazl Barati, Ali Khakpour

期刊论文

Effective and selective adsorption of uranyl ions by porous polyethylenimine-functionalized carboxylated chitosan

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

期刊论文

Synthesis of graphene oxide nanoribbons/chitosan composite membranes for the removal of uranium from

Xuewen Hu, Yun Wang, Jinbo Ou Yang,Yang Li, Peng Wu, Hengju Zhang, Dingzhong Yuan, Yan Liu, Zhenyu Wu, Zhirong Liu

期刊论文

Regulatory issues for genetically modified animals

Perry Bradbury HACKETT

期刊论文