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Novel polyethyleneimine/TMC-based nanofiltration membrane prepared on a polydopamine coated substrate

Zhe Yang, Xiaoyu Huang, Jianqiang Wang, Chuyang Y. Tang

《化学科学与工程前沿(英文)》 2018年 第12卷 第2期   页码 273-282 doi: 10.1007/s11705-017-1695-2

摘要: Most commercial NF membranes are negatively charged at the pH range of a typical feed solution. In order to enhance the removal of cations (such as Mg or Ca ), we utilized polyethyleneimine (PEI) and trimesoyl chloride (TMC) to perform interfacial polymerization reaction on a polydopamine coated hydrolyzed polyacrylonitrile substrate to obtain a positively charged nanofiltration membrane. Effects of polydopamine coating time, PEI concentration, TMC reaction time and concentration on the membrane physicochemical properties and separation performance were systematically investigated using scanning electron microscopy, streaming potential and water contact angle measurements. The optimal NF membrane showed high rejection for divalent ions (93.6±2.6% for MgSO , 92.4±1.3% for MgCl , and 90.4±2.1% for Na SO ), accompanied with NaCl rejection of 27.8±2.5% with a permeation flux of 17.2±2.8 L·m ·h at an applied pressure of 8 bar (salt concentrations were all 1000 mg·L ). The synthesized membranes showed promising potentials for the applications of water softening.

关键词: nanofiltration     polyethyleneimine     trimesoyl chloride     polydopamine     positively charged rejection layer    

THE ANTHOCYANIN BIOSYNTHETIC REGULATOR MDMYB1 POSITIVELY REGULATES ASCORBIC ACID BIOSYNTHESIS IN APPLE

《农业科学与工程前沿(英文)》 2021年 第8卷 第2期

摘要:

Ascorbic acid (AsA, vitamin C) is involved in the regulation of many aspects of plant growth and development. It is an essential micronutrient for humans and can prevent scurvy, maintain the health of gums and blood vessels, reduce the level of plasma cholesterol and enhance the immune systen. Apple cultivars Orin and Guanghui were crossed to obtain a group of hybrid offspring with and without red flesh in the course of assessing apple germplasm resources. Unexpectedly, the red-flesh apples had higher AsA contents than other apples. Further studies showed that the anthocyanin biosynthetic regulator MdMYB1 directly activates the expression of dehydroascorbate reductase gene MdDHAR, thus promoting the activity of the DHAR enzyme and the accumulation of AsA. This finding reveals the mechanism leading to high AsA levels in red-flesh apples and suggests a new idea to cultivate red-flesh apples with high AsA contents and produce AsA efficiently and without pollution.

 

Temporal evolution of charged and neutral nanoparticle concentrations during atmospheric new particle

E. Rohan Jayaratne, Buddhi Pushpawela, Lidia Morawska

《环境科学与工程前沿(英文)》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0862-x

摘要: Over 100 new particle formation events were studied. In 50 events, charged and neutral particles were not formed at the same time. In 42 of these events the charged particles formed before the neutral particles. Their subsequent growth rates were not determined by the particle charge. The result suggests that ion induced nucleation plays a role in particle formation. Time series of nanoparticle number concentration during new particle formation (NPF) events in the urban environment of Brisbane, Australia, showed that the formation of charged particles often occurred before that of neutral particles. We monitored 241 days during the calendar year 2012 over which NPF events were observed on 108 days. We studied the times at which the charged and neutral particle concentrations in the size range 1.8–3.2 nm reached their peak values and found that they were clearly different in 50 events with the peak neutral particle concentration lagging behind the charged particle concentration during 42 of these events with a mean time lag of 24±12 min. While the charged particles were more likely to form before the neutral particles, once formed, the growth rate of the particles did not depend on their charge. While ion-induced nucleation is not the dominant mechanism of NPF in the atmosphere, our observations suggest that the presence of ions in the atmosphere plays a role that cannot be ignored.

关键词: Charged particles     Cluster ions     Secondary particles     Environmental pollution    

Shear wall layout optimization of tall buildings using Quantum Charged System Search

Siamak TALATAHARI, Mahdi RABIEI

《结构与土木工程前沿(英文)》 2020年 第14卷 第5期   页码 1131-1151 doi: 10.1007/s11709-020-0660-1

摘要: This paper presents a developed meta-heuristic algorithm to optimize the shear walls of tall reinforced concrete buildings. These types of walls are considered as lateral resistant elements. In this paper, Quantum Charged System Search (QCSS) algorithm is presented as a new optimization method and used to improve the convergence capability of the original Charged System Search. The cost of tall building is taken as the objective function. Since the design of the lateral system plays a major role in the performance of the tall buildings, this paper proposes a unique computational technique that, unlike available works, focuses on structural efficiency or architectural design. This technique considers both structural and architectural requirements such as minimum structural costs, torsional effects, flexural and shear resistance, lateral deflection, openings and accessibility. The robustness of the new algorithm is demonstrated by comparing the outcomes of the QCSS with those of its standard algorithm.

关键词: Quantum Charged System Search     shear wall     layout optimization     tall buildings    

THE ANTHOCYANIN BIOSYNTHETIC REGULATOR MDMYB1 POSITIVELY REGULATES ASCORBIC ACID BIOSYNTHESIS IN APPLE

Jianping AN, Xiaofei WANG, Chunxiang YOU, Yujin HAO

《农业科学与工程前沿(英文)》   页码 231-235 doi: 10.15302/J-FASE-2020367

摘要: Ascorbic acid (AsA, vitamin C) is involved in the regulation of many aspects of plant growth and development. It is an essential micronutrient for humans and can prevent scurvy, maintain the health of gums and blood vessels, reduce the level of plasma cholesterol and enhance the immune systen. Apple cultivars Orin and Guanghui were crossed to obtain a group of hybrid offspring with and without red flesh in the course of assessing apple germplasm resources. Unexpectedly, the red-flesh apples had higher AsA contents than other apples. Further studies showed that the anthocyanin biosynthetic regulator MdMYB1 directly activates the expression of dehydroascorbate reductase gene , thus promoting the activity of the DHAR enzyme and the accumulation of AsA. This finding reveals the mechanism leading to high AsA levels in red-flesh apples and suggests a new idea to cultivate red-flesh apples with high AsA contents and produce AsA efficiently and without pollution.

关键词: anthocyanin     apples     ascorbic acid     MdMYB1     vitamin C    

RGO-MXene membranes with wettability-regulated channels: improved water permeability and electro-enhanced rejection

《环境科学与工程前沿(英文)》 2023年 第17卷 第1期 doi: 10.1007/s11783-023-1601-8

摘要:

● Electroconductive RGO-MXene membranes were fabricated.

关键词: Reduced graphene oxide     MXene     Membrane     Water permeance     Dye rejection     Electro-assistance    

Ductility loss of hydrogen-charged and releasing 304L steel

Yanfei WANG, Jianming GONG, Yong JIANG, Wenchun JIANG, Wang JIANG

《机械工程前沿(英文)》 2013年 第8卷 第3期   页码 298-304 doi: 10.1007/s11465-013-0265-7

摘要:

The mechanical properties and fracture behavior of 304L austenitic stainless steel after cathodic hydrogen charging and hydrogen spontaneously releasing are investigated by tensile tests. Flat tensile specimens were cathodic hydrogen charged at various current densities. For each density, two specimens were charged at the same condition. When the charging process completed, one specimen was tensile immediately to fracture and the other was aged to release the hydrogen out of it and then was also tensile to fracture. The resulting tensile properties and micrographs of fracture surfaces of these specimens were evaluated and compared. The results show ductility loss occurred in the hydrogen-charged specimens and the loss increased as the current density increasing. After hydrogen releasing, the specimens recovered a certain extent but not all of its original ductility. Scanning electron microscope (SEM) micrographs of fracture surfaces reveal that irreversible damage had developed in the hydrogen-releasing specimens during the releasing process rather than the charging process. This consequence can be ascribed to the high tensile stress caused by non-uniform hydrogen distribution during hydrogen releasing.

关键词: hydrogen embrittlement     ductility loss     hydrogen releasing     control strategy     304L austenitic stainless steel    

Effect of electrokinetic property of charged polyether sulfone membrane on bovine serum albumin fouling

Xiaorong Meng, Shanshan Huo, Lei Wang, Xudong Wang, Yongtao Lv, Weiting Tang, Rui Miao, Danxi Huang

《环境科学与工程前沿(英文)》 2017年 第11卷 第2期 doi: 10.1007/s11783-017-0907-9

摘要: Negatively charged CMPES and positively charged QAPES membranes were fabricated. Charge modification reduced the adhesion forces between PES UF membranes and BSA. QAPES-BSA / was weaker than that of CMPES-BSA at pH 3 and on the contrary at pH 9. Flux decline rate was positively correlated with the adhesion forces of membrane-BSA. Variation of adhesion was consistent with that of potential absolute values. Negatively charged carboxymethylated polyethersulfone (CMPES) and positively charged quaternized polyethersulfone (QAPES) ultrafiltration (UF) membranes were prepared by bulk chemical modification and non-solvent induced phase separation method. The effects of PES membrane interfacial electrokinetic property on the bovine serum albumin (BSA) membrane fouling behavior were studied with the aid of the membrane-modified colloidal atomic force microscopy (AFM) probe. Electrokinetic test results indicated that the streaming potential (D ) of QAPES membrane was not consistent with its expected value, however, within the pH range of 3–10, the potentials of two charged-modified PES membranes were more stable than the unmodified membrane. When pH value was 3, 4.7 or 9, the interaction behavior between charged PES membrane and BSA showed that there was significant linear correlation between the jump distance of membrane-BSA adhesion force ( ) and the potential absolute value. Charged modification significantly reduced the adhesion of PES membrane-BSA, and the adhesion data was good linear correlated with the flux decline rate in BSA filtration process, especially reflected in the CMPES membrane. The above experimental facts proved that the charged membrane interfacial electric double layer structure and its electrokinetic property had strong ties with the protein membrane fouling behavior.

关键词: Charged PES UF membrane     BSA     Electrokinetic characterization     Adhesion force     Jump distance    

Simulation of the optimal heat rejection pressure for transcritical CO

Junlan YANG, Yitai MA, Minxia LI, Hua TIAN

《能源前沿(英文)》 2010年 第4卷 第4期   页码 522-526 doi: 10.1007/s11708-010-0027-8

摘要: In order to optimize and control transcritical CO refrigeration cycle, a mathematical model was developed to simulate the system performance. The simulation results show that a maximum COP exists at the optimal heat rejection pressure not only for throttle valve cycle but also for expander cycle. Also, the optimal heat rejection pressures of the throttle valve cycle are greater than those of the expander cycle under the same condition. In order to further obtain correlation of the optimal heat rejection pressure for transcritical CO expander cycle, it is necessary to analyze the impact degree of compressor efficiency, expander efficiency, gas cooler outlet temperature and evaporation temperature. Based on the simulation results, the values of the optimal heat rejection pressure for the expander cycle were regressed in terms of gas cooler outlet temperature and evaporation temperature at given compressor efficiency and expander efficiency. Finally, two types of polynomial correlations were obtained. One is cubic form, with an average deviation of less than 0.5% and the other is simplified form, with an average deviation of less than 1%. It is, therefore, convenient to use either correlation to simulate the performance of transcritical CO expander cycle.

关键词: transcritical CO2 cycle     optimal heat rejection pressure     simulation     expander    

Novel Ag-AgBr decorated composite membrane for dye rejection and photodegradation under visible light

Yixing Wang, Liheng Dai, Kai Qu, Lu Qin, Linzhou Zhuang, Hu Yang, Zhi Xu

《化学科学与工程前沿(英文)》 2021年 第15卷 第4期   页码 892-901 doi: 10.1007/s11705-020-2011-0

摘要: Photocatalytic membranes have received increasing attention due to their excellent separation and photodegradation of organic contaminants in wastewater. Herein, we bound Ag-AgBr nanoparticles onto a synthesized polyacrylonitrile-ethanolamine (PAN-ETA) membrane with the aid of a chitosan (CS)-TiO layer via vacuum filtration and partial reduction. The introduction of the CS-TiO layer improved surface hydrophilicity and provided attachment sites for the Ag-AgBr nanoparticles. The PAN-ETA/CS-TiO /Ag-AgBr photocatalytic membranes showed a relatively high water permeation flux (~ 47 L·m ·h ·bar ) and dyes rejection (methyl orange: 88.22%; congo red: 95%; methyl blue: 97.41%; rose bengal: 99.98%). Additionally, the composite membranes exhibited potential long-term stability for dye/salt separation (dye rejection: ~97%; salt rejection: ~6.5%). Moreover, the methylene blue and rhodamine B solutions (20 mL, 10 mg·L ) were degraded approximately 90.75% and 96.81% in batch mode via the synthesized photocatalytic membranes under visible light irradiation for 30 min. This study provides a feasible method for the combination of polymeric membranes and inorganic catalytic materials.

关键词: Ag-AgBr     dye rejection     photodegradation     visible light    

Combustion and emission characteristics of a turbo-charged common rail diesel engine fuelled with diesel-biodiesel-DEE

Ni ZHANG, Zuohua HUANG, Xiangang WANG, Bin ZHENG

《能源前沿(英文)》 2011年 第5卷 第1期   页码 104-114 doi: 10.1007/s11708-011-0138-x

摘要: The combustion and emission characteristics of a turbo-charged, common rail diesel engine fuelled with diesel-biodiesel-DEE blends were investigated. The study reports that the brake-specific fuel consumption of diesel-biodiesel-DEE blends increases with increase of oxygenated fuel fractions in the blends. Brake thermal efficiency shows little variation when operating on different diesel-biodiesel-DEE blends. At a low load, the NO emission of the diesel-biodiesel-DEE blends exhibits little variation in comparison with the biodiesel fraction. The NO emission slightly increases with increase in the biodiesel fraction in diesel-biodiesel-DEE blends at medium load. However, the NO emission increases remarkably with increase of the biodiesel fraction at high load. Particle mass concentration decreases significantly with increase of the oxygenated-fuels fraction at all engine speeds and loads; particle number concentration decreases remarkably with increase of the oxygenated-fuels fraction. HC and CO emissions decrease with increasing oxygenated-fuels fraction in these blends.

关键词: Combustion     particulate emissions     diesel-biodiesel-DEE blend     diesel engine    

Gut microbiota and its implications in small bowel transplantation

null

《医学前沿(英文)》 2018年 第12卷 第3期   页码 239-248 doi: 10.1007/s11684-018-0617-0

摘要:

The gut microbiota is mainly composed of a diverse population of commensal bacterial species and plays a pivotal role in the maintenance of intestinal homeostasis, immune modulation and metabolism. The influence of the gut microbiota on solid organ transplantation has recently been recognized. In fact, several studies indicated that acute and chronic allograft rejection in small bowel transplantation (SBT) is closely associated with the alterations in microbial patterns in the gut. In this review, we focused on the recent findings regarding alterations in the microbiota following SBT and the potential roles of these alterations in the development of acute and chronic allograft rejection. We also reviewed important advances with respect to the interplays between the microbiota and host immune systems in SBT. Furthermore, we explored the potential of the gut microbiota as a microbial marker and/or therapeutic target for the predication and intervention of allograft rejection and chronic dysfunction. Given that current research on the gut microbiota has become increasingly sophisticated and comprehensive, large cohort studies employing metagenomic analysis and multivariate linkage should be designed for the characterization of host–microbe interaction and causality between microbiota alterations and clinical outcomes in SBT. The findings are expected to provide valuable insights into the role of gut microbiota in the development of allograft rejection and other transplant-related complications and introduce novel therapeutic targets and treatment approaches in clinical practice.

关键词: gut microbiota     small bowel transplantation     acute rejection     chronic rejection     mucosal immunity     biomarker     microbiota-targeted therapy    

Role of membrane and compound properties in affecting the rejection of pharmaceuticals by different RO

Yang-ying Zhao, Fan-xin Kong, Zhi Wang, Hong-wei Yang, Xiao-mao Wang, Yuefeng F. Xie, T. David Waite

《环境科学与工程前沿(英文)》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0975-x

摘要: This study was conducted to assess the merits and limitations of various high-pressure membranes, tight nanofiltration (NF) membranes in particular, for the removal of trace organic compounds (TrOCs). The performance of a low-pressure reverse osmosis (LPRO) membrane (ESPA1), a tight NF membrane (NF90) and two loose NF membranes (HL and NF270) was compared for the rejection of 23 different pharmaceuticals (PhACs). Efforts were also devoted to understand the effect of adsorption on the rejection performance of each membrane. Difference in hydrogen bond formation potential (HFP) was taken into consideration. Results showed that NF90 performed similarly to ESPA1 with mean rejection higher than 95%. NF270 outperformed HL in terms of both water permeability and PhAC rejection higher than 90%. Electrostatic effects were more significant in PhAC rejection by loose NF membranes than tight NF and LPRO membranes. The adverse effect of adsorption on rejection by HL and ESPA1 was more substantial than NF270 and NF90, which could not be simply explained by the difference in membrane surface hydrophobicity, selective layer thickness or pore size. The HL membrane had a lower rejection of PhACs of higher hydrophobicity (log D>0) and higher HFP (>0.02). Nevertheless, the effects of PhAC hydrophobicity and HFP on rejection by ESPA1 could not be discerned. Poor rejection of certain PhACs could generally be explained by aspects of steric hindrance, electrostatic interactions and adsorption. High-pressure membranes like NF90 and NF270 have a high promise in TrOC removal from contaminated water.

关键词: Trace organic compounds (TrOCs)     Nanofiltration (NF)     Adsorption     Membrane properties     Water treatment    

巨噬细胞在器官移植急性排斥反应中的双重作用 Review

谭亮, 郭易难, 冯畅, 侯仰潇, 谢续标, 赵勇

《工程(英文)》 2022年 第10卷 第3期   页码 21-29 doi: 10.1016/j.eng.2021.10.015

摘要:

天然免疫细胞在移植免疫反应中发挥着重要作用。巨噬细胞是重要的天然免疫细胞;在发生排斥反应的同种异基因移植器官中,巨噬细胞也是浸润的众多免疫细胞之一。巨噬细胞的浸润与器官移植的短期和长期效果呈负相关。在功能方面,巨噬细胞具有异质性和可塑性。在器官移植排斥反应中,巨噬细胞可以为适应性免疫提呈同种异基因抗原以及提供共刺激信号和细胞因子,也可以直接损伤移植器官。此外,一些具有免疫调节功能的巨噬细胞亚群,可以通过抑制排斥反应和促进免疫耐受来保护移植器官。尽管目前研究人员已认识到巨噬细胞在移植器官损伤过程中的潜在作用,但他们对巨噬细胞在移植排斥反应中的不同作用关注不够。为此,本文就巨噬细胞在急性移植免疫反应中的独特作用以及免疫抑制剂对巨噬细胞的影响进行了综述和讨论。通过分析发现,对于巨噬细胞在移植免疫中的作用的相关研究中,应更多地关注其复杂性和关键功能,并应更多地致力于开发针对巨噬细胞的免疫抑制药物,并使之有利于提高移植器官的长期存活率和移植免疫耐受的建立。

关键词: 巨噬细胞     移植     耐受     排斥反应     调节性巨噬细胞    

DK型纳滤膜对水中微量邻苯二甲酸酯的吸附及截留特性

金叶,吴礼光,张林

《中国工程科学》 2014年 第16卷 第7期   页码 36-41

摘要:

邻苯二甲酸酯(PAEs)是一类典型的环境激素,对人体健康具有较大的危害。本文采用DK型纳滤膜去除水中微量邻苯二甲酸酯,分析了水中微量邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸正二丁酯(DNBP)和邻苯二甲酸异二丁酯(DIBP)等在DK型纳滤膜表面的吸附行为,考察了4 种邻苯二甲酸酯的辛醇/水分配系数(logKow)和相对分子质量(Mw)对其在DK型纳滤膜表面的吸附和膜的截留特性的影响。结果表明Freundlich 吸附方程能较好地描述4 种邻苯二甲酸酯在DK型纳滤膜表面的动态吸附行为;DK型纳滤膜对水中微量邻苯二甲酸酯的截留特性表现为膜面吸附作用和膜孔筛分效应,吸附平衡后的截留机理取决于膜孔的筛分效应,DK型纳滤膜对DMP、DEP、DNBP、DIBP的截留率分别为55 %、78 %、96 %和96.8 % (0.5 MPa,30 ℃,DMP、DEP、DNBP、DIBP浓度均为300 μg/L),表明DK型纳滤膜能高效去除水中的DNBP和DIBP。

关键词: 邻苯二甲酸酯     纳滤     吸附     截留    

标题 作者 时间 类型 操作

Novel polyethyleneimine/TMC-based nanofiltration membrane prepared on a polydopamine coated substrate

Zhe Yang, Xiaoyu Huang, Jianqiang Wang, Chuyang Y. Tang

期刊论文

THE ANTHOCYANIN BIOSYNTHETIC REGULATOR MDMYB1 POSITIVELY REGULATES ASCORBIC ACID BIOSYNTHESIS IN APPLE

期刊论文

Temporal evolution of charged and neutral nanoparticle concentrations during atmospheric new particle

E. Rohan Jayaratne, Buddhi Pushpawela, Lidia Morawska

期刊论文

Shear wall layout optimization of tall buildings using Quantum Charged System Search

Siamak TALATAHARI, Mahdi RABIEI

期刊论文

THE ANTHOCYANIN BIOSYNTHETIC REGULATOR MDMYB1 POSITIVELY REGULATES ASCORBIC ACID BIOSYNTHESIS IN APPLE

Jianping AN, Xiaofei WANG, Chunxiang YOU, Yujin HAO

期刊论文

RGO-MXene membranes with wettability-regulated channels: improved water permeability and electro-enhanced rejection

期刊论文

Ductility loss of hydrogen-charged and releasing 304L steel

Yanfei WANG, Jianming GONG, Yong JIANG, Wenchun JIANG, Wang JIANG

期刊论文

Effect of electrokinetic property of charged polyether sulfone membrane on bovine serum albumin fouling

Xiaorong Meng, Shanshan Huo, Lei Wang, Xudong Wang, Yongtao Lv, Weiting Tang, Rui Miao, Danxi Huang

期刊论文

Simulation of the optimal heat rejection pressure for transcritical CO

Junlan YANG, Yitai MA, Minxia LI, Hua TIAN

期刊论文

Novel Ag-AgBr decorated composite membrane for dye rejection and photodegradation under visible light

Yixing Wang, Liheng Dai, Kai Qu, Lu Qin, Linzhou Zhuang, Hu Yang, Zhi Xu

期刊论文

Combustion and emission characteristics of a turbo-charged common rail diesel engine fuelled with diesel-biodiesel-DEE

Ni ZHANG, Zuohua HUANG, Xiangang WANG, Bin ZHENG

期刊论文

Gut microbiota and its implications in small bowel transplantation

null

期刊论文

Role of membrane and compound properties in affecting the rejection of pharmaceuticals by different RO

Yang-ying Zhao, Fan-xin Kong, Zhi Wang, Hong-wei Yang, Xiao-mao Wang, Yuefeng F. Xie, T. David Waite

期刊论文

巨噬细胞在器官移植急性排斥反应中的双重作用

谭亮, 郭易难, 冯畅, 侯仰潇, 谢续标, 赵勇

期刊论文

DK型纳滤膜对水中微量邻苯二甲酸酯的吸附及截留特性

金叶,吴礼光,张林

期刊论文