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Characteristics and fate behavior of environmentally persistent free radicals in atmospheric particulate matter
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作者 WANG Xueying CUI Long +2 位作者 XUE Yonggang HO Kinfai HUANG Yu 《地球环境学报》 CSCD 2024年第4期596-611,共16页
Background,aim,and scope Environmentally persistent free radicals(EPFRs)have received significant attention due to their longer lifetime and stable existence in various environments.The strong environmental migration ... Background,aim,and scope Environmentally persistent free radicals(EPFRs)have received significant attention due to their longer lifetime and stable existence in various environments.The strong environmental migration ability of particulate matter allows EPFRs to migrate over long-distance transport,thereby impacting the quality of the local atmospheric environment.Additionally,EPFRs can also adhere to atmospheric particles and interact with typical gaseous pollutants to affect atmospheric chemical reactions.EPFRs can produce some reactive organic species,promoting oxidative stress in the human body,damaging biological macromolecules and ultimately affecting the organism health.EPFRs are considered as a novel type of pollutant that affects human health.Despite their significance,there are few literatures available on the characteristics and fate behaviors of EPFRs up to date.Therefore,supplemental reviews are crucial for providing comprehensive understanding of EPFRs.Materials and methods This review summarizes the characteristics of EPFRs in particulate matter,outlines the generation mechanism and influencing factors of EPFRs,and the impacts of EPFRs on environmental quality and organism health.Results The content of EPFRs in particulate matter ranges from 1017 to 1020 spins∙g−1.Due to the strong mobility of atmospheric particulate matter,the long-term exposure to high levels of EPFRs may aggravate the impact of particulate matter on human health.The interaction between EPFRs and typical gaseous pollutants can alter their fate and influence atmospheric chemical reactions.EPFRs are mainly produced by transition metal elements and substituted aromatic hydrocarbons through electron transfer.Additionally,the chemical bond rupture of organic substances through heat treatment or ultraviolet radiation can also produce EPFRs,and heterogeneous reactions are capable producing them as well.The production of EPFRs is not only influenced by transition metal elements and precursors,but also by various environmental factors such as oxygen,temperature,light radiation,and relative humidity.Discussion EPFRs in atmospheric particulates matters are usually rich in fine particulates with obvious seasonal and regional variations.They can easily enter the human respiratory tract and lungs with inhalable particulates,thereby increasing the risk of exposure.Additionally,EPFRs in atmospheric particulates can interact with some typical gaseous pollutants,impacting the life and fate of EPFRs in the atmosphere,and alter atmospheric chemical reactions.Traditionally,EPFRs are generated by transition metal elements and substituted aromatic hydrocarbons undergoing electron transfer in the post-flame and cool-zone regions of combustion systems and other thermal processes to remove HCl,H_(2)O or CO groups,ultimately produce semiquinones,phenoxyls,and cyclopentadienyls.Recent studies have indicated that EPFRs can also be generated under the conditions of without transition metal elemental.Organics can also produce EPFRs through chemical bond rupture during heat treatment or light radiation conditions,as well as through some heterogeneous reactions and photochemical secondary generation of EPFRs.The presence or absence of oxygen has different effects on the type and yield of EPFRs.The concentration,type,and crystal type of transition metal elements will affect the type,content,and atmospheric lifetime of EPFRs.It is generally believed that the impact of transition metal element types on EPFRs is related to the oxidation-reduction potential.The combustion temperature or heat treatment process significantly affects the type and amount of EPFRs.Factors such as precursor loading content,pH conditions,light radiation and relative humidity also influence the generation of EPFRs.EPFRs can interact with pollutants in the environment during their migration and transformation process in environmental medium.This process accelerates the degradation of pollutants and plays a crucial role in the migration and transformation of organic pollutants in environmental media.The reaction process of EPFRs may lead to the production of reactive oxygen species(ROS)such as∙OH,which can induce oxidative stress,inflammation and immune response to biological lung cells and tissues,leading to chronic respiratory and cardiopulmonary dysfunction,cardiovascular damage and neurotoxic effects,ultimately impacting the health of organisms.Conclusions The interaction mechanism between EPFRs in particulate matter and gaseous pollutants remains unclear.Furthermore,research on the generation mechanism of EPFRs without the participation of transition metals is not comprehensive,and the detection of EPFRs is limited to simple qualitative categories and lack accurate qualitative analysis.Recommendations and perspectives Further research should be conducted on the generation mechanism,measurement techniques,migration pathways,and transformation process of EPFRs.It is also important to explore the interaction between EPFRs in atmospheric particulate matter and typical gaseous pollutants. 展开更多
关键词 particulate matter(PM) environmentally persistent free radicals(EPFRs) formation mechanism influencing factors
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中国城市垃圾研究的典型实例──长春市垃圾普查与整治 被引量:4
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作者 苏小四 张贻侠 闫静奇 《长春科技大学学报》 CAS CSCD 北大核心 2001年第4期376-381,共6页
根据垃圾在人地系统中具有的社会性、时空分异性和制约性等特点 ,认为中国城市垃圾研究只有在多学科综合研究的基础上 ,才能为解决日益紧迫的垃圾成灾问题寻找一条根治办法。以长春市为实例 ,开展了中国城市垃圾的研究。长春市城市垃圾... 根据垃圾在人地系统中具有的社会性、时空分异性和制约性等特点 ,认为中国城市垃圾研究只有在多学科综合研究的基础上 ,才能为解决日益紧迫的垃圾成灾问题寻找一条根治办法。以长春市为实例 ,开展了中国城市垃圾的研究。长春市城市垃圾在空间分布上具有丛聚性、成环性和自相似性的特点。垃圾的物质组成具有明显的时空变异特征 ,而且在很大程度上可受人为因素控制。追踪调查表明 ,大约有 3 / 4的垃圾量来源于非居民家庭。长春市垃圾回收缺乏再生行业支持。兴办垃圾产业可望成为整治城市垃圾并推动地区经济增长的一项有效措施。根据城市垃圾的基本特征并应用综合治理的理念 ,提出了符合长春市市情的 10项治理措施。 展开更多
关键词 中国 城市垃圾 人地系统观 长春市 垃圾整治 丛聚 成环性 空间分布 自相似
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Numerical simulation of ductile fracture behavior for aluminum alloy sheet under cyclic plastic deformation 被引量:3
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作者 胡星 赵亦希 +1 位作者 李淑慧 林忠钦 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第7期1595-1601,共7页
A numerical analysis of mechanical behavior of aluminum alloy sheet under cyclic plastic deformation was investigated.Forming limit at fracture was derived from Cockcroft-Latham ductile damage criterion.The strain pat... A numerical analysis of mechanical behavior of aluminum alloy sheet under cyclic plastic deformation was investigated.Forming limit at fracture was derived from Cockcroft-Latham ductile damage criterion.The strain path of bending center of incremental roller hemming could be accepted as a kind of plane strain bending deformation process.Incremental rope roller hemming could be used to alleviate ductile fracture behavior by changing the stress state of the hemming-effected area.SEM observation on the fracture surface indicates that cyclic plastic deformation affects ductile fracture mechanism. 展开更多
关键词 aluminum alloy ductile damage incremental forming cyclic plastic deformation
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Synthesis and Curing Properties of a Novel Novolac Curing Agent Containing Naphthyl and Dicyclopentadiene Moieties 被引量:8
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作者 任华 孙建中 +1 位作者 吴斌杰 周其云 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第1期127-131,共5页
A novel novolac curing agent containing both naphthalene and dicyclopentadiene (DCPD) moieties was prepared to produce a highly heat-resistant cured polymer network. The chemical structure was characterized using Four... A novel novolac curing agent containing both naphthalene and dicyclopentadiene (DCPD) moieties was prepared to produce a highly heat-resistant cured polymer network. The chemical structure was characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance, mass spectrometry, and gel permeation chro-matography analyses. The thermal properties of the resulting polymer from diglycidyl ether of bisphenol A epoxy resin cured with the novel curing agent were evaluated using dynamic mechanical thermal analysis and thermogra-vimetric analysis. Compared with the conventional curing agent, the resulting polymer cured with naphtha-lene/DCPD navolac shows considerable improvement in heat resistant properties such as higher glass transition temperature (Tg) and thermal stability. The result also shows better moisture resistance because of the hydrophobic nature of naphthalene/DCPD structure. 展开更多
关键词 epoxy curing agent heat resistance NAPHTHOL DICYCLOPENTADIENE
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Chiral basket-handle porphyrin-Co complexes for the catalyzed asymmetric cycloaddition of CO_2 to epoxides 被引量:1
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作者 Xiying Fu Xinyao Jing +4 位作者 Lili Jin Lilong Zhang Xiaofeng Zhang Bin Hu Huanwang Jing 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第5期997-1003,共7页
The catalytic synthesis of cyclic carbonates via the cycloaddition of CO2 to epoxides is a standard methodology for CO2 fixation.For this purpose,chiral basket-handle porphyrin-Co complexes were devised,prepared,and f... The catalytic synthesis of cyclic carbonates via the cycloaddition of CO2 to epoxides is a standard methodology for CO2 fixation.For this purpose,chiral basket-handle porphyrin-Co complexes were devised,prepared,and fully characterized by nuclear magnetic resonance,mass spectrometry,Fourier transform infrared spectroscopy,ultraviolet-visible spectroscopy,and specific rotation.The proposed metalloporphyrin catalysts were synthesized with either 1,1'-bi-2-naphthol or L-phenylalanine,which have different chirality,and then applied to the coupling of propylene oxide and CO2 for generating chiral cyclic carbonates with good enantioselectivity under extremely mild conditions in the presence of tetrabutyl ammonium chloride as a co-catalyst.The good enantioselectivity in the cycloaddition reaction is attributed to a synergistic interplay between the chiral porphyrin catalysts and the substrate.The mechanism and enantioselectivity of the asymmetric cycloaddition reaction is discussed. 展开更多
关键词 Carbon dioxide fixation Chiral resolution CYCLOADDITION EPOXIDE Chiral porphyrin-cobalt complex
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Coal forming environments and their relationship to tectonic activity in the Cévennes Stephanian coal basin 被引量:1
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作者 王华 庄新国 +1 位作者 任建业 张瑞生 《Journal of Coal Science & Engineering(China)》 2002年第2期23-30,共8页
Coal forming environments in the tectonically controlled intermontane Stephanian Cévennes coal basin (Massif central, France) show a complex interelationship between structural and sedimentological features. The ... Coal forming environments in the tectonically controlled intermontane Stephanian Cévennes coal basin (Massif central, France) show a complex interelationship between structural and sedimentological features. The study of the general structural features and the geometry of the coal beds developed during the different stages in the evolution of the basin, and the spatial relation of the lithofacial units to the early tectonic activities, lead the authors to suggest the following model. The synsedimentary faults that occurred as both intrabasinal and marginal faults controlled not only the spatial distribution, shape and thickness of the detrital rock units and coal seams, but also caused the inversion of the tectonic style. The marginal faults exercised important controls on the geometry of the basin and the distribution of lithofacial units. However due to the subsidence of the central part of the basin and the depocenter, and the to differences in the timing and intensity of the displacement the coal enrichment zones shifted both vertically and laterally. This eventually resulted in the inversion of the whole tectonic framework from semi graben through graben to a new semi graben. The style and rate of the tectonic movement and basin filling that occurred in the Stephanian Cévennes coal basin were in turn closely linked with the tectonic movement in the surrounding area. Therefore the authors propose that the environment and processes of coal formation in this basin are closely linked to its tectonic evolution. 展开更多
关键词 Cévennes coal basin Stephanian characteristic of coal seam coal forming environment tectonic movement
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Degradation behaviors,thermostability and mechanical properties of poly(ethylene terephthalate)/polylactic acid blends 被引量:1
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作者 夏学莲 刘文涛 +4 位作者 唐新颖 史向阳 王丽娜 何素芹 朱诚身 《Journal of Central South University》 SCIE EI CAS 2014年第5期1725-1732,共8页
It is difficult for polyethylene terephthalate (PET) to degrade,which caused severe pollution.In this work,polylactic acid (PLA) was introduced to improve the degradation of PET.PET/PLA was synthesized by extrusio... It is difficult for polyethylene terephthalate (PET) to degrade,which caused severe pollution.In this work,polylactic acid (PLA) was introduced to improve the degradation of PET.PET/PLA was synthesized by extrusion blending.The thermal,crystalline and mechanical properties of blends were investigated with TGA,DSC,WAXD and universal testing machine.The degradation of the blends in soil,acid and alkaline buffer solutions was assessed,respectively.It was found that the introduction of a little PLA promoted crystallization of PET during injection molding process.The starting decomposition temperature lowered from 412.1 ℃ of pure PET to 330.4 ℃ at 50% PLA content,tensile and bending strength of blends gradually decreased with the PLA content increasing,while the degradation rate improved.Alkaline environment was most beneficial for blends to degrade.The degradation mechanism was discussed. 展开更多
关键词 DEGRADATION polyester: polylactic acid mechanical property
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Post-synthesis modification of porous organic polymers with amine: a task-specific microenvironment for CO2 capture 被引量:2
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作者 Yankai Li Li Yang +2 位作者 Xiang Zhu Jun Hu Honglai Liu 《International Journal of Coal Science & Technology》 EI 2017年第1期50-59,共10页
A porous organic polymer named FC-POP was facilely synthesized with extraordinary porosity and excellent stability. Further covalent incorporation of various amines including single amine group, multi-amine groups of ... A porous organic polymer named FC-POP was facilely synthesized with extraordinary porosity and excellent stability. Further covalent incorporation of various amines including single amine group, multi-amine groups of diethylenediamine (DETA), and poly-amine groups of polyethylenimine (PEI) to the network gave rise to task-specific modification of the microenvironments to make them more suitable for CO2 capture. As a result, significant boost of CO2 adsorption capacity of 4.5 mmol/g (for FC-POP-CH2DETA, 273 K, 1 bar) and the CO2/N2 selectivity of 736.1 (for FC- POP-CH2PEI) were observed after the post-synthesis amine modifications. Furthermore, these materials can be regener- ated in elevated temperature under vacuum without apparent loss of CO2 adsorption capacity. 展开更多
关键词 Porous organic polymers Friedel-Crafts alkylation Post-synthesis Amine modification CO2 capture
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Synthesis and Biological Activity of N-Heteroaromatic- substituted Thiophene-2-Carbohydrazides
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作者 Mohammed A. Al-Nuri Ahmad I. Husein 《Journal of Chemistry and Chemical Engineering》 2011年第7期648-651,共4页
New heteroring-substituted thiophene-2-carbohydrazides incorporating pyrrole, thiophene, and pyridine moieties have been synthesized, characterized, and screened for possible antimicrobial activity. Some of the synthe... New heteroring-substituted thiophene-2-carbohydrazides incorporating pyrrole, thiophene, and pyridine moieties have been synthesized, characterized, and screened for possible antimicrobial activity. Some of the synthesized compounds exhibited promising antibacterial activities, but rather modest antifungal activity. 展开更多
关键词 HYDRAZONES ANTIMICROBIAL antibacterial antifungal.
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The synthesis of tetracyclic coumarins via decarboxylative asymmetric[4+2]cycloadditions enabled by Pd(0)/Cu(I)synergistic catalysis
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作者 Kai Wang Xiangfeng Lin +2 位作者 Qian Li Yan Liu Can Li 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第7期1812-1817,共6页
Tetracyclic coumarins are a class of important compounds with diverse and superior pharmacolog‐ical activities.However,a direct stereoselective method from simple and readily‐made coumarins derivatives remains chall... Tetracyclic coumarins are a class of important compounds with diverse and superior pharmacolog‐ical activities.However,a direct stereoselective method from simple and readily‐made coumarins derivatives remains challenging due to the inertness of coumarins as dienophiles.Herein,we de‐velop a decarboxylative asymmetric[4+2]cycloaddition of 3‐cyanocoumarins with vinyl benzoxa‐zinones,affording the coumarin‐derived condensed rings bearing three continuous stereocenters in high yields with excellent diastereoselectivities(>20/1 d.r.)and enantioselectivities(up to 99%ee).This direct enantioselective reaction was achieved by a Pd(0)/Cu(I)bimetallic catalytic system.The mechanism studies indicated that the synergistic activation effect,in which chiral Cu(I)as an availa‐ble Lewis acid catalyst activates 3‐cyanocoumarin and chiral Pd(0)complex activates benzoxazi‐none by the formation ofπ‐allyl‐palladium intermediate,plays an important role on the stereoselec‐tive control.The current work provides a new activation modes of Cu catalyst in the Pd/Cu bimetal‐lic catalytic system. 展开更多
关键词 Synergistic catalysis Pd(0)/Cu(I)catalysis Asymmetric catalysis [4+2]Cycloaddition Tetracyclic coumarins Chiral catalysis
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3D Photo-Fabrication for Tissue Engineering and Drug Delivery 被引量:6
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作者 Rúben F.Pereira Paulo J.Bártolo 《Engineering》 SCIE EI 2015年第1期90-112,共23页
The most promising strategies in tissue engineering involve the integration of a triad of biomaterials, living cells, and biologically active molecules to engineer synthetic environments that closely mimic the healing... The most promising strategies in tissue engineering involve the integration of a triad of biomaterials, living cells, and biologically active molecules to engineer synthetic environments that closely mimic the healing milieu present in human tissues, and that stimulate tissue repair and regeneration. To be clinically effective, these environments must replicate, as closely as possible, the main characteristics of the native extracellular matrix(ECM) on a cellular and subcellular scale. Photo-fabrication techniques have already been used to generate 3D environments with precise architectures and heterogeneous composition, through a multi-layer procedure involving the selective photocrosslinking reaction of a light-sensitive prepolymer. Cells and therapeutic molecules can be included in the initial hydrogel precursor solution, and processed into 3D constructs. Recently, photofabrication has also been explored to dynamically modulate hydrogel features in real time, providing enhanced control of cell fate and delivery of bioactive compounds. This paper focuses on the use of 3D photo-fabrication techniques to produce advanced constructs for tissue regeneration and drug delivery applications. State-of-the-art photo-fabrication techniques are described, with emphasis on the operating principles and biofabrication strategies to create spatially controlled patterns of cells and bioactive factors. Considering its fast processing, spatiotemporal control, high resolution, and accuracy, photo-fabrication is assuming a critical role in the design of sophisticated 3D constructs. This technology is capable of providing appropriate environments for tissue regeneration, and regulating the spatiotemporal delivery of therapeutics. 展开更多
关键词 3D photo-fabrication BIOMATERIALS TISSUEENGINEERING drug delivery
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Optimization of block-floating-point realizations for digital controllers with finite-word-length considerations
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作者 吴俊 胡协和 +1 位作者 陈生 褚健 《Journal of Zhejiang University Science》 EI CSCD 2003年第6期651-657,共7页
The closed-loop stability issue of finite-precision realizations was investigated for digital control-lers implemented in block-floating-point format. The controller coefficient perturbation was analyzed resultingfrom... The closed-loop stability issue of finite-precision realizations was investigated for digital control-lers implemented in block-floating-point format. The controller coefficient perturbation was analyzed resultingfrom using finite word length (FWL) block-floating-point representation scheme. A block-floating-point FWL closed-loop stability measure was derived which considers both the dynamic range and precision. To facilitate the design of optimal finite-precision controller realizations, a computationally tractable block-floating-point FWL closed-loop stability measure was then introduced and the method of computing the value of this measure for a given controller realization was developed. The optimal controller realization is defined as the solution that maximizes the corresponding measure, and a numerical optimization approach was adopted to solve the resulting optimal realization problem. A numerical example was used to illustrate the design procedure and to compare the optimal controller realization with the initial realization. 展开更多
关键词 Digital controller Finite word length Block floating point Closed loop stability OPTIMIZATION
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Effect of CaO composition on oxidation and burning behaviors of AM50 Mg alloy
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作者 Jin-Kyu LEE Shae K.KIM 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第A01期23-27,共5页
Oxidation and burning behaviors were studied for CaO added AM50 Mg composites which were manufactured by conventional melting and casting processes without SF6 protective gas. CaO added AM50 Mg composites show the sta... Oxidation and burning behaviors were studied for CaO added AM50 Mg composites which were manufactured by conventional melting and casting processes without SF6 protective gas. CaO added AM50 Mg composites show the stable oxidation resistance, while AMS0 Mg alloys show the poor oxidation resistance. The effects of CaO addition on the burning resistance under ambient, nitrogen and dry air atmospheres were examined for CaO added AM50 Mg composites. With increasing CaO addition, the burning temperature increases under ambient, nitrogen and dry air atmospheres. The burning temperatures of small test specimen under all conditions greatly increase even by 0.3% CaO (mass fraction) addition into AM50 Mg alloys. 展开更多
关键词 Mg alloy CAO oxidation behavior burning behavior
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Carcass Characteristics and Environmental Parameters Effects on Carcass Composition of Lori-Bakhtiari Sheep 被引量:1
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作者 M. A. Talebi M. Karami 《Journal of Agricultural Science and Technology(A)》 2011年第8期1245-1248,共4页
In this study, data of body weight at slaughter (SW; n = 465), hot carcass weight (HCW; n = 465), cold carcass weight (CCW; n = 401), carcass lean weight (CLW; n = 314), carcass bone weight (CBW; n = 401), c... In this study, data of body weight at slaughter (SW; n = 465), hot carcass weight (HCW; n = 465), cold carcass weight (CCW; n = 401), carcass lean weight (CLW; n = 314), carcass bone weight (CBW; n = 401), carcass total fat weight (CTFW; n = 314) and fat-tail weight (FTW; n = 401) in Lori-Bakhtiari sheep were measured to determine their possible use in breeding programmers aimed at improving ability to carcass quality in this breed. Lambs were slaughtered at 195 + 27 days of age. The method of slaughtering and cultting was Iranian cutting approach. SAS procedures were used for the statistical analysis. Means and their respective standard deviations for SW, HCW, CCW, CLW, CBW, CTFW and FTW were 45.41 ± 6.86, 22.81 ± 4.32, 22.53 ± 4.18, 11.14 ± 1.71, 3.47 ± 0.43, 7.19 ± 2.42 and 3.65 ± 1.37 kg, respectively. The coefficients of variation for CTFW and FTW were 33.62 percent and 38.01 percent, respectively. Environmental effects of kind of rearing after weaning and type of birth on HCW, CCW, CLW, CTFW and FTW traits were significant. Consequently, considerable variation exists for carcass composition traits, especially for carcass fat and fat-tail. 展开更多
关键词 Carcass composition enviromental factors Lori-Bakhtiari SHEEP
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H4SiW6Mo6O40-Doped Polyaniline-Synthesis, characterization and catalytic properties of acetals and ketals 被引量:2
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作者 YANG Shui-jin DU xin—xian PhilippeG.Merle 《Journal of Chemistry and Chemical Engineering》 2008年第4期35-41,共7页
A new environmental friendly catalyst, HaSiWrMo6O40/PAn was prepared and identified by means of FT-IR, XRD and TG/DTA. The optimum conditions have been found, that was, mass ratio of m(PAn): m(HaSiW6Mo6On.) was 1... A new environmental friendly catalyst, HaSiWrMo6O40/PAn was prepared and identified by means of FT-IR, XRD and TG/DTA. The optimum conditions have been found, that was, mass ratio of m(PAn): m(HaSiW6Mo6On.) was 1:1.25, volume of methanol was 20 mL, and the reflux reaction time was 2h. The structural identity of Keggin units was preserved after the incorporation into polyaniline matrix. H4SiW6Mo6040/PAn was used as catalyst in catalytic synthesis of acetals and ketals. Effects of n(aldehyde(ketone )): n(glycol), catalyst dosage and reaction time on yield were investingated. Optimal conditions were: n(aldehyde(ketone)): n(glycol)=1.0: 1.5; mass fraction of catalyst to reactants, 0.5%; reaction time, 1.0 h and cyclohexane as water-stripped reagent, 15 mL. Under these conditions, yields of actels and ketals were 31.9%-91.6%. 展开更多
关键词 2 4-dimethyl-2-ethoxycarbonylmethyl-1 3-dioxo-lane H4SiW6Mo6O4O polyaniline ACETALATION KETALATION catalyst
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Synthesis and Mollucicidal Activity of Some New Bicyclic and Polycyclic Pyrimidine Derivatives
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作者 Mohamed Abdel-Megid Mohamed Abdel-Hamid Awas +2 位作者 Magdy Seada Kamelia Mohamed Elmhdy Mortta Mohamed Elsayed 《Journal of Chemistry and Chemical Engineering》 2010年第5期41-53,共13页
Hydrazinolysis ofethylthiopyrimidine derivative 2 gave 2-hydrazinopyrimidine 3 which used as a convenient precursor for the synthesis of pyrazolylpyrimidines, hydrazones and pyrimidotriazines. Also, treatment of 2 wit... Hydrazinolysis ofethylthiopyrimidine derivative 2 gave 2-hydrazinopyrimidine 3 which used as a convenient precursor for the synthesis of pyrazolylpyrimidines, hydrazones and pyrimidotriazines. Also, treatment of 2 with ethyl chloroacetate yielded N^-carbethoxymethyl-2-ethylthio-pyrimidine 15, which on reaction with ethyl carbazate and hydrazine hydrate afforded pyrimidotriazine and imidazopyrimidine, respectively. Chlorination of 2 using phosphorous oxycbloride yielded 4-chloropyrimidine 18, which reacted with some heterocyclic compounds having vicinal amino cyano groups to give some new polynuclear heterocyclic system. Also, the effect of some active methylene compounds on 18 was also studied. Some of the newly synthesized compounds were tested as mollucicidal agents against Biomphlaria alexandrina snails that caused intestinal bilharzias, the national problem in Egypt. 展开更多
关键词 Pyrazolylpyrimidines pyrimidotriazines imidazopyrimidines pyrimidopyrimidines mollucicidal activity.
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One-pot conversion of cyclohexanol to ε-caprolactam using a multifunctional Na_2WO_4-acidic ionic liquid catalytic system
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作者 Hefang Wang Liyuan Jia +2 位作者 Rongbin Hu Meidan Gao Yanji Wang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第1期58-64,共7页
Na2WO4‐acidic ionic liquid was used as a simple, ecofriendly, recyclable and efficient catalytic system for the one‐pot conversion of cyclohexanol to ε‐caprolactam. The effect of the structure of the ionic liquid ... Na2WO4‐acidic ionic liquid was used as a simple, ecofriendly, recyclable and efficient catalytic system for the one‐pot conversion of cyclohexanol to ε‐caprolactam. The effect of the structure of the ionic liquid on the catalytic activity of this system was investigated, and the results revealed that sulfonic acid‐functionalized ionic liquids with HSO4? as an anion gave the best results. The highly efficient performance of this catalyst system was attributed to the phase‐transfer behavior of the cation of the ionic liquid, the improved coordination of the substrate to bisperoxotungstate duringthe oxidation reaction, and the stabilization of the intermediate formed during the Beckmann rearrangement. 展开更多
关键词 CYCLOHEXANOL ε‐Caprolactam One‐pot synthesis Acidic ionic liquid Cyclohexanone oxime
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Experimental Study of Natural Gas Storage in Hydrates
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作者 孙志高 王如竹 +1 位作者 郭开华 樊栓狮 《Journal of Shanghai Jiaotong university(Science)》 EI 2004年第3期80-82,87,共4页
Hydrate formation rate plays an important role in the making of hydrates for natural gas storage. The effect of sodium dodecyl sulfate (SDS), alkyl polysaccharide glycoside (APG) and cyclopentane (CP) on natural gas h... Hydrate formation rate plays an important role in the making of hydrates for natural gas storage. The effect of sodium dodecyl sulfate (SDS), alkyl polysaccharide glycoside (APG) and cyclopentane (CP) on natural gas hydrate formation rate, induction time and storage capacity was studied. Micellar surfactant solutions were found to increase hydrate formation rate in a quiescent system and improve hydrate formation rate and natural gas storage capacity. The process of hydrate formation includes two stages with surfactant presence. Hydrate forms quickly in the first stage, and then the formation rate is slowed down. Surfactants (SDS or APG) reduce the induction time of hydrate formation. The effect of an anionic surfactant (SDS) on gas storage in hydrates is more pronounced compared to a nonionic surfactant (APG). CP also reduces the induction time of hydrate formation, but can not improve the natural gas storage capacity in hydrates. 展开更多
关键词 gas hydrate synthetic natural gas SURFACTANT CYCLOPENTANE STORAGE
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Synthesis of Mesoporous Titanium Silicalite-1 with High Stability in Cyclohexanone Ammoximation 被引量:3
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作者 王亚权 叶家鑫 +3 位作者 王书海 林永杰 王守桂 刘伟 《Transactions of Tianjin University》 EI CAS 2016年第3期254-260,共7页
Mesoporous titanium silicalite-1(TS-1)was hydrothermally synthesized with the addition of triethanolamine(TEA)in the conventional process, and used in the cyclohexanone ammoximation in a continuous slurry reactor. The... Mesoporous titanium silicalite-1(TS-1)was hydrothermally synthesized with the addition of triethanolamine(TEA)in the conventional process, and used in the cyclohexanone ammoximation in a continuous slurry reactor. The as-prepared TS-1 was characterized with X-ray diffraction(XRD), scanning electron microcopy(SEM), N_2 adsorption-desorption, Fourier transform infrared(FT-IR)spectroscopy, UV-Visible(UV-Vis)diffuse reflectance spectra and UV Raman spectroscopy. The results indicated that the addition of TEA resulted in the formation of mesopores and the slight increase of framework titanium in TS-1. TS-1 synthesized with the addition of TEA exhibited a higher stability in the cyclohexanone ammoximation than that without the addition of TEA, attributing to the increase of mesopore volumes and the slight increase of the framework titanium in TS-1. However, when the addition of TEA was up to TEA/SiO_2 ratio of 0.24, the crystallinity and framework titanium of TS-1 decreased markedly, and the average crystal sizes of TS-1 increased, with the catalyst stability becoming poor. 展开更多
关键词 TS-1 TRIETHANOLAMINE cyclohexanone ammoximation MESOPORE STABILITY
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Theoretical Study of Mechanism and Regioselectivity of 1,3-dipolar Cycloaddition of N-[methyl]-C-[5-nitro-2-furyl] Nitrilimine with Dimethyl 7-oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylate
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作者 Farid Moeinpour 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第2期165-168,I0001,共5页
The mechanism and regioselectivity of 1,3-dipolar cycloaddition of N-[methyl]-C-[5-nitro-2-furyl] nitrilimine with dimethyl 7-oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylate were investigated using activation energ... The mechanism and regioselectivity of 1,3-dipolar cycloaddition of N-[methyl]-C-[5-nitro-2-furyl] nitrilimine with dimethyl 7-oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylate were investigated using activation energy calculations and density functional theory-based reactivity indexes. The reaction proceeds by an asynchronous concerted mechanism. The calculations are performed at the B3LYP/6-31G(d) level of theory and the obtained results are in agreement with experimental outcome. 展开更多
关键词 Regioselectivity 1 3-dipolar cycloaddition Nitrilimine DFT-based reactivity index B3LYP calculation
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