检索结果-南通市图书馆

α-环糊精主客体识别超分子水凝胶的制备及其宏观流变性能构建过程研究

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

高分子通报 2024年第2期37卷 229-237页

作者：贺杰叶子王宏申陈庆梅赵伟刘航瑞西南石油大学化学化工学院四川省油气田应用化学重点实验室成都610500 中海油能源发展股份有限公司工程技术分公司天津300452 中国石油西南油气田分公司天然气研究院成都610213 中国石油川庆钻探工程有限公司地质勘探开发研究院成都610051

采用7 wt%的α-环糊精(α-CD)溶液和5 wt%的甲氧基聚乙二醇甲基丙烯酸酯均聚物(PMPEGA-2000)溶液制备了α-CD/PMPEGA-2000超分子水凝胶,并对其形貌、结构、形成条件和宏观流变学性能构建过程进行了表征和研究。结果表明,体积比不低于1.... 详细信息

采用7 wt%的α-环糊精(α-CD)溶液和5 wt%的甲氧基聚乙二醇甲基丙烯酸酯均聚物(PMPEGA-2000)溶液制备了α-CD/PMPEGA-2000超分子水凝胶,并对其形貌、结构、形成条件和宏观流变学性能构建过程进行了表征和研究。结果表明,体积比不低于1.5:1是两种溶液混合后形成凝胶的必要条件;当体积比为2:1时,形成的凝胶黏度最大。热重分析、X射线粉末衍射分析和扫描电镜结果表明,该凝胶是基于α-CD与PMPEGA-2000之间的主客体识别所形成,具有三维网络结构。光学微流变分析结果显示,该凝胶宏观流变性能的构建过程实则是凝胶内部主客体识别交联点不断增多,网络结构强度不断增强的过程。该过程始于α-CD溶液与PMPEGA-2000溶液混合后的8′36′′,在64′00′′后基本完成,耗时约55′24′′。

关键词：超分子水凝胶三维网络结构主客体识别微流变宏观流变性能

在线全文

学校读者我要写书评

暂无评论

延迟成胶弹性硅酸凝胶堵水剂及其性能研究

应用化工 2024年第4期53卷 769-773页

作者：贺杰刘航瑞陈庆梅杨超越叶子西南石油大学化学化工学院四川省油气田应用化学重点实验室四川成都610500 中国石油西南油气田分公司天然气研究院四川成都610500

针对现有硅酸凝胶堵水剂普遍存在成胶时间短、成胶后脆性大的问题,结合L油田油藏条件,通过考察活化剂类型及用量,弹性改善剂类型及用量,以及水玻璃用量对成胶时间和弹性模量的影响,得出了一种延迟成胶弹性硅酸凝胶堵水剂。其配方为:6%... 详细信息

针对现有硅酸凝胶堵水剂普遍存在成胶时间短、成胶后脆性大的问题,结合L油田油藏条件,通过考察活化剂类型及用量,弹性改善剂类型及用量,以及水玻璃用量对成胶时间和弹性模量的影响,得出了一种延迟成胶弹性硅酸凝胶堵水剂。其配方为:6%水玻璃+0.85%活化剂三元弱酸一铵GL-1+0.1%弹性改善剂正电胶,该配方在油藏温度65℃下,成胶强度达到E级的时间为72 h,成胶后的弹性模量为589.46 Pa。采用填砂管实验评价了堵水剂的注入性及封堵性,结果表明堵水剂在L油田中具有良好的注入性及封堵性,在渗透率为1168.06×10^(-3)~5061.57×10^(-3)μm^(2)的填砂管中,注入0.8 PV的最高注入压力仅有0.72 MPa,封堵率均>96%。该堵水剂可用于L油田的油井堵水。

关键词：油井堵水延迟成胶弹性硅酸凝胶堵水剂注入性及封堵性

Genome-wide identification and characterization of the JAZ gene family and its expression patterns under various abiotic stresses in Sorghum bicolor

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2022年第12期21卷 3540-3555页

作者： DU Qiao-li FANG Yuan-peng JIANG Jun-mei chen mei-qing LI Xiang-yang XIE Xin Key Laboratory of Agricultural Microbiology College of AgricultureGuizhou UniversityGuiyang 550025P.R.China State Key Laboratory Breeding Base of Green Pesticides and Agricultural Bioengineering/Key Laboratory of Green Pesticides and Agricultural Bioengineering Ministry of EducationGuizhou UniversityGuiyang 550025P.R.China

The jasmonate ZIM domain(JAZ)protein belongs to the TIFY((TIF[F/Y]XG)domain protein)family,which is composed of several plant-specific proteins that play important roles in plant growth,development,and defense ***,the mechanism of the sorghum JAZ family in response to abiotic stress remains *** the present study,a total of 17 JAZ genes were identified in sorghum using a Hidden Markov Model *** addition,real-time quantification polymerase chain reaction(RT-qPCR)was used to analyze the gene expression patterns under abiotic *** on phylogenetic tree analysis,the sorghum JAZ proteins were mainly divided into nine subfamilies.A promoter analysis revealed that the SbJAZ family contains diverse types of promoter cis-acting elements,indicating that JAZ proteins function in multiple pathways upon stress stimulation in *** to RT-qPCR,SbJAZ gene expression is ***,under cold,hot,polyethylene glycol,jasmonic acid,abscisic acid,and gibberellin treatments,the expression patterns of SbJAZ genes were distinctly different,indicating that the expression of SbJAZ genes may be coordinated with different ***,the overexpression of SbJAZ1 in Escherichia coli was found to promote the growth of recombinant cells under abiotic stresses,such as PEG 6000,NaCl,and 40℃ ***,our findings help us to better understand the potential molecular mechanisms of the SbJAZ family in sorghum in response to abiotic stresses.

关键词： Sorghum bicolor gene family identification JAZ family abiotic stress expression pattern

在线全文

学校读者我要写书评

暂无评论

生乳中脂多糖的来源及其影响因素

中国奶牛 2024年第8期 41-45页

作者：陆松翠陈美庆张养东中国农业科学院北京畜牧兽医研究所/农业农村部奶及奶制品质量安全控制重点实验室北京100193

脂多糖(LPS)是革兰氏阴性菌外膜的重要组成成分,在细胞分裂、外膜囊泡脱落或细菌细胞死亡的过程中,LPS会被释放到周围的介质中,也被称为内毒素。本文全面阐述了乳中LPS的来源及其相关影响因素,以期为后续对乳中LPS的相关研究及防控提供... 详细信息

脂多糖(LPS)是革兰氏阴性菌外膜的重要组成成分,在细胞分裂、外膜囊泡脱落或细菌细胞死亡的过程中,LPS会被释放到周围的介质中,也被称为内毒素。本文全面阐述了乳中LPS的来源及其相关影响因素,以期为后续对乳中LPS的相关研究及防控提供理论参考。

关键词：脂多糖生乳来源影响因素

Cosmological interpretation for the stochastic signal in pulsar timing arrays

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 43-50页

作者： Yu-mei Wu Zu-cheng chen qing-Guo Huang School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Astronomy Beijing Normal UniversityBeijing 100875China Advanced Institute of Natural Sciences Beijing Normal UniversityZhuhai 519087China Department of Physics and Synergistic Innovation Center for Quantum Effects and Applications Hunan Normal UniversityChangsha 410081China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

The pulsar timing array(PTA)collaborations have recently reported compelling evidence for a stochastic signal consistent with a gravitational-wave *** this paper,we combine the latest data sets from NANOGrav,PPTA,and EPTA to explore cosmological interpretations for the PTA signal from first-order phase transitions,domain walls,and cosmic strings,*** find that the domain wall model is strongly disfavored with the Bayes factors compared with the first-order phase transitions and cosmic strings being 1/90 and 1/189,respectively,breaking the degeneracy among these models in individual data *** also find that:(1)a strong phase transition at temperatures below the electroweak scale is favored,and the bubble collisions make the dominant contribution to the energy density spectrum;(2)a small reconnection probability p<1.55×10^(-1)allowed by strings in(super)string theory is favored at the 95%confidence level,and ground-based detectors can further constrain the parameter space.

关键词： puslar timing arrays gravitational-wave background first-order phase transitions domain walls cosmic strings

Role of adaptation measures in addressing heatwave exposure in China

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第1期15卷 148-157页

作者： Qin-mei HAN qing-chen CHAO Shao SUN Pei-Jun SHI National Climate Centre China Meteorological AdministrationBeijing 100081China State Key Laboratoryof Severe Weather Chinese Academy of Meteorological Sciences Beijing 0o08lChina Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China

Heatwave exposure has increased dramatically because of climate warming and population growth,along with their interactive ***,effective adaptation measures can reduce these ***,the dynamic changes,regional inequality in adaptive capacity and their potential contributions to reducing exposure in the future remain *** study quantifies the impact of adaptive capacity and underscores regional variations in heatwave magnitudes,population exposure and adaptation levels in *** projected the future adaptive capacity using air-conditioner penetration,factoring in climate cooling requirements and individuals'purchasing *** population and gross domestic product(GDP)data from four Shared Socioeconomic Pathways(SSP1,SSP2,SSP3 and SSP5)and daily temperature data from four SSP-based emission scenarios(SSP1-2.6,SSP2-4.5,SSP3-7.0 and SSP5-8.5),we estimated heatwave duration,population exposure and avoided impacts through adaptation across China and its *** show a substantial increase in heatwave duration in Southwest and Southern China,especially under the SSP5-8.5 scenario,with a projection of 163.2±36.7 d during *** the SSP3|SSP3-7.0 scenario,total exposure reaches 156.4±76.8 billion person d per year,which is the highest among all scenarios and 23 times greater than that in 1986-2005 without *** considering adaptation measures,a noteworthy reduction in population exposure is observed,especially in the SSP3|SSP3-7.0 and SSP5JSSP5-8.5 scenarios,with reductions of(62.6±3.9)%and(65.8±5.1)%,respectively,compared with the scenario without adaptation during *** regional disparities in avoided impacts are also evident,with variations of up to 50%across different *** implementation of effective and environmentally friendly adaptation measures can notably address climate change,thereby alleviating the profound threats posed to human well-being.

关键词： Heatwaves Population exposure Adaptation Future projection China

A Low Cost, Green Sustainable and Biodegradable Biomass-based Fluorine-free Water and Oil Repellent

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第4期42卷 480-491页

作者： Zhi-Wei Shen Shu-Feng Hu chen Zeng Wei-qing Kong mei-Fang Zhu State Key Laboratory for Modification of Chemical Fibers&Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai201620China State Key Laboratory of Pulp and Paper Engineering School of Light Industry and EngineeringSouth China University of TechnologyGuangzhou510630China

With the global ban on plastics intensifying, the substitution of plastic with paper has garnered increasing attention. However, the inadequate water and oil repellency of pulp molding hinders its practical applications. Currently, the common method to enhance the oil and water repellency of pulp molding is by adding fluorinated water and oil repellents. Nevertheless, fluorinated compounds are environmentally and physiologically harmful. Therefore, the development of fluorine-free, water and oil repellent alternatives is crucial. In this study, chitosan and stearic acid were utilized as the first and second layers of the oil and water repellent coatings, respectively. The coated samples exhibited favorable water repellency, with a water contact angle of 116.4°, and excellent oil repellency, achieving a 12/12 rating on the kit scale. Importantly, the samples did not exhibit any leakage after being soaked in hot water and hot oil at 95±5℃ for 30 min, demonstrating remarkable performance as a barrier against hot water and oil. Moreover, the coated samples displayed outstanding mechanical properties, thermal stability, biodegradability, and recyclability. The approach presented in this study is simple, cost-effective, environmentally friendly, and represents a promising technique for producing fluoride-free, oil-and water-resistant pulp molding products.

关键词： Biomass Fluoride-free Oil-andwater-resistant Plasticfree

Electronegativity-assisted optimized electronic structure of functionalized-Pt catalysts for boosting oxygen reduction kinetics

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 1965-1976页

作者： Jin Long Kai-Wen Zhuang Wei Liao Yan An Bin Wang chen-Zhong Wu Jian-Xin Cao qing Wang Jun-Song chen qing-mei Wang Guizhou University Key Laboratory of Green Chemical and Clean Energy Technology School of Chemistry and Chemical EngineeringGuizhou UniversityGuiyang 550025China Guizhou University Engineering Research Center of Effcient Utilization for Industrial Waste Guizhou UniversityGuiyang 550025China Institute of Dual-Carbon and New Energy Technology Innovation and Development of Guizhou Province Guiyang 550025China Department of Dermatology West China HospitalSichuan UniversityChengdu610041China Institute for Catalysis Hokkaido UniversitySapporo 001-0021Japan School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China Interdisciplinary Materials Research Center Institute for Advanced StudyChengdu UniversityChengdu 610106China

Opportunity to harmonize aspects of oxygen reduction reaction(ORR)performance and structure,and morphology,as well as composition,is urgent for the commercialization of proton exchange membrane fuel ***,we demonstrate the design and synthesis of a functionalized-supported-Pt catalyst(Pt@HNC)featuring a hollow nitrogen-modified dodecahedral carbon substrate obtained by a stress-induced-shrink tailoring *** as-obtained Pt@HNC catalyst possesses enhanced ORR per-formance,in particular with half-wave potential,mass activity(MA)and specific activity,which greatly exceed the commercial Pt/*** density functional theory(DFT)calculations further confirmed that the charge redistribution induced by the electronegativity differences improved the electron interaction between Pt and HNC *** optimized electronic structure of Pt weakens the reaction energy barrier on the Pt@HNC surface and adsorption of^(*)OH species,thus cooperatively improving the intrinsic activity toward ***,our work indeed provides a guide for the future design of functional nanomaterials in the field of catalysts and clean energy.

关键词： Proton exchange membrane fuel cell(PEMFC) Oxygen reduction catalysis Supported Pt-based catalyst Stability

Effect of Sc on Al_(3)Fe phase and mechanical properties of as-cast AA5052 aluminum alloy

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第3期21卷 257-264页

作者： Yang Li qing Yu Feng-feng chen Jia-wen He Hong-mei Yang Meng-nie Li Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical *** studies have demonstrated that the addition of Sc to aluminum alloys can improve both the microstructure and properties of the *** this study,the effect of Sc on the Fe-rich phase and properties of the AA5052 aluminum alloy was studied by adding 0%,0.05%,0.2%,and 0.3%*** results show that with the increase of Sc,the coarse needle-like Fe-rich phase gradually transforms into Chinese-script and then nearly spherical particles,reduce the size of Fe-rich phase,and refine the grain with increase of high angle grain boundaries(HAGBs).These microstructure changes enhance the strength of the AA5052 alloy through Sc *** ductility of the alloy is obviously improved because the addition of a lower amount of Sc changes the morphology of Fe-rich phase from needle-like into a Chinese-script,and it is subsequently reduced as a result of significant increase in HAGBs with increasing Sc content.

关键词： AA5052 aluminum alloy Al3Fe phase mechanical properties grain boundary