Results 1 to 10 of about 1,260,379 (169)
Zhongguo youzhi, 2023 为获得天然可再生、环境友好的宽黏度范围的椰子油基酯类润滑油，先由新戊二醇(NG)和己二酸(AA)合成不同平均聚合度的中间体，再分别与椰子油脂肪酸反应制备一系列黏度可调控的椰子油基新戊二醇己二酸低聚酯(简称低聚酯)。考察了中间体的主要合成条件带水剂种类、反应温度、反应时间、新戊二醇与己二酸物质的量比(nNG/nAA)对中间体转化率和平均聚合度的影响，比较分析不同平均聚合度的中间体及其低聚酯的FTIR红外光谱，并测定了不同平均聚合度中间体制备的低聚酯黏度。结果表明：nNG/nAA可显著调控中间体的平均聚合度，
何节玉1,2，王泽1，朱佳萍1，金云康1 HE Jieyu1,2, WANG Ze1, ZHU Jiaping1, JIN Yunkang1
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Gongye shui chuli, 2023 以聚合物驱油为代表的三次采油技术已经在我国各大主力油田逐步推广和应用，随聚合物用量不断增大，油田含聚洗井液的处理量也随之剧增。由于聚合物能够促进油水混合物的乳化，洗井液中的油水分离速率极为缓慢，且含聚洗井液的黏度大，与常规洗井液混合后循环利用将对油田水系统产生诸多不利影响。在分析了油田含聚洗井液组分和常规氧化处理方法的基础上，针对现有联合处理站工艺固化、空间受限以及罐车排放速度快、降解处理时间短等问题，提出了超声-臭氧联合降解聚合物的工艺方法，并搭建了相应的室内试验平台。以含聚洗井液黏度下降率 ...
王尔珍 +7 more
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Psychometric framework for coexistence with large carnivores
Conservation Biology, EarlyView.Abstract Human–carnivore coexistence is essential for biodiversity conservation, yet measuring the attitudes and behaviors that support it remains methodologically challenging. We developed psychometric scales to assess willingness to coexist with carnivores and the underlying beliefs of this coexistence through an iterative expert elicitation process ...
Benjamin Ghasemi +14 more
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Vocabulary Strategy Instruction in the Argentine EFL Context: Teachers’ Perspectives and Practices
International Journal of Applied Linguistics, EarlyView.ABSTRACT Despite extensive research on vocabulary strategy instruction (VSI), little has been known about teachers’ perspectives on how it is understood and implemented in practice. This study investigated Argentinian EFL teachers’ priorities in vocabulary instruction, their perceived knowledge of learner strategies for spoken vocabulary, and factors ...
Isobel Kai‐Hui Wang, Andrew D. Cohen
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Lipase-catalyzed synthesis of R-Poly (3-hydroxybutyrate) oligomer(脂肪酶催化合成聚R-3-羟基丁酸乙酯寡聚物研究)
Zhejiang Daxue xuebao. Lixue ban, 2018 聚R-3-羟基丁酸酯是一类具有重要生理作用的聚合物，其合成方法一直是手性聚合物合成领域的研究热点之一.在充分考察底物构型、溶剂等因素对酶促动力学拆分/聚合反应影响的基础上，结合过渡金属配合物对醇的原位外消旋化作用与酶促聚合反应，建立了一种绿色、高效的酶促动态动力学拆分/聚合一锅合成聚R-3-羟基丁酸酯的方法.通过该方法制备所得聚合物的分子量可以达到2.0×103 Da.通过改变聚合单体的光学纯度还可实现对聚合物分子量的调控，在不同光学纯度聚合单体的聚合反应中，聚合物的分子量可以较为均匀地分布在0.3 ...
XIABo(夏波), WUQi(吴起)
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Justice in coexistence: Pastoralism and large carnivores on the Qinghai‐Tibet Plateau
People and Nature, Volume 8, Issue 7, Page 2186-2199, July 2026.Abstract The conflict between livestock husbandry and large carnivore conservation presents significant challenges in grassland ecosystems worldwide. Achieving sustainable coexistence among herders, livestock and large carnivores requires reconciling diverse perspectives and interests through equitable, inclusive and fair processes that address both ...
Yufang Gao, Yue Yu
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Microstructure Engineering Toward High Cost‐Effective Nd–Fe–B Sintered Magnets: A Review
Rare Metals, Volume 45, Issue 7, July 2026.ABSTRACT Nd–Fe–B sintered magnets, critical for enhancing electromechanical conversion efficiency and operational stability in wind turbines and electric vehicle drives, are prized for their outstanding coercivity, high remanence, and superior maximum energy product.
Dongmin Zhang +5 more
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Rare Metals, Volume 45, Issue 7, July 2026.ABSTRACT This study developed a metal–modified fluoroethylene vinyl ether (FEVE) organic coating on 6061 aluminum alloy, supported by a micro‐arc oxidation (MAO) pretreatment layer, to enhance corrosion resistance and antifouling performance in marine environments.
Chang Liu +5 more
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四川大学学报. 自然科学版, 1994 光电落球粘度计的研制赵北君，朱世富，李正辉，银淑君（四川大学材料科学系）傅师申（成都科技大学纺织化学工程系）聚合物流体的粘度是聚合物材料研制和生产工艺过程中非常重要的宏观中间控制指标之一。聚合物浓溶液的粘度与聚合物的分子量、浓度、温度及受力状态密切相...
赵北君 +4 more
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Mechanoluminescent Mixed‐Anion Borate Sr2B5O9Cl:Eu for Dynamic Anticounterfeiting
Rare Metals, Volume 45, Issue 7, July 2026.ABSTRACT Mechanoluminescence (ML)—the emission of light in response to mechanical stimuli—offers a direct and visually intuitive route for transducing mechanical information into optical signals. Herein, we report a mixed‐anion strategy to prepare mixed‐anion borate Sr2B5O9Cl:Eu phosphors through a facile, low‐temperature, and ambient‐atmosphere solid ...
Yuhong Han +7 more
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