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Single thiolate replacement of metal nanoclusters

Science China Chemistry 2024年第2期67卷 523-528页

作者： Ambreen Ambreen Yue Zhou Wanmiao Gu Qing You Liang Fang Guoqing bian nan Yan nan Xia Zhikun Wu Key Laboratory of Materials Physics Anhui Key Laboratory of Nanomaterials and NanotechnologyInstitute of Solid State PhysicsHefei Institutes of Physical Science(HFIPS)Chinese Academy of SciencesHefei230031China University of Science and Technology of China Hefei230601China Institute of Physical Science and Information Technology Anhui UniversityHefei230601China

Surface thiolates play important roles in evincing the structures and properties of thiolated metal nanoclusters—one type of recently emerging inorganic-organic hybrids,and thus the thiolate substitution,especially single thiolate substitution,is highly desirable for subtly tailoring the structures and properties of metal nanoclusters.However,such a single-thiolate substituting is challenging,and its influence on the metal-metal and metal-sulfur bonds remains mysterious due to the absence of the singlethiolate-substituted structure.Here,we developed a combined method,concurrently synthesized the single-thiolate-substituted nanocluster and its parent nanocluster,and successfully resolved their structures by single crystal X-ray crystallography,which reveals that the single thiolate substitute has an obvious influence on the metal-metal and metal-sulfur bond lengths although it has no effect on the absorption profile.Interestingly,the metal-metal and metal-sulfur bonds show various thermal extensibility and even the negative thermal expansion phenomena of the Au–S bond were observed in the single-thiolate-substituted nanocluster.The bond length-related stability was also observed.Overall,this study highlights a novel synthesis method and offers novel structural insights and an in-depth structure-property correlation of thiolated metal nanoclusters.

关键词： metal nanoclusters single thiolate replacement thermal expansion stability intercluster interaction

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Dual Strengthened Control of Recrystallization Behavior on CVCDE Magnesium Alloy Containing Characteristic Structure

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Acta Metallurgica Sinica(English Letters) 2023年第11期36卷 1805-1821页

作者： nan bian Feng Li Wentao Niu Chao Li Yuanqi Li School of Materials Science and Chemical Engineering Harbin University of Science and TechnologyHarbin150040China Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin150080China Heilongjiang Provincial Key Laboratory of Light Metal Materials Modification and Green Forming Technology Harbin University of Science and TechnologyHarbin150040China

Various characteristic structures in typical magnesium alloys,including dislocation cells,substructures and twins,have an important influence on the dynamic recrystallization behavior,and the DRX(dynamic recrystallization)behavior is closely related to the grain refinement and texture weakening of the hot deformed structure.Therefore,this study reveals the influence of the above characteristic structures on the dynamic recrystallization behavior of magnesium alloys,which have great significance for regulating the high-performance hot deformed microstructure of magnesium alloys and optimizing the macro mechanical properties.In this study,continuous variable channel direct extrusion(CVCDE)magnesium alloy was prepared by CVCDE,and its macro mechanical properties including hardness and uniaxial tension were characterized.The thermoplastic deformation behavior and texture evolution of magnesium alloy with characteristic structure were analyzed by electron back-scattering diffraction technology.It is found that the dislocation recombination was realized by deformation mechanism(slip,climb and cross slip),the formation of grain substructure in coarse grains and the induction of recrystallization by twins promote the recrystallization behavior in hot deformed structures more adequate,which effectively improves the degree of microstructure refinement and deformation uniformity.

关键词： Characteristic structure Continuous variable channel direct extrusion(CVCDE) Dynamic recrystallization Regulation Mechanical property

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Development status and prospect of underground thermal energy storage technology

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Journal of Groundwater Science and Engineering 2024年第1期12卷 92-108页

作者： Ying-nan Zhang Yan-guang Liu Kai bian Guo-qiang Zhou Xin Wang Mei-hua Wei School of Earth science and Engineering Hebei University of EngineeringHandan 056038Hebei ProvinceChina Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological SciencesShijiazhuang 050061China Technology Innovation Center of Geothermal&Hot Dry Rock Exploration and Development Ministry of Natural ResourcesShijiazhuang 050061China Shanxi Key Laboratory for Exploration and Exploitation of Geothermal Resources Taiyuan 030024China Shanxi Geological Engineering Exploration Institute Taiyuan 030024China

Underground Thermal Energy Storage(UTES)store unstable and non-continuous energy underground,releasing stable heat energy on demand.This effectively improve energy utilization and optimize energy allocation.As UTES technology advances,accommodating greater depth,higher temperature and multi-energy complementarity,new research challenges emerge.This paper comprehensively provides a systematic summary of the current research status of UTES.It categorized different types of UTES systems,analyzes the applicability of key technologies of UTES,and evaluate their economic and environmental benefits.Moreover,this paper identifies existing issues with UTES,such as injection blockage,wellbore scaling and corrosion,seepage and heat transfer in cracks,etc.It suggests deepening the research on blockage formation mechanism and plugging prevention technology,improving the study of anticorrosive materials and water treatment technology,and enhancing the investigation of reservoir fracture network characterization technology and seepage heat transfer.These recommendations serve as valuable references for promoting the high-quality development of UTES.

关键词： Aquifer thermal energy storage Borehole thermal energy storage Cavern thermal energy storage Thermal energy storage technology Benefit evaluation

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Mechanism of plasticity enhancement of AZ31B magnesium alloy sheet by accumulative alternating back extrusion

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Journal of Magnesium and Alloys 2023年第5期11卷 1791-1801页

作者： Ye Wang Feng Li nan bian Hua Qiu Du Peng Da Huo School of Materials Science and Engineering Harbin University of Science and TechnologyHarbin 150040PR China Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080PR China

Accumulative alternating back extrusion was a potential fine-grain modification method.In this paper,it was an innovative attempt to develop high-performance magnesium alloy sheet by this process.Under the condition of 350 K,commercial AZ31 magnesium alloy was made into billet by accumulative alternating back extrusion,and then extruded into fine-grain magnesium alloy sheet.Through a systematic study of its microstructure and mechanical properties,the results showed that the initial state had an important influence on the evolution of the structure during extrusion.After accumulative alternating back extrusion to produce the billet,the grain size of the sheet obtained by extrusion was significantly refined,which was related to the accumulation of deformation and grain refinement during the alternating loading process.Grain refinement caused the proportion of dynamic recrystallization inside the sheet with 2 cycles of accumulative alternating back extrusion to drop to 27%.With the increase of extrusion cycles from 2 to 4,the high density of dislocations led to an increase in the proportion of dynamic recrystallization and finer grains.The texture changed from strong basal texture to weak bimodal texture.The results of uniaxial tensile test show that due to grain refinement and texture change,the yield strength was significantly reduced,and the plasticity was significantly improved.It was verified that accumulative alternating back extrusion was meaningful for subsequent processing,and it also provided scientific guidance for the development of fine-grained magnesium alloy sheet.

关键词： Magnesium alloy Alternating back extrusion Microstructure uniformity Bimodal texture Texture weakening Sheet anisotropy

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Research progress on temperature field evolution of hot reservoirs under low-temperature tailwater reinjection

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Journal of Groundwater Science and Engineering 2024年第2期12卷 205-222页

作者： Xin Wang Guo-qiang Zhou Yan-guang Liu Ying-nan Zhang Mei-hua Wei Kai bian School of Earth science and Engineering Hebei University of EngineeringHandan 056038HebeiChina Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological SciencesShijiazhuang 050061China Technology Innovation Center of Geothermal&Hot Dry Rock Exploration and Development Ministry of Natural ResourcesShijiazhuang 050061China Shanxi Key Laboratory for Exploration and Exploitation of Geothermal Resources Taiyuan 030024China Shanxi Geological Engineering Exploration Institute Taiyuan 030024China

This paper focuses on the study of the evolutionary mechanism governing the temperature field of geothermal reservoir under low-temperature tailwater reinjection conditions,which is crucial for the sustainable geothermal energy management.With advancing exploitation of geothermal resources deepens,precise understanding of this mechanism becomes paramount for devising effective reinjection strategies,optimizing reservoir utilization,and bolstering the economic viability of geothermal energy development.The article presents a comprehensive review of temperature field evolution across diverse heterogeneous thermal reservoirs under low-temperature tailwater reinjection conditions,and analyzes key factors influ-encing this evolution.It evaluates existing research methods,highlighting their strengths and limitations.The study identifies gaps in the application of rock seepage and heat transfer theories on a large scale,alongside the need for enhanced accuracy in field test results,particularly regarding computational effi-ciency of fractured thermal reservoir models under multi-well reinjection conditions.To address these shortcomings,the study proposes conducting large-scale rock seepage and heat transfer experiments,coupled with multi-tracer techniques for field testing,aimed at optimizing fractured thermal reservoir models'computational efficiency under multi-well reinjection conditions.Additionally,it suggests integrat-ing deep learning methods into research endeavors.These initiatives are of significance in deepening the understanding of the evolution process of the temperature field in deep thermal reservoirs and enhancing the sustainability of deep geothermal resource development.

关键词： Geothermal reinjection Seepage heat transfer Tracer test Numerical simulation Thermal breakthrough

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Effect of Accumulative Strain on Grain Refinement and Strengthening of ZM6 Magnesium Alloy During Continuous Variable Cross-Section Direct Extrusion

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Acta Metallurgica Sinica(English Letters) 2015年第5期28卷 649-655页

作者： Feng Li Wei Shi nan bian Hong-Bin Wu School of Materials Science and Engineering Harbin University of Science and Technology

In order to study the influence of die combination on continuous variable cross-section direct extrusion （CVCDE） in the extrusion process, the accumulative strain formula is derived, and it can be known that the extrusion ratio of various stages directly determines the size of corresponding stage strain by formula. In this paper, as an example of the two interim dies, three die combinations of different angles and extrusion ratio are designed. Aviation magnesium alloy ZM6 is studied, and the results show that dynamic recrystallization is even more complete when continuous shear deformation occurs, so that the refinement and homogenization of microstructure are obtained. By the use of different die combinations, the accumulative strain increases under the conditions of same total extrusion ratio. Thus, the refined crystalline strengthening effect of extrusion deformation can be further analyzed. Due to the dead-zone defects, the actual accumulative strain decreases significantly and the effect of microstructure and performance improvements also decreases with it. Therefore, the optimal design of die combination is the key to the process and product of CVCDE, which provides a scientific basis for the development of severe plastic deformation.

关键词： Continuous variable cross-section direct extrusion （CVCDE） Die combination Accumulative strain Magnesium alloys Severe plastic deformation

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乳杆菌强化发酵对苦荞酵素抗氧化特性及风味的影响

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食品工业科技 2024年第2期45卷 118-125页

作者：边名鸿袁天萌杨南韩保林黄丹丹许强四川轻化工大学生物工程学院四川宜宾644000 川北医学院四川南充637000 南充生物医药产业技术研究院四川南充637000

为提高苦荞酵素的口感与抗氧化能力,以还原力、SOD酶活力作为主要指标,分别考察植物乳杆菌(LBS8、MRS5)、副植物乳杆菌(MC6)、副干酪乳杆菌(SL1)4株乳杆菌强化发酵苦荞酵素情况,筛选1株优良菌株并研究其接种量、初始糖度、发酵温度、料... 详细信息

为提高苦荞酵素的口感与抗氧化能力,以还原力、SOD酶活力作为主要指标,分别考察植物乳杆菌(LBS8、MRS5)、副植物乳杆菌(MC6)、副干酪乳杆菌(SL1)4株乳杆菌强化发酵苦荞酵素情况,筛选1株优良菌株并研究其接种量、初始糖度、发酵温度、料液比对苦荞酵素发酵的影响,通过单因素实验及正交试验优化苦荞酵素发酵工艺。结果表明,植物乳杆菌LBS8发酵苦荞酵素还原力、SOD酶活力更强,将其作为强化菌株经单因素实验与正交优化,得到最佳工艺条件为:接种量6%,初始糖度16°Brix,发酵温度32℃,料液比1:7。所得酵素中还原力相当于0.753 mg/mL VC标准溶液,SOD酶活力为272.12 U/mL,总黄酮含量为0.521 mg/mL,总酚含量为2.75 mg/mL,谷胱甘肽含量为0.273 mg/mL,与对照组相比均有显著提升。通过GC-MS分析,苦荞酵素中含有乙酸乙酯、亚油酸乙酯、十一酸乙酯、丁二酮等特征性香味物质,赋予苦荞酵素独特的风味。与市售酵素发酵剂相比,利用植物乳杆菌强化发酵酵素总黄酮增加247%,总酚增加2%,谷胱甘肽增加36.5%,还原力提高30.73%,抗氧化能力提高30.09%,香味及口感更为丰富,表明植物乳杆菌强化发酵有利于提升苦荞酵素品质。

关键词：乳杆菌苦荞酵素发酵工艺风味

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熊去氧胆酸治疗1个月后的碱性磷酸酶水平和基线红细胞分布宽度对原发性胆汁性胆管炎治疗应答的预测价值

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临床肝胆病杂志 2024年第3期40卷 496-501页

作者：王楠胡蓉卞石惠仲威张鹏飞谭友文江苏大学附属人民医院老年科江苏镇江212002 江苏大学附属医院心血管科江苏镇江212002 江苏大学附属第三人民医院肝病科江苏镇江212004

目的研究基线红细胞分布宽度(RDW)和熊去氧胆酸(UDCA)治疗1个月后的ALP水平预测原发性胆汁性胆管炎(PBC)患者对UDCA治疗的应答情况。方法回顾性分析2015年1月—2022年7月于江苏大学附属第三人民医院肝病中心确诊的127例PBC患者资料,收... 详细信息

目的研究基线红细胞分布宽度(RDW)和熊去氧胆酸(UDCA)治疗1个月后的ALP水平预测原发性胆汁性胆管炎(PBC)患者对UDCA治疗的应答情况。方法回顾性分析2015年1月—2022年7月于江苏大学附属第三人民医院肝病中心确诊的127例PBC患者资料,收集基线指标、治疗1个月后以及1年后随访数据。根据巴黎-Ⅰ标准将患者分为应答良好组和应答欠佳组,分析2组患者临床及实验室特征,以及与UDCA应答之间的相关性,利用Logistic回归法分析与UDCA治疗应答相关的独立危险因素。利用ROC曲线下面积(AUC)确定相关指标的最佳临界值,根据界值将患者再次分组,分析两组间基线指标、应答情况的差异。符合正态分布的计量资料两组间比较采用成组t检验;非正态分布的计量资料两组间比较采用Mann-Whitney U检验。计数资料组间比较则采用χ^(2)检验。结果UDCA应答欠佳组患者基线TBil、AST/ALT、ALP、RDW、RDW-CV以及UDCA治疗1个月后的ALP水平明显高于应答良好组(Z值分别为-4.792、-3.697、-2.399、-4.102、-3.220、-4.236,P值均<0.05);应答欠佳组患者基线Alb、Hb、淋巴细胞数、红细胞比容及BMI水平明显低于应答良好组(Z值分别为-3.592、-3.603、-2.602、-3.829、-2.432,P值均<0.05);应答欠佳组患者基线前白蛋白、白球比、载脂蛋白A、游离三碘甲状腺原氨酸水平明显低于应答良好组(t值分别为4.530、3.402、3.485、3.639,P值均<0.001)。应答良好组患者存在肝硬化、合并胆囊结石胆囊炎以及贫血占比较低,两组间差异均有统计学意义(χ^(2)值分别为20.815、3.892、12.283,P值均<0.05)。与UDCA应答相关的独立危险因素为基线RDW(OR=1.157,95%CI:1.028~1.301,P=0.015)及治疗1个月后的ALP水平(OR=1.012,95%CI:1.005~1.020,P=0.002),其AUC分别为0.713、0.720。基线RDW≥正常值上限且UDCA治疗1个月后ALP≥2.2倍正常值上限组患者UDCA应答率更低(42.6%vs 8.2%,χ^(2)=20.813,P<0.001)。结论基线RDW≥正常值上限同时UDCA治疗1个月后ALP≥2.2倍正常值上限的患者对UDCA的生化应答率更低。

关键词：原发性胆汁性胆管炎熊去氧胆酸危险因素生化学应答

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收缩管与拉瓦尔管在液体雾化中的对比研究

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力学季刊 2024年第1期45卷 42-57页

作者：苏男梁俊凯朱勇铮赵冲严微微边鑫中国计量大学计量测试工程学院浙江杭州310018 浙江大学工程力学系浙江杭州310027 杭州时光机智能电子科技有限公司浙江杭州310018

为探究新型透皮给药方式中不同形状微管对雾化的影响,本文以收缩管和拉瓦尔管为对象展开研究.首先,我们使用相位多普勒粒子分析仪(Phase Doppler Particle Analyzer, PDPA)对经两类微管雾化后的液滴进行速度和粒径分布的测量.然后,为了... 详细信息

为探究新型透皮给药方式中不同形状微管对雾化的影响,本文以收缩管和拉瓦尔管为对象展开研究.首先,我们使用相位多普勒粒子分析仪(Phase Doppler Particle Analyzer, PDPA)对经两类微管雾化后的液滴进行速度和粒径分布的测量.然后,为了解管内流动情况,我们利用动态压强传感器对管内气体压强进行了测量,并利用纹影法对管内流动情况进行观察.最后,我们利用高速液滴对皮肤模型进行了喷射试验,其中使用亚甲基蓝和伊文思蓝作为染色试剂,新鲜猪耳作为喷射对象.PDPA实验表明,液滴经拉瓦尔管的雾化比经收缩管的雾化更充分.压强测量结果表明拉瓦尔管内存在激波,进而证明了管内发生过超声速.纹影实验更直观地表明在本研究关注的拉瓦尔管内,气体流动在扩张段形成的不是正激波,而是两道交错的斜激波.皮肤模型喷射实验结果表明雾化后高速液滴穿透了角质层,展示了微喷管在医美行业透皮给药中有潜在的应用价值.该工作为新颖透皮给药方式的进一步研究奠定了基础.

关键词：收缩管拉瓦尔管雾化 PDPA 纹影法

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12个燕麦品种在黄土高原沟壑区生产性能及适应性

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草业科学 2024年第5期41卷 1175-1188页

作者：景芳刘彦明南铭边芳任生兰陈富张成君甘肃农业大学草业学院甘肃兰州730070 甘肃省定西市农业科学研究院甘肃定西743000 甘肃省农业科学院作物研究所甘肃兰州730070

为筛选适宜黄土高原沟壑区种植的高产、抗倒伏、抗病性强的燕麦(Avena sativa)品种,以国内外引进的12个燕麦品种为试验材料,分析其产量相关性状、倒伏率和病害发生率,并利用灰色关联度分析和聚类分析法进行综合评价。结果表明:12个燕麦... 详细信息

为筛选适宜黄土高原沟壑区种植的高产、抗倒伏、抗病性强的燕麦(Avena sativa)品种,以国内外引进的12个燕麦品种为试验材料,分析其产量相关性状、倒伏率和病害发生率,并利用灰色关联度分析和聚类分析法进行综合评价。结果表明:12个燕麦品种干草产量为10800.00~15233.33 kg·hm^(−2),平均干草产量13298.61 kg·hm^(−2);种子产量为3095.24~7857.14 kg·hm^(−2),平均值5407.14 kg·hm^(−2);其中,‘坝燕6号’的倒伏率较低,红叶病和锈病发病率最低,为抗倒伏兼抗病品种。灰色关联度分析结果表明:株高、干草产量、叶茎比在灰色关联评价系统中所占权重最高,是品种选择时的重要指标。采用聚类分析方法将12个燕麦品种划分为3个类群,第Ⅰ类群可作为饲草品种,第Ⅱ类群可作为籽粒型品种,第Ⅲ类群倒伏率及病情指数低,抗逆性好。综合灰色关联度和聚类分析方法,筛选出适宜黄土高原沟壑区种植的产量高、适应性好的饲草型燕麦品种‘加燕2号’,籽粒型燕麦品种‘坝燕6号’和‘美达’。

关键词：饲草产量种子产量农艺性状倒伏病害灰色关联度评价聚类分析

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