检索结果-南通市图书馆

Microstructure and tensile properties of Ti-62421S alloy plate with different annealing treatments

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2018年第7期37卷 568-573页

作者： Yong-Ling Wang xiao-yun Song Wen Ma Wen-Jing Zhang Wen-Jun ye Song-xiao Hui State Key Laboratory of Nonferrous Metals and Processes General Research Institute for Nonferrous Metals Division of Science and Technology Information General Research Institute for Nonferrous Metals

Ti-62421S （Ti-6A1-2Sn-4Zr-2Nb-lMo-0.2Si） is a novel short-time using high-temperature titanium alloy. The effects of annealing on microstructure and tensile properties of Ti-62421S alloy plate were studied through optical microscopy （OM）, electron probe microanalysis （EPMA）, transmission electron microscopy （TEM）, and tensile tests. The results show that, with annealing tem- perature increasing, the volume fraction of primary α（αp）- phase decreases while that of transformed β（βt）-structure and secondary α （αs）-phase increases. The room-temperature strength and plasticity are insensitive to annealing temperature. However, with annealing temperature increasing, the tensile strength decreases at 550℃, while increases at 600 and 650℃ instead. It is suggested that, at 550℃, the strengthening mechanism is mainly boundary strengthening and the biggest contributor is ap-phase by providing αp/β-boundary area. Above 600 ℃, the strengthening mechanism is grain strengthening, where αs-phase strengthens the β-phase.

关键词： High temperature titanium alloy Ti-62421S Heat treatment Microstructure Tensile properties

The complex roles of m^(6)A modifications in neural stem cell proliferation, differentiation, and self-renewal and implications for memory and neurodegenerative diseases

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第6期20卷 1582-1598页

作者： Yanxi Li Jing Xue Yuejia Ma Ke ye Xue Zhao Fangliang Ge Feifei Zheng Lulu Liu Xu Gao Dayong Wang Qing Xia Department of Biochemistry and Molecular Biology College of Basic Medical SciencesHarbin Medical UniversityHarbinHeilongjiang ProvinceChina College of Basic Medical Sciences Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Basic Medical Institute Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina Key Laboratory of Heilongjiang Province for Genetically Modified Animals Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Translational Medicine Research and Cooperation Center of Northern China Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina Dongzhimen Hospital Beijing University of Chinese MedicineBeijingChina

N6-methyladenosine(m^(6)A), the most prevalent and conserved RNA modification in eukaryotic cells, profoundly influences virtually all aspects of mRNA metabolism. mRNA plays crucial roles in neural stem cell genesis and neural regeneration, where it is highly concentrated and actively involved in these processes. Changes in m^(6)A modification levels and the expression levels of related enzymatic proteins can lead to neurological dysfunction and contribute to the development of neurological diseases. Furthermore, the proliferation and differentiation of neural stem cells, as well as nerve regeneration, are intimately linked to memory function and neurodegenerative diseases. This paper presents a comprehensive review of the roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, as well as its implications in memory and neurodegenerative diseases. m^(6)A has demonstrated divergent effects on the proliferation and differentiation of neural stem cells. These observed contradictions may arise from the time-specific nature of m^(6)A and its differential impact on neural stem cells across various stages of development. Similarly, the diverse effects of m^(6)A on distinct types of memory could be attributed to the involvement of specific brain regions in memory formation and recall. Inconsistencies in m^(6)A levels across different models of neurodegenerative disease, particularly Alzheimer's disease and Parkinson's disease, suggest that these disparities are linked to variations in the affected brain regions. Notably, the opposing changes in m^(6)A levels observed in Parkinson's disease models exposed to manganese compared to normal Parkinson's disease models further underscore the complexity of m^(6)A's role in neurodegenerative processes. The roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, and its implications in memory and neurodegenerative diseases, appear contradictory. These inconsistencies may be a

关键词： Alzheimer's disease cell self-renewal central nervous system memory microglia nerve regeneration neurodegenerative diseases neurogenesis RNA methylation

Performance analysis of the mooring system of a two-module scientific research and demonstration platform

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2021年第5期33卷 901-914页

作者： Xin-yun Ni xiao-ming Cheng Bo Wu Jun Ding Yong-lin ye Ze Sun China Ship Scientific Research Center Wuxi 214082China

A mooring system has been designed for the position keeping of a two-module semi-submersible platform which is connected by hinge-type *** the excitation of ocean waves,the relative motion between the two modules can be *** is therefore no longer adequate to model the platform as a single rigid body in the analysis of the performance of the mooring *** this study,an analysis method has been developed based on the three-dimensional frequency domain hydroelasticity theory in conjunction with the time domain quasi-static analysis method of mooring actions,which takes into account of the coupling effect of the platform motion and mooring *** proposed method is verified by comparing the numerical results with the measured data obtained from the on-site *** comparison shows a good agreement,and demonstrates the feasibility and effectiveness of the proposed method for the analysis of the module responses and mooring tensions of multi-module floating platforms.

关键词： Mooring system coupled analysis sea trial verification two-module floating platform hydroelasticity theory numerical comparison

Two new chalcones from Fordia cauliflora

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 Chemical Letters 2010年第7期21卷 818-820页

作者： Zhi Yuan Liang xiao Sheng Yang ye Wang xiao Jiang Hao Qian yun Sun The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academy of Sciences Guiyang 550002China School of Chemistry and Life Science Guizhou Normal CollegeGuiyang 550003China

Two new chalcones,β,2′,4′,5′-tetramethoxychalcone 1,andβ,2′,5′-trimethoxyfurano[4″,5″：3′,4′]-chalcone 2 were obtainedfrom an ethyl acetate-soluble fraction of ethanol extract of the stem of Fordia *** chem... 详细信息

关键词： Fordia cauliflora Chalcone Chemical structures

A"4D"systemic view on meridian essence:Substantial,functional,chronological and cultural attributes

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2022年第2期20卷 96-103页

作者： xiao ye Yu-lan Ren yun-hui Chen Ji Chen xiao-jiao Tang Zong-ming Zhang aInstitute of Literature in Chinese Medicine Nanjing University of Chinese MedicineNanjing 210023Jiangsu ProvinceChina Humanities and Management School Zhejiang Chinese Medical UniversityHangzhou 310053Zhejiang ProvinceChina School of Chinese Classics Chengdu University of Traditional Chinese MedicineChengdu 611137Sichuan ProvinceChina School of Basic Medicine Chengdu University of Traditional Chinese MedicineChengdu 611137Sichuan ProvinceChina State Key Laboratory of Biotherapy West China Hospital of Sichuan UniversityChengdu 610041Sichuan ProvinceChina School of Foreign Languages Chengdu University of Traditional Chinese MedicineChengdu 611137Sichuan ProvinceChina School of Basic Medicine Zhejiang Chinese Medical UniversityHangzhou 310053Zhejiang ProvinceChina

The term Jingluo,translated as meridian or channel,is a core component of traditional Chinese medicine(TCM)and has played a fundamental role in guiding the clinical practice of acupuncture for thousands of ***,the essence of the meridian remains elusive and is a source of both confusion and debate for *** this study,a“4 D”systemic view on the essence of the meridian,namely substantial,functional,chronological,and cultural dimensions,was proposed based on a review of the ancient medical classics,recent research developments,and results from clinical *** studies have primarily focused on the substantial dimension of the meridian system,with scant interpretation about its functional *** systemic data nor evaluations have been adequately ***,a limited but increasing number of studies have focused on the chronological and cultural *** investigations that embody the holistic concept of TCM and integrate the systemic modes and advanced techniques with dominant diseases of TCM need to be performed to obtain a more comprehensive understanding of the essence of *** goal of this study is to yield useful information in understanding the essence of meridians and provide a reference and perspective for further research.

关键词： Acupuncture Meridian Essence Substance Function Chronology Culture

Solvent-Controlled Construction of Molecular Chains and Bowls/Sieves from a Bent Dipyridyl Ligand

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2021年第9期39卷 2523-2528页

作者： xiao-yun Tian xiao-Xian Chen Chao Wang Zi-Ming ye Dong-Dong Zhou Jie-Peng Zhang MOE Key Laboratory of Bioinorganic and Synthetic Chemistry School of ChemistrySun Yat-Sen UniversityGuangzhouGuangdong 510275China

Solvothermal reactions of 3,6-di(pyridin-4-yl)-9H-carbazole(dpc)with Cu(ll)yielded crystals of two new coordination complexes,namely[Cu(CH_(3)COO)_(2)(dpc)(H_(2)O)_(2)]n-xGuest(1)and[Cu_(13)(HCOO)_(16)(dpc)16(H_(2)O)6](HCOO)10-Guest(2),in which CH_(3)COO_and HCOO-were generated from the hydrolysis of the solvents A/zAZ-dimethylacetamide(DMA)and A/zA/-dimethylformamide(DMF),***-crystal X-ray diffraction showed that 1 possesses simple wavy coordination chains,while 2 possesses large molecular bowls/sieves with outer and inner effective sizes of 30.2 × 30.2 × 25.5 A^(3) and 15.0 × 15.0 × 18.6 A^(3),respectively,which consists of 4 linear Cu_(3)(HCOO)_(4)(H_(2)O)clusters and 12 dpc ligands as the square-shaped wall and a claw-like Cu(dpc)_(4) fragment as the ***-free 2 can adsorb considerable amounts of CO_(2)/H_(2)O and CH_(3)OH but completely exclude C2H4 and C3H6z which shows a potential application for olefin drying.

关键词： Self-assembly Crystal engineering Microporous materials Molecular sieve Olefin drying

Thermally activated delayed fluorescence enhanced by macrocyclization

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

Science China Chemistry 2025年

作者： Shuo Li Chenghao Zhu Lijun Mao Xin Zhang Zecong ye Chunju Li Da Ma School of Pharmaceutical and Chemical Engineering & Institute for Advanced Studies Taizhou University School of Chemical Engineering and Light Industry Guangdong University of Technology Tianjin Key Laboratory of Structure and Performance for Functional Molecules Tianjin Normal University

Thermally activated delayed fluorescence (TADF) depends on reverse intersystem crossing (RISC) from the lowest triplet to the singlet excited state. Here, a macrocyclization strategy is developed to achieve TADF emission by promoting RISC. 5-(9Hcarbazol-9-yl) isophthalonitrile, a fluorescent molecule, is coupled with 1,4-dimethoxybenzene by methylene bridges to form a macrocycle with TADF emission. Experimental results and theoretical calculation indicate that the macrocyclization strategy contributes to RISC promotion and suppression of nonradiative decay, resulting in effective TADF emission transformed from prompt fluorescence. Three TADF luminophores are cyclized with the same strategy, and an enhanced TADF emission of up to3.8 folds is observed. The marriage of macrocycle chemistry and luminescent materials will provide new guidelines for designing efficient TADF materials.

关键词：

Transient simulation of a pump-turbine with misaligned guide vanes during turbine model start-up

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2014年第5期30卷 646-655页

作者： ye-Xiang xiao Ruo-Fu xiao State Key Laboratory of Hydroscience and Engineering & Department of Thermal Engineering Tsinghua University College of Water Resources and Civil Engineering China Agricultural University

Experimental studies of a model pump-turbine S-curve characteristics and its improvement by misaligned guide vanes （MGV） were extended to prototype pump turbine through 3-D transient flow simulations. The unsteady Reynolds-averaged Navier-Stokes equations with the SST turbulence model were used to model the transient flow within the entire flow passage of a reversible pump-turbine with and without misaligned guide vanes during turbine model start-up. The unstable S-curve and its improvement by using misaligned guide vane were verified by model test and simulation. The transient flow calculations were used to clarify the variations of pressure pulse and internal flow behavior in the entire flow passage. The use of misaligned guide vanes can eliminate the S-curve characteristics of a pump-turbine, and can significantly increase the pressure pulse amplitude in the entire flow passage and the runner radial forces during start-up. The MGV only decreased the pulse amplitude on the guide vane suction side when the rotating speed was less than 50% rated speed. The hydraulic reason is that the MGV dramatically changed the flow patterns inside the entire flow passage, and destroyed the symmetry of the flow distribution inside the guide vane and runner.

关键词： Transient flow. Pump turbine. Misaligned guide vane Model test Pressure pulse

Simplified Scheme for Testing Symmetrization Postulate for Photons

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2007年第5期47卷 913-915页

作者： ye Sai-yun Department of Electronic Science and Applied Physics Fuzhou University Fuzhou 350002 China

We propose a scheme for testing the small violations of the symmetrization postulate （SP） for photons in cavity QED. In the scheme, a degenerate A-type three-level atom is sent through a cavity field initially in a q-deformed coherent state. After an appropriate interaction time, the atom is measured by a state-selective detector. The probability that the atom makes a transition from one of the lower states to the other characterizes the violation of the SP. In the scheme, only one atom is required and classical fields are unnecessary, which is prior to the previous schemes.

关键词： symmetrization postulate photon Raman interaction