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汞电极表面痕量DNA的电化学响应及其检测(英文)

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南开大学学报（自然科学版） 2005年第3期38卷 93-96页

作者：韩君史海滨安■顺一陈强南开大学生命科学学院天津300071 日本东北大学药学研究科

用电化学方法来研究在汞电极上的DNA样本并得到了一个较为理想的DNA的响应电流.实验结果表明,尽管不同DNA样本在检测结果上有着微小的差异,但它们都证实这种电化学方法可作为一种新的系统性的分析痕量DNA方法.因此,可以发展一种由电化... 详细信息

用电化学方法来研究在汞电极上的DNA样本并得到了一个较为理想的DNA的响应电流.实验结果表明,尽管不同DNA样本在检测结果上有着微小的差异,但它们都证实这种电化学方法可作为一种新的系统性的分析痕量DNA方法.因此,可以发展一种由电化学方法促进的极谱法来检测痕量的DNA.在最适条件下,以这种方法检测DNA的浓度范围在2～20 μg/mL内呈良好的线性关系.检测极限为1.0μg/mL.相对标准偏差为4.5%(10μg/mL DNA,6次连续检测).鉴于电化学技术的优点,这一方法可能在生物化学和分子生物学领域发挥作用.

关键词： DNA 极谱法检测

Oxidation behavior and improvement in nonflammability of LPSO-type Mg–Zn–Y–Sr alloy

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Journal of Magnesium and Alloys 2024年第2期12卷 742-749页

作者： Shin-ichi Inoue Kazumasa Iwanaga Yoshihito Kawamura Magnesium Research Center Kumamoto University2-39-1 KurokamiChuo-kuKumamoto 860-8555Japan Department of Materials Science Graduate School of Science and TechnologyKumamoto University2-39-1 KurokamiChuo-kuKumamoto 860-8555Japan

Mg_(97)Zn_(1)Y_(2)alloys with high ignition temperatures were developed by adding *** addition of Sr resulted in the formation of a uniform and thin Y_(2)O_(3)***–Zn–Y alloys containing at least 0.25 at.%Sr exhibited ignition temperatures of 1270–1320 *** a result of EDS measurement,Sr was found to be concentrated in the Y_(2)O_(3)*** addition,a mixed film of MgO and Sr O formed on the outer layer in the 1.5 at.%Sr-containing Mg_(97)Zn_(1)Y_(2)*** findings suggest that the uniform and thin Y_(2)O_(3)film that maintains high soundness at high temperatures was formed owing to valence control and the formation of a protective outer oxide film.

关键词： Magnesium alloy Yttrium Strontium High-temperature oxidation Nonflammability

Natural Convection Melting in a Rectangular Heat Storage Tank of Carbon Nanotube Dispersed Latent Heat Storage Material

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Journal of Thermal Science 2024年第3期33卷 847-855页

作者： Shin-ichi MORITA Tomoya SAITO Kazunori TAKAI Yasutaka HAYAMIZU Naoto HARUKI Division of Mechanical and Electrical Engineering Kitami Institute of Technology165 Koen-choKitami-shiHokkaido090-8507Japan National Institute of Technology Yonago College4448 Hikona-cyoYonago-shiTottori683-8502Japan Okayama Prefectural University 111 KubokiSoja-shiOkayama719-1197Japan

A dispersion system fluid can convect even if the dispersoid is a solid ***,heat exchange performance can be improved while maintaining fluidity using a material with high thermal conductivity as the *** study presents the melting performance evaluation results of a latent heat storage material with a carbon nanotube(CNT)dispersion system with high thermal conductivity,which enhances the thermal conductivity of the latent heat storage material and does not limit free *** the thermal conductivity and enhancing the melting convection of the heat storage material result in increased latent heat storage *** this study,the thermal conductivity of the latent heat storage material was successfully increased by dispersing CNTs in the *** 0.1%(in mass)of multi-wall CNT(MWCNT)was dispersed in a paraffin-based latent heat storage material,the shear stress increased by 1.5 times at a shear rate of 500 s^(-1),while taking into account the potential effects of convective ***,a latent heat storage experiment was conducted in a rectangular heat storage tank using the CNT dispersion composition ratio as a parameter.A rectangular vessel with a heated vertical surface was used for the latent heat storage *** melting speed was determined by comparing the amount of latent heat stored in a CNT-dispersed latent heat storage material and a single-phase latent heat storage material *** experimental results show that the time required for the latent heat storage material to completely melt in the heat storage tank was the shortest for the single-phase latent heat storage material ***,the fastest melting progress was observed for the sample with 0.02%(in mass)MWCNT content in the melting rate range of up to approximately 40%in the *** results indicate that this phenomenon is caused by the difference in the melting rates in the upper part of the *** generated data are useful for det

关键词： latent heat storage phase change carbon nano tube free convection heat transfer

Catalyst-free electrochemical S_(N)Ar of electron-rich fluoroarenes using carboxylic acids

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eScience 2024年第5期4卷 120-131页

作者： anzai Shi Yaowen Liu Ranran Zhang Zile Zhu Youai Qiu State Key Laboratory and Institute of Elemento-Organic Chemistry Frontiers Science Center for New Organic MatterCollege of ChemistryNankai University94 Weijin RoadTianjin 300071China

Herein,an electrochemically driven catalyst-free nucleophilic aromatic substitution(S_(N)Ar)of electron-rich fluoroarenes with carboxylic acids as weak nucleophiles under mild conditions was reported.A series of highly valuable ester derivatives were obtained in a direct and rapid *** transformation features commercially available reagents and an exceptionally broad substrate scope with good functional group tolerance,using cheap and abundant electrodes and completed within a short reaction ***-scale synthesis and complex biorelevant compounds ligation further highlighted the potential utility of the *** mechanistic investigations and density functional theory(DFT)calculations verified the feasibility of the proposed pathway of this transformation.

关键词： Electrochemistry DefluorinationElectrochemical S_(N)Ar Catalyst-free process Carboxylic acids

Optimizing piezoelectric performance of complex perovskite through increasing diversity of B-site cations

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Journal of Materials Science & Technology 2024年第3期170卷 78-86页

作者： Mengdi Cheng Dongyan Zhang Yangxi Yan Zhimin Li Pangpang Wang Ri-ichi Murakami School of Advanced Materials and Nanotechnology Xidian UniversityXi’an 710126China Nanomaterials Group Institute of SystemInformation Technologies and Nanotechnologies(ISIT)Fukuoka Industry-Academia Symphonicity(FiaS)4-1 KyudaishinmachiNishi-kuFukuoka 819-0388Japan School of Mechanical Engineering Chengdu UniversityChengdu 610106China

Piezoelectric materials with unique properties are hugely appealing for high sensitivity sensors and ultrasonic ***,Pb(Ni_(1/3)Nb_(2/3))O_(3)-Pb(Yb_(1/2)Nb_(1/2))O_(3)-PbTiO_(3)piezoelectric system was designed and investigated in *** optimized piezoelectric response(d_(33)=826 pC/N,d_(33)∗=1017 pm/V)together with good temperature stability and negligible performance degradation up to 10^(6) cycles was achieved in 0.58PNN-0.10PYN-0.32PT *** analysis revealed the amplification of intrinsic and extrinsic contributions in MPB region due to more spontaneous polarization orientations and an increase in chemical disorder of system after the introduction of *** origin of high piezoelectric response was investigated through the combination of scanning electron microscopy and piezoresponse force *** diversity of B-site cations was shown to enhance local structural heterogeneity,weaken long-range ferroelectric ordered domains,and lower free energy barrier via the formation of nanodomain configuration that promoted polarization rotation,thereby improving piezoelectric properties of the ***,it is suggested that increasing the diversity of B-site cations is an effective strategy for achieving outstanding piezoelectric performance.

关键词： PNN-PYN-PT ceramics Piezoelectricity enhancement Relaxation behavior Domain structure

石英晶体微天平实时监测低密度脂蛋白在胆固醇修饰葡聚糖上的吸附及其动力学研究

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高等学校化学学报 2005年第6期26卷 1166-1169页

作者：韩松岩刘东波黄亮王深琪刘清平安齐顺一长哲郎陈强南开大学生命科学学院天津300071 南开大学生物活性材料教育部重点实验室天津300071 日本东北大学大学院药学研究科仙台9808578

利用石英晶体微天平实时监测低密度脂蛋白(LDL)在胆固醇修饰葡聚糖(CMD)上的吸附,并对其吸附动力学进行研究.结果表明,CMD与LDL之间的相互作用符合Langmuir吸附方程,当LDL浓度(ng/μL)为9.9,12.38和14.14时,其吸附平衡常数[K/(mol·L-1... 详细信息

利用石英晶体微天平实时监测低密度脂蛋白(LDL)在胆固醇修饰葡聚糖(CMD)上的吸附,并对其吸附动力学进行研究.结果表明,CMD与LDL之间的相互作用符合Langmuir吸附方程,当LDL浓度(ng/μL)为9.9,12.38和14.14时,其吸附平衡常数[K/(mol·L-1·s-1)]分别为0.0477,0.0536和0.0628,表面吸附量(ng/cm2)分别为107.6,139.6和167.9.最大吸附量达到284.8ng/cm2,吸附率为72.91%.

关键词：石英晶体微天平胆固醇修饰葡聚糖低密度脂蛋白吸附

Key issues on magnetic reconnection at Mercury

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Earth and Planetary Physics 2024年第5期8卷 673-685页

作者： jun Zhong Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences

Magnetic reconnection processes and their impact on planetary magnetospheric dynamics exhibit significant differences due to differences in upstream solar wind conditions and internal planetary environments. Current understanding of reconnection phenomena at Mercury is rooted in the MESSENGER mission. However, direct detection of reconnection remains rare. Here, we aim to assess the limitations of MESSENGER in detecting reconnection in Mercury's space and to discuss key issues of reconnection that will be addressed by BepiColombo, including the dynamics of magnetic flux ropes, particle acceleration, density asymmetric reconnection,IMF-driven near-tail structures, and potential modes of magnetospheric convection.

关键词： magnetic reconnection Mercury MESSENGER BepiColombo

Numerical investigation of non-uniform temperature fields for proppant and fluid phases in supercritical CO_(2)fracturing

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Particuology 2024年第7期90卷 149-163页

作者： Boyu Liu jun Yao Research Center of Multiphase Flow in Porous Media China University of Petroleum(East China)Qingdao 266000China

The non-uniform temperature distribution in supercritical CO_(2)(Sc-CO_(2))fracturing influences the density,viscosity,and volume expansion or shrinkage rate of Sc-CO_(2),impacting proppant *** study presents a coupled computational fluid dynamics-discrete element method and heat transfer model to examine the effects of proppant bed shape and the heat transfers of proppant-wall,proppant-fluid,and fluid-wall on the fluid and proppant temperature *** Sc-CO_(2)volume expansion is assessed under various temperature conditions by evaluating the volume-averaged Sc-CO_(2)*** factors,including proppant size,shape,thermal conductivity,concentration,temperature difference,and injection velocity,are carefully analyzed to elucidate their *** findings elucidate the existence of four distinct zones in the fluid temperature *** zone exhibits different magnitudes of temperature change under diverse conditions and undergoes dynamic transformations with the development of the proppant *** fluid-wall heat transfer and the fluid temperatures in Zones C and D are significantly subject to the fluid injection velocity(governing the heating duration),the temperature difference between fluid and formation(impacting the magnitude of heat flux),and the proppant bed shape(controlling the effective heating area).Additionally,the proppant-wall and proppant-fluid heat transfers determine the temperatures of both the proppant bed and the fluid within Zone B,showing a strong correlation with proppant thermal conductivity,proppant size,injection velocity,and temperature *** proposed coupled model provides valuable insights into the temperature distributions and flow behaviors of temperature-dependent fracturing fluids and proppants.

关键词： CFD-DEM Heat transfer Compressible fluid CO_(2)sequestration Proppant transport

Geometric Error Identification of Gantry-Type CNC Machine Tool Based on Multi-Station Synchronization Laser Tracers

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 150-162页

作者： jun Zha Huijie Zhang School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China Xi’an Jiaotong University Suzhou Academy Suzhou 215123China

Laser tracers are a three-dimensional coordinate measurement system that are widely used in industrial *** propose a geometric error identification method based on multi-station synchronization laser tracers to enable the rapid and high-precision measurement of geometric errors for gantry-type computer numerical control(CNC)machine *** method also improves on the existing measurement efficiency issues in the single-base station measurement method and multi-base station time-sharing measurement *** consider a three-axis gantry-type CNC machine tool,and the geometric error mathematical model is derived and established based on the combination of screw theory and a topological analysis of the machine kinematic *** four-station laser tracers position and measurement points are realized based on the multi-point positioning principle.A self-calibration algorithm is proposed for the coordinate calibration process of a laser tracer using the Levenberg-Marquardt nonlinear least squares method,and the geometric error is solved using Taylor’s first-order linearization *** experimental results show that the geometric error calculated based on this modeling method is comparable to the results from the Etalon laser *** a volume of 800 mm×1000 mm×350 mm,the maximum differences of the linear,angular,and spatial position errors were 2.0μm,2.7μrad,and 12.0μm,respectively,which verifies the accuracy of the proposed *** research proposes a modeling method for the precise measurement of errors in machine tools,and the applied nature of this study also makes it relevant both to researchers and those in the industrial sector.

关键词： Multi-point positioning Multi-station synchronization CNC machine tool Geometric error Error separation