检索结果-南通市图书馆

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

基于合肥光源数据库的束流寿命分析与诊断

核电子学与探测技术 2024年第1期44卷 131-138页

作者：杨锐余海山孙晓康汪冠良宣科刘功发中国科学技术大学国家同步辐射实验室合肥230029

高质量的电子束流寿命数据可以直接反映装置的健康状态,为了获得高质量的束流寿命数据,提出一种束流寿命数据清洗方法,并开展了影响束流寿命的关键因素研究。基于合肥光源历史数据库对2022年以来累积的束流寿命原始数据进行分析,采用Pyt... 详细信息

高质量的电子束流寿命数据可以直接反映装置的健康状态,为了获得高质量的束流寿命数据,提出一种束流寿命数据清洗方法,并开展了影响束流寿命的关键因素研究。基于合肥光源历史数据库对2022年以来累积的束流寿命原始数据进行分析,采用Python开发了自动化数据清洗程序,用于获取和处理合肥光源的原始束流寿命数据,以获得长时间跨度的束流寿命变化趋势。通过使用Pearson相关系数对束流寿命异常原因进行分析,发现合肥光源束流寿命受储存环真空压强和高频腔压的影响较大。该束流寿命清洗程序处理快捷,获取的高质量束流寿命数据可以为合肥光源的健康状态检测诊断和预警提供重要依据。

关键词：合肥光源束流寿命数据处理 Pearson相关系数

维普期刊数据库

同方期刊数据库

630MPa热处理带肋高强钢筋机械锚固性能试验研究

在线全文

学校读者我要写书评

暂无评论

建筑结构 2024年第6期54卷 84-90页

作者：戎贤孙小康赵川李艳艳徐超王凤亮谭冰河北工业大学土木与交通学院天津300401 中国二十二冶集团有限公司唐山063000 中建八局第二建设有限公司济南250022

为了研究630MPa热处理带肋高强钢筋的机械锚固性能分别采用单侧贴焊锚固与端头塞焊锚板的形式,对2组60个试件进行拉拔试验。研究不同锚固条件下混凝土抗拉强度、锚固长度、钢筋直径、混凝土保护层厚度及配箍率对其机械锚固性能的影响。... 详细信息

为了研究630MPa热处理带肋高强钢筋的机械锚固性能分别采用单侧贴焊锚固与端头塞焊锚板的形式,对2组60个试件进行拉拔试验。研究不同锚固条件下混凝土抗拉强度、锚固长度、钢筋直径、混凝土保护层厚度及配箍率对其机械锚固性能的影响。结果表明:630MPa热处理带肋高强钢筋机械锚固试件具有3种破坏形式,即混凝土劈裂、钢筋拔出、钢筋屈服,端头塞焊锚板试件抗滑移效果更优。试件的机械锚固强度随着混凝土抗拉强度、混凝土保护层厚度、配箍率的增大而增大,随着锚固长度、钢筋直径的增加而减小。基于试验结果建立了630MPa热处理带肋高强钢筋机械锚固强度计算公式,结果表明该公式计算值与试验值吻合较好。

关键词：热处理带肋高强钢筋机械锚固性能荷载-滑移曲线机械锚固强度

维普期刊数据库

Analysis of Propagation Characteristics of Electromagnetic Disturbance from the Off-Line of Pantograph-Catenary in High-Speed Railway Viaducts

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2020年第5期29卷 966-972页

作者： LI Meng WEN Yinghong sun xiaokang WANG Guodong School of Electronic and Information Engineering Beijing Jiaotong University Beijing Engineering Research Center of EMC and GNSS Technology for Rail Transportation Hangzhou Hikvision Digital Technology Co. Ltd.

Pantograph arcing caused by Off-line of pantograph-catenary(OLPC) will generate Electromagnetic disturbance(EMD), which will affect train control system and communication system. This paper proposes a simplified model of the train and pantograph to investigate propagation characteristics of EMD from OLPC in the viaduct scenario, containing attenuation law in transverse and longitudinal directions. As a result, the electric field strength of EMD from OLPC increases with distance in transverse direction from 10 m to 30 m in the viaduct scenario, which is different from the ground scenario. Thefitting formulas are found to research the attenuation law at different frequency points. We get the conclusion that the limit and measurement distance is not applicable for the viaduct scenario in current standard. To prove this,measurement in the viaduct scenario is completed, and the plausible evidence to explain the result is *** results are useful in the measurement of radiated emissions, on-board equipment layout and the research of standard in high-speed railway.

关键词： Electromagnetic disturbance (EMD) Off-line of pantograph-catenary (OLPC) Propagation Measurement Viaduct

响应面法优化羟化酶催化酪醇合成羟基酪醇工艺

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

化学与生物工程 2024年第7期41卷 44-49,55页

作者：刘英梅郭新艳张秀华张小刚刘飞张艳艳於怀龙袁丹丹孙晓康山东省药学科学院山东省生物药物重点实验室山东省多糖类药物工程实验室多糖类药物发酵与精制国家地方联合工程实验室山东济南250101

以pET-22b为载体,将基因HpaB、HpaC在*** BL21(DE3)中表达,得到高纯度的羟化酶HpaB、HpaC,并采用单因素实验和响应面法对羟化酶催化酪醇合成羟基酪醇的反应条件进行优化。确定最佳反应条件如下:温度为32℃、缓冲液为20 mmol·L^(-1)磷... 详细信息

以pET-22b为载体,将基因HpaB、HpaC在*** BL21(DE3)中表达,得到高纯度的羟化酶HpaB、HpaC,并采用单因素实验和响应面法对羟化酶催化酪醇合成羟基酪醇的反应条件进行优化。确定最佳反应条件如下:温度为32℃、缓冲液为20 mmol·L^(-1)磷酸钾缓冲液(pH值7)、酪醇浓度为17.67 mmol·L^(-1)、HpaC加量为0.78 mg·mL^(-1)、NADH浓度为9.88 mmol·L^(-1)、FAD浓度为2.88μmol·L^(-1),在此条件下,酪醇转化率为99.99%,底物酪醇几乎完全转化为羟基酪醇。该研究为酶法催化合成羟基酪醇的工业化生产提供了理论基础。

关键词：羟基酪醇羟化酶响应面法酪醇转化率生物合成

维普期刊数据库博看期刊

Laser-assisted synthesis of PtPd alloy for efficient ethanol oxidation

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第7期17卷 6032-6037页

作者： Zihang Chen Tong Liu Huijuan Zhang Beibei Pang Yuanhua sun Longfei Hu Qiquan Luo xiaokang Liu Linlin Cao Tao Yao School of Nuclear Science and Technology National Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230029China Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China

The inefficiency of ethanol oxidation reaction(EOR)presents a significant obstacle in harnessing renewable biofuels with high energy density into *** efforts,most Pt-based catalysts still suffer from drawbacks such as poor activity and susceptibility to CO poisoning,particularly in acidic ***,we employed a physical laser-assisted approach to synthetize a PtPd alloy with a 1:1 atomic *** alloy demonstrates remarkable performance in acidic EOR,boasting a high mass activity of 1.86 A·mgPt^(−1)and competitive resistance to *** in situ synchrotron radiation infrared spectroscopy with theoretical calculations,we reveal that the synergic interaction between Pt and Pd enhances both the adsorption of OH*intermediate and the dehydrogenation ability of *** work will prove the feasibility of synthesizing bimetallic alloys by a physical laser-assisted strategy and promote the development of advanced alloy electrocatalysts.

关键词： laser-assisted strategy Pt-based alloy in situ synchrotron radiation infrared spectroscopy ethanol oxidation reaction synergic interaction

Ground pressure and overlying strata structure for a repeated mining face of residual coal after room and pillar mining

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2016年第4期26卷 645-652页

作者： Jiang Bangyou Wang Lianguo Lu Yinlong sun xiaokang Jin Gan State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and Technology Xuzhou 221008 China

To investigate the abnormal ground pressures and roof control problem in fully mechanized repeated mining of residual coal after room and pillar mining,the roof fracture structural model and mechanical model were developed using numerical simulation and theoretical *** roof fracture characteristics of a repeated mining face were revealed and the ground pressure law and roof supporting conditions of the repeated mining face were *** results indicate that when the repeated mining face passes the residual pillars,the sudden instability causes fracturing in the main roof above the old goaf and forms an extra-large rock block above the mining face.A relatively stable ‘‘Voussoir beam" structure is formed after the advance fracturing of the main *** the repeated mining face passes the old goaf,as the large rock block revolves and touches gangue,the rock block will break secondarily under overburden rock *** example calculation was performed involving an integrated mine in Shanxi province,results showed that minimum working resistance values of support determined to be reasonable were respectively 11,412 kN and 10,743 kN when repeated mining face passed through residual pillar and ***-site ground pressure monitoring results indicated that the mechanical model and support resistance calculation were reasonable.

关键词：岩层结构地压采面采后复采工作面残煤房柱顶板裂缝

维普期刊数据库

A dynamic soil freezing characteristic curve model for frozen soil

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3339-3352页

作者： xiaokang Li Xu Li Jiankun Liu Key Laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing100044China School of Civil Engineering Sun Yat-sen UniversityZhuhai519082China

The soil freezing characteristic curve(SFCC)plays a fundamental role in comprehending thermohydraulic behavior and numerical simulation of frozen *** study proposes a dynamic model to uniformly express SFCCs amidst varying total water contents throughout the freezing-thawing ***,a general model is proposed,wherein the unfrozen water content at arbitrary temperature is determined as the lesser of the current total water content and the reference value derived from saturated *** dynamic performance of this model is verified through test ***,in accordance with electric double layer(EDL)theory,the theoretical residual and minimum temperatures in SFCC are calculated to be-14.5℃to-20℃for clay particles and-260℃,*** ensure that the SFCC curve ends at minimum temperature,a correction function is introduced into the general ***,a simplified dynamic model is proposed and investigated,necessitating only three parameters inherited from the general ***,both general and simplified models are evaluated based on a test database and proven to fit the test data exactly across the entire temperature *** recommended parameter values for various types of soils are ***,this study provides not only a theoretical basis for most empirical equations but also proposes a new and more general equation to describe the SFCC.

关键词： Frozen soils Unsaturated soils Soil freezing characteristic curve(SFCC) Mathematic models

Atomically precise Ru-O-Ru clusters for enhanced water dissociation in alkaline hydrogen evolution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第8期17卷 6993-7000页

作者： Dong Liu Li Xu Sicheng Li Airong Xu Yuanhua sun Tong Liu Mengyuan Liu Huijuan Wang xiaokang Liu Tao Yao Tao Ding Hefei National Research Center for Physical Sciences at the Microscale School of Nuclear Science and TechnologyKey Laboratory of Precision and Intelligent ChemistryNational Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230029China Experimental Center of Engineering and Materials Science University of Science and Technology of ChinaHefei 230026China

Atomic clusters typically exhibit distinctive electronic structures and physicochemical ***,as the size decreases,their ability to adsorb and dissociate water also diminishes,thereby affecting chemical reactions involving water *** the adsorption and dissociation capabilities of atomic clusters towards water molecules and elucidating the mechanisms underlying their performance enhancement have become important research ***,employing the carrier-anchored strategy,Ru-O-Ru atomic clusters were prepared and displayed excellent activity and durability in the hydrogen evolution ***,the Ru-O-Ru atomic clusters exhibited only 86 mV overpotential at 100 mA·cm−^(2) and superior membrane-electrode-assembly activity than commercial Ru/C *** radiation-based Fourier transform infrared spectroscopic measurements revealed that the modification of oxygen in Ru-O-Ru units promoted the reorientation of water molecules from a H-up orientation to H-down,therefore,enhanced the formation of strong hydrogen-bond network of interfacial water on the surface of Ru-O-Ru clusters,leading to enhanced adsorption and dissociation of water and accelerated Volmer *** findings provide a potential strategy and deep insights for the development of atomic clusters in electrocatalysts.

关键词： hydrogen evolution in-situ Fourier transform infrared(FTIR) Ru catalysts electrocatalysis atomic clusters

Speech at the 7th China Standardization Forum

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Standardization 2010年第6期55卷 4-7页

作者： sun xiaokang Vice Administrator Standardization Administration of P.R.China

Hello, leaders, guests and comrades:Today, the representatives of the standardization professionals in China gather in Jinan to join in the 7th China Standardization Forum. This forum will focus on the theme of 'Implementing Standard Strategy, Accelerating Transformation of Economic Development Mode'. It is of great significance to strengthen standardization, push forward standardization strategy and serve the adjustment and transformation of the economy.

关键词：标准化论坛中国专业人士标准战略经济发展经济转型