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Chemoselective hydrogenation of α,β-unsaturated aldehydes with modified Pd/C catalyst

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Chinese Chemical Letters 2012年第7期23卷 773-776页

作者： Wen Qiang Du Ze Ming Rong Yan liang Yong Wang Xin Yi lu Yi Fan Wang lian hai lu State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian 116024China

Selective hydrogenation of α, β-unsaturated aldehydes with modified Pd/C catalyst was *** reduction of C=O bond could be efficiently inhibited by the addition of carbonates,and high selectivity to the corresponding saturated aldehydes was achieved under mild *** protocol provides an alternative for efficient preparation of saturated aldehydes.

关键词： Pd/C catalyst α,β-Unsaturatcd aldehydes Hydrogenation Selectivity

Dynamical complexity of Anosov systems driven by a quasi-periodic force

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Science China Mathematics 2025年第1期68卷 89-136页

作者： Wen Huang Zeng lian Kening lu Department of Mathematics University of Science and Technology of ChinaHefei 230026China School of Mathematics Sichuan UniversityChengdu 610065China

Consider C^(2)Anosov systems on a compact manifold driven by a quasi-periodic *** study their dynamical complexity on various levels from the perspectives of both path-wise dynamics and stochastic *** that these systems are non-wandering(i.e.,every point in the phase space is nonwandering),we prove a set of results:(1)the existence of abundance of random periodic points;(2)a random Livsic theorem;(3)a random Mañé-Bousch-Conze-Guivarc'h lemma;(4)the existence of strong random ***,a concrete example constructed on a 2-dimensional torus is also given to uncover some interesting phenomena of the systems.

关键词： random Anosov systems Anosov system on bers entropy random periodic orbit random horseshoe cohomological equation random Livsic theorem random Bousch-Mañécohomology lemma

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基于多变量自动回归的评分数据异常检测算法

计算机工程与设计 2018年第6期39卷 1629-1632,1652页

作者：孙连海卢颖成都师范学院计算机科学学院四川成都611130 西安工业大学计算机科学与工程学院陕西西安710021

将用户对产品评价数据视为用户基本行为和异常行为的组合,应用多变量自动回归方法进行用户基本行为的发现和异常行为的检测。将用户的评价值分布表示为累积分布,将评价值表示为基本行为和异常行为的线性组合的生成过程。针对评价值中混... 详细信息

将用户对产品评价数据视为用户基本行为和异常行为的组合,应用多变量自动回归方法进行用户基本行为的发现和异常行为的检测。将用户的评价值分布表示为累积分布,将评价值表示为基本行为和异常行为的线性组合的生成过程。针对评价值中混入的异常行为的稀疏性,基于噪音数据的高斯分布,给出相应的最小化目标函数。实验结果表明,该算法能很好地描述时序评价序列中用户的基本行为和异常行为,与相关算法相比能更好的对未来的评价值进行预测。

关键词：自动回归异常检测稀疏性产生过程高斯噪声

Optimization of production well patterns for natural gas hydrate reservoir: Referring to the results from production tests and numerical simulations

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China Geology 2025年第1期8卷 39-57页

作者： Lang-feng Mu Hao-tian Liu Chi Zhang Yi Zhang hai-long lu School of Earth and Space Sciences Peking UniversityBeijing 100871China Beijing International Center for Gas Hydrate School of Earth and Space SciencesPeking UniversityBeijing 100871China Chinese Academy of Geological Sciences China Geological SurveyMinistry of Natural Resources Beijing 100037China College of Engineering Peking UniversityBeijing 100871China National Engineering Research Center of Natural Gas Hydrate Exploration and Development Guangzhou 511458China China National Oil and Gas Exploration and Development LTD Corporation Petro-ChinaBeijing 100034China

Natural gas hydrate is a clean energy source with substantial resource *** contrast to conventional oil and gas,natural gas hydrate exists as a multi-phase system consisting of solids,liquids,and gases,which presents unique challenges and complicates the mechanisms of seepage and *** domestic and international natural gas hydrate production tests typically employ a single-well production *** this approach has seen some success,it continues to be hindered by low production rates and short production ***,there is an urgent need to explore a new well network to significantly increase the production of a single *** paper provides a comprehensive review of the latest advancements in natural gas hydrate research,including both laboratory studies and field *** further examines the gas production processes and development outcomes for single wells,dual wells,multi-branch wells,and multi-well systems under conditions of depressurization,thermal injection,and CO_(2) *** this basis,well types and well networks suitable for commercial exploitation of natural gas hydrate were explored,and the technical direction of natural gas hydrate development was *** study shows that fully exploiting the flexibility of complex structural wells and designing a well network compatible with the reservoir is the key to improving production from a single ***,multi-well joint exploitation is identified as an effective strategy for achieving large-scale,efficient development of natural gas hydrate.

关键词： Gas Hydrate Production Depressurization Heat Injection Replacement Multi-Branch Well Well patterns Hydrate exploration engineering

Bistable switch molecule DPACdCl_(4) showing four physical channels and high phase transition temperature

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Chinese Chemical Letters 2025年第1期36卷 591-596页

作者： Ying-Yu Zhang Jia-Qi luo Yan Han Wan-Ying Zhang Yi Zhang hai-Feng lu Da-Wei Fu Institute for Science and Applications of Molecular Ferroelectrics Key Laboratory of the Ministry of Education for Advanced Catalysis MaterialsZhejiang Normal UniversityJinhua 321004China Ordered Matter Science Research Center Jiangsu Key Laboratory for Science and applications of Molecular FerroelectricsSoutheast UniversityNanjing 211189China

Multiple switchable physical channels within one material or device,encompassing optical,electrical,thermal,and mechanical pathways,can enable multifunctionality in mechanical-thermal-opto-electronic *** integrated encryption and enhanced performance in storage and sensing presents a formidable challenge in the synthesis and functionality of new *** an effort to overcome the complexities associated with these multiple physical functions,this study investigates the large-size crystal of DPACdCl_(4)(DPA=diisopropylammonium),revealing significant features in rare multi-channel *** compound demonstrates the ability to switch between"OFF/0"and"ON/1"states in the mechanical-thermal-opto-electronic ***,DPACd Cl_(4)possesses four switchable physical channels,characterized by a higher phase transition temperature of 440.7 K and a competitive piezo-electric coefficient of 46 pC/***,solid-state NMR analysis indicates that thermally activated molecular vibrations significantly contribute to its multifunctional switching capabilities.

关键词： Organic-inorganic hybrid Phase transition Crystal Perovskite Piezoelectricity

Integrating well logs, 3D seismic, and earthquake data for comprehensive prediction of 3D in-situ stress orientations: A case study from the Weiyuan area in the Sichuan Basin, China

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Petroleum Science 2025年第1期22卷 210-221页

作者： Huan Cao Yang Zhao hai-Chao Chen Le-Le Zhang Cheng-Gang Xian Ji-Dong Yang lu Liu State Key Laboratory of Petroleum Resources and Engineering and Unconventional Petroleum Research Institute China University of Petroleum (Beijing) Department of Geophysics China University of Petroleum (East China) Aramco Beijing Research Center Aramco Asia

Determining the orientation of in-situ stresses is crucial for various geoscience and engineering applications. Conventional methods for estimating these stress orientations often depend on focal mechanism solutions(FMSs) derived from earthquake data and formation micro-imager(FMI) data from well ***, these techniques can be costly, depth-inaccurate, and may lack spatial coverage. To address this issue, we introduce the use of three-dimensional(3D) seismic data(active sources) as a lateral constraint to approximate the 3D stress orientation field. Recognizing that both stress and fracture patterns are closely related to seismic velocity anisotropy, we derive the orientation of azimuthal anisotropy from multi-azimuth 3D seismic data to compensate for the lack of spatial stress orientation information. We apply our proposed workflow to a case study in the Weiyuan area of the Sichuan Basin, China, a region targeted for shale gas production. By integrating diverse datasets, including 3D seismic, earthquakes, and well logs, we develop a comprehensive 3D model of in-situ stress(orientations and magnitudes). Our results demonstrate that the estimated anisotropy orientations from 3D seismic data are consistent with the direction of maximum horizontal principal stress(SHmax) obtained from FMIs. We analyzed 12earthquakes(magnitude > 3) recorded between 2016 and 2020 for their FMSs and compressional axis(Paxis) orientations. The derived SHmax direction from our 3D stress model is 110°ES(East-South), which shows excellent agreement with the FMSs(within 3.96°). This close alignment validates the reliability and precision of our integrated method for predicting 3D SHmax orientations.

关键词： In-situ stress orientation SHmax Azimuthal velocity anisotropy Focal source mechanism Formation micro-imager

Nd@C3N4-photoredox/chlorine dual catalyzed synthesis and evaluation of antitumor activities of 4-alkylated sulfonyl ketimines

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Chinese Chemical Letters 2025年第2期36卷 412-416页

作者： Hong-Tao Ji Yu-Han lu Yan-Ting Liu Yu-Lin Huang Jiang-Feng Tian Feng Liu Yan-Yan Zeng hai-Yan Yang Yong-Hong Zhang Wei-Min He Department of Ophthalmology The Affiliated Nanhua Hospital Hengyang Medical School University of South China School of Chemistry and Chemical Engineering University of South China Department of lung Cancer and Gastroenterology Hunan Cancer Hospital The Affiliated Cancer Hospital of Xiangya School of Medicine Central South University

The first example of Nd@C3N4-photoredox/chlorine dual catalyzed alkylation with unactivated alkanes as the alkyl sources has been developed,which allows for the synthesis of various 4-alkylated cyclic sulfonyl *** this process,chlorine functions as both a redox and hydrogen atom transfer *** synergism of the reversible Nd2+/Nd3+and Clˉ/Cl˙redox pairs significantly enhances overall photocatalytic *** in vitro anticancer activity of 4-alkylated products was evaluated by using the CCK8assay against both human choroidal melanoma （MUM-2B） and lung cancer （A549） *** 3da showed approximately triple the potency of 5-fluorouracil.

关键词： Chlorine Dual catalysis Hydrogen atom transfer Redox catalyst Semiconductor

基于铁塔模型和双向天牛须的改进RRT轨迹规划方法

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控制与决策 2025年第3期40卷 955-962页

作者：陆超都海波合肥工业大学电气与自动化工程学院

为了提高输电铁塔高空作业自动化水平和保障高空作业机器人设备安全,针对传统RRT和A*等算法在角钢塔高空复杂环境中无法快速规划机械臂安全轨迹的问题,提出一种基于铁塔模型的双向天牛须知情快速随机扩展树轨迹规划算法(BI-RRT*Connect)... 详细信息

为了提高输电铁塔高空作业自动化水平和保障高空作业机器人设备安全,针对传统RRT和A*等算法在角钢塔高空复杂环境中无法快速规划机械臂安全轨迹的问题,提出一种基于铁塔模型的双向天牛须知情快速随机扩展树轨迹规划算法(BI-RRT*Connect).首先,数字重构高空机器人作业环境,利用模型配准方法获取输电铁塔精准模型信息;然后,根据铁塔模型寻求机械臂末端点与作业目标间的可行路径,并添加天牛须算法来改进随机采样过程,采用两只天牛相互寻找快速获取初始路径解;最后,将初始路径作为先验知识构建椭圆体采样区域来优化路径.在Unity环境下搭建实验平台将所提出算法与RRT*Connect和A*等4种传统算法进行比较,实验结果表明,所提出算法在输电铁塔多种作业区域下均具有求解速度快、求解质量高的良好效果.

关键词：轨迹规划数字模型 RRT 天牛须算法采样方法 Unity

High-temperature strength of gel casting silica-based ceramic core

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China Foundry 2025年

作者： hai-tian Zhang Yan Liu Cheng-dong Wang Zhong-liang lu Kai Miao Sai Li Yu Han Di-chen Li State Key Laboratory of Manufacturing Systems Engineering School of Mechanical Engineering Xi'an Jiaotong University

Considering the fracture problem of the silica-based ceramic core in the integrated casting of hollow turbine blades during directional solidification, the influence of various whiskers, including silicon carbide whiskers,silicon nitride whiskers, and mullite whiskers, on the high-temperature strength of the silica-based ceramic core was investigated. Additionally, the formation of microstructure morphology and phase structure was *** results show that silicon carbide whiskers can reduce the microcracks caused by the shrinkage of cristobalite. During the sintering process, some of the silicon carbide whiskers oxidize and react with aluminum powder to form mullite, which can improve the high-temperature strength of the ceramic cores. When the content of silicon carbide whiskers is 3wt.%, the high-temperature bending strength of the cores reaches the maximum value of 21 MPa. Silicon nitride whiskers decompose in a high-temperature environment and react with aluminum powder in the matrix material to form mullite whiskers. When the content of silicon nitride whiskers is 5wt.%,the high-temperature bending strength of the cores reaches 20 MPa. By adding mullite whiskers, a structure of cristobalite wrapped mullite whiskers can be formed to achieve toughening. When the content of mullite whiskers is 4wt.%, the high-temperature bending strength can reach 17.2 MPa. By comparing the performance of silicon carbide whiskers, silicon nitride whiskers, and mullite whiskers, along with conducting slurry viscosity tests and casting experiments, it is determined that a ceramic slurry containing 4wt.% mullite whiskers is the most suitable for making the cores used in the integrated casting of hollow turbine blades.

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