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Chinese Journal of Structural Chemistry 2005年第12期24卷 1355-1358页

作者： WANG Long-sheng ZHANG Jian-Jun HU sheng-Min FU Rui-biao WU Xin-Tao State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterThe Chinese Academy of SciencesFuzhouFujian 350002China

A new mononuclear tin（Ⅳ） complex [Sn（edt）2L]·CH2Cl2 （edt = ethane-1,2-dithiolate, L = di-2-pyridyl-ketone p-phenyldiamine） was obtained by a one-pot reaction which involves in situ formation of a new Schiff-base ligand L. The title compound （C22H24C12N484Sn） crystallizes in monoclinic, space group P211n with a = 13.438（1）, b = 12.2657（10）, c = 17.1477（13） k,, β = 99.323（ 1 ）°, V = 2789.1 （4） A, Z = 4, Mr = 662.28, Dc= 1.577g/cm^3, F（000） = 1328,μ= 1.426 mm^-1, the final R = 0.0450 and wR = 0.1077 for 3868 observed reflections （1 〉 2σ））. In the title compound, Sn^4＋ ion is six-coordinated with four sulfur atoms of two edt ligands and two nitrogen atoms of the ligand di-2-pyridyl-ketone p-phenyldiamine to form a highly distorted octahedron.

关键词： tin p-phenyldiamine ethene-1,2-thiolate di-2-pyridyl-ketone Schiff-base

Paleoporosity and critical porosity in the accumulation period and their impacts on hydrocarbon accumulation—A case study of the middle Es3 member of the Paleogene formation in the Niuzhuang Sag, Dongying Depression, Southeastern Bohai Bay Basin, East Chi

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Petroleum Science 2014年第4期11卷 495-507页

作者： liu Mingjie liu Zhen Sun Xiaoming Wang biao School of Geoscience and Technology Southwest Petroleum University State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Research Institute of Geophysical Exploration of Huabei Oilfield CNPC

Similar reservoir sandbodies and fault conduit systems in the sandstone reservoirs in the middle Es3 member of the Niuzhuang Sag have been problematic for a long time. The following problems remain unsolved： 1） The distribution of sandstone porosity is inconsistent with the hydrocarbon accumulation. The oil sandstones have low porosity instead of high porosity. 2） Sandstones, which have the same properties, have different levels of oiliness, and the sandstones with almost the same properties show different degrees of oil-bearing capacity. This study analyzes the condition of reservoirs in the research area during the accumulation period in terms of paleoporosity estimation and discusses the critical porosity of the sandstone reservoirs during the same period. The following conclusions can be drawn from the results. 1） Although reservoir properties are low at present and some reservoirs have become tight, the paleoporosity ranging from 18% to 25% is greater than the critical porosity of 13.9%. As the： loss of porosity is different in terms of burial history, the present porosity cannot reflect porosity during the accumulation period. Similar/y, high porosity during the accumulation period does not indicate that tbe present porosity is high. 2） The present reservoir location is consistent with the distribution of high paleoporosity during the accumulation period. This result indicates that high porosity belts are prone to hydrocarbon accumulation because of the dominant migration pathways generated as a result of property discrepancies under similar fault conduit conditions. Consequently, the hydrocarbon mainly accumulates in high porosity belts. Paleoporosity during the accumulation period is found to be a vital controlling factor. Therefore, high paleoporosity sandstones in the middle Es3 member of the Niuzhuang Sag have great potential for future exploration.

关键词： Paleoporosity critical porosity dominant migration pathways hydrocarbon accumulation,middle Es3 member Niuzhuang Sag Bohai Bay Basin

Effect of pressurizing speed on filling behavior of gradual expansion structure in low pressure casting of ZL205A alloy

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China Foundry 2018年第4期15卷 276-282页

作者： Shan-guang liu Chuan-biao Luo Guo-ai Li Wen-lin Gao Zheng Lu sheng-long Dai Beijing Institute of Aeronautical Materials Beijing 100095China

The mold filling behavior of gradual expansion structure in low pressure casting was studied by two phase flow model using the Volume of Fluid method, and was verified by water simulation with a Plexiglas mold. To get smooth mold filling process and provide a guide for the pressurizing speed design in the producing practice, the mathematical model with the pressurizing speed, expansion angle and height of the gradual expansion structure was established. For validation experiments, ZL205 A alloy castings were produced under two different pressurizing speeds. Weibull probability plots were used to assess the fracture mechanisms under different pressurizing speeds. Mechanical properties of ZL205 A alloy were applied to assess the entrainment of oxide film. The results show that the filling process of a gradual expansion structure in a low pressure casting can be divided into the spreading stage and filling stage by gate velocity. The gate velocity continues to increase in the gradual expansion structure, and increases with the increase of pressurizing speed or expansion angle. Under the effect of the falling fluid raised by the jet flow along the sidewall, the fluid velocity decreases in the jet zone from ingate to free surface. As such, oxide film entrainment does not occur when the gate velocity is greater than the critical velocity, andthe gate velocity no longer reflects the real state of the free surface. The scatter of the mechanical properties is strongly affected by the entrainment of oxide films.

关键词： low pressure casting two phase flow water simulation oxide film ZL205A alloy

Finite-time PID control for nonlinear nonaffine systems

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Science China(Information Sciences) 2024年第11期67卷 238-251页

作者： Zhiqing liu Ronghu CHI biao HUANG Zhongsheng HOU College of Mathematics and Physics Qingdao University of Science and Technology College of Automation and Electronic Engineering Qingdao University of Science and Technology Department of Chemical and Materials Engineering University of Alberta School of Automation Qingdao University

This article proposes a finite-time proportional-integral-derivative(FT-PID) control method to fast stabilize the control system to achieve the desired performance within the predesignated time *** a considered nonaffined nonlinear system, we develop a new dynamic linearization approach to reformulate the system model as a linear data model(LDM) whose arguments are consistent with that used in the PID control law. Then, a projection algorithm is presented to estimate the unknown pseudo gradient vector of the LDM. Subsequently, an adaptive tuning algorithm is designed to update the three PID parameters by solving linear matrix inequalities in terms of the predesignated error precision and the finite-time instant. The finite-time convergence of the proposed FT-PID control system is shown mathematically, which guarantees a pre-specified error precision to be achieved within the predesignated finite-time instants. As a result, not only can the proposed FT-PID control save the control cost but it also improves the production efficiency. The simulation study verifies the results.

关键词： PID control finite-time control nonlinear nonaffine systems linear data model finite-time convergence

Nitrogen addition promotes soil carbon accumulation globally

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Science China Life Sciences 2025年第1期 284-293页

作者： Xuemei Yang Suhui Ma Erhan Huang Danhua Zhang Guoping Chen Jiangling Zhu Chengjun Ji biao Zhu Lingli liu Jingyun Fang Institute of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking University Ministry of Education Key Laboratory for Transboundary Ecosecurity of Southwest China School of Ecology and Environmental ScienceYunnan University State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of Sciences

Soil is the largest carbon(C) reservoir in terrestrial ecosystems and plays a crucial role in regulating the global C cycle and climate *** nitrogen(N) deposition has been widely considered as a critical factor affecting soil organic carbon(SOC) storage, but its effect on SOC components with different stability remains unclear. Here, we analyzed extensive empirical data from 304 sites worldwide to investigate how SOC and its components respond to N addition. Our analysis showed that N addition led to a significant increase in bulk SOC(6.7%), with greater increases in croplands(10.6%) and forests(6.0%) compared to grasslands(2.1%). Regarding SOC components, N addition promoted the accumulation of plant-derived C(9.7%–28.5%) over microbial-derived C(0.2%), as well as labile(5.7%) over recalcitrant components(–1.2%), resulting in a shift towards increased accumulation of plant-derived labile C. Consistently, N addition led to a greater increase in particulate organic C(11.9%) than mineral-associated organic C(3.6%), suggesting that N addition promotes C accumulation across all pools, with more increase in unstable than stable pools. The responses of SOC and its components were best predicted by the N addition rate and net primary productivity. Overall, our findings suggest that N enrichment could promote the accumulation of plant-derived and non-mineral associated C and a subsequent decrease in the overall stability of soil C pool, which underscores the importance of considering the effects of N enrichment on SOC components for a better understanding of C dynamics in soils.

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Skeleton-Based Human Action Recognition via Screw Matrices

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Chinese Journal of Electronics 2017年第4期26卷 790-796页

作者： DING Wenwen liu Kai XU biao CHENG Fei School of Computer Science and Technology Xidian University School of Mathematical Sciences Huaibei Normal University

With the recent advent of low-cost acquisition depth cameras, extracting 3D body skeleton has become relatively easier, which significantly lighten many difficulties in 2D videos including occlusions, shadows and background extraction, etc. Directly perceived features,for example points, lines and planes, can be easily extracted from 3D videos such that we can employ rigid motions to represent skeletal motions in a geometric *** apply screw matrices, acquired by using rotations and translations in 3D space, to model single and multi-body rigid motion. Since screw matrices are members of the special Euclidean group SE(3), an action can be represented as a point on a Lie group, which is a differentiable manifold. Using Lie-algebraic properties of screw algebra, isomorphic to se(3), the classical algorithms of machine learning in vector space can be expanded to manifold space. We evaluate our approached on three public3 D action datasets: MSR Action3 D dataset, UCF Kinect dataset and Florence3D-Action Dataset. The experimental results show that our approaches either match or exceed state-of-the-art skeleton-based human action recognition approaches.

关键词： Skeleton joints Human activity recogni tion Screw algebra Lie group Lie algebra

An Improved Thin Film Brick-Wall Model of Black Hole Entropy

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Chinese Physics Letters 2001年第2期18卷 310-312页

作者： liu Wen-biao ZHAO Zheng Department of Physics Institute of Theoretical PhysicsBeijing Normal UniversityBeijing 100875

We improve the brick-wall model to take only the contribution of a thin film near the event horizon into *** improvement not only gives us a satisfactory result,but also avoids some drawbacks in the original brick-wall method such as the little mass approximation,neglecting logarithm term,and taking the term L3 as the contribution of the vacuum surrounding a black *** is found that there is an intrinsic relation between the event horizon and the *** event horizon is the characteristic of a black hole,so the entropy calculating of a black hole is also naturally related to its horizon.

关键词： horizon black Entropy

Screening study of transition metal oxide catalysts supported on ceria-modified titania for catalytic oxidation of toluene

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第6期12卷 461-469页

作者： Dan-qing YU Yue liu Zhong-biao WU Department of Environmental Engineering Zhejiang University Hangzhou 310027 China Zhejiang Provincial Engineering Research Center of Industrial Boiler & Furnace Flue Gas Pollution Control Hangzhou 310027 China

Six transition metal oxides were added in ceria-modified titania using a sol-gel method for catalytic oxidation of *** MnOx based catalyst was found to be the most active one,with which toluene could be decomposed completely at 200 *** greatest Mn/Ti and molar ratio of the mobile oxygen to the total oxygen concentration,together with a large surface area and a low reduction peak-starting temperature,would result in its best activity in toluene oxidation.

关键词： Transition metal oxides CeO2/TiO2 Sol-gel method Catalytic oxidation Toluene

System distortion analysis and compensation of DIFS signals for wideband imaging radar

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Science China(Information Sciences) 2015年第2期58卷 42-57页

作者： liu Yang HOU QingKai XU ShiYou TIAN biao National University of Defense Technology

System distortion is inevitable in wideband imaging radar, which needs to be compensated *** traditional wideband imaging radar for space surveillance, a linear frequency modulation signal is transmitted and the echoed signal is received with dechirping processing. In this case, the system distortion changes with the target range, making it hard to compensate the distortion. However, the direct intermediate frequency sampling(DIFS) signal maintains the complete system distortion and avoids the range variant distortion in the dechirped signal. Therefore, it is more convenient to perform system compensation in DIFS signal. In this paper, the distortion factors affecting the wideband radar systems are introduced. Then, the influence of the amplitude phase distortion on the focusing quality is analyzed in detail. Finally, a system compensation method in the frequency domain based on least squares estimation is proposed. In the proposed method, the compensation vectors are extracted from the calibration tower echoes for DIFS compensation. Inverse synthetic aperture radar imagery of targets can be achieved with improved focus quality. Simulations and real-data experiments confirm the effectiveness of the proposal.

关键词： system distortion direct intermediate frequency sampling(DIFS) system compensation least squares estimation(LSE) wideband imaging radar

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西兰花苗中萝卜硫素合成的调控手段研究进展

食品科学 2025年第1期46卷 210-217页

作者：李翠方胜赵忠良刘海杰中国农业大学食品科学与营养工程学院北京100083 江苏新希望生态科技有限公司江苏徐州221150

萝卜硫素(sulforaphane,SFN)具有抗肿瘤、抗炎、抗氧化、减轻肥胖等多种生物学活性,在西兰花苗中含量最高,使西兰花苗在保健食品和药品开发方面具有广阔的应用前景。本文首先综述SFN在西兰花苗中的合成及降解过程,重点讨论在西兰花苗生... 详细信息

萝卜硫素(sulforaphane,SFN)具有抗肿瘤、抗炎、抗氧化、减轻肥胖等多种生物学活性,在西兰花苗中含量最高,使西兰花苗在保健食品和药品开发方面具有广阔的应用前景。本文首先综述SFN在西兰花苗中的合成及降解过程,重点讨论在西兰花苗生长阶段采用不同处理手段对SFN及其合成相关因子含量的影响,并对其作用机理进行总结分析,最后提出目前还存在的问题及对未来研究方向的展望,为提高植物源食品功能性的相关研究提供一定参考。

关键词：西兰花苗硫代葡萄糖苷萝卜硫素生成机理调控