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Establishment and verification of a shrinking core model for dilute acid hydrolysis of lignocellulose

Cunwen WANG, Xiaoling DUAN, Weiguo WANG, Zihao LI, Yuanhang QIN

《能源前沿（英文）》 2012年 第6卷 第4期   页码 413-419 doi: 10.1007/s11708-012-0212-z

摘要： The kinetics of lignocellulose hydrolysis under the conditions of high temperature and dilute acid (mass fraction 0.05%) was investigated in this paper. By studying the reducing sugar concentration versus reaction temperature (170°C–220°C) and reaction time (150–1800 s) during the hydrolysis process of five kinds of crop straw (rice, wheat, cotton, rape and corn), the shrinking core model was established, and the differential equation of the model and its analytical solution were obtained. With a numerical calculation method, the kinetic equation was estimated, and the degradation of reducing sugar obeyed first-order kinetics was obtained. The calculated results from the equations agreed well with the original experimental data. The calculation by the model showed that the reducing sugar concentration increases as the size of the particles decrease, and the uniform particles increase.

关键词： lignocellulose     dilute acid hydrolysis     shrinking core model    

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Effect of pressure on gasification reactivity of three Chinese coals with different ranks

Chunyu LI, Jiantao ZHAO, Yitian FANG, Yang WANG

《化学科学与工程前沿（英文）》 2010年 第4卷 第4期   页码 385-393 doi: 10.1007/s11705-010-0501-1

摘要： The gasification reactivities of three kinds of different coal ranks (Huolinhe lignite, Shenmu bituminous coal, and Jincheng anthracite) with CO and H O was carried out on a self-made pressurized fixed-bed reactor at increased pressures (up to 1.0 MPa). The physicochemical characteristics of the chars at various levels of carbon conversion were studied via scanning electron microscopy (SEM), X-ray diffraction (XRD), and BET surface area. Results show that the char gasification reactivity increases with increasing partial pressure. The gasification reaction is controlled by pore diffusion, the rate decreases with increasing total system pressure, and under chemical kinetic control there is no pressure dependence. In general, gasification rates decrease for coals of progressively higher rank. The experimental results could be well described by the shrinking core model for three chars during steam and CO gasification. The values of reaction order with steam were 0.49, 0.46, 0.43, respectively. Meanwhile, the values of reaction order with CO were 0.31, 0.28, 0.26, respectively. With the coal rank increasing, the pressure order is higher, the activation energies increase slightly with steam, and the activation energy with CO increases noticeably. As the carbon conversion increases, the degree of graphitization is enhanced. The surface area of the gasified char increases rapidly with the progress of gasification and peaks at about 40% of char gasification.

关键词： coal     gasification     pressure     reaction order     shrinking core model    

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Effects of radiation and heat source/sink on unsteady MHD boundary layer flow and heat transfer over a shrinking

Krishnendu Bhattacharyya

《化学科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 376-384 doi: 10.1007/s11705-011-1121-0

摘要： In this paper, an investigation is made to study the effects of radiation and heat source/sink on the unsteady boundary layer flow and heat transfer past a shrinking sheet with suction/injection. The flow is permeated by an externally applied magnetic field normal to the plane of flow. The self-similar equations corresponding to the velocity and temperature fields are obtained, and then solved numerically by finite difference method using quasilinearization technique. The study reveals that the momentum boundary layer thickness increases with increasing unsteadiness and decreases with magnetic field. The thermal boundary layer thickness decreases with Prandtl number, radiation parameter and heat sink parameter, but it increases with heat source parameter. Moreover, increasing unsteadiness, magnetic field strength, radiation and heat sink strength boost the heat transfer.

关键词： MHD boundary layer     unsteady flow     heat transfer     thermal radiation     heat source/sink     shrinking sheet     suction/injection    

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东太湖湖泊水面萎缩的状况及影响

魏清福

《中国工程科学》 2010年 第12卷 第6期   页码 123-126

摘要：

东太湖是长江中下游地区典型的草型湖泊，是太湖的浅水湖湾和主要出水通道，也是上海市、浙江省杭嘉湖城镇供水取水口的主要来水水源和江苏省吴江市的供水水源地，具有防洪、供水、水生态环境保护和水产养殖等多种功能。近半个世纪以来在自然和人为因素的长期作用下，东太湖水面不断缩小，湖泊形态和水生态环境遭到严重破坏，湖泊衰亡进程加快，其行洪、供水、水生态环境保护等湖泊良好的服务功能无法正常发挥。回顾东太湖的演变历程，初步探讨了东太湖水面萎缩的现状及对湖泊功能的影响，并针对目前规划采取的治理措施提出了几点看法，供湖泊治理参考。

关键词： 东太湖     水面     萎缩     影响     关键技术    

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微型医疗设备变得更智能

Chris Palmer

《工程（英文）》 2021年 第7卷 第1期   页码 8-10 doi: 10.1016/j.eng.2020.12.004

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Postprocessor development for ultrasonic cutting of honeycomb core curved surface with a straight blade

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0729-8

摘要： When ultrasonically cutting honeycomb core curved parts, the tool face of the straight blade must be along the curved surface’s tangent direction at all times to ensure high-quality machining of the curved surface. However, given that the straight blade is a nonstandard tool, the existing computer-aided manufacturing technology cannot directly realize the above action requirement. To solve this problem, this paper proposed an algorithm for extracting a straight blade real-time tool face vector from a 5-axis milling automatically programmed tool location file, which can realize the tool location point and tool axis vector conversion from the flat end mill to the straight blade. At the same time, for the multi-solution problem of the rotation axis, the dependent axis rotation minimization algorithm was introduced, and the spindle rotation algorithm was proposed for the tool edge orientation problem when the straight blade is used to machine the curved part. Finally, on the basis of the MATLAB platform, the dependent axis rotation minimization algorithm and spindle rotation algorithm were integrated and compiled, and the straight blade ultrasonic cutting honeycomb core postprocessor was then developed. The model of the machine tool and the definition of the straight blade were conducted in the VERICUT simulation software, and the simulation machining of the equivalent entity of the honeycomb core can then be realized. The correctness of the numerical control program generated by the postprocessor was verified by machining and accuracy testing of the two designed features. Observation and analysis of the simulation and experiment indicate that the tool pose is the same under each working condition, and the workpieces obtained by machining also meet the corresponding accuracy requirements. Therefore, the postprocessor developed in this paper can be well adapted to the honeycomb core ultrasonic cutting machine tool and realize high-quality and high-efficient machining of honeycomb core composites.

关键词： honeycomb core     straight blade     ultrasonic cutting     tool pose     postprocessor    

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Recent advances in gold-metal oxide core-shell nanoparticles: Synthesis, characterization, and their

Michelle Lukosi,Huiyuan Zhu,Sheng Dai

《化学科学与工程前沿（英文）》 2016年 第10卷 第1期   页码 39-56 doi: 10.1007/s11705-015-1551-1

摘要： Heterogeneous catalysis with core-shell structures has been a large area of focus for many years. This paper reviews the most recent work and research in core-shell catalysts utilizing noble metals, specifically gold, as the core within a metal oxide shell. The advantage of the core-shell structure lies in its capacity to retain catalytic activity under thermal and mechanical stress, which is a pivotal consideration when synthesizing any catalyst. This framework is particularly useful for gold nanoparticles in protecting them from sintering so that they retain their size, structure, and most importantly their catalytic efficiency. The different methods of synthesizing such a structure have been compiled into three categories: seed-mediated growth, post selective oxidation treatment, and one-pot chemical synthesis. The selective oxidation of carbon monoxide and reduction of nitrogen containing compounds, such as nitrophenol and nitrostyrene, have been studied over the past few years to evaluate the functionality and stability of the core-shell catalysts. Different factors that could influence the catalyst’s performance are the size, structure, choice of metal oxide shell and noble metal core and thereby the interfacial synergy and lattice mismatch between the core and shell. In addition, the morphology of the shell also plays a critical role, including its porosity, density, and thickness. This review covers the synthesis and characterization of gold-metal oxide core-shell structures, as well as how they are utilized as catalysts for carbon monoxide (CO) oxidation and selective reduction of nitrogen-containing compounds.

关键词： core-shell     characterization     core-shell structure     Different     stability    

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Property-performance relationship of core-shell structured black TiO photocatalyst for environmental

《环境科学与工程前沿（英文）》 2023年 第17卷 第9期 doi: 10.1007/s11783-023-1711-3

摘要：

● Properties and performance relationship of CSBT photocatalyst were investigated.

关键词： Black TiO2     Core-shell structure     Property-performance relationship     Agro-industrial effluent     Environmental remediation    

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Experiment and calculation on seismic behavior of RC composite core walls with concealed steel truss

Wanlin CAO , Weihua CHANG , Changjun ZHAO , Jianwei ZHANG ,

《结构与土木工程前沿（英文）》 2009年 第3卷 第3期   页码 255-261 doi: 10.1007/s11709-009-0043-0

摘要： To improve the seismic performance of reinforced concrete core walls, reinforced concrete composite core walls with concealed steel truss were proposed and systemically investigated. Two 1/6 scale core wall specimens, including a normal reinforced concrete core wall and a reinforced concrete composite core wall with concealed steel truss, were designed. The experimental study on seismic performance under cyclic loading was carried out. The load-carrying capacity, stiffness, ductility, hysteretic behavior and energy dissipation of the core walls were discussed. The test results showed that the seismic performance of core walls is improved greatly by the concealed steel truss. The calculated results were found to agree well with the actual measured ones.

关键词： reinforced concrete     steel truss     core walls     seismic performance    

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Effects of inclination angles of disc cutter on machining quality of Nomex honeycomb core in ultrasonic

Yidan WANG, Renke KANG, Yan QIN, Qian MENG, Zhigang DONG

《机械工程前沿（英文）》 2021年 第16卷 第2期   页码 285-297 doi: 10.1007/s11465-021-0631-9

摘要： Ultrasonic cutting with a disc cutter is an advanced machining method for the high-quality processing of Nomex honeycomb core. The machining quality is influenced by ultrasonic cutting parameters, as well as tool orientations, which are determined by the multi-axis machining requirements and the angle control of the cutting system. However, in existing research, the effect of the disc cutter orientation on the machining quality has not been studied in depth, and practical guidance for the use of disc cutters is lacking. In this work, the inclined ultrasonic cutting process with a disc cutter was analyzed, and cutting experiments with different inclination angles were conducted. The theoretical residual height models of the honeycomb core, as a result of the lead and tilt angles, were established and verified with the results obtained by a linear laser displacement sensor. Research shows that the residual height of the honeycomb core, as a result of the tilt angle, is much larger than that as a result of the lead angle. Furthermore, the tearing of the cell wall on the machined surface was observed, and the effects of the ultrasonic vibration, lead angle, and tilt angle on the tear rate and tear length of the cell wall were studied. Experimental results revealed that ultrasonic vibration can effectively decrease the tearing of the cell wall and improve the machining quality. Changes in the tilt angle have less effect than changes in the lead angle on the tearing of the cell wall. The determination of inclination angles should consider the actual processing requirements for the residual height and the machining quality of the cell wall. This study investigates the influence of the inclination angles of a disc cutter on the machining quality of Nomex honeycomb core in ultrasonic cutting and provides guidelines for machining.

关键词： Nomex honeycomb core     disc cutter     inclined ultrasonic cutting     machining quality    

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Improving performance portability for GPU-specific OpenCL kernels onmulti-core/many-coreCPUs by analysis-based

Mei WEN,Da-fei HUANG,Chang-qing XUN,Dong CHEN

《信息与电子工程前沿（英文）》 2015年 第16卷 第11期   页码 899-916 doi: 10.1631/FITEE.1500032

摘要： OpenCL is an open heterogeneous programming framework. Although OpenCL programs are functionally portable, they do not provide performance portability, so code transformation often plays an irreplaceable role. When adapting GPU-specific OpenCL kernels to run on multi-core/many-core CPUs, coarsening the thread granularity is necessary and thus has been extensively used. However, locality concerns exposed in GPU-specific OpenCL code are usually inherited without analysis, which may give side-effects on the CPU performance. Typically, the use of OpenCL’s local memory on multi-core/many-core CPUs may lead to an opposite performance effect, because local-memory arrays no longer match well with the hardware and the associated synchronizations are costly. To solve this dilemma, we actively analyze the memory access patterns using array-access descriptors derived from GPU-specific kernels, which can thus be adapted for CPUs by (1) removing all the unwanted local-memory arrays together with the obsolete barrier statements and (2) optimizing the coalesced kernel code with vectorization and locality re-exploitation. Moreover, we have developed an automated tool chain that makes this transformation of GPU-specific OpenCL kernels into a CPU-friendly form, which is accompanied with a scheduler that forms a new OpenCL runtime. Experiments show that the automated transformation can improve OpenCL kernel performance on a multi-core CPU by an average factor of 3.24. Satisfactory performance improvements are also achieved on Intel’s many-integrated-core coprocessor. The resultant performance on both architectures is better than or comparable with the corresponding OpenMP performance.

关键词： OpenCL     Performance portability     Multi-core/many-core CPU     Analysis-based transformation    

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Interfacial charge transfer and photocatalytic activity in a reverse designed BiO/TiO core-shell

《能源前沿（英文）》 2021年 第15卷 第3期   页码 732-743 doi: 10.1007/s11708-021-0772-x

摘要： In this study, the electronic and photocatalytic properties of core-shell heterojunctions photocatalysts with reversible configuration of TiO2 and Bi2O3 layers were studied. The core-shell nanostructure, obtained by efficient control of the sol-gel polymerization and impregnation method of variable precursors of semiconductors, makes it possible to study selectively the role of the interfacial charge transfer in each configuration. The morphological, optical, and chemical composition of the core-shell nanostructures were characterized by high-resolution transmission electron microscopy, UV-visible spectroscopy and X-ray photoelectron spectroscopy. The results show the formation of homogenous TiO2 anatase and Bi2O3 layers with a thickness of around 10 and 8 nm, respectively. The interfacial charge carrier dynamic was tracked using time resolved microwave conductivity and transition photocurrent density. The charge transfer, their density, and lifetime were found to rely on the layout layers in the core-shell nanostructure. In optimal core-shell design, Bi2O3 collects holes from TiO2, leaving electrons free to react and increase by 5 times the photocatalytic efficiency toward H2 generation. This study provides new insight into the importance of the design and elaboration of optimal heterojunction based on the photocatalyst system to improve the photocatalytic activity.

关键词： photocatalysis     core-shell     heterojunction     H2     TiO2     Bi2O3    

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Construction of PS/PNIPAM core-shell particles and hollow spheres by using hydrophobic interaction and

ZHU Dongmei, WANG Fei, GAO Cuiling, XU Zheng

《化学科学与工程前沿（英文）》 2008年 第2卷 第3期   页码 253-256 doi: 10.1007/s11705-008-0049-5

摘要： This paper reports an easy and effective way to fabricate polystyrene/poly (-isopropylacrylamide) (PS/PNIPAM) core-shell particles and PNIPAM hollow spheres. The main point of the method is to take advantage of the hydrophobic interaction between initiator and PS particles. The hydrophobic azodiisobutyronitriles automatically concentrate around the PS particles and initiate polymerization of -isopropylacrylamide (NIPAM) and the crosslinker methylene bisacrylamide (MBA), which dissolve in the aqueous phase, at the surface of the PS nanoparticles. Then, PNIPAM adheres to the PS particles to form a core-shell structure as a result of their hydrophobic interaction. This interaction is due to the unique property of PNIPAM, namely, its ability to transition from hydrophilic to hydrophobic when the temperature rises to 32°C. Furthermore, the hollow PNIPAM spheres were obtained by etching the PS core with chloroform.

关键词： initiator     core-shell     transition     polystyrene/poly     advantage    

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CC@BCN@PANI core-shell nanoarrays as ultra-high cycle stability cathode for Zn-ion hybrid supercapacitors

《能源前沿（英文）》 2023年 第17卷 第4期   页码 555-566 doi: 10.1007/s11708-023-0882-8

摘要： Exploring cathode materials that combine excellent cycling stability and high energy density poses a challenge to aqueous Zn-ion hybrid supercapacitors (ZHSCs). Herein, polyaniline (PANI) coated boron-carbon-nitrogen (BCN) nanoarray on carbon cloth surface is prepared as advanced cathode materials via simple high-temperature calcination and electrochemical deposition methods. Because of the excellent specific capacity and conductivity of PANI, the CC@BCN@PANI core-shell nanoarrays cathode shows an excellent ion storage capability. Moreover, the 3D nanoarray structure can provide enough space for the volume expansion and contraction of PANI in the charging/discharging cycles, which effectively avoids the collapse of the microstructure and greatly improves the electrochemical stability of PANI. Therefore, the CC@BCN@PANI-based ZHSCs exhibit superior electrochemical performances showing a specific capacity of 145.8 mAh/g, a high energy density of 116.78 Wh/kg, an excellent power density of 12 kW/kg, and a capacity retention rate of 86.2% after 8000 charge/discharge cycles at a current density of 2 A/g. In addition, the flexible ZHSCs (FZHSCs) also show a capacity retention rate of 87.7% at the current density of 2 A/g after 450 cycles.

关键词： CC@BCN@PANI cathode     Zn-ion hybrid supercapacitor     core-shell nanoarrays     high energy density     ultra-high cycle stability    

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On the Core Essence of Engineering Management Theory

Ji-shan He

《工程管理前沿（英文）》 2014年 第1卷 第3期   页码 260-269 doi: 10.15302/J-FEM-2014035

摘要： At present, China’s economy is in rapid growth. The scale of engineering construction is significantly increasing and a number of major projects have been completed and put into use, bringing the engineering management practice new issues and challenges with each passing day. In the meantime, Chinese scholars are constantly summarizing what they have learnt in these activities and making great effort to gradually establish their own theoretical system of engineering management, of which the core essence of theoretical system of engineering management becomes a critically important topic. By studying our engineering management theory and practice, this paper preliminarily sums up the core essence of the engineering management theory in China as: “establishing a perfect harmony between human and nature through a people-oriented approach and dual innovation”, with a hope to help and enrich the research on the theoretical system of engineering management in China.

关键词： engineering management     theoretical system     people-oriented concept     perfect harmony between human and nature    

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标题 作者 时间 类型 操作

Establishment and verification of a shrinking core model for dilute acid hydrolysis of lignocellulose

Cunwen WANG, Xiaoling DUAN, Weiguo WANG, Zihao LI, Yuanhang QIN

期刊论文

Effect of pressure on gasification reactivity of three Chinese coals with different ranks

Chunyu LI, Jiantao ZHAO, Yitian FANG, Yang WANG

期刊论文

Effects of radiation and heat source/sink on unsteady MHD boundary layer flow and heat transfer over a shrinking

Krishnendu Bhattacharyya

期刊论文

东太湖湖泊水面萎缩的状况及影响

魏清福

期刊论文

微型医疗设备变得更智能

Chris Palmer

期刊论文

Postprocessor development for ultrasonic cutting of honeycomb core curved surface with a straight blade

期刊论文

Recent advances in gold-metal oxide core-shell nanoparticles: Synthesis, characterization, and their

Michelle Lukosi,Huiyuan Zhu,Sheng Dai

期刊论文

Property-performance relationship of core-shell structured black TiO photocatalyst for environmental

期刊论文

Experiment and calculation on seismic behavior of RC composite core walls with concealed steel truss

Wanlin CAO , Weihua CHANG , Changjun ZHAO , Jianwei ZHANG ,

期刊论文

Effects of inclination angles of disc cutter on machining quality of Nomex honeycomb core in ultrasonic

Yidan WANG, Renke KANG, Yan QIN, Qian MENG, Zhigang DONG

期刊论文

Improving performance portability for GPU-specific OpenCL kernels onmulti-core/many-coreCPUs by analysis-based

Mei WEN,Da-fei HUANG,Chang-qing XUN,Dong CHEN

期刊论文

Interfacial charge transfer and photocatalytic activity in a reverse designed BiO/TiO core-shell

期刊论文

Construction of PS/PNIPAM core-shell particles and hollow spheres by using hydrophobic interaction and

ZHU Dongmei, WANG Fei, GAO Cuiling, XU Zheng

期刊论文

CC@BCN@PANI core-shell nanoarrays as ultra-high cycle stability cathode for Zn-ion hybrid supercapacitors

期刊论文

On the Core Essence of Engineering Management Theory

Ji-shan He

期刊论文