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New form of geodetic coordinate system taking two length quantity as coordinate parameters

Yimin SHI, Ziyang ZHU, Yeming FAN

《结构与土木工程前沿（英文）》 2009年 第3卷 第1期   页码 105-110 doi: 10.1007/s11709-009-0014-5

摘要： A new form of geodetic coordinate system based on geodesic coordinates instead of geodetic longitude and latitude was proposed. The vertical and horizontal geodesic coordinates measured with length were defined as coordinate parameters, but the two families of coordinate curves were still meridians and parallel circles. The first fundamental form on the ellipsoidal surface and its three coefficients were deduced by the geodesic coordinate. The formula for the latitudinal scale factor of length for geodetic parallel lines was derived, by which the obtained result conformed to that standard value calculated from geodetic latitude, and it is applicable in the range of 400 km from north to south. Therefore, it lays the foundation for establishing the differential equation and differential relationship based on this type of coordinate parameters; and consequently, it is convenient and accurate enough to operate on the ellipsoidal surface in this new form of geodetic coordinate system.

关键词： geodetic coordinate system     meridian and parallel circle     coordinate parameter     the first fundamental form on the ellipsoidal surface     latitudinal scale factor of length    

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Closed surface modeling with helical line measurement data

LI Ruqiong, LI Guangbu, WANG Yuhan

《机械工程前沿（英文）》 2007年 第2卷 第1期   页码 72-76 doi: 10.1007/s11465-007-0012-z

摘要： Models for surface modeling of free-form surface and massive data points are becoming an important feature in commercial computer aided design/computer-aided manufacturing software. However, there are many problems to be solved in this area, especially for closed free-form surface modeling. This article presents an effective method for cloud data closed surface modeling from asynchronous profile modeling measurement. It includes three steps: first, the cloud data are preprocessed for smoothing; second, a helical line is segmented to form triangle meshes; and third, Bezier surface patches are created over a triangle mesh and trimmed to shape on an entire surface. In the end, an illustrative example of shoe last surface modeling is given to show the availability of this method.

关键词： free-form surface     helical     triangle     design/computer-aided manufacturing     effective    

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Mechanism of methanol decomposition on the Pd/WC(0001) surface unveiled by first-principles calculations

Jinhua Zhang, Yuanbin She

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 1052-1064 doi: 10.1007/s11705-019-1908-y

摘要： In this study, the decomposition of methanol into the CO and H species on the Pd/tungsten carbide (WC)(0001) surface is systematically investigated using periodic density functional theory (DFT) calculations. The possible reaction pathways and intermediates are determined. The results reveal that saturated molecules, i.e., methanol and formaldehyde, adsorb weakly on the Pd/WC(0001) surface. Both CO and H prefer three-fold sites, with adsorption energies of ‒1.51 and ‒2.67 eV, respectively. On the other hand, CH O stably binds at three-fold and bridge sites, with an adsorption energy of ‒2.58 eV. However, most of the other intermediates tend to adsorb to the surface with the carbon and oxygen atoms in their sp and hydroxyl-like configurations, respectively. Hence, the C atom of CH OH preferentially attaches to the top sites, CHOH and CH O adsorb at the bridge sites, while COH and CHO occupy the three-fold sites. The DFT calculations indicate that the rupture of the initial C–H bond promotes the decomposition of CH OH and CH OH, whereas in the case of CHOH, O–H bond scission is favored over the C–H bond rupture. Thus, the most probable methanol decomposition pathway on the Pd/WC(0001) surface is CH OH → CH OH → -CHOH → CHO → CO. The present study demonstrates that the synergistic effect of WC (as carrier) and Pd (as catalyst) alters the CH OH decomposition pathway and reduces the noble metal utilization.

关键词： density functional theory     methanol     direct methanol fuel cells     WC(0001)-supported Pd monolayer     decomposition mechanism    

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New insights into mercury removal mechanism on CeO

Ling Li, Yu He, Xia Lu

《环境科学与工程前沿（英文）》 2018年 第12卷 第2期 doi: 10.1007/s11783-018-1007-1

摘要： First-principles calculations were performed to investigate the mechanism of Hg adsorption and oxidation on CeO (111). Surface oxygen activated by the reduction of Ce to Ce was vital to Hg adsorption and oxidation processes. Hg was fully oxidized by the surface lattice oxygen on CeO (111), without using any other oxidizing agents. HCl could dissociate and react with the Hg adatom on CeO (111) to form adsorbed Hg–Cl or Cl–Hg–Cl groups, which promoted the desorption of oxidized Hg and prevented CeO catalyst deactivation. In contrast, O–H and H–O–H groups formed during HCl adsorption consumed the active surface oxygen and prohibited Hg oxidation. The consumed surface oxygen was replenished by adding O into the flue gas. We proposed that oxidized Hg desorption and maintenance of sufficient active surface oxygen were the rate-determining steps of Hg removal on CeO -based catalysts. We believe that our thorough understanding and new insights into the mechanism of the Hg removal process will help provide guidelines for developing novel CeO -based catalysts and enhance the Hg removal efficiency.

关键词： Elemental mercury removal     Surface adsorption     Ceria     First-principles calculations    

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The fundamental theory of traditional Chinese medicine and the consideration in its research strategy

Zhenji Li, Chunbo Xu

《医学前沿（英文）》 2011年 第5卷 第2期   页码 208-211 doi: 10.1007/s11684-011-0126-x

摘要： Stressing the uniqueness and complexity of traditional Chinese medicine (TCM) theory system, this paper analyzes the characteristics of TCM as a discipline from four perspectives: scientific nature, fundamental theory, clinical practice, and pharmacological action. It suggests that when the research strategy of TCM theory is designed, the core theory of TCM should be emphasized on the theoretical research on TCM original thinking theory, TCM theory, Chinese materia medica and formulas, acupuncture and moxibustion, meridians and collaterals, and other related fields. Researchers and practitioners should ensure that the basic research on TCM theory is based on clinical practice, research methods (both traditional and contemporary) are exploited, and methodological innovation is underscored. The rule of TCM development should be followed and the characteristics and advantages of TCM carried forward. Meanwhile, the methods and theory of contemporary science and technology should be exploited to fulfill the goal of inheriting, enriching, and developing the fundamental theory of TCM.

关键词： fundamental theory     traditional Chinese medicine     research strategy    

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Combination form analysis and experimental study of mechanical properties on steel sheet glass fiber

《结构与土木工程前沿（英文）》 2021年 第15卷 第4期   页码 834-850 doi: 10.1007/s11709-021-0743-7

摘要： The concept of steel sheet glass fiber reinforced polymer (GFRP) composite bar (SSGCB) was put forward. An optimization plan was proposed in the combined form of SSGCB. The composite principle, material selection, and SSGCB preparation technology have been described in detail. Three-dimensional finite element analysis was adopted to perform the combination form optimization of different steel core structures and different steel core contents based on the mechanical properties. Mechanical tests such as uniaxial tensile, shear, and compressive tests were carried out on SSGCB. Parametric analysis was conducted to investigate the influence of steel content on the mechanical properties of SSGCB. The results revealed that the elastic modulus of SSGCB had improvements and increased with the rise of steel content. Shear strength was also increased with the addition of steel content. Furthermore, the yield state of SSGCB was similar to the steel bar, both of which indicated a multi-stage yield phenomenon. The compressive strength of SSGCB was lower than that of GFRP bars and increased with the increase of the steel core content. Stress-strain curves of SSGCB demonstrated that the nonlinear-stage characteristics of SSGCB-8 were much more obvious than other bars.

关键词： steel sheet GFRP composite bar     combination form     numerical modeling     mechanical properties test     strength    

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From systematicness to complexity: Fundamental thinking of mega-project management

Zhaohan SHENG, Han LIN

《工程管理前沿（英文）》 2018年 第5卷 第1期   页码 125-127 doi: 10.15302/J-FEM-2018001

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General closed-form inverse kinematics for arbitrary three-joint subproblems based on the product of

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0681-7

摘要： The inverse kinematics problems of robots are usually decomposed into several Paden–Kahan subproblems based on the product of exponential model. However, the simple combination of subproblems cannot solve all the inverse kinematics problems, and there is no common approach to solve arbitrary three-joint subproblems in an arbitrary postural relationship. The novel algebraic geometric (NAG) methods that obtain the general closed-form inverse kinematics for all types of three-joint subproblems are presented in this paper. The geometric and algebraic constraints are used as the conditions precedent to solve the inverse kinematics of three-joint subproblems. The NAG methods can be applied in the inverse kinematics of three-joint subproblems in an arbitrary postural relationship. The inverse kinematics simulations of all three-joint subproblems are implemented, and simulation results indicating that the inverse solutions are consistent with the given joint angles validate the general closed-form inverse kinematics. Huaque III minimally invasive surgical robot is used as the experimental platform for the simulation, and a master–slave tracking experiment is conducted to verify the NAG methods. The simulation result shows the inverse solutions and six sets given joint angles are consistent. Additionally, the mean and maximum of the master–slave tracking experiment for the closed-form solution are 0.1486 and 0.4777 mm, respectively, while the mean and maximum of the master–slave tracking experiment for the compensation method are 0.3188 and 0.6394 mm, respectively. The experiments results demonstrate that the closed-form solution is superior to the compensation method. The results verify the proposed general closed-form inverse kinematics based on the NAG methods.

关键词： inverse kinematics     Paden–Kahan subproblems     three-joint subproblems     product of exponential     closed-form solution    

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China Launched the First Wastewater Resource Recovery Factory in Yixing

《环境科学与工程前沿（英文）》 2022年 第16卷 第1期 doi: 10.1007/s11783-021-1496-1

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Sustainable intensification of agriculture in sub-Saharan Africa: first things first!

Bernard VANLAUWE, Achim DOBERMANN

《农业科学与工程前沿（英文）》 2020年 第7卷 第4期   页码 376-382 doi: 10.15302/J-FASE-2020351

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Subcellular distribution and chemical form of Pb in hyperaccumulator

Yanqun ZU,Yuan LI,Huan MIN,Fangdong ZHAN,Li QIN,Jixiu WANG

《环境科学与工程前沿（英文）》 2015年 第9卷 第2期   页码 250-258 doi: 10.1007/s11783-014-0643-3

摘要： Solution culture was conducted in order to understand accumulation characteristics and chemical forms of Pb in ( ) and the response of root exudates to Pb addition. The results showed that: 1) Pb contents in the shoot and root of increased with increasing in Pb concentrations in solution. 2) The contents of Pb chemical forms under Pb addition followed as: HAc extractable fraction (F )>HCl extractable fraction (F )>NaCl extractable fraction (F )>ethanol-extractable fraction (F )>water extractable fraction (F ). 3) Increased Pb level in the medium caused increases in Pb contents in the four subcellular fractions of shoots and roots, with most accumulation in FIV (Fraction IV, soluble fraction) in shoots and FI (Fraction I, cell wall fraction) in roots. 4) Contents of soluble sugar and free amino acid of root exudates increased with increasing Pb concentration in solution. Significantly positive correlations between Pb and contents of soluble sugar and free amino acid were observed. 5) With Pb concentrations in solution, low molecular weight organic acids (LMWOAs) contents followed the tendency: tartaric acid>acetic acid>malic acid>citric acid. Significantly positive correlation was observed between Pb and citric acid contents. The results indicate that soluble sugars, free amino acid and citric acid in root exudates of facilitate the absorption and accumulation of Pb, which exist in NaCl-, HCl- and HAc- extractable Pb forms, FI and FIV fractions, resulting in tolerance of to Pb.

关键词： Pb     Arenaria orbiculata     chemical forms     subcellular distribution     root exudates     hydroponic culture    

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Conformal analysis of fundamental frequency of vibration of elastic clamped plates

QI Hongyuan, ZHU Hengjun

《机械工程前沿（英文）》 2007年 第2卷 第4期   页码 429-432 doi: 10.1007/s11465-007-0073-z

摘要： To calculate the fundamental frequency of vibration of special-shaped and elastic clamped plates, the conformal mapping theory is adopted to separate the interpolating points of a complicated boundary into odd and even sequences, both of which can be mutually iterated, so that the conformal mapping function between the complicated region and the unit dish region is established. Trigonometric interpolation and convergence along the normal direction methods are provided, and the complex coefficients of the conformal mapping function are calculated. Galerkin method is used to obtain the solution of fundamental frequency in the vibrating differential function of the complicated vibrating region. Finally, taking ellipse elastic clamped plates as an example, the effects on fundamental frequency coefficient caused by eccentric ratio and area size are analyzed.

关键词： direction     theory     vibration     odd     complicated boundary    

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Generation of closed-form inverse kinematics for reconfigurable robots

ZHAO Jie, WANG Weizhong, GAO Yongsheng, CAI Hegao

《机械工程前沿（英文）》 2008年 第3卷 第1期   页码 91-96 doi: 10.1007/s11465-008-0013-6

摘要： For reconfigurable robots, the automatic generation of inverse kinematics is a key problem, because such robots may assume various configurations. In this paper, the screw and product-of-exponentials (POE) formula are used to model the kinematics of reconfigurable robots. The POE formula can be converted to canonical subproblems through decomposition and adjoint transformation. Three classes and 28 types of subproblems containing geometric or algebraic solutions are identified and solved, which can be reused in different configurations. A generalized, decomposable, and reusable approach for close-form inverse kinematics of reconfigurable robots is developed based on POE and subproblems. The effectiveness of this method is shown in an example.

关键词： different     effectiveness     generation     reconfigurable     algebraic    

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虚拟企业是企业发展的新形式

李昕,李冀

《中国工程科学》 2001年 第3卷 第9期   页码 81-85

摘要：

文章试图应用现代管理的新理论，剖析知识经济时代企业的一种新形式--虚拟企业的产生和发展，指出其类型、特点及其优势，并对如何促进虚拟企业在我国的健康发展提出了见解。

关键词： 知识经济     虚拟企业     企业新形式    

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Fabrication of form stable NaCl-Al2O3 composite for thermal energy storage by cold sintering process

Bilyaminu Suleiman, Qinghua Yu, Yulong Ding, Yongliang Li

《化学科学与工程前沿（英文）》 2019年 第13卷 第4期   页码 727-735 doi: 10.1007/s11705-019-1823-2

摘要： A form stable NaCl-Al O (50-50 wt-%) composite material for high temperature thermal energy storage was fabricated by cold sintering process, a process recently applied to the densification of ceramics at low temperature ˂ 300°C under uniaxial pressure in the presence of small amount of transient liquid. The fabricated composite achieved as high as 98.65% of the theoretical density. The NaCl-Al O composite also retained the chloride salt without leakage after 30 heating-cooling cycles between 750°C–850°C together with a holding period of 24 h at 850°C. X-ray diffraction measurements indicated congruent solubility of the alumina in chloride salt, excellent compatibility of NaCl with Al O , and chemical stability at high temperature. Structural analysis by scanning electron microscope also showed limited grain growth, high density, uniform NaCl distribution and clear faceted composite structure without inter-diffusion. The latent heat storage density of 252.5 J/g was obtained from simultaneous thermal analysis. Fracture strength test showed high sintered strength around 5 GPa after 50 min. The composite was found to have fair mass losses due to volatilization. Overall, cold sintering process has the potential to be an efficient, safe and cost-effective strategy for the fabrication of high temperature thermal energy storage materials.

关键词： cold sintering process     composite fabrication     thermal energy storage     phase change materials    

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标题 作者 时间 类型 操作

New form of geodetic coordinate system taking two length quantity as coordinate parameters

Yimin SHI, Ziyang ZHU, Yeming FAN

期刊论文

Closed surface modeling with helical line measurement data

LI Ruqiong, LI Guangbu, WANG Yuhan

期刊论文

Mechanism of methanol decomposition on the Pd/WC(0001) surface unveiled by first-principles calculations

Jinhua Zhang, Yuanbin She

期刊论文

New insights into mercury removal mechanism on CeO

Ling Li, Yu He, Xia Lu

期刊论文

The fundamental theory of traditional Chinese medicine and the consideration in its research strategy

Zhenji Li, Chunbo Xu

期刊论文

Combination form analysis and experimental study of mechanical properties on steel sheet glass fiber

期刊论文

From systematicness to complexity: Fundamental thinking of mega-project management

Zhaohan SHENG, Han LIN

期刊论文

General closed-form inverse kinematics for arbitrary three-joint subproblems based on the product of

期刊论文

China Launched the First Wastewater Resource Recovery Factory in Yixing

期刊论文

Sustainable intensification of agriculture in sub-Saharan Africa: first things first!

Bernard VANLAUWE, Achim DOBERMANN

期刊论文

Subcellular distribution and chemical form of Pb in hyperaccumulator

Yanqun ZU,Yuan LI,Huan MIN,Fangdong ZHAN,Li QIN,Jixiu WANG

期刊论文

Conformal analysis of fundamental frequency of vibration of elastic clamped plates

QI Hongyuan, ZHU Hengjun

期刊论文

Generation of closed-form inverse kinematics for reconfigurable robots

ZHAO Jie, WANG Weizhong, GAO Yongsheng, CAI Hegao

期刊论文

虚拟企业是企业发展的新形式

李昕,李冀

期刊论文

Fabrication of form stable NaCl-Al2O3 composite for thermal energy storage by cold sintering process

Bilyaminu Suleiman, Qinghua Yu, Yulong Ding, Yongliang Li

期刊论文