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Rolling-element bearings in China： From ancient times to the 20th century

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Frontiers of Mechanical Engineering 2016年第1期11卷 33-43页

作者： lie SUN ang li Institute for the History of Natural Sciences Chinese Academy of Sciences Beijing 100190 China

The development of rolling-element bearings in China has spanned a long period. Based on several typical and important cases, the present article reconstructs the history of rolling-element bearings in China by dividing it into four stages according to the various characteristics of the bearings. The first stage represents the origin of rolling beatings in China, which remains controversial because of several suspected races and cages that were likely the components of bearings more than a millennium ago. At the second stage, a type of simple roller bearing was used for astronomical instru- ments not later than the 13th century based on clear philological and physical evidence. A similar bearing was also applied to an abridged armillary in the 17th century. Another type of spherical thrust bearings with rolling elements, which is a key component of a traditional Chinese windmill, could support a rotating shaft that moves rotationally and at an angle. At the third stage, the Chinese began studying and using the so-called European- style bearing since the 17th century. Moreover, over the last 100 years, the modem rolling bearing industry was gradually established in China, particularly because of the technology transfer from the Soviet Union in the 1950s. At the fourth stage, the Chinese government initiated the relatively rapid development of beating technology. The govemment launched the ＂bearing movement＂ from the 1950s to the 1960s to establish the modem bearing industry and to promote rolling bearings as replacement for traditional sliding bearings. Furthermore, a number of large professional factories and institutions in China have continually introduced advanced technology and equip- ment. At present, these companies and institutions play a significant role in the intemational bearing industry.

关键词： rolling-element bearing China early rolling bearings technology transfer bearing movement

Toward stable and highly reversible zinc anodes for aqueous batteries via electrolyte engineering

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Journal of Energy Chemistry 2023年第8期83卷 209-228,I0007页

作者： ang li Jiayi li Yurong He Maochun Wu Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China Schoolof Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001HeilongjiangChina

Featuring low cost, high abundance, low electrochemical potential, and large specific capacity, zinc(Zn)metal holds great potential as an anode material for next-generation rechargeable aqueous ***, the poor reversibility resulting from dendrite formation and side reactions poses a major obstacle for its practical application. Electrolyte, which is regarded as the “blood” of batteries, has a direct impact on reaction kinetics, mass transport, and side reactions and thus plays a key role in determining the electrochemical performance of Zn electrodes. Therefore, considerable efforts have been devoted to modulating the electrolytes to improve the performance of Zn electrodes. Although significant progress has been made, achieving stable and highly reversible Zn electrodes remains a critical challenge. This review aims to provide a systematic summary and discussion on electrolyte strategies for highperformance aqueous Zn batteries. The(electro)-chemical behavior and fundamental challenges of Zn electrodes in aqueous electrolytes are first discussed. Electrolyte modulation strategies developed to address these issues are then classified and elaborated according to the underlying ***, remaining challenges and promising future research directions on aqueous electrolyte engineering are highlighted. This review offers insights into the design of highly efficient electrolytes for new generation of rechargeable Zn batteries.

关键词： Rechargeable aqueous zinc batteries zinc anode Dendrite growth Side reactions Electrolyte engineering

Characteristics and geological significance of carbon and oxygen isotopes of the Permian Lucaogou Formation dolomite in the southern Junggar Basin, northwestern China

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Journal of Palaeogeography 2024年第4期13卷 862-882页

作者： Gang liu Guo-Zhi Wang Na li Hong-ling He Nan-Nan Lu Qing Lei zi-ang Wang College of Earth and Planetary Sciences Chengdu University of TechnologyChengdu 610059Sichuan ProvinceChina National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu 610059Sichuan ProvinceChina Hebei Survey Institute of Coal Geology Xingtai 054000Hebei ProvinceChina sichuan Earthquake Agency Chengdu 610041Sichuan ProvinceChina

Anomalously positive δ^(13)C values in ancient dolomites are very *** gray argillaceous rocks of the lacustrine sediments of the Permian Lucaogou Formation are important source rocks in the Junggar Basin,and dolomites of varying thicknesses from 10 cm to 150 cm are often interspersed in argillaceous *** on the study of petrographic sections,this paper systematically analyzes the carbon and oxygen isotopes of dolomite and discusses the causes of abnormally high carbon isotope values and their significance in reconstructing paleoenvironment and *** results show that carbon isotope values are abnormally high in the dolomite of Lucaogou Formation,and the δ^(13)C value is between+3.2‰PDB and+19.6‰PDB,with an average of+9.7‰*** δ^(18)O values range from-17.4‰PDB to-1.7‰PDB,with an average of-8.1‰*** the lower part to the upper part of the Lucaogou Formation,the carbon isotope value gradually increases and becomes increasingly positive,and the carbon isotope of the dolomite deposited near the shore is more positive than that of the dolomite deposited far from the *** anomalously positive δ^(13)C of the dolomite is mainly caused by microbial methanogenesis,with some contribution from *** are mainly distributed at the redox *** controls the salinity and fluctuation of the redox interface in sedimentary *** positive deviation difference in carbon isotopes between nearshore and offshore sedimentary dolomites may be related to the location of the redox interface during ***,the petrographic features and carbon and oxygen isotope signatures of the sections reflect the gradual evolution of the paleolake from a hydrologically open environment to a hydrologically closed one and the possible transition of the paleoclimate from a relatively warm to an arid condition,which is possibly a geochemical response to global climate change in the Permian period.

关键词： Junggar Basin Lucaogou Formation Dolomite Positive carbon isotope anomaly Paleoenvironment

Bound states in the continuum based on the total internal reflection of Bloch waves

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National Science Review 2023年第1期10卷 178-186页

作者： Peng Hu Chongwu Xie Qianju Song ang Chen Hong Xiang Dezhuan Han Jian zi College of Physics Chongqing University State Key Laboratory of Surface Physics Key Laboratory of Microand Nano-Photonic Structures (Ministry of Education) and Department of Physics Fudan University Chongqing Key Laboratory for Strongly Coupled Physics

A photonic-crystal slab can support bound states in the continuum(BICs) that have infinite lifetimes but are embedded into the continuous spectrum of optical modes in free *** formation of BICs re quires a total internal reflection(TIR) condition at both interfaces between the slab and the free ***,we show that the TIR of Bloch waves can be directly obtained based on the generalized Fresnel equations *** each of these Bloch waves picks up a phase with integer multiples of 2π for traveling a round trip,light can be perfectly guided in the slab,namely forming a BIC.A BIC solver with low computational complexity and fast convergence speed is developed,which can also work efficiently at high frequencies beyond the diffraction limit where multiple radiation channels *** examples of multi-channel BICs are shown and their topological nature in momentum space is also *** can be attributed to the coincidence of the topological charges of far-field radiations from different radiation *** concept of the generalized TIR and the TIR-based BIC solver developed offer highly effective approaches for explorations of BICs that could have many potential applications in guided-wave optics and enhanced light-matter interactions.

关键词： bound states in the continuum total internal reflection Bloch waves generalized Fresnel equations topological charges

Rhodium-Catalyzed Direct C-H Alkenylation of Indoles with Alkenyl Borates

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Chinese Journal of Chemistry 2021年第10期39卷 2823-2828页

作者： Ze-Tian Wang zi-ang Zheng Peng-Jie li Chun-Ni Zhou Shao-Jun Cai Biao Xiao liang Wang Key Laboratory of Optoelectronic Chemical Materials and Devices Ministry of EducationSchool of Chemical and Environmental EngineeringJianghan University8 Sanjiaohu RoadWuhanHubei430056 China

Main observation and conclusion A new Rh(Ⅲ)-catalyzed direct C—H alkenylation of 2,3-unsubstitued indoles with alkenyl borates through C—H activation followed by transmetallation was *** protocol provides an efficient method for the synthesis of terminal C2-alkenylindoles under mild conditions,and also shows broad substrate scope and high functional group tolerance with respect to both ***,the C2-alkenylated indole can be easily transformed into carboline derivative,which is an important polycyclic indole moiety in natural products and drug molecules.

关键词： Rhodium C-H activation Terminal alkenylindoles Alkenyl borates Nitrogen heterocycles

Hollow spherical titanium dioxide nanoparticles for energy and environmental applications

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Particuology 2015年第5期13卷 13-23页

作者： Peng Zhang ang li Jinlong Gong Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityCollaborative Innovation Center of Chemical Science and Engineering

Hollow spherical titanium dioxide （TiO2） nanoparticles possess unique properties toward energy and environmental applications, because of the intrinsic properties of TiO2 and benefits induced by their hollow structure. A detailed understanding of TiO2 hollow spheres will promote their use in sustainable energy and environmental applications. This perspective details current methods for synthesizing hollow spherical TiO2 nanoparticles, and their performance in dye-sensitized solar cells, photocatalysts, and batteries. This perspective will promote the design and innovative thinking on the application of hollow spherical metal oxide nanooarticles.

关键词： TiO2 Hollow sphere Dye-sensitized solar cell Photocatalyst Battery

Quintic spline smooth semi-supervised support vector classification machine

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Journal of Systems Engineering and Electronics 2015年第3期26卷 626-632页

作者： Xiaodan Zhang Jinggai Ma Aihua li ang li School of Mathematics and Physics University of Science and Technology Beijing Department of Mathematical Sciences Montclair State University

A semi-supervised vector machine is a relatively new learning method using both labeled and unlabeled data in classifi- cation. Since the objective function of the model for an unstrained semi-supervised vector machine is not smooth, many fast opti- mization algorithms cannot be applied to solve the model. In order to overcome the difficulty of dealing with non-smooth objective functions, new methods that can solve the semi-supervised vector machine with desired classification accuracy are in great demand. A quintic spline function with three-times differentiability at the ori- gin is constructed by a general three-moment method, which can be used to approximate the symmetric hinge loss function. The approximate accuracy of the quintic spiine function is estimated. Moreover, a quintic spline smooth semi-support vector machine is obtained and the convergence accuracy of the smooth model to the non-smooth one is analyzed. Three experiments are performed to test the efficiency of the model. The experimental results show that the new model outperforms other smooth models, in terms of classification performance. Furthermore, the new model is not sensitive to the increasing number of the labeled samples, which means that the new model is more efficient.

关键词： semi-supervised support vector classification machine smooth quintic spline function convergence.

Precise asymptotics in the law of the logarithm for random fields in Hilbert space

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第4期8卷 651-659页

作者： FU Ke-ang ZHang li-xin Department of Mathematics Zhejiang University Hangzhou 310027 China

Consider the positive d-dimensional lattice Z^d（d≥2） with partial ordering ≤, let {XK; K∈Z＋^d} be i.i.d, random variables taking values in a real separable Hilbert space （H, ｜｜·｜｜） with mean zero and covariance operator ∑ and set partial sums SN =∑K≤nXK,K,N∈Z＋^d. Under some moment conditions, we obtain the precise asymptotics of a kind of weighted infinite series for partial sums SN as ε↓ by using the truncation and approximation methods. The results are related to the convergence rates of the law of the logarithm in Hilbert space, and they also extend the results of （Gut and Spataru, 2003）.

关键词： The law of the logarithm Random field Hilbert space. Tail probabilitv. Truncation method

Study on the prediction and inverse prediction of detonation properties based on deep learning

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Defence Technology（防务技术） 2023年第6期24卷 18-30页

作者： zi-hang Yang Ji-li Rong zi-tong Zhao Department of Mechanics School of Aerospace EngineeringBeijing Institute of TechnologyBeijing100081China

The accurate and efficient prediction of explosive detonation properties has important engineering significance for weapon *** methods for predicting detonation performance include empirical formulas,equations of state,and quantum chemical calculation *** recent years,with the development of computer performance and deep learning methods,researchers have begun to apply deep learning methods to the prediction of explosive detonation *** deep learning method has the advantage of simple and rapid prediction of explosive detonation ***,some problems remain in the study of detonation properties based on deep *** example,there are few studies on the prediction of mixed explosives,on the prediction of the parameters of the equation of state of explosives,and on the application of explosive properties to predict the formulation of *** on an artificial neural network model and a one-dimensional convolutional neural network model,three improved deep learning models were established in this work with the aim of solving these *** training data for these models,called the detonation parameters prediction model,JWL equation of state(EOS)prediction model,and inverse prediction model,was obtained through the KHT thermochemical *** training,the model was tested for overfitting using the validation-set *** the model-accuracy test,the prediction accuracy of the model for real explosive formulations was tested by comparing the predicted value with the reference *** results show that the model errors were within 10%and 3%for the prediction of detonation pressure and detonation velocity,*** accuracy refers to the prediction of tested explosive formulations which consist of TNT,RDX and *** the prediction of the equation of state for explosives,the correlation coefficient between the prediction and the reference curves was above *** the prediction of the inverse predi

关键词： Deep learning Detonation properties KHT thermochemical Code JWL equation of states Artificial neural network One-dimensional convolutional neural network