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The Formation Logic of the Digital Divide and Feasible Ways to Cross It:An Access-Based Analysis

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Contemporary Social Sciences 2023年第3期8卷 29-42页

作者： Xu Haixin yang chen yang Chanchan Sichuan University

How enterprises overcome the digital divide in a digital economy is a topic related to efficiency and *** formation of the digital divide has showcased a certain level of objectivity and is also influenced by the characteristics of enterprises *** on the model that expands the information and communication technology(ICT)access,concept,we explored the digital divide’s formation logic of the digital divide and feasible ways to cross *** findings shed light on its formation logic,which includes elements of the subjective will of enterprises to transform,the fear of transformation,the dependence on development paths,and the cost of using digital technology,all of which have contributed to disparities in enterprises’motivational *** addition,differences in the construction of digital infrastructure,financial strengths,business models,and heterogeneity in cluster networks have led to differences in enterprises’material *** absorptive capacity of enterprises has affected their skill access,while the management capability influences the application access of *** also found that crossing the digital divide requires the joint efforts of governments,markets,and enterprises in the four access dimensions.

关键词： digital divide ICT access digital technology motivational access skill access

Near-Threshold Wide-Voltage Design Review

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Tsinghua Science and Technology 2023年第4期28卷 696-718页

作者： Yan Zhao Jun yang Chao chen Weiwei Shan Peng Cao Yongliang Zhou Ziyu Li Tai yang National Application Specific Integrated Circuit(ASIC)Center Southeast UniversityNanjing 210096China

This paper presents a comprehensive review of near-threshold wide-voltage designs on memory,resilient logic designs,low voltage Radio Frequency(RF)circuits,and timing *** the prosperous development of wearable applications,low power consumption has become one of the primary challenges for IC *** improve the power efficiency,the prefer scheme is to operate at an ultra low voltage of Near Threshold Voltage(NTV).For the performance variation and degradation,a self-adaptive margin assignment technique is proposed in the low *** proposed technique tracks the circuit states in real time and dynamically allocates voltage margins,reducing the minimum supply voltage and achieving higher energy *** self-adaptive margin assignment technique can be used in Static Random Access Memory(SRAM),digital circuits,and analog/RF *** on the self-adaptive margin assignment technique,the minimum voltage in the 40 nm CMOS process is reduced to 0.6 V or even lower,and the energy efficiency is increased by 3–4 times.

关键词： Near Threshold Voltage(NTV) wide-voltage memory resilient logic design low voltage Radio Frequency(RF) timing analysis

A state of art review on time series forecasting with machine learning for environmental parameters in agricultural greenhouses

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Information Processing in Agriculture 2024年第2期11卷 143-162页

作者： Gedi Liu Keyang Zhong Huilin Li Tao chen yang Wang National Innovation Center for Digital Fishery China Agricultural University100083 BeijingChina Key Laboratory of Smart Farming Technologies for Aquatic Animal and Livestock Ministry of Agriculture and Rural AffairsChina Agricultural University100083 BeijingChina Beijing Engineering and Technology Research Center for Internet of Things in Agriculture China Agricultural University100083 BeijingChina College of Information and Electrical Engineering China Agricultural University100083 BeijingChina Department of Chemical and Process Engineering University of SurreyGU27XH GuildfordUnited Kingdom

Agricultural greenhouse production has to require a stable and acceptable environment,it is therefore essential for future greenhouse production to obtain full and precisely internal dynamic environment *** modeling based on machine learning methods,e.g.,intelligent time series prediction modeling,is a popular and suitable way to solve the above *** this article,a systematic literature review on applying advanced time series models has been systematically conducted via a detailed analysis and evaluation of 61 pieces selected from 221 *** historical process of time series model application from the use of data and information strategies was first ***,the accuracy and generalization of the model from the selection of model parameters and time steps,providing a new perspective for model development in this field,were compared and ***,the systematic review results demonstrate that,compared with traditional models,deep neural networks could increase data structure mining capabilities and overall information simulation capabilities through innovative and effective structures,thereby it could also broaden the selection range of environmental parameters for agricultural facilities and achieve environmental prediction end-to-end optimization via intelligent time series model based on deep neural networks.

关键词： Horticultural greenhouse environment Time series algorithms Prediction Deep neural networks

A bioinspired high-modulus mineral hydrogel binder for improving the cycling stability of microsized silicon particle-based lithium-ion battery

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Nano Research 2019年第5期12卷 1121-1127页

作者： Meng Tian Xiao chen Shengtong Sun Dong yang Peiyi Wu State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceLaboratory for Advanced MaterialsFudan UniversityShanghai 200433China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of ChemistryChemical Engineering and BiotechnologyCenter for Advanced Low-dimension MaterialsDonghua UniversityShanghai 201620China

Silicon with high specific capacity is deemed an ideal anode material for lithium ion batteries,which,however suffers from low cycling life due to its dramatic volume ***-soluble polymer binders recently gain increasing attention by providing an eco-friendly and low-cost way in improving the cycling stability of Si-based ***,a novel bioinspired supramolecular mineral hydrogel binder consisting of polyacrylic acid (PAA) physically crosslinked with amorphous calcium carbonate (ACC) nanoparticles is designed for high-performance anodes made from low-cost microsized Si *** to its organic-inorganic hydrophilic nature,ACC-PAA hybrid binder exhibits the reported highest modulus (~22 GPa) for polymer binders in electrolyte,even higher than lithiated Si species (Li15Si4,~12 GPa).Together with its excellent adhesion and electrochemical stability,ACC-PAA binder can effectively suppress the pulverization of Si particles and maintain the mechanical integrity of electrodes during ***,even with a low binder content,the anode still shows an initial discharge capacity of 2,973 mAh·g^-1 and Coulombic efficiency of 81.5%,and retains 75% at a current density of 600 mA·g^-1 after 100 *** present organic-inorganic hybrid mineral binder may open a new approach for designing more effective polymer binders for Si-based lithium-ion batteries.

关键词： polymer binder mineral hydrogel microsized silicon particle lithium-ion battery

Precipitate Behavior in Fe–20Cr–30Ni–2Nb Austenitic Heat-Resistant Steel

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Acta Metallurgica Sinica(English Letters) 2015年第4期28卷 424-429页

作者： Hiroki Ishikawa Chi Zhang Sheng-Wei chen Zhi-Gang yang School of Materials Science and Engineering Tsinghua University Department of Chemistry and Materials Science Tokyo Institute of Technology

In this study, the precipitation behavior of a new austenitic heat-resistant steel （Fe-20Cr-30Ni-2Nb, in at%） was investigated. The effects of alloying addition of boron （B） and lanthanum （La） on the microstructure of the austenitic steel were scrutinized using SEM, EPMA, TEM, and XRD. The results showed that the addition of B enhanced the precipitation of bar-type Laves phase. A small precipitate with high La concentration was observed at the grain boundary in the alloy without aging; similar precipitates without La also presented in region adjacent to the La single phase. This result indicates that La can exist independently and does not contribute to the formation of new compounds. However, in both B- and La-modified alloy, B appeared in the precipitate free zone. In the alloy containing both B and La, only Fe2Nb Laves- phase precipitates, as indicated by the XRD result.

关键词： Precipitation free zone Grain boundary Phase transformation Microstructure Fe-20Cr-30Ni-2Nb austenitic heat-resistant steel

Orthogonal transformation operation theorem of a spatial universal uniform rotating magnetic field and its application in capsule endoscopy

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Science China(Technological Sciences) 2017年第6期60卷 854-864页

作者： ZHANG YongShun YU ZiChun yang HuiYuan HUANG YunKui chen Jun Key Laboratory for Precision & Non-traditional Machining of Ministry of Education of China Dalian University of Technology The State Key Laboratory of Mechanical Transmissions Chongqing University Department of Mechanical Engineering School of Naval Architecture and Ocean Engineering Harbin Institute of Technology

According to the anti-phase sine current superposition theorem, the orientation, the magnetic flux density, the angular speed and the rotational direction of the spatial universal rotating magnetic field (SURMF) can be controlled within the tri-axial orthogonal square Helmholtz coils (TOSHC). Nevertheless, three coupling direction angles of the normal vector of the SURMF in the Descartes coordinate system cannot be separately controlled, thus the adjustment of the orientation of the SURMF is difficult and the flexibility of the robotic posture control is restricted. For the dimension reduction and the decoupling of control variables, the orthogonal transformation operation theorem of the SURMF is proposed based on two independent rotation angular variables, which employs azimuth and altitude angles as two variables of the three-phase sine current superposition formula derived by the orthogonal rotation inverse transformation. Then the unique control rules of the orientation and the rotational direction of the SURMF are generalized in each spatial quadrant, thus the scanning of the normal vector of the SURMF along the horizontal or vertical direction can be achieved through changing only one variable, which simplifies the control process of the orientation of the SURMF greatly. To validate its feasibility and maneuverability, experiments were conducted in the animal intestine utilizing the innovative dual hemisphere capsule robot (DHCR) with active and passive modes. It was demonstrated that the posture adjustment and the steering rolling locomotion of the DHCR can be realized through single variable control, thus the orthogonal transformation operation theorem makes the control of the orientation of the SURMF convenient and flexible significantly. This breakthrough will lay a foundation for the human-machine interaction control of the SURMF.

关键词： dual hemisphere capsule robot (DHCR) spatial universal rotating magnetic field (SURMF) orthogonal transformation operation variable decoupling

Petroleum geochemistry and origin of shallow-buried saline lacustrine oils in the slope zone of the Mahu sag, Junggar Basin, NW China

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Petroleum Science 2023年第6期20卷 3363-3378页

作者： Dong-Yong Wang Mei-Jun Li yang Zhou lu yang Yuan-Feng yang Er-Ting Li Jun Jin Xian-Li Zou Bo-Dong Xu State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China College of Chemistry and Environmental Engineering Sichuan University of Science and EngineeringZigong643000SichuanChina College of Resources and Environment Chengdu University of Information TechnologyChengdu610225SichuanChina Baikouquan Oil Production Plant Xinjiang Oilfield Company CNPCKaramay834000XinjiangChina Research Institute of Experiment and Detection of Xinjiang Oilfield Company CNPC Karamay834000XinjiangChina Faculty of Petroleum China University of Petroleum(Beijing)at KaramayKaramay834000XinjiangChina

Recently, significant oil discoveries have been made in the shallower pay zones of the Jurassic Badaowan Formation (J_(1)b) in the Mahu Sag, Junggar Basin, Northwest China. However, little work has been done on the geochemical characteristics and origins of the oil in the J_(1)b reservoir. This study analyzes 44 oil and 14 source rock samples from the area in order to reveal their organic geochemical characteristics and the origins of the oils. The J_(1)b oils are characterized by a low Pr/Ph ratio and high β-carotene and gammacerane indices, which indicate that they were mainly generated from source rocks deposited in a hypersaline environment. The oils are also extremely enhanced in C_(29) regular steranes, possibly derived from halophilic algae. Oil-source correlation shows that the oils were derived from the Lower Permian Fengcheng Formation (P_(1)f) source rocks, which were deposited in a strongly stratified and highly saline water column with a predominance of algal/bacterial input in the organic matter. The source rocks of the Middle Permian lower-Wuerhe Formation (P_(2)w), which were deposited in fresh to slightly saline water conditions with a greater input of terrigenous organic matter, make only a minor contribution to the J_(1)b oils. The reconstruction of the oil accumulation process shows that the J_(1)b oil reservoir may have been twice charged during Late Jurassic–Early Cretaceous and the Paleogene–Neogene, respectively. A large amount volume of hydrocarbons generated in the P_(1)f source rock and leaked from T_(1)b oil reservoirs migrated along faults connecting source beds and shallow-buried secondary faults into Jurassic traps, resulting in large-scale accumulations in J_(1)b. These results are crucial for understanding the petroleum system of the Mahu Sag and will provide valuable guidance for petroleum exploration in the shallower formations in the slope area of the sag.

关键词： Molecular marker Saline lacustrine oil Petroleum origin Lower Permian Fengcheng Formation Shallow-buried reservoir Mahu Sag

AN INTEGRATED COUPLING ELEMENT FOR VEHICLE-RAIL-BRIDGE INTERACTION SYSTEM WITH A NON-UNIFORM CONTINUOUS BRIDGE

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Acta Mechanica Solida Sinica 2015年第3期28卷 313-330页

作者： Hongyin yang Zhijun chen Shaofan Li Hailong Zhang Jianping Fan School of Civil Engineering and Mechanics Huazhong University of Science and Technology Department of Civil and Environmental Engineering University of California at Berkeley

An integrated coupling element considering wheel-rail interface for analyzing the dynamic responses of vehicle-rail-bridge interaction system with a non-uniform continuous bridge is presented. The governing equations of the interaction system are established first, and the solution procedure and assembly method of the coupling element are demonstrated. Finally, the accuracy, efficiency and function of the integrated coupling element are tested using two numerical examples. The influences of different combinations of rail and bridge element length in the coupling element on the solution are investigated, and the effects of different rail irregularities on the dynamic responses are discussed.

关键词： vehicle-rail-bridge dynamic interaction integrated coupling element non-uniform continuous beam wheel-rail contact rail irregularity

Quantum network coding for multi-unicast problem based on 2D and 3D cluster states

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Science China(Information Sciences) 2016年第4期59卷 5-19页

作者： Jing LI Xiubo chen Xingming SUN Zongpeng LI Yixian yang Information Security Center State Key Laboratory of Networking and Switching TechnologyBeijing University of Posts and Telecommunications Department of Computer Science University of Calgary School of Computer and Software Nanjing University of Information Science & Technology

We mainly consider quantum multi-unicast problem over directed acyclic network, where each source wishes to transmit an independent message to its target via bottleneck channel. Taking the advantage of global entanglement state 2D and 3D cluster states, these problems can be solved efficiently. At first, a universal scheme for the generation of resource states among distant communication nodes is provided. The corresponding between cluster and bigraph leads to a constant temporal resource cost. Furthermore, a new approach based on stabilizer formalism to analyze the solvability of several underlying quantum multi-unicast networks is presented. It is found that the solvability closely depends on the choice of stabilizer generators for a given cluster state. And then, with the designed measurement basis and parallel measurement on intermediate nodes, we propose optimal protocols for these multi-unicast sessions. Also, the analysis reveals that the resource consumption involving spatial resources, operational resources and temporal resources mostly reach the lower bounds.

关键词： quantum information network coding multi-unicast cluster state stabilizer formalism