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Diurnal and seasonal variation of glacier meltwater hydrochemistry in Qiyi glacierized catchment in Qilian Mountains, Northwest China: implication for chemical weathering

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Journal of Mountain Science 2018年第5期15卷 1035-1045页

作者： wu Xiao-bo State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences

In glacierized catchments, glacier runoff typically shows a strong diurnal cycle in the ablation season(June-September). To elucidate the effect of these processes on the chemical weathering, fresh snowfall and water samples were collected and studied from the supraglacial river, proglacial river,and gauging site in Qiyi glacierized catchment Qilian Mountains, Northwestern China, in the summer of2011. The pH and electronic conductivity(EC) were determined in the field, and the concentrations of major ions(Na^+, K^+, Mg^(2+), Ca^(2+), Cl^-, SO_4^(2-), NO_3^-) were measured. The results indicated that EC linearly increased with increasing distance from the glacial snout, and the concentrations of major ions increased with increasing water-rock interaction time. Along the flow path of the glacier runoff, Na^+ and Cl^-are more concentrated than other ions in the supraglacial river while Mg^(2+) and SO_4^(2-)are more concentrated than other ions at the gauging site. The discharge, pH, EC,and the concentrations of major ions exhibited significant diurnal variation along the flow path. On the other hand, the amplitude of variation diminished from upstream to downstream along the flow *** chemical weathering rate(Na^++K^++Mg^(2+)+Ca^(2+))was determined to be 10.9 t/yr/km^2. Moreover,further research indicated that the sampling method influenced the assessment of chemical weathering rates. When the sample was collected randomly in one diurnal cycle of hydrography, the estimated ionic flux could deviate-47%~73% based on estimated hourly data. In contrast, if three samples were collected at peak, base flow and the discharge decreasing rate starts to slow down in one diurnal cycle of hydrography, respectively, the deviation would be less than 15%. The smaller the diurnal variation of discharge, the smaller deviation calculated.

关键词： Diurnal variation Hydrochemistry Chemical weathering rate

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基于密度泛函理论研究Co、Ni、As掺杂载金黄铁矿的电子结构和稳定性

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原子与分子物理学报 2025年第1期42卷 145-155页

作者：吴德宝唐云李国辉吴波聂光华贵州大学矿业学院贵阳550025 贵州省非金属矿产资源综合利用重点试验室贵阳550025 紫金矿业集团股份有限公司龙岩364000

Co、Ni、As掺杂的黄铁矿晶体具有不同物理性质,会影响其载金性能和氧化行为.论文基于密度泛函理论计算,采用了CASTEP软件对载金黄铁矿以及不同晶体缺陷的载金黄铁矿进行模拟计算,以研究Co、Ni、As掺杂载金黄铁矿的电子结构,并据此分析... 详细信息

Co、Ni、As掺杂的黄铁矿晶体具有不同物理性质,会影响其载金性能和氧化行为.论文基于密度泛函理论计算,采用了CASTEP软件对载金黄铁矿以及不同晶体缺陷的载金黄铁矿进行模拟计算,以研究Co、Ni、As掺杂载金黄铁矿的电子结构,并据此分析其稳定性.综合半导体类型和能量分析,不同晶体缺陷的载金黄铁矿稳定性顺序为:Fe_(32)S_(63)AsAu

关键词：载金黄铁矿掺杂密度泛函理论氧化预处理

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Study on the flow field uniformity of hydro-floating ship lift combined type hydraulic-driven system based on the residual energy theory

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Journal of Hydrodynamics 2022年第6期34卷 1156-1161页

作者： bo wu Ya-an Hu Shu Xue State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing210029China Key Laboratory of Transport Technology in Navigation Building Construction Nanjing Hydraulic Research InstituteNanjing210029China

The hydro-floating ship lift originally invented in China is a major innovation in the field of navigation *** shaft water levels synchronization of its unique hydraulic-driven system plays a crucial role in reducing the torque of the synchronous shafts and ensuring the safety and stability operation of the ship *** study aims to investigate the muti-shaft water level synchronization and the flow velocity uniformity of the combined type hydraulic-driven *** on the theory of residual energy,a new index m2 proposed in this study is more suitable for evaluating the flow velocity uniformity of the combined hydraulic-driven ***,the critical value of m2=75 is calculated via the results of the scaled physical mode test as the threshold of water flow uniformity,and it provides a basis for determining the reasonable height of the pressure stabilizing chamber.

关键词： Hydro-floating ship lift water levels synchronism residual energy velocity distribution uniformity coefficient

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SIMULATIONS OF MECHANICAL BEHAVIOR OF POLYCRYSTALLINE COPPER WITH NANO-TWINS

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Acta Mechanica Solida Sinica 2008年第3期21卷 189-197页

作者： bo wu Yueguang Wei State-Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China

Mechanical behavior and microstructure evolution of polycrystalline copper with nano-twins were investigated in the present work by finite element simulations. The fracture of grain boundaries are described by a cohesive interface constitutive model based on the strain gradient plasticity theory. A systematic study of the strength and ductility for different grain sizes and twin lamellae distributions is performed. The results show that the material strength and ductility strongly depend on the grain size and the distribution of twin lamellae microstructures in the polycrystalline copper.

关键词： nanocrystalline twinned copper mechanical behavior cohesive model finite element simulation

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Pointwise characterizations of curvature and second fundamental form on Riemannian manifolds

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Science China Mathematics 2018年第8期61卷 1407-1420页

作者： Fengyu Wang bo wu Center for Applied Mathematics Tianjin University Department of Mathematics Swansea University School of Mathematical Sciences Fudan University

Let M be a complete Riemannian manifold possibly with a boundary?*** any C^1-vector field Z,by using gradient/functional inequalities of the(reflecting)diffusion process generated by L:=?+Z,pointwise characterizations are presented for the Bakry-Emery curvature of L and the second fundamental form of?M if it *** characterizations extend and strengthen the recent results derived by Naber for the uniform norm‖RicZ‖∞on manifolds without boundaries.A key point of the present study is to apply the asymptotic formulas for these two tensors found by the first author,such that the proofs are significantly simplified.

关键词： curvature second fundamental form diffusion process path space

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The impact of regulatory and financial discrimination on China's low-carbon development:Considering firm heterogeneity

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Advances in Climate Change Research 2020年第2期11卷 72-84页

作者： TANG Wei-Qi MENG bo wu Li-bo CIB Research Shanghai200120China Center for Energy Economics and Strategy Studies Fudan UniversityShanghai200433China Institute of Developing Economies–JETRO Chiba2618545Japan Tokyo Foundation for Policy Research Tokyo1066234Japan School of Economics Fudan UniversityShanghai200433China

Firms in China within the same industry but with different ownership and size have different production functions and face different emission regulations and financial conditions,thus can give very different responses to environmental *** fact has been largely ignored in most of the low-carbon development related *** an augmented Chinese input–output table in which information about firm size(large-and small and medium-sized firms)and ownership(state-,foreign-,and private-owned firms)are explicitly reported,a dynamic computable general equilibrium model is developed in this study to analyze the impact of alternative low-carbon policy designs with different regulatory coverage and financial equalization on heterogeneous *** simulation results show that,with the fully balanced regulation coverage and equalized financial system for heterogeneous firms,the total green investment accounts for 4%of GDP in 2030 for fulfilling China's commitment to reduce carbon emissions,which is the lowest among the various scenarios;about one-third of this investment is made by small and private firms;at the same time,green investment efficiency will be the highest,about 84%higher than that of the business-as-usual ***,a market-oriented and new technology-driven arrangement and mechanism for sharing emission reduction burden and allocating green investment across heterogeneous firms,especially to small and medium-sized firms,is crucial for China to achieve a more ambitious emission target in the long run.

关键词： Small-and medium-sized enterprise(SME) Green finance Firm heterogeneity ETS CO2 emissions Low-carbon Chinese economy

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Dynamic simulation of urban water metabolism under water environmental carrying capacity restrictions

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Frontiers of Environmental Science & Engineering 2016年第1期10卷 114-128页

作者： Weihua ZENG bo wu Ying CHAI State Key Laboratory of Water Environmental Simulation School of Environment Beijing Normal University Beijing 100875 China School of Environment Beijing Normal University Beijing 100875 China

A revised concept for urban water metabolism （UWM） is presented in this study to address the inadequacies in current research on UWM and the problems associated with the traditional urban water metabolic process. Feedback loops can be analyzed to increase the water environmental carrying capacity （WECC） of the new urban water metabolism system （UWMS） over that of a traditional UWMS. An analysis of the feedback loops of an UWMS was used to construct a system dynamics （SD） model for the system under a WECC restriction. Water metabolic processes were simulated for different scenarios using the Tongzhou District in Beijing as an example. The results for the newly developed UWM case showed that a water environment of Tongzhou District could support a population of 1.1926 × 106, an irrigation area of 375.521 km2, a livestock of 0.7732 × 106, and an industrial value added of ￥193.14 × 109 （i.e. about US$28.285 × 109） in 2020. A sensitivity analysis showed that the WECC could be improved to some extent by constructing new sewage treatment facilities or by expanding the current sewage treatment facilities, using reclaimed water and improving the water circulation system.

关键词： urban water metabolism system (UWMS),system dynamic simulation water environmental carryingcapacity (WECC) feedback loops bilateral control

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Wavelet Neural Network Based on NARMA-L2 Model for Prediction of Thermal Characteristics in a Feed System

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Chinese Journal of Mechanical Engineering 2011年第1期24卷 33-41页

作者： JIN Chao wu bo HU Youmin State Key Laboratory for Digital Manufacturing Equipment and Technology Huazhong University of Science and Teehnology Wuhan 430074 China School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

Research of thermal characteristics has been a key issue in the development of high-speed feed system. Most of the work carried out thus far is based on the principle of directly mapping the thermal error against the temperature of critical machine elements irrespective of the operating conditions. But recent researches show that different sets of operating parameters generated significantly different error values even though the temperature of the machine elements generated was similar. As such, it is important to develop a generic thermal error model which is capable of evaluating the positioning error induced by different operating parameters. This paper ultimately aims at the development of a comprehensive prediction model that can predict the thermal characteristics under different operating conditions （feeding speed, load and preload of ballscrew） in a feed system. A novel wavelet neural network based on feedback linearization autoregressive moving averaging （NARMA-L2） model is introduced to predict the temperature rise of sensitive points and thermal positioning errors considering the different operating conditions as the model inputs. Particle swarm optimization（PSO） algorithm is brought in as the training method. According to ISO230-2 Positioning Accuracy Measurement and ISO230-3 Thermal Effect Evaluation standards, experiments under different operating conditions were carried out on a self-made quasi high-speed feed system experimental bench HUST-FS-001 by using Pt100 as temperature sensor, and the positioning errors were measured by Heidenhain linear grating scale. The experiment results show that the recommended method can be used to predict temperature rise of sensitive points and thermal positioning errors with good accuracy. The work described in this paper lays a solid foundation of thermal error prediction and compensation in a feed system based on varying operating conditions and machine tool characteristics.

关键词： wavelet neural network NARMA-L2 model particle swarm optimization thermal positioning error feed system

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Resource allocation with minimum transmit power in multicast OFDM systems

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Journal of Systems Engineering and Electronics 2010年第3期21卷 355-360页

作者： bo wu Jun Shen Haige Xiang School of Electronics Engineering and Computer Science Peking University Beijing 100871 R R. China

To minimize the total transmit power for multicast service in an orthogonal frequency division multiplexing（OFDM） downlink system,resource allocation algorithms that adaptively allocate subcarriers and bits are *** proposed algorithms select users with good channel conditions for each subcarrier to reduce the transmit power,while guaranteeing each user＇s instantaneous minimum rate *** resource allocation problem is first formulated as an integer programming（IP） problem,and then,a full search algorithm that achieves an optimal solution is *** reduce the computation load,a suboptimal algorithm is *** suboptimal algorithm decouples the joint resource allocation problem by separating subcarrier and bit ***-like algorithms are employed in both *** results illustrate that the proposed algorithms can significantly reduce the transmit power compared with the conventional multicast approach and the performance of the suboptimal algorithm is close to the optimum.

关键词： resource allocation multicast orthogonal frequency division multiplexing (OFDM) integer programming (IP) greedy algorithm.

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Two-Parameter Block Triangular Splitting Preconditioner for Block Two-by-Two Linear Systems

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Communications on Applied Mathematics and Computation 2023年第4期5卷 1601-1615页

作者： bo wu Xingbao Gao School of Mathematics and Statistics Ningxia UniversityYinchuan750021NingxiaChina School of Mathematics and Statistics Shaanxi Normal UniversityXi’an710062ShaanxiChina

This paper proposes a two-parameter block triangular splitting(TPTS)preconditioner for the general block two-by-two linear *** eigenvalues of the corresponding preconditioned matrix are proved to cluster around 0 or 1 under mild *** limited numerical results show that the TPTS preconditioner is more efficient than the classic block-diagonal and block-triangular preconditioners when applied to the flexible generalized minimal residual(FGMRES)method.

关键词： Block triangular splitting Block two-by-two linear systems Eigenvalues Preconditioner flexible generalized minimal residual(FGMRES)

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