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Mass-accreting white dwarfs and type Ia supernovae

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Research in Astronomy and Astrophysics 2018年第5期18卷 1-28页

作者： bo wang Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan Observatories Chinese Academy ofSciences Kunming 650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

Type Ia supernovae（SNe Ia） play a prominent role in understanding the evolution of the Universe. They are thought to be thermonuclear explosions of mass-accreting carbon-oxygen white dwarfs（CO WDs） in binaries, although the mass donors of the accreting WDs are still not well determined. In this article, I review recent studies on mass-accreting WDs, including H-and He-accreting WDs. I also review currently most studied progenitor models of SNe Ia, i.e., the single-degenerate model（including the WD＋MS channel, the WD＋RG channel and the WD＋He star channel）, the doubledegenerate model（including the violent merger scenario） and the sub-Chandrasekhar mass *** progress on these progenitor models is discussed, including the initial parameter space for producing SNe Ia, the binary evolutionary paths to SNe Ia, the progenitor candidates for SNe Ia, the possible surviving companion stars of SNe Ia, some observational constraints, etc. Some other potential progenitor models of SNe Ia are also summarized, including the hybrid CONe WD model, the core-degenerate model, the double WD collision model, the spin-up/spin-down model and the model of WDs near black holes. To date, it seems that two or more progenitor models are needed to explain the observed diversity among SNe Ia.

关键词： supernovae general - binaries close - stars evolution - white dwarfs

Seed density affects post-dispersal seed predation:evidence from a seed removal experiment of 62 species

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Integrative Zoology 2020年第2期15卷 135-143页

作者： bo wang School of Resources and Environmental Engineering Anhui UniversityHefeiAnhui ProvinceChina Center for Integrative Conservation Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan ProvinceChina

Post-dispersal seed predation plays an important role in plant demography and biodiversity ***ever,the effects of seed density on seed predation from previous studies have been *** dissected the effects of density on the 2-step processes of seed predation using 101520 seeds from 62 plant species in an alpine pine forest for 3 consecutive *** this study we explained the current controversy surrounding the effects of density on seed *** encounter frequency(at least 1 seed being predated from an experiment depot)showed positive density dependence,while seed exploitation(the proportion of seeds being predated of the encountered depots)showed negative density *** density effects showed a consistent trend but with different magnitudes of effect across *** seed predation is the combination of seed encounter and seed *** seed predation could be either positively or negatively density-dependent and was contingent on the magnitude of the difference between positive density-dependent seed encounter and negative density-dependent seed *** results also indicated that studies including only a few species would produce biased results,because the density effect on seed predation differed greatly among plant *** studies should include a large number of plant species that possess a wide range of diverse seed traits to avoid potential bias and produce more comprehensive and accurate results.

关键词： density rodent seed encounter seed predation seed removal

Regional wind power forecasting model with NWP grid dataoptimized

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Frontiers in Energy 2017年第2期11卷 175-183页

作者： Zhao wang Weisheng wang bo wang State Key Laboratory of Operation and Control of Renewable Energy &Storage Systems China Electric Power Research Institute Beijing100192 China Department of Electrical Engineering TsinghuaUniversity Beijing 100084 China State Key Laboratory of Operation and Control of Renewable Energy &Storage Systems China Electric Power Research Institute Beijing100192 China

Unlike the traditional fossil energy, wind, as the clean renewable energy, can reduce the emission of the greenhouse gas. To take full advantage of the environmental benefits of wind energy, wind power forecasting has to be studied to overcome the troubles brought by the variable nature of wind. Power forecasting for regional wind farm groups is the problem that many power system operators care about. The high-dimensional feature sets with redundant information are frequently encountered when dealing with this problem. In this paper, two kinds of feature set construction methods are proposed which can achieve the proper feature set either by selecting the subsets or by transforming the original variables with specific combinations. The former method selects the subset according to the criterion of minimal-redundancy-maximal-relevance (mRMR), while the latter does so based on the method of principal component analysis (PCA). A locally weighted learning method is also proposed to utilize the processed feature set to produce the power forecast results. The proposed model is simple and easy to use with parameters optimized automatically. Finally, a case study of 28 wind farms in East China is provided to verify the effectiveness of the proposed method.

关键词： regional wind power forecasting feature set minimal-redundancy-maximal-relevance (mRMR) principal component analysis (PCA) locally weighted learning model

Dynamically reconfigurable architecture for symmetric ciphers

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Science China(Information Sciences) 2016年第4期59卷 67-82页

作者： bo wang Leibo LIU National Laboratory for Information Science and Technology Tsinghua University

In this paper, a very large scale integration(VLSI) architecture for a reconfigurable cryptographic processor is presented. Several optimization methods have been introduced into the design process. The interconnection tree between rows(ICTR) method reduces the interconnection complexity and results in a small area overhead. The hierarchical context organization(HCO) scheme reduces the total context size and increases the dynamic configuration speed. Most symmetric ciphers, including AES, DES, SHACAL-1, SMS4, and ZUC, can be implemented using the proposed architecture. Experimental results show that the proposed architecture has obvious advantages over current state-of-the-art architectures reported in the literature in terms of performance,area efficiency(throughput/area) and energy efficiency(throughput/power).

关键词： reconfigurable cryptographic architecture symmetric cryptography algorithm flexibility performance area efficiency energy efficiency

Preparation of Macroscopic Quantum Superposition States of Cavity Modes Using rf-SQUIDs in a Cavity

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Communications in Theoretical Physics 2008年第6期49卷 1599-1602页

作者： wang bo State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics the Chinese Academy of Sciences Wuhan 430071 China

We propose a potential scheme of preparing Schrodinger-cat state of the cavity mode by placing an rfsuperconducting quantum interference device （rf-SQUID） in a single-mode microwave cavity. By properly adjusting the detuning and the strength regarding the radiation fields, we show how to generate single-mode Schrodinger-cat state. Generalizing this method we discuss the generation of the engtangled coherent states. The experimental feasibility of our scheme is discussed under consideration of the cavity decay.

关键词： SchrSdinger-cat states rf-SQUID cavity

Development of an oscillating grinding machine tool based on error analysis

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Science China(Technological Sciences) 2020年第6期63卷 912-922页

作者： wang LiPing wang Dong wang bo LI WeiHua Institute of Manufacturing Engineering Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Beier Machine Tool Works Co. LTDBeijing 102444China

Oscillating grinding machine tool is the core equipment when machining crankshaft pin journal,which directly determines the final *** paper describes the development of an oscillating grinding machine tool based on error ***,the error analysis of oscillating grinding for crankshaft pin journal is carried out,including the effect on machining accuracy caused by each error and corresponding error *** results show that the tracking error of X-axis has the greatest influence on the grinding accuracy of pin journal,thus,the grinding carriage feed system is the critical component of an oscillating grinding machine tool,which should be given priority during the development ***,the development of an oscillating grinding machine tool is *** whole structure is given,and the grinding carriage feed system is emphatically presented involving drive mode and assembly *** components of the oscillating grinding machine tool are also ***,some grinding experiments are performed on the prototype,and the results show that all workpieces are qualified under different conditions,which verify the performance of the developed oscillating grinding machine tool.

关键词： oscillating grinding machine tool error analysis crankshaft pin journal grinding carriage feed system

Forecasted Scenarios of Regional Wind Farms Based on Regular Vine Copulas

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Journal of Modern Power Systems and Clean Energy 2020年第1期8卷 77-85页

作者： Zhao wang Weisheng wang Chun Liu bo wang State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems China Electric Power Research InstituteBeijingChina Department of Electrical Engineering Tsinghua UniversityBeijingChina

Owing to the uncertainty and volatility of wind energy,forecasted wind power scenarios with proper spatio-temporal correlations are needed in various decision-making problems involving power *** this study,forecasted scenarios are generated from an estimated multi-variate distribution of multiple regional wind *** to the theory of copulas,marginal distributions and the dependence structure of multi-variate distribution are modeled through the proposed distance-weighted kernel density estimation method and the regular vine(R-vine)copula,*** to the flexibility of decomposing correlations of high dimensions into different types of pair-copulas,the R-vine copula provides more accurate results in describing the complicated dependence of wind *** the case of 26 wind farms located in East China,highquality forecasted scenarios as well as the corresponding probabilistic forecasting and point forecasting results are obtained using the proposed method,and the results are evaluated using a comprehensive verification framework.

关键词： Forecasted scenarios wind power distanceweighted kernel density estimation(KDE) regular vine(R-vine)copula spatio-temporal correlation

Area-preserving mean curvature flow of rotationally symmetric hypersurfaces with free boundaries

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Science China Mathematics 2016年第3期59卷 493-502页

作者： wang Kun bo Department of Mathematics Zhejiang University

We consider the area-preserving mean curvature flow with free Neumann boundaries. We show that a rotationally symmetric n-dimensional hypersurface in R^(n+1)between two parallel hyperplanes will converge to a cylinder with the same area under this flow. We use the geometric properties and the maximal principle to obtain gradient and curvature estimates, leading to long-time existence of the flow and convergence to a constant mean curvature surface.

关键词： area-preserving mean curvature flow symmetric hypersurfaces free boundary

Correlation between anxiety, depression, and social stress in young patients with thoracolumbar spine fractures

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World Journal of Psychiatry 2025年第1期15卷 83-92页

作者： bo wang Da Shi Yin-Di Sun bo Dong Joint Ward of Orthopedics Department of TCM Honghui HospitalXi'an Jiaotong UniversityXi’an 710054Shaanxi ProvinceChina Pain Ward of Orthopedics Department of TCM Honghui HospitalXi'an Jiaotong UniversityXi’an 710054Shaanxi ProvinceChina

BACKGROUND Traumatic injuries,such as falling,car accidents,and crushing mostly cause spinal fractures in young and middle-aged people,and>50%of them are thoracolumbar *** kind of fracture is easily combined with serious injuries to peripheral nerves and soft tissues,which causes paralysis of the lower limbs if there is no timely rehabilitation *** patients with thoracolumbar fractures find it difficult to recover after the operation,and they are prone to depression,low self-esteem,and other negative *** To investigate the association between anxiety,depression,and social stress in young patients with thoracolumbar spine fractures and the effect on rehabilitation *** This study retrospectively analyzed 100 patients admitted to the orthopedic department of Honghui Hospital,Xi’an Jiaotong University who underwent thoracolumbar spine fracture surgery from January 2022 to June *** general data of the patients were assessed with the Hamilton anxiety scale(HAMA),Hamilton depression scale(HAMD),life events scale,and social support rating scale(SSRS)to identify the correlation between anxiety,depression scores,and social stress and social *** Japanese Orthopedic Association(JOA)was utilized to evaluate the rehabilitation outcomes of the patients and to analyze the effects of anxiety and depression scores on *** According to the scores of HAMD and HAMA in all patients,the prevalence of depression in patients was 39%(39/100),and the prevalence of anxiety was 49%(49/100).Patients were categorized into non-depression(n=61)and depression(n=39),non-anxiety(n=51),and anxiety(n=49)*** significant differences in gender,occupation,Pittsburgh Sleep Quality Index(PSQI)score,and monthly family income were observed between the non-depression and depression groups(P<0.05).A significant difference in occupation and PSQI score was found between the non-anxiety and anxiety *** depression(r=0

关键词： Patients with thoracolumbar fractures Anxiety Depression Social pressure Social support