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Inherent relationship between process parameters,crystallization and mechanical properties of continuous carbon fiber reinforced PEEK composites

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Defence Technology（防务技术） 2023年第6期24卷 269-284页

作者： Xiao-long Ma li-hua wen Shi-yu Wang Jin-you Xiao wen-hao li Xiao Hou School of Astronautics Northwestern Polytechnical UniversityXi'an710072China China Aerospace Science and Technology Corporation Beijing100048China

High-performance thermoplastic composites have been developed as significant structural materials for cutting-edge equipment in the aerospace and defence ***,the internal mechanism of processing parameters on mechanical properties in the manufacturing process of thermoplastic composite structures is still a serious *** purpose of this study is to investigate the process/crystallization/property relationships for continuous carbon fiber(CF)reinforced polyether-ether-ketone(PEEK)*** composite laminates are fabricated according to orthogonal experiments via the thermoforming *** mechanical performance is investigated in terms of crystallization properties and fracture morphology *** results show that the mechanical performance and crystallization properties of thermoplastic composites are significantly affected by the coupling of processing *** increased molding temperature,pressure,and holding time improve the degree of fiber/matrix infiltration and affect the crystallinity and crystalline morphology of the matrix,which further influences the mechanical properties of the *** is reflected in the test results that crystallinity has an approximately linear effect on mode-I interlaminar fracture toughness and transverse flexural *** well as the higher molding temperature can destroy the pre-existent crystals to improve the toughness of the matrix,and the well-defined crystalline structures can be observed when fabricated at higher temperatures and longer periods of holding time.

关键词： Polymer matrix composites Thermoplastic Processing parameters Mechanical properties Crystallization

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Oncological outcome of unresectable lung metastases without extrapulmonary metastases in colorectal cancer

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World Journal of Gastroenterology 2010年第26期16卷 3318-3324页

作者： li, wen-hua Peng, Jun-Jie Xiang, Jia-Qing Chen, Wei Cai, San-Jun Zhang, wen Fudan Univ Shanghai Canc Ctr Dept Med Oncol Shanghai 200032 Peoples R China Fudan Univ Shanghai Canc Ctr Dept Colorectal Surg Shanghai 200032 Peoples R China Fudan Univ Shanghai Canc Ctr Dept Thorac Surg Shanghai 200032 Peoples R China Univ Michigan Dept Biostat Ann Arbor MI 48710 USA

AIM: To explore the oncological outcomes of unresectable lung metastases without extrapulmonary metastases in colorectal cancer. METHODS: Patients with unresectable isolated lung metastases from colorectal cancer were prospectively collected in a single institution during a 5-year period. All patients received either the fluorouracil/leucovorin plus oxaliplatin, fluorouracil/leucovorin plus irinotecan or capecitabine plus oxaliplatin regimen as first-line treatment. The resectability after preoperative chemotherapy was evaluated. Patients' outcome and predictive factors for overall survival were also investigated by univariate and multivariate ***: A total of 70 patients were included in the study. After standardized fi rst-line chemotherapy, only 4 patients (5.7%) were converted to resectable disease. The median overall survival time in all patients was 19 mo (95% CI: 12.6-25.4), with a 2-year overall survival rate of 38.8%. No survival difference was found among different fi rst-line chemotherapeutic regimens. Prognostic analysis demonstrated that only the fi rst response assessment for fi rst-line treatment was the independent factor for predicting overall survival. The median survival time in partial response, stable disease and progressive disease patients were 27 mo, 16 mo and 8 mo (P = 0.00001). CONCLUSION: Pulmonary metastasectomy can only be performed in a small part of unresectable lung metastases patients after chemotherapy. Patients' first response assessment is an important prognostic factor.

关键词： Colorectal cancer Lung Metastases Chemotherapy

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Micro-vibration Modeling and Verification of Shutter Mechanism of Survey Space Telescope

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Research in Astronomy and Astrophysics 2023年第1期23卷 242-253页

作者： Tong-Lei Jiang li-hua wen Hu Zhan Bo Wang Yong-Chao Yang School of Astronautics Northwestern Polytechnical UniversityXi’an 710072China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China

The scientific research mission of the Survey Space Telescope(also known as the China Space Station Telescope,CSST)imposes rigorous requirements on the observation ***,microvibrations generated by the shutter mechanism can seriously affect the performance of the highly precise and sensitive instruments *** study presents a dynamic model and verifies its performance using experimental ***,a five-degreeof-freedom nonlinear dynamic model that considers all interference sources and bearing nonlinearity is *** validity of the proposed model is verified using experimental measurements of the microvibration *** obtained results proved that the proposed dynamic model can accurately predict the characteristics of the microvibrations caused by the shutter mechanism in the design stage and provide a theoretical basis for the development of CSST.

关键词： telescopes-surveys-methods numerical-methods analytical

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Influence of ginseng cultivation under larch plantations on plant diversity and soil properties in liaoning Province,Northeast China

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Journal of Mountain Science 2016年第9期13卷 1598-1608页

作者： liU Wei-wei liU Mou-cheng li wen-hua ZENG Fan-shun QU Yi Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China liaoning Academy of Forestry Shenyang 110032China

Currently, transforming the mode of forest management and developing multiple forest management practices are actively encouraged in China. As one forest management type, ginseng cultivation under larch plantations has been developed significantly in the east of liaoning Province. However, research on the influence of the ecological environment for this mode of production is still deficient. Based on this, our study compares the plant diversity and soil properties in the ginseng cultivation under larch plantations(LG) with larch plantations(LP) and natural secondary forests(SF). First, we randomly selected three plots for each of the three stand types which have similar stand characteristics; then, we carried out a plant diversity survey and soil sampling in each of the nine plots. The results show that no significant difference was found in plant diversity between LG and LP, but theevenness of herbs was significantly lower in LG than LP. No obvious changes in soil physical properties were found in LG, but a significant decrease in most of the soil nutrient content was presented in LG. Furthermore, we found a correlation between plant diversity(H') and soil properties in the three kinds of stand types, especially between herbaceous plant diversity and soil properties. We conclude that ginseng cultivation under larch plantations has no obvious effect on plant diversity, except the herbaceous evenness. Soil fertility can be depleted significantly in LG, but physical structures are not affected. Moreover, maintaining the diversity of herbaceous plants and controlling the density of ginseng cultivation in LG by farmers are important for the ecological environment. Based on this study and its good comprehensive benefits and with the support of policy, we think this forest management type should be promoted moderately in the region.

关键词： Forest management Ginseng cultivation Larch plantations Secondary forests Plant diversity Soil properties Changbai Mountain

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Construction and Resource Locating of Semantic P2P Grid Based on Description Logics

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Wuhan University Journal of Natural Sciences 2006年第1期11卷 78-82页

作者： SUN Xiao-lin LU Zheng-ding li Yu-hua wen Kun-mei li Rui-xuan College of Computer Science and Technology HuazhongUniversity of Science and Technology Wuhan 430074Hubei China

This paper proposes an algorithm applied in se mantic P2P network based on the description logics with the purpose for realizing the concepts distribution of resources, which makes the resources semantic locating easy. With the idea of the consistent hashing in the Chord, our algorithm stores the addresses and resources with the values of the same type to select instance. In addition, each peer has its own ontology, which will be completed by the knowledge distributed over the network during the exchange of CHGs （classification hierarchy graphs）. The hierarchy classification of concepts allows to find matching resource by querying to the upper level concept because the all concepts described in the CHG have the same root.

关键词： semantic P2P description logics consistent hashing ontology CHG (classification hierarchy graphs)

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Single Machine Scheduling Problem with Release Dates and Two Hierarchical Criteria to Minimize Makespan and Stocking Cost

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Chinese Quarterly Journal of Mathematics 2006年第1期21卷 103-109页

作者： li wen-hua Department of Mathematics Zhengzhou University Zhengzhou 450052 China

In this paper, the single machine scheduling problem with release dates and two hierarchical criteria is discussed. The first criterion is to minimize makespan, and the second criterion is to minimize stocking cost. We show that this problem is strongly NP-hard. We also give an O（n^2） time algorithm for the special case that all stocking costs of jobs in unit time are 1.

关键词： scheduling release dates hierarchical criteria

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Analysis and research on the processing threshold of femtosecond laser

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Optoelectronics Letters 2020年第5期16卷 343-348页

作者： CHEN Zi-jian ZHANG lian MA Zeng-hong li wen-hua Energy Engineering School Tianjin Sino-German University of Applied SciencesTianjin 300350China Basic Courses Department Tianjin Sino-German University of Applied SciencesTianjin 300350China School of Physics Nankai UniversityTianjin 300071China

In this work,the intensity distribution formula of the focused femtosecond(fs)laser beam is *** was used to establish the light intensity distribution model of the focused fs laser under the processing condition,and the light intensity of focused fs laser under different laser power was *** the fs laser processing platform was *** glass was etched by fs laser,and the SU-8 photoresist was processed by fs laser two-photon polymerization(2PP).By adjusting the change of laser power,the etching and polymerization lines of different sizes are *** on the simulation results and experimental results,the estimated etching threshold of the glass using the fs laser is 5.0966×10^16 W/m^2,and the estimated processing threshold of SU-8 photoresist by 2PP using the fs laser is 1.1942×10^14 W/m^*** work is helpful to further analyze the applications of fs laser *** provides guidance and reference for different kinds of fs laser processing methods.

关键词： laser femtosecond processing

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Residential Energy Consumption and Associated Carbon Emission in Forest Rural Area in China: A Case Study in Weichang County

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Journal of Mountain Science 2014年第3期11卷 792-804页

作者： LUN Fei Josep G. CANADELL XU Zhong-qi HE Lu YUAN Zheng ZHANG Dan li wen-hua liU Mou-cheng Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences University of Chinese Academy of Sciences Global Carbon Project CSIRO Marine and Atmospheric Research GPO Box 3023 Canberra ACT 2601 Australia College of Forestry Agricultural University of Hebei

Rural energy consumption in China has increased dramatically in the last decades, and has become a significant contributor of carbon emissions. Yet there is limited data on energy consumption patterns and their evolution in forest rural areas of China. In order to bridge this gap, we report the findings of field surveys in forest villages in Weichang County as a case study of rural energy consumption in northern China. We found that the residential energy consumption per household is 3313 kgce yr^-1 （kilogram standard coal equivalent per year）, with energy content of 9.7×lO7 kJ yr^-1, including 1783 kgce yr^-1 from coal, 1386 kgce yr^-1 from fuel wood, 96 kgce yr^-1 from electricity, and 49 kgce yr^-1 from LPG. Per capita consumption is 909 kgce yr^-1 and its energy content is 2.7×lO7 kJ yr^-1. Due to a total energy utilization efficiency of 24.6%, all the consumed energy can only supply about 2.4×107 kJ yr^-1 of efficient energy content. Secondly, household energy consumption is partitioned into 2614 kgce yr^-1 for heating, 616 kgce yr^-1 for cooking, and 117 kgce yr^-1 for home appliances. Thirdly, the associated carbon emissions oer household are 2556 kzC yr^-1, includinz1022 kgC yr^-1 from unutilized fuel wood （90% of the total fuel wood）. The rest of emissions come from the use of electricity （212 kgC yr^-1, coal （13Ol kgC yr^-1 and LPG （21 kgC yr^-1. Fourthly, local climate, family size and household income have strong influences on rural residential energy consumption. Changes in storage and utilization practices of fuel can lead to the lO%-30% increase in the efficiency of fuel wood use, leading to reduced energy consumption by 924 kgce yr^-1 per household （27.9% reduction） and 9Ol kgC yr^-1 of carbon emissions （35-3% reduction）.

关键词： Energy consumption Carbon emission Rural areas Fuelwood Utilization efficiency

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Study on the degree of satisfaction on the functions of the financial system used in E-commerce enterprises based on Fuzzy AHP

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Journal of Modern Accounting and Auditing 2007年第11期3卷 26-31页

作者： li wen-hua TAO Ping School of Management Harbin Institute of Technology Harbin 150001 China

In this paper, a comparison analysis is made on the functions of three generally used financial software, R/3 by SAP, a German company, U8 by Ufida Software Co. Ltd and K/3 by Kingdee. Then, a questionnaire survey has been conducted to financial staffs in the E-commerce enterprises to find out the degree of satisfaction on the functions of the above systems. The result indicates that most financial staffs are moderately satisfied. Furthermore, to judge the correction of the above questionnaire conclusion, Fuzzy Analytical Hierarchy Process is employed to firstly establish an integral financial appraisal index system and then put forward a comprehensive evaluation model for the functions of financial system used in E-commerce enterprises.

关键词： Fuzzy AHP E-commerce functions of financial system

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Research on the capital structural optimization based on the coexistence condition of company＇s income tax and individual income tax

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Journal of Modern Accounting and Auditing 2008年第4期4卷 49-54页

作者： TAO Ping li wen-hua School of Management Harbin Institute of Technology Harbin 150001 China

Capital structure denotes enterprises＇ form and proportion relation of various long-term funds source. The capital structure is the combination problem of the long-term funds about enterprise development and it is the quantity and proportion between every fund form. This paper analyzes the various factors which affect capital structural decision-making, and introduces capital structural optimization theory of the shelter benefit of tax revenue and bankruptcy cost balance. It studies the method and the evaluation criterion of capital structural optimization. And it constructs capital structural optimization model of coexistence condition of company＇s income tax and individual income tax. This will be very helpful for the rationality of enterprise capital structure.

关键词： capital structure capital structural optimization income tax shelter benefit of tax revenue

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