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Metadata Feedback and Utilization for Data Deduplication Across WAN

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Journal of Computer Science & Technology 2016年第3期31卷 604-623页

作者： Bing zhou Jiang-Tao wen State Key Laboratory on Intelligent Technology and Systems Tsinghua University Beijing 100084 China Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China Department of Computer Science and Technology Tsinghua University Beijing 100084 China

Data deduplication for file communication across wide area network （WAN） in the applications such as file synchronization and mirroring of cloud environments usually achieves significant bandwidth saving at the cost of significant time overheads of data deduplication. The time overheads include the time required for data deduplication at two geographi- cally distributed nodes （e.g., disk access bottleneck） and the duplication query/answer operations between the sender and the receiver, since each query or answer introduces at least one round-trip time （RTT） of latency. In this paper, we present a data deduplication system across WAN with metadata feedback and metadata utilization （MFMU）, in order to harness the data deduplication related time overheads. In the proposed MFMU system, selective metadata feedbacks from the receiver to the sender are introduced to reduce the number of duplication query/answer operations. In addition, to harness the metadata related disk I/O operations at the receiver, as well as the bandwidth overhead introduced by the metadata feedbacks, a hysteresis hash re-chunking mechanism based metadata utilization component is introduced. Our experimental results demonstrated that MFMU achieved an average of 20%~40% deduplication acceleration with the bandwidth saving ratio not reduced by the metadata feedbacks, as compared with the ＂baseline＂ content defined chunking （CDC） used in LBFS （Low-bandwith Network File system） and exiting state-of-the-art Bimodal chunking algorithms based data deduplication solutions.

关键词： data deduplication wide area network (WAN) metadata feedback metadata utilization

Improving Metadata Caching Efficiency for Data Deduplication via In-RAM Metadata Utilization

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Journal of Computer Science & Technology 2016年第4期31卷 805-819页

We describe a data deduplication system for backup storage of PC disk images, named in-RAM metadata utilizing deduplication （IRwMUD）. In-RAM hash granularity adaptation and miniLZO based data compression are firstly proposed to reduce the in-RAM metadata size and thereby reduce the space overheads required by the in-RAM metadata caches. Secondly, an in-RAM metadata write cache, as opposed to the traditional metadata read cache, is proposed for further reducing metadata-related disk I/O operations and improving deduplication throughput. During deduplication, the metadata write cache is managed following the LRU caching policy. For each manifest that is hit in the metadata write cache, an expensive manifest reloading operation from the disk is avoided. After deduplieation, all the manifests in the metadata write cache are cleared and stored on the disk. Our experimental results using 1.5 TB real-world disk image dataset show that I） IR-MUD achieved about 95% size reduction for the deduplication metadata, with a small time overhead introduced, 2） when the metadata write cache was not utilized, with the same RAM space size for the metadata read cache, IR-MUD achieved a 400% higher RAM hit ratio and a 50% higher deduplication throughput, as compared with the classic Sparse Indexing deduplication system where no metadata utilization approaches are utilized, and 3） when the metadata write cache was utilized and enough RAM space was available, IR-MUD achieved a 500% higher RAM hit ratio compared with Sparse Indexing and a 70% higher deduplication throughput compared with IR-MUD with only a single metadata read cache. The in-RAM metadata harnessing and metadata write caching approaches of IR-MUD can be applied in most parallel deduplication systems for improving metadata caching efficiency.

关键词： data deduplication cache metadata utilization

Group decision-making method based on entropy and experts cluster analysis

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Journal of Systems Engineering and Electronics 2011年第3期22卷 468-472页

作者： xuan zhou Fengming Zhang Xiaobin Hui Kewu Li Engineering College Air Force Engineering UniversityXi'an 710038P.R.China

According to the aggregation method of experts＇ evaluation information in group decision-making,the existing methods of determining experts＇ weights based on cluster analysis take into account the expert＇s preferences and the consistency of expert＇s collating vectors,but they lack of the measure of information *** it may occur that although the collating vector is similar to the group consensus,information uncertainty is great of a certain ***,it is clustered to a larger group and given a high *** this,a new aggregation method based on entropy and cluster analysis in group decision-making process is provided,in which the collating vectors are classified with information similarity coefficient,and the experts＇ weights are determined according to the result of classification,the entropy of collating vectors and the judgment matrix ***,a numerical example shows that the method is feasible and effective.

关键词： group decision-making judgment matrix entropy information similarity coefficient cluster analysis.

非层状二维γ-In_(2)Se_(3)的各向异性生长及其光学特性

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原子与分子物理学报 2025年第6期42卷 58-65页

作者：雷子煊张文婷夏晓凤王红艳西南交通大学物理科学与技术学院材料先进技术重点实验室成都610031

非层状二维(2D)γ-In_(2)Se_(3)具有优异的光学和电学性能,在超薄柔性器件和光电探测领域具有广泛的应用前景.然而,相较于层状的类石墨烯材料,非层状材料固有的各向同性化学键,使得其二维各向异性生长面临较大的挑战.本研究构建了一种... 详细信息

非层状二维(2D)γ-In_(2)Se_(3)具有优异的光学和电学性能,在超薄柔性器件和光电探测领域具有广泛的应用前景.然而,相较于层状的类石墨烯材料,非层状材料固有的各向同性化学键,使得其二维各向异性生长面临较大的挑战.本研究构建了一种新的化学气相沉积(CVD)生长策略,成功制备了高质量的2Dγ-In_(2)Se_(3).首次选用低熔点的铟粉为前驱体,有效降低了生长温度.此外,生长过程去除了CVD法合成二维硒化物时不可避免的危险气体H_(2),这不仅能有效抑制InSe副产物的形成,还降低了实验危险性.通过探究原料用量、生长温度及时间等参数对样品形貌和厚度的影响,获得了最佳生长窗口.详细表征了2Dγ-In_(2)Se_(3)的微观形貌、化学组分、晶体结构和光学特性等.结果表明,样品具有强烈的光致发光(PL)效应,与γ-In_(2)Se_(3)的直接带隙属性相吻合.随着厚度的减小,PL峰会发生蓝移,说明光学带隙随之增大.Raman光谱显示,不同厚度的样品其特征峰也会发生移动,说明厚度会影响2Dγ-In_(2)Se_(3)的分子振动行为.由此可见,通过生长参数调控2Dγ-In_(2)Se_(3)的厚度,可实现对其光学带隙和分子振动行为的调控,这将为相关的理论研究和光电器件应用提供基本的材料平台.

关键词：非层状材料二维γ-In_(2)Se_(3) 化学气相沉积各向异性生长带隙

Production of Transgenic Anliucheng Sweet Orange(Citrus sinensis Osbeck) with Xa21 Gene for Potential Canker Resistance

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Journal of Integrative Agriculture 2014年第11期13卷 2370-2377页

作者： LI Ding-li XIAO xuan GUO wen-wu Key Laboratory of Horticultural Plant Biology Ministry of Education/College of Horticulture & Forestry Sciences Huazhong Agricultural University College of Life and Environmental Sciences Gannan Normal University

Citrus canker, an epidemic quarantine disease caused by Xanthomonas axonopodis pv. citri, has brought a great damage in citrus production worldwide. Herein, a rice PRR （pattern recognition receptor） gene Xa21 together with GUS reporter gene and hygromycin phosphotransferase gene （HPT） was introduced into Anliucheng sweet orange （Citrus sinensis Osbeck） via Agrobacterium-mediated transformation of embryogenic callus. The transgenic calluses were screened on MT basal medium containing hygromycin （HYG） and detected by histochemical GUS staining. The transgenic plantlets were recovered through somatic embryogenesis pathway. The regenerated plantlets were accustomed to and maintained in the greenhouse. The transgene integration of recovered plantlets was identiifed by PCR and Southern blot hybridization. It showed that all the transgenic plantlets tested had undergone single copy integration, the expression of Xa21 in eight different transgenic lines detected by qRT-PCR can be divided into three grades, high for T5 and T6, middle for T4 and low for the rest. The tolerance to citrus canker disease of the three recovered transgenic lines T2, T4 and T6 was assessed by in vitro pin-puncture inoculation. The results showed that all the three transgenic lines conferred improved resistance to citrus canker bacterium infection and the T4 transgenic line displayed the highest resistance. The mechanism and feasibility of rice Xa21 in triggering innate immunity in citrus was brielfy discussed.

关键词： citrus canker Xa21 sweet orange pattern recognition receptors (PRRs)

Fabrication of a superamphiphobic coating by a simple and flexible method

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Particuology 2018年第4期16卷 33-39页

作者： Pengfei Jiang Yanli Li Chuan Zhang xuan zhou YongJiang School of Chemistry and Chemical Engineering. Southeast University Nanjing 211189 China Chengxian College Southeast University Nanjing 210088 China

A facile and flexible method to prepare raspberry-like nanoparticles that can be used as a superamphipho- bic coating is reported. Anatase TiO2 nanoparticles were chosen as the core because of their irregular morphology and photocatalytic performance. Anatase TiO2 nanoparticles were surrounded tightly by tiny functional fluoride-silica nanoparticles via the hydrolysis-condensation reaction of tetraethoxysi- lane and IH, 1H, 2H, 2H-perfluorodecyl triethoxysilane. The obtained Si-F@TiO2 nanoparticles can be sprayed or dipped directly onto various substrates. The coated film exhibited quite good liquid resistance, even when subjected to water jetting and sand abrasion. The photocatalytic effect of the coated anatase TiO2 with respect to formaldehyde was also studied and discussed. This method will provide more opportunities and fast access to practical applications in surface, environmental, and energy engineering.

关键词： Superamphiphobic coating TiO2 nanoparticle Fluoride-silica nanoparticle Photocatalytic effect Formaldehyde

Assessment of Future Drought in Southwest China Based on CMIP5 Multimodel Projections

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Advances in Atmospheric Sciences 2014年第5期31卷 1035-1050页

作者： WANG Lin CHEN wen zhou wen Center for Monsoon System Research Institute of Atmospheric Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Guy Carpenter Asia-Pacific Climate Impact Centre School of Energy and EnvironmentCity University of Hong Kong

In the last decade, a series of severe and extensive droughts have swept across Southwest China, resulting in tremendous economic losses, deaths, and disruption to society. Consequently, this study is motivated by the paramount importance of as- sessing future changes in drought in Southwest China. Precipitation is likely to decrease over most parts of Southwest China around the beginning of the century, followed by widespread precipitation increases; the increase in potential evapotran- spiration （PET）, due to the joint effects of increased temperature and surface net radiation and decreased relative humidity, will overwhelm the whole region throughout the entire 21st century. In comparative terms, the enhancement of PET will outweigh that of precipitation, particularly under Representative Concentration Pathway （RCP） 8.5, resulting in intensified drought. Generally, the drying tendency will be in the southeast portion, whereas the mountainous region in the northwest will become increasingly wetter owing to abundant precipitation increases. Droughts classified as moderate/severe according to historical standards will become the norm in the 2080s under RCP4.5/RCP8.5. Future drought changes will manifest different characteristics depending on the time scale： the magnitude of change at a time scale of 48 months is nearly twice as great as that at 3 months. Furthermore, we will see that not only will incidences of severe and extreme drought increase dramatically in the future, but extremely wet events will also become more probable.

关键词： drought Standardized Precipitation Evapotranspiration Index spatial disaggregation Southwest China

Catalytic effect in lithium metal batteries: From heterogeneous catalyst to homogenous catalyst

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Journal of Energy Chemistry 2024年第3期90卷 305-326,I0008页

作者： Haining Fan xuan-wen Gao Hailong Xu Yichun Ding Shi-Xue Dou wen-Bin Luo School of Fashion and Textiles The Hong Kong Polytechnic UniversityHong Kong 100872China Institute for Energy Electrochemistry and Urban Mines Metallurgy School of MetallurgyNortheastern UniversityShenyang 110819LiaoningChina Institute of Energy Materials Science University of Shanghai for Science and TechnologyShanghai 200000China State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710000ShaanxiChina

Lithium metal batteries are regarded as prominent contenders to address the pressing needs owing to the high theoretical *** the broader implementation,the primary obstacle lies in the intricate multi-electron,multi-step redox reaction associated with sluggish conversion kinetics,subsequently giving rise to a cascade of parasitic *** order to smooth reaction kinetics,catalysts are widely introduced to accelerate reaction rate via modulating the energy *** past decades,a large amount of research has been devoted to the catalyst design and catalytic mechanism exploration,and thus the great progress in electrochemical performance has been ***,it is necessary to make a comprehensive review toward key progress in catalyst design and future development *** this review,the basic mechanism of lithium metal batteries is provided along with corresponding advantages and existing challenges detailly *** main catalysts employed to accelerate cathode reaction with emphasis on their catalytic mechanism are summarized as ***,the rational design and innovative direction toward efficient catalysts are suggested for future application in metal-sulfur/gas battery and *** review is expected to drive and benefit future research on rational catalyst design with multi-parameter synergistic impacts on the activity and stability of next-generation metal battery,thus opening new avenue for sustainable solution to climate change,energy and environmental issues,and the potential industrial economy.

关键词： Energy storage and conversion Metal battery Sulfur battery Air battery Catalytic effect Heterogeneous catalyst Homogeneous catalyst

Comparison of Different Excitation Schemes in Bimodal Atomic Force Microscopy in Air and Liquid Environments

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Acta Mechanica Solida Sinica 2021年第2期34卷 163-173页

作者： Zhenyang Huang Pengfei wen Xilong zhou Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics School of ScienceWuhan University of TechnologyWuhan 430070China

Bimodal amplitude modulation atomic force microscopy(AM-AFM)is widely used in nanoscale topography and compositional contrast imaging for various *** this work,we use computational simulation to compare the dynamic behaviors of AFM cantilevers in three commonly used excitation schemes in bimodal AM-AFM,i.e.,the cantilever base excitation,the cantilever end excitation,and the uniform excitation along the length of the cantilever,in both air and liquid *** amplitude and phase spectroscopy curves and the frequency responses acquired from the three excitation schemes are compared and *** results would be useful in guiding the selection of excitation methods and the optimization of imaging conditions.

关键词： Atomic force microscopy Amplitude modulation Bimodal Excitation schemes