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CAVITATING SUPPRESSION OF LOW SPECIFIC SPEED CENTRIFUGAL PUMP WITH GAP DRAINAGE BLADES

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Journal of Hydrodynamics 2012年第5期24卷 729-736页

作者： zhu bing CHEN Hong-xun Shanghai Institute of Applied Mathematics and Mechanics and Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai UniversityShanghai 200072China

This paper aims to clarify the cavitation suppression mechanism of the gap structure impeller based on the analysis of cavitation characteristics in a low specific speed centrifugal pump. In order to obtain reliable and consistent numerical results, some numerical considerations and modeling methodology were demonstrated and researched, and a check of the time and space resolution were also conducted. Hence the predicted cavitation performance of the two centrifugal pumps were investigated and compared with experimental results, and they were in qualitative agreement. It was confirmed that the new gap structure impeller has a very good characteristic of inhibiting cavitation, especially in large flow area, the present numerical method can effectively capture the major internal flow features in the centrifugal pump, through the comparison of the two type impeller flow fields, the cavitation suppression mechanism of the gap impeller may be the combination effects of the small vice blade＇s guiding flow and gap tunnel＇s auto-balancing of pressure.

关键词： Low Specific Speed Centrifugal Pump (LSSCP) gap drainage blade cavitation suppression numerical simulation

Super-resolution image reconstruction based on three-step-training neural networks

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Journal of Systems Engineering and Electronics 2010年第6期21卷 934-940页

作者： Fuzhen zhu Jinzong Li bing zhu Dongdong Ma Institute of Image Information Technology and Engineering Harbin Institute of Technology Heilongjiang 150001 R R. China

A new method of super-resolution image reconstruction is proposed, which uses a three-step-training error backpropagation neural network （BPNN） to realize the super-resolution reconstruction （SRR） of satellite image. The method is based on BPNN. First, three groups learning samples with different resolutions are obtained according to image observation model, and then vector mappings are respectively used to those three group learning samples to speed up the convergence of BPNN, at last, three times consecutive training are carried on the BPNN. Training samples used in each step are of higher resolution than those used in the previous steps, so the increasing weights store a great amount of information for SRR, and network performance and generalization ability are improved greatly. Simulation and generalization tests are carried on the well-trained three-step-training NN respectively, and the reconstruction results with higher resolution images verify the effectiveness and validity of this method.

关键词： image reconstruction super-resolution three-steptraining neural network BP algorithm vector mapping.

Nucleosome assembly and epigenetic inheritance

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Protein & Cell 2010年第9期1卷 820-829页

作者： Mo Xu bing zhu Graduate Program Peking Union Medical College and Chinese Academy of Medical SciencesBeijing 100730China National Institute of Biological Sciences Beijing 102206China

In eukaryotic cells,histones are packaged into octameric core particles with DNA wrapping around to form nucleosomes,which are the basic units of chromatin(Kornberg and Thomas,1974).Multicellular organisms utilise chromatin marks to translate one single genome into hundreds of epigenomes for their corresponding cell *** of epigenetic status is critical for the maintenance of gene expression profile during mitotic cell divisions(Allis et al.,2006).During S phase,canonical histones are deposited onto DNA in a replication-coupled manner(Allis et al.,2006).To understand how dividing cells overcome the dilution of epigenetic marks after chromatin duplication,DNA replication coupled(RC)nucleosome assembly has been of great *** this review,we focus on the potential influence of RC nucleosome assembly processes on the maintenance of epigenetic status.

关键词： nucleosome assembly epigenetic inheritance DNA replication coupled

Circular object recognition based on shape parameters

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Journal of Systems Engineering and Electronics 2007年第2期18卷 199-204页

作者： Chen Aijun Li Jinzong zhu bing Inst. of Image Information Technology and Engineering Harbin Inst. of Technology Harbin 150001 P. R. China

To recognize circular objects rapidly in satellite remote sensing imagery, an approach using their geometry properties is presented. The original image is segmented to be a binary one by one dimension maximum entropy threshold algorithm and the binary image is labeled with an algorithm based on recursion technique. Then, shape parameters of all labeled regions are calculated and those regions with shape parameters satisfying certain conditions are recognized as circular objects. The algorithm is described in detail, and comparison experiments with the randomized Hough transformation （RHT） are also provided. The experimental results on synthetic images and real images show that the proposed method has the merits of fast recognition rate, high recognition efficiency and the ability of anti-noise and anti-jamming. In addition, the method performs well when some circular objects are little deformed and partly misshapen.

关键词： Circular object Pattern recognition Shape parameter Region labeling Image segmentation

Mitotic inheritance of DNA methylation: more than just copy and paste

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Journal of Genetics and Genomics 2021年第1期48卷 1-13页

作者： Xuan Ming bing zhu Yingfeng Lia National Laboratory of Biomacromolecules Institute of BiophysicsChinese Academy of SciencesBeijing 100101China College of Life Sciences University of Chinese Academy of SciencesBeijing 100049China

Decades of investigation on DNA methylation have led to deeper insights into its metabolic mechanisms and biological *** understanding was fueled by the recent development of genome editing tools and our improved capacity for analyzing the global DNA methylome in mammalian *** review focuses on the maintenance of DNA methylation patterns during mitotic cell *** discuss the latest discoveries of the mechanisms for the inheritance of DNA methylation as a stable epigenetic *** also highlight recent evidence showing the rapid turnover of DNA methylation as a dynamic gene regulatory mechanism.A body of work has shown that altered DNA methylomes are common features in aging and *** discuss the potential links between methylation maintenance mechanisms and diseaseassociated methylation changes.

关键词： DNMT1 Mitotic DNA methylation inheritance Neighboring reinforcement model Aging-associated methylation changes

An analysis of an ethanol-based, whole-crop refinery system in China

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Chinese Journal of Chemical Engineering 2016年第11期24卷 1609-1618页

作者： Zhiqiang Zhang Shanying Hu Dingjiang Chen bing zhu Department of Chemical Engineering Tsinghua University

Bio-fuel can be used to help transition from a petroleum-based society to a bio-based society. Ever since the China Development and Reform Commission suspended the approval of crop processing programs, second-generation bio-ethanol research and industrialization processes have attracted significant attention. In 2020, bio-ethanol production is predicted to reach 10 million tons. Currently, there are a few domestic enterprises that have established different scaled pilot or demonstration bases for cellulosic ethanol, which reduce the cost of ethanol by continuously improving pretreatment and hydrolysis techniques. In the next three years, these enterprises will realize large-scale commercial production. Given the practical problems in cellulosic ethanol plant construction and operation(e.g., marketing price variation and difficulties in feedstock collection), this paper began with the concept of a "whole-crop refinery" and presented a solution to the integration of industry and agriculture as well as multi-crop refining. This paper then took the whole-crop refining system of corn as an example and presented an analysis of the logistics, energy flow, and economical efficiency of the system. The results demonstrated that the integrated system could properly reduce the required fixed investments in production equipment,shared utilities, and wastewater treatment facilities, as well as reduction of energy consumption. Although the proposed system has several problems, it brings the long-term goal of large-scale commercial application closer than ever.

关键词： Whole-crop refinery Cellulosic ethanol Biomass Corn stover

Finite-Time Stabilization for Constrained Discrete-time Systems by Using Model Predictive Control

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1656-1666页

作者： bing zhu Xiaozhuoer Yuan Li Dai Zhiwen Qiang IEEE the Seventh Research Division Beihang UniversityBeijing 100191China the School of Automation Beijing Institute of TechnologyBeijing 100081China

In this paper, a model predictive control(MPC)framework is proposed for finite-time stabilization of linear and nonlinear discrete-time systems subject to state and control constraints. The proposed MPC framework guarantees the finite-time convergence property by assigning the control horizon equal to the dimension of the overall system, and only penalizing the terminal cost in the optimization, where the stage costs are not penalized explicitly. A terminal inequality constraint is added to guarantee the feasibility and stability of the closed-loop *** feasibility can be improved via augmentation. The finite-time convergence of the proposed MPC is proved theoretically,and is supported by simulation examples.

关键词： Constraints deadbeat control finite-time stabilization model predictive control(MPC)

Cleavage of Nucleotides by Lanthanide Metal Complexes

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Chemical Research in Chinese Universities 1999年第2期15卷 24-29页

作者： zhu bing ZHAO Daqing Ni Jiazuan Laboratory of Rare Earth Chemistry and Physics Changchun Institute of Applied ChemistryChinese Academy of ScienceChangchun130022

The present work revealed that the praseodymium()complex of 2carboxyethylgermanium sesquioxide(Ge132)promotes the hydrolysis of the phosphodiester linkages of 3,5cyclic adenosine monophosphate(cAMP),3,5cyclic deoxyadenosine monophosphate(dcAMP),5adenosine monophosphate(5AMP)and 5deoxyadenosine monophosphate(5dAMP)under mild *** cAMP and dcAMP were hydrolyzed sitespecifically,yielding predominantly 3monophosphates,the main products of the cleavage of 5AMP and 5dAMP included adenosine(Ado),deoxyadenosine(dAdo)and free phosphates respectively.A hydrolytic mechanism was proposed for cAMP,dcAMP,5AMP and 5dAMP.

关键词： Lanthanide metal() complexes Nucleotides cleavage Artificial nucleases complexes Nucleotides cleavage Artificial nucleases

Recruitment and reinforcement: maintaining epigenetic silencing

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Science China(Life Sciences) 2018年第5期61卷 515-522页

作者： Chengzhi Wang bing zhu Jun Xiong National Laboratory of Biomacromolecules CAS Center for Excellence in Biomacromolecules Institute of BiophysicsChinese Academy of Sciences College of Life Sciences University of Chinese Academy of Sciences

Cells need to appropriately balance transcriptional stability and adaptability in order to maintain their identities while responding robustly to various stimuli. Eukaryotic cells use an elegant "epigenetic" system to achieve this functionality. "Epigenetics" is referred to as heritable information beyond the DNA sequence, including histone and DNA modifications, nc RNAs and other chromatin-related components. Here, we review the mechanisms of the epigenetic inheritance of a repressive chromatin state,with an emphasis on recent progress in the field. We emphasize that(i) epigenetic information is inherited in a relatively stable but imprecise fashion;(ii) multiple cis and trans factors are involved in the maintenance of epigenetic information during mitosis; and(iii) the maintenance of a repressive epigenetic state requires both recruitment and self-reinforcement *** mechanisms crosstalk with each other and form interconnected feedback loops to shape a stable epigenetic system while maintaining certain degrees of flexibility.

关键词： heterochromatin heterochromatin maintenance polycomb H3K27me3 H3K9me2/3