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ENERGY-SAVING TYPE OF HYDRAULIC WORKOVER RIG AND SIMULATION FOR LOWERING PIPESTRING

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Chinese Journal of Mechanical Engineering 2005年第3期18卷 424-428页

作者： Zhang Lujun Gu Xinyi chen su School of Mechanical and Automobile Engineering Yantai University Yantai 264005 China Drilling Technology Research Institute Shengli Petroleum Administrative Bureau Dongying 257000 China

Research has been done on an energy-saving type of hydraulic workover rig. This rig can recover and reuse the potential energy which is released by the pipestring when lowered, and the equipped power of this rig is only one third of an ordinary rig. The structure and theory of this rig are introduced. The mathematical model of lowering the pipestring is established and a simulation analysis is conducted. Through simulation some conclusions are obtained： The lighter the pipestring is, the less velocity of lowering the pipestring is; The smaller the throttle valve path area is, the less velocity of lowering the pipestring is; Different air vessel volumes have no evident effect on the pipestring lowering velocity. The actual measure results prove that the simulation results are right. Finally, the energy-saving effect of this rig is proved by the field test results.

关键词： Energy-saving Workover rig Energy-recovering Simulation

Urban public health assessment and pattern analysis： comparison of four cities in different countries

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Frontiers of Earth Science 2013年第2期7卷 191-198页

作者： Meirong su chen chen Weiwei LU Gengyuan LIU Zhifeng YANG Bin chen State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China

Urban public health is an important global issue, and receives extensive attention. It is necessary to compare urban public health status among different cities, so that each city can define its own health patterns and limiting factors. The following assessment indicators were established to evaluate urban public health status： living conditions, physical health, education and culture, envir- onmental quality, and social security. A weighted-sum model was used in combination with these indicators to compare the urban public health status in four cities-- Beijing, New York, London, and Tokyo--using data for 2000-2009. Although the urban public health level of Beijing was lower than that of the other cities, it showed the greatest increase in this level over the study period. Different patterns of urban public health were identified： London had the most balanced, steady pattern （almost all factors performed well and developed stably）; New York and Tokyo showed balanced, but unsteady patterns （most factors remained high, though social security and environ- mental quality fluctuated）; Beijing had the most unba- lanced, unsteady pattern （the different factors were at different levels, and education and culture and social security fluctuated）. For enhanced urban public health status, environmental quality and education and culture clearly need to be improved in Beijing. This study demonstrates that a comparison of different cities is helpful in identifying limiting factors for urban public health and providing an orientation for future urban development.

关键词： public health urban ecosystem health pattern limiting factor

Engineering particles towards 3D supraballs-based passive cooling via grafting CDs onto colloidal photonic crystals

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Chinese Chemical Letters 2024年第4期35卷 457-463页

作者： Jie Wu Xiaoqing Yu Guoxing Li su chen State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 210009China

Particle engineering has opened the floodgates to material science in both fundamental and application field. However, covalent interactions have not yet been adequately designed in the particle engineering for functional colloidal photonic crystals(CPCs). Herein, we achieved covalent coupling between carboxylrich poly(styrene-acrylic acid)(P(St-AA)) monodispersed colloidal particles and amine-rich carbon dots(CDs) based on an feasible and universal particle engineering strategy. The designed CDs-grafted P(St-AA)monodispersed colloidal particles initiate a hydrogen bond-driven assembly mode and ensure the construction of large-scale crack-free CPCs. Moreover, the CDs equipped with selective broad-band absorption capacity could improve the saturation of structural colors for high-visibility CPCs. Furthermore, an injectable photonic hydrogel(IPH) is developed to design CPC supraball hydrogel via integrating the CDsgrafted P(St-AA) CPC supraballs with supramolecular hydrogel. Combining superior flexibility, sufficient self-healing capacity of supramolecular hydrogel with visual optical information of our CPC supraballs, a cyclically reversible coding and decoding system was developed. Meanwhile, we firstly demonstrated the novel strategy of 3D supraballs-based passive cooling. The designed 3D CPC supraball hydrogel presents nearly full observation angle reflections behavior and excellent water evaporation capacity and achieves3.6 ℃ temperature drops, showing the application advantages in 3D thermal management. This work not only provides a new insight for manipulating optical properties of CPCs, but also demonstrates an easyto-perform platform, as well as indicates the direction for the promising application of CPCs.

关键词： Particle engineering Carbon dots Colloidal photonic crystals Passive cooling Digital coding

Time-domain dynamic constitutive model suitable for mucky soil site seismic response

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 1-13页

作者： Dong Qing chen su Jin Liguo Zhou Zhenghua Li Xiaojun Architectural Engineering Institute Huaiyin Institute of TechnologyHuai’an 223600China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100020China Institute of Geophysics China Earthquake AdministrationBeijing 100089China College of Transportation Science and Engineering Nanjing Tech UniversityNanjing 211816China

Soil nonlinear behavior displays noticeable effects on the site seismic *** study proposes a new functional expression of the skeleton curve to replace the hyperbolic skeleton *** integrating shear modulus and combining the dynamic skeleton curve and the damping degradation coefficient,the constitutive equation of the logarithmic dynamic skeleton can be obtained,which considers the damping effect in a soil dynamics *** on the finite difference method and the multi-transmitting boundary condition,a 1D site seismic response analysis program called Soilresp1D has been developed herein and used to analyze the time-domain seismic response in three types of *** the same time,this study also provides numerical simulation results based on the hyperbolic constitutive model and the equivalent linear *** results verify the rationality of the new soil dynamic constitutive *** can analyze the mucky soil site nonlinear seismic response,reflecting the deformation characteristics and damping effect of the silty *** hysteresis loop area is more extensive,and the residual strain is evident.

关键词： seismic response time-domain dynamic constitutive model logarithmic dynamic skeleton dampening effect mucky soil

Research on induced pluripotent stem cells and the application in ocular tissues

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International Journal of Ophthalmology(English edition) 2015年第4期8卷 818-825页

作者： Xiao-Ling Guo Jian-su chen Key Laboratory for Regenerative Medicine Ministry of Education Jinan University Eye Institute Medical College of Jinan University Department of Ophthalmology the First Clinical Medical College of Jinan University

·Induced pluripotent stem cells(i PSCs) were firstly induced from mouse fibroblasts since 2006, and then the research on i PSCs had made great progress in the following years. i PSCs were established from different somatic cells through DNA, RNA, protein or small molecule pathways and transduction vehicles. With continuous improvement of technology on reprogramming, the induction of i PSCs became more secure and effective, and showed enormous promise for clinical applications. We reviewed different reprogramming of somatic cells, four kinds of pathways of reprogramming and three types of transduction vehicles, and discuss the research of i PSCs in ophthalmology and the prospect of i PSCs applications.

关键词： induced pluripotent stem cells reprogramming ocular tissues

Recent progress of transition metal-based biomass-derived carbon composites for supercapacitor

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Rare Metals 2023年第3期42卷 769-796页

作者： Ya-Nan Zhang chen-Yang su Jun-Lei chen Wen-Huan Huang Rui Lou Shaanxi Key Laboratory of Chemical Additives for Industry College of Chemistry and Chemical EngineeringShaanxi University of Science and TechnologyXi'an 710021China

supercapacitors(SCs)have been considered as the most promising energy storage device due to high power density,long cycle life,and fast energy storage and efficient *** excellent electrode materials of SCs generally have based on large porous structure,excellent conductivity,and heteroatom doping for charge *** various electrode materials,biomass-derived carbon materials have received widespread attention owing to excellent performances,environmental friendliness,lowcost and ***,composites materials based on biomass-derived carbon and transition metalbased material can obtain more advantages of structural and performance than single component,which opens up a new way for the fabrication of high-performance SC electrode ***,this review aims to the recent progress on the design and fabrication of biomassderived carbons/transition metal-based composites in supercapacitor ***,the development trends and challenges of biomass-derived electrode materials have been discussed and prospected.

关键词： Biomass-derived carbon Transition metal composites supercapacitor(SC) Electrochemical

Progress and prospects of Mg-based amorphous alloys in azo dye wastewater treatment

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Journal of Magnesium and Alloys 2024年第3期12卷 873-889页

作者： Yanan chen Fengchun chen Liang Li chen su Bo Song Hongju Zhang Shengfeng Guo Fusheng Pan School of Materials and Energy Southwest UniversityChongqing 400715China Analytical and Testing Center Southwest UniversityChongqing 400715China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

Mg-based amorphous alloys exhibit efficient catalytic performance and excellent biocompatibility with a promising application probability,specifically in the field of azo dye wastewater ***,the problems like difficulty in preparation and poor cycling stability need to be *** present,Mg-based amorphous alloys applied in wastewater degradation are available in powder and *** amorphous alloy powder fabricated by ball milling has a high specific surface area,and its reactivity is thousands of times better than that of gas atomized alloy *** the development is limited due to the high energy consumption,difficult and costly process of powder *** single roller melt-spinning method is a new manufacturing process of amorphous alloy *** to amorphous powder,the specific surface area of amorphous ribbon is relatively lower,therefore,it is necessary to carry out surface modification to enhance *** is a way that can form a pore structure on the surface of the amorphous alloys,increasing the specific surface area and providing more reactive sites,which all contribute to the catalytic *** the optimal conditions for Mg-based amorphous alloys in wastewater degradation by adjusting amorphous alloy composition,choosing suitable method to preparation and surface modification,reducing cost,expanding the pH range will advance the steps to put Mg-based amorphous alloys in industrial environments into practice.

关键词： Mg-based amorphous alloys Azo dyes Dealloying surface modification Wastewater degradation.

Expression profiling of the BpIAA gene family and the determination of IAA levels in Betula platyphylla tetraploids

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Journal of Forestry Research 2019年第3期30卷 855-867页

作者： Wendi Xu su chen Jing Jiang Guifeng Liu State Key Laboratory of Forest Genetics and Tree Breeding Northeast Forestry University

Betula platyphylla sukaczev tetraploids have significantly larger leaf, fruit and stoma (gigantic phenotype) than diploids of the same species;however, the mechanism underlying this difference remains unclear. Tetraploid B. platyphylla transcriptome data have indicated that the expression of genes related to indole-3-acetic acid (IAA) biosynthesis and signal transduction was altered after genome duplication. IAA exerts pleiotropic effects on growth and development by inducing the expression of Aux/IAA. We identified 20 Aux/IAA genes (BpIAA1– BpIAA20) in B. platyphylla distributed across 10 chromosomes. Multiple alignment and motif analyses revealed that nine BpIAA proteins shared all four conserved domains. Phylogenetic analysis indicated that Aux/IAA families were divided into four subfamilies and that there were two pairs of BpIAA sister genes. The BpIAAs were differentially expressed in diploids and tetraploids. Moreover, the expression levels of the nine BpIAA genes were specifically up-regulated in tetraploids from June to September compared with May (except August 5th) in tetraploids, while they were down-regulated in diploids. IAA levels were more than twofold higher in tetraploids than diploids during the vegetative season. These results indicate that genome duplication of B. platyphylla caused the up-regulated of genes involved in IAA synthesis, and the increased concentration of IAA may induce the constitutive expression of 20 BpIAA genes. Therefore, the significant changes in the expression patterns of the BpIAAs contributed to the gigantic phenotype of tetraploids to some extent. Our research sheds light on the phenotypic variations observed in B. platyphylla tetraploids.

关键词： Betula platyphylla suk. Tetraploid Aux/IAA Expression profile IAA

GPSA:A Greedy Pull-based Scheduling Approach for P2P Live Streaming under Heterogeneous Environments

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China Communications 2010年第2期7卷 42-52页

作者： chen Wei su Sen Yang Fangchun Shuang Kai State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

Pull-based P2P live streaming is a promising solution for the large scale streaming systems, like PPStream, PPlive, due to its high scalability, low cost and high resilience. However, they usually suffer from bad delay performance. In this paper, we seek to improve the delay performance under ensuring video display quality stemming from chunk scheduling. And so we model Pull-based chunk scheduling problem as a multi-objective optimization problem to minimize the video delay and maximize video display quality in the environment of heterogeneous upload bandwidths, heterogeneous and dynamic propagation delays. Finally we put up with a greedy Pull-based scheduling approach(GPSA) to solve the optimization problem. The evaluation shows GPSA can outperform two classical chunk scheduling approaches and adapt to dynamic variance of propagation delays.

关键词： P2P live streaming pull-based scheduling heterogeneous environments delay performaDce