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Defence Technology（防务技术） 2021年第5期17卷 1617-1624页

作者： Wan-li Wei Yu-wen Wu Chun-sheng Weng quan zheng National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing210094China

Due to the pressure gain combustion characteristics,the rotating detonation combustor(RDC)can enhance thermodynamic cycle ***,the performance of gas-turbine engine can be further improved with this combustion *** the present study,the RDC operation performance with a turbine guide vane(TGV)is experimentally *** and air are used as propellants while hydrogen and air mass flow rate are about 16.1 g/s and 500 g/s and the equivalence ratio is about 1.0.A pre-detonator is used to ignite the ***-frequency dynamic pressure transducers and silicon pressure sensors are employed to measure pressure oscillations and static pressure in the combustion *** experimental results show that the steady propagation of rotating detonation wave(RDW)is observed in the combustion chamber and the mean propagation velocity is above 1650 m/s,reaching over 84%of theoretical Chapman-Jouguet detonation *** and counterclockwise propagation directions of RDW are *** clockwise propagation direction,the static pressure is about 15%higher in the combustor compared with counterclockwise propagation direction,but the RDW dominant frequency is *** the oblique shock wave propagates across the TGV,the pressure oscillations reduces *** addition,as the detonation products flow through the TGV,the static pressure drops up to 32%and 43%for clockwise and counterclockwise propagation process respectively.

关键词： Rotating detonation combustor Propagation direction Turbine guide vane Operation performance

Predictors of complications after prophylactic ileostomy reversal for rectal cancer:A retrospective study

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World Journal of Gastrointestinal Surgery 2024年第5期16卷 1354-1362页

作者： quan Lv Xin-Peng Shu Dong Peng Si-Qi Li zheng Xiang Department of Gastrointestinal Surgery The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Chongqing Key Laboratory of Department of General Surgery The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China

BACKGROUND Previous studies have analyzed the risk factors for complications after ileostomy reversal for rectal cancer(RC),but there were significant differences in the reported risk factors for complications after stoma *** studies have analyzed the risk factors for stoma-related complications and overall postoperative com-plications *** To analyze the risk factors for overall complications and stoma-related complications after ileostomy reversal for patients with *** This was a retrospective study of 439 patients who underwent ileostomy reversal at a clinical center and were followed up between September 2012 and September *** variables are expressed as the mean±SD and were analyzed with independent-sample t tests,while frequency variables are expressed as n(%),and theχ2 test or Fisher’s exact test was *** and multivariate logistic regression analyses were used to identify predictors of overall complications and stoma-related *** The overall complication rate after ileostomy reversal was 11.4%.Patients with lower preoperative albumin concentration(P<0.01),greater blood loss(P=0.017),and longer operative times(P<0.01)were more likely to experience postoperative *** incidence of stoma-related complications was 6.4%.Analysis of the study showed that a higher body mass index(BMI)(P<0.01),preoperative comorbid hypertension(P=0.049),time from primary surgery to ileostomy reversal(P<0.01)and longer operation time(P=0.010)were more likely to result in stomarelated complications *** logistic regression analysis revealed that a lower preoperative albumin level(P<0.01,OR=0.888,95%CI:0.828-0.958)was an independent risk factor for overall ***,multivariate analysis revealed that BMI(P<0.01,OR=1.176,95%CI:1.041-1.330)and time from primary surgery to ileostomy reversal(P<0.01,OR=1.140,95%CI:1.038-1.252)were independent risk factors for stoma-related compl

关键词： Ileostomy Reversal Risk factors Complications Rectal cancer

自然辩证法与中国式现代化——中国自然辩证法研究会2023年学术年会综述

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自然辩证法研究 2023年第12期39卷 6-7页

作者：郑泉中国科协学会服务中心北京100081 中国自然辩证法研究会北京100045

为深入学习贯彻党的二十大精神,深刻理解和推进中国式现代化,2023年12月17日,中国自然辩证法研究会2023年学术年会在京召开。本次年会由中国自然辩证法研究会主办,主题为“自然辩证法与中国式现代化”。党的二十大报告明确提出以中国式... 详细信息

为深入学习贯彻党的二十大精神,深刻理解和推进中国式现代化,2023年12月17日,中国自然辩证法研究会2023年学术年会在京召开。本次年会由中国自然辩证法研究会主办,主题为“自然辩证法与中国式现代化”。党的二十大报告明确提出以中国式现代化全面推进中华民族伟大复兴。自然辩证法作为马克思主义理论的重要组成部分,在推进中国式现代化征程上应成为时代化中国化思想指引。

关键词：自然辩证法中国式现代化马克思主义理论中国自然辩证法研究会学术年会中华民族伟大复兴中国化时代化

Control of surface wettability via strain engineering

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Acta Mechanica Sinica 2013年第4期29卷 543-549页

作者： Wei Xiong Jefferson Zhe Liu Zhi-Liang Zhang quan-Shui zheng Department of Engineering Mechanics and Center for Nano and Micro Mechanics Tsinghua University Department of Mechanical and Aerospace Engineering Monash University Department of Structural Engineering Norwegian University of Science and Technology (NTNU)

Reversible control of surface wettability has wide applications in lab-on-chip systems, tunable optical lenses, and microfluidic tools. Using a graphene sheet as a sam- ple material and molecular dynamic simulations, we demon- strate that strain engineering can serve as an effective way to control the surface wettability. The contact angles 0 of water droplets on a graphene vary from 72.5° to 106° under biaxial strains ranging from -10% to 10% that are applied on the graphene layer. For an intrinsic hydrophilic surface （at zero strain）, the variation of 0 upon the applied strains is more sensitive, i.e., from 0° to 74.8°. Overall the cosines of the contact angles exhibit a linear relation with respect to the strains. In light of the inherent dependence of the contact an- gle on liquid-solid interfacial energy, we develop an analytic model to show the cos 0 as a linear function of the adsorption energy Eads of a single water molecule over the substrate sur- face. This model agrees with our molecular dynamic results very well. Together with the linear dependence of Eads on bi- axial strains, we can thus understand the effect of strains on the surface wettability. Thanks to the ease of reversibly ap- plying mechanical strains in micro/nano-electromechanical systems, we believe that strain engineering can be a promis- ing means to achieve the reversibly control of surface wetta- bility.

关键词： Wettability ~ Strain engineering ~ Molecular dy-namics simulation

Asymptotic Behavior of Global Classical Solutions to Quasilinear Hyperbolic Systems of Diagonal Form

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Journal of Mathematical Research and Exposition 2010年第1期30卷 29-40页

作者： quan zheng School of Mathematical Sciences Fudan University Shanghai 200433 P. R. China

This paper deals with the asymptotic behavior of global classical solutions to quasilinear hyperbolic systems of diagonal form with weakly linearly degenerate characteristic fields. On the basis of global existence and uniqueness of C^1 solution, we prove that the solution to the Cauchy problem approaches a combination of C^1 traveling wave solutions when t tends to the infinity.

关键词： quasilinear hyperbolic systems of diagonal form weak linear degeneracy global classical solution rich system traveling wave.

Insights from metagenomic,metatranscriptomic,and molecular ecological network analyses into the effects of chromium nanoparticles on activated sludge system

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Frontiers of Environmental Science & Engineering 2020年第4期14卷 53-63页

作者： quan zheng Minglu Zhang Tingting Zhang Xinhui Li Minghan Zhu Xiaohui Wang Beijing Engineering Research Center of Environmental Material for Water Purification College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029China Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry Beijing Technology and Business UniversityBeijing 100048China

The objectives of this study were to investigate the influence of chromium nanoparticles(Cr NPs)on the nitrogen and phosphorus removal performance and the bacterial structures of an activated sludge(AS)***,we through molecular ecological networks(MENs)discussed the bacterial *** last we researched the change of the functional genes and their expression patterns related to nitrogen and phosphorus removaT in an AS *** results showed that long-term exposure to 1 mg/L Cr NPs significantly promoted the denitrifying process and phosphorus removal in the AS *** relative abundance of denitrifying and phosphorus removal microorganisms,such as Denitratisoma,Thauera,Dechloromonas,and Defluviicoccus,increased *** Accumulibacter,well-known as polyphosphate-accumulating organisms(PAOs),increased significantly;the relative abundance of Candidatus Competibacter,known as glycogen-accumulating organisms(GAOs),decreased ***,metagenomic and metatranscriptomic analysis revealed that most of the genera related to denitrifying and phosphorus removal had greatly increased,according to the quantities of denitrifying and phosphorus genes,and the corresponding transcription likewise greatly ***,MENs analysis showed that although the overall network became smaller and looser in the presence of Cr NPs,the microbial connections among members related to nitrogen and phosphorus removal were *** abundance increases of denitrifiers and PAOs,and their increased transcription of functional genes,together with the enhanced interactions may be associated with the promotion of the denitrifying process and phosphorus removal.

关键词： Chromium nanoparticles(Cr NPs) Metagenomic analysis Metatranscriptomic analysis Molecular ecological networks(MENs) Nitrogen and phosphorus removal

A study of sea level variability and its long-term trend in the South China Sea

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Acta Oceanologica Sinica 2016年第9期35卷 22-33页

作者： XU Ying LIN Mingsen zheng quan'an SONG Qingtao YE Xiaomin College of Information Science and Engineering Ocean University of China National Satellite Ocean Application Service State Oceanic Administration Key Laboratory of Space Ocean Remote Sensing and Application State Oceanic Administration Department of Atmospheric and Oceanic Science University of MarylandCollege Park

On the basis of the satellite maps of sea level anomaly（MSLA） data and in situ tidal gauge sea level data,correlation analysis and empirical mode decomposition（EMD） are employed to investigate the applicability of MSLA data,sea level correlation,long-term sea level variability（SLV） trend,sea level rise（SLR） rate and its geographic distribution in the South China Sea（SCS）.The findings show that for Dongfang Station,Haikou Station,Shanwei Station and Zhapo Station,the minimum correlation coefficient between the closest MSLA grid point and tidal station is *** suggests that the satellite altimeter MSLA data are effective to observe the coastal SLV in the *** the monthly scale,coastal SLV in the western and northern part of SCS are highly associated with coastal *** the seasonal scale,SLV of the coastal area in the western part of the SCS is still strongly influenced by the coastal current system in summer and *** Pacific change can affect the SCS mainly in winter rather than summer and the affected area mostly concentrated in the northeastern and eastern parts of the ***,the average SLR in the SCS is 90.8 mm with a rising rate of（5.0±0.4） mm/a during1993–*** SLR rate from the southern Luzon Strait through the Huangyan Seamount area to the Xisha Islands area is higher than that of other areas of the SCS.

关键词： South China Sea sea level variability correlation analysis empirical mode decomposition

Embrittlement Mechanism due to Slow Cooling During Quenching for M152 Martensitic Heat Resistant Steel

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Journal of Iron and Steel Research(International) 2010年第6期17卷 60-66页

作者： YANG Gang WANG Chang LIU Xin-quan LIU zheng-dong Central Iron and Steel Research Institute Beijing 100081 China

The mechanism of brittleness of M152 martensitic heat resistant steel due to slow cooling during quenching was experimentally investigated. The mechanical property tests and microstructure observation were conducted by TEM and XRD. The results showed that the presence of irreversible brittleness during slow cooling of quenching for M152 steel is attributed to the continuous M23C6 precipitation along prior austenite grain boundaries and M2C along prior residual austenite film. The residual austenite in the steel was unstable and decomposed after the precipitation of second phase during the process of slow cooling of quenching. The low cooling rate within the temperature range from 820 ℃ to 660 ℃ plays a key role in impact toughness, and the precipitation of second phase in the same temperature range results in irreversible brittleness.

关键词： M152 martensitic heat resistant steel brittleness carbides decomposition residual austenite

QoE-Driven DASH Multicast Scheme for 5G Mobile Edge Network

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Journal of Communications and Information Networks 2021年第2期6卷 153-165页

作者： Xiaobin Tan Lei Xu quan zheng Simin Li Bei Liu Laboratory for Future Networks the University of Science and Technology of ChinaHefei 230027China The 54th Research Institute of China Electronic Technology Corporation Shijiazhuang 050081.China

Dynamic adaptive streaming over HTTP(DASH)can adaptively select the appropriate video bitrate for mobile *** edge computing(MEC)scenario is of great benefit to improve the performance of mobile networks by providing computing and storage *** the utilization of spectrum resources can be improved by multicast transmission,but the performance of the multicast transmission will be directly affected by the selected grouping algorithm and resource allocation *** order to improve the quality of experience(QoE)of video users in the 5G MEC scenario,this paper proposes a QoE-driven DASH multicast scheme,which mainly covers the grouping algorithm and the adaptive bitrate(ABR)*** of all,we take the optimized target QoE as the basis for grouping and propose an adaptive grouping algorithm that can dynamically adjust the grouping ***,we design a joint optimization ABR algorithm based on the prediction of QoE,which comprehensively considers the process of resource allocation and bitrate decision-making based on the prediction of QoE of video segments in a certain forward-looking field of *** simulation results show that the proposed DASH multicast scheme performs well in QoE and fairness.

关键词： DASH mobile edge computing multicast quality of experience adaptive bitrate algorithm

quantum Tunneling Radiation of Reissner-Nordstrom de Sitter Black Hole with a Global Monopole

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Communications in Theoretical Physics 2006年第3期45卷 457-460页

作者： JIANG Qing-quan YANG Shu-zheng LI Hui-Ling Institute of Theoretical Physics West China Normal University Nanchong 637002 China

适用的 Parikh 的量通道模型，我们与全球单极学习 Reissner-Nordstrom de 保姆黑洞的量通道放射。如果我们考虑精力保存，通道在领带事件地平线和宇宙的地平线评估的结果表演与 Bekenstein-Hawkingentropy 有关，并且真散发光谱不正是... 详细信息

适用的 Parikh 的量通道模型，我们与全球单极学习 Reissner-Nordstrom de 保姆黑洞的量通道放射。如果我们考虑精力保存，通道在领带事件地平线和宇宙的地平线评估的结果表演与 Bekenstein-Hawkingentropy 有关，并且真散发光谱不正是热的。

关键词：量子隧道辐射黑洞球形单极子能量守恒隧穿比率