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Journal of Iron and Steel Research(International) 2018年第10期25卷 1054-1061页

作者： peng-tao liu Qing-xue Huang Li-feng Ma tao Wang College of Mechanical Engineering Taiyuan University of Technology Taiyuan 030024 Shanxi China Shanxi Provincial Key Laboratory of Metallurgical Equipment Design and Technology Taiyuan University of Science and Technology Taiyuan 030024 Shanxi China Heavy Machinery Engineering Research Center of the Ministry Education Taiyuan University of Science and Technology Taiyuan 030024 Shanxi China

In order to predict flow instability of wear-resistant steel BTW1, the hot compressions of wear-resistant steel BTW1 were firstly performed at the temperature of 900-1150 ℃ and at the strain rate of 0.05-15 s-1. Then, the constitutive relation was established based on Arrhenius-type hyperbolic sine equation. The results demonstrated that the flow stress depended on the deformation temperature and strain rate. When the deformation temperature kept constant, the flow stress increased as the strain rate increased. When the strain rate remained constant, the flow stress decreased as the temperature increased. The flow stresses calculated by constitutive equations were in a good agreement with experimental results. The apparent activation energy for deformation in the above processing region was estimated to be 369 kJ tool-1. A processing map could be obtained by the superimposition of an instability map on a power dissipation map. Based on the analysis of processing map and the microstructures, the theological instability regimes of strain rate and temperature for hot deformation of wear-resistant steel BTWl had been identified.

关键词： Wear-resistant steel BTW 1 Processing map Constitutive equation Hot deformation Dynamicrecrystallization

Influence of slip ratio on worn-surface microstructure and fatigue wear behavior of D2 wheel steel

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Journal of Iron and Steel Research(International) 2018年第12期25卷 1278-1286页

作者： Chun-peng liu Xiu-juan Zhao peng-tao liu Chong Xu Rui-ming Ren School of Material Science and Engineering Dalian Jiaotong UniversityDalian 116028LiaoningChina Key Laboratory of Critical Materials of Rail Transportation in Liaoning Province Dalian Jiaotong University Dalian 116028LiaoningChina School of Mechanical Engineering Dalian Jiaotong UniversityDalian 116028LiaoningChina

To investigate the worn-surface microstructure and fatigue cracks in D2 wheel steel under the pure rolling and 0.5% slip ratio conditions,a rolling wear test using a GPM-40 wear machine to simulate the wheel/rail operation was performed. After testing,a transmission electron microscope,a scanning electron microscope with electron backscatter diffraction,and micro-hardness testers were used to characterize the microstructure and fatigue cracks.The surface microstrncture and hardness of the pure rolling sample were in a steady state after 8 × 10^4 cycles;however,the 0.5% slip ratio sample reached a steady state after 7 × 10^3 cycles.Regardless of whether the test uses the slip ratio,the orientation of lamellar pearlites gradually became parallel to the surface and a portion of lamellar cementites was fragmented and dissolved during the formation of steady-state microstructure.The slip ratio accelerates this process.The hardening mechanism of the samples shows a decrease in the lamellar spacing of pearlite and the refinement of proeutectoid ferrite (PF).As the number of cycles increased,plastic deformation of samples became increasingly severe and the wear mechanism of the samples was fatigue wear in steady state.The sample surfaces formed shallow cracks,which gradually peeled off.The slip ratio accelerated the initiation and propagation of fatigue cracks because of the high friction stress on the contact surface.Most fatigue cracks initiated at the interface of pearlite and PF and in the PF region.

关键词： D2 wheel steel Slip ratio Wom-surface microstructure Wheel/rail system Rolling wear

Controlling Roll Temperature by Fluid-Solid Coupled Heat Transfer

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Chinese Journal of Mechanical Engineering 2018年第5期31卷 66-79页

作者： Jing-Feng Zou Li-Feng Ma Guo-Hua Zhang Zhi-Quan Huang Jin-Bao Lin peng-tao liu Heavy Machinery Engineering Research Center of the Ministry Education Taiyuan University of Science and Technology Taiyuan 030024 China School of Mechanical Engineering Taiyuan University of Technology Taiyuan 030024 China

Currently, when magnesium alloy sheet is rolled, the method of controlling roll temperature is simple and inaccurate. Furthermore, roll temperature has a large influence on the quality of magnesium alloy sheet; therefore, a new model using circular fluid flow control roll temperature has been designed. A fluid heat transfer structure was designed, the heat transfer process model of the fluid heating roll was simplified, and the finite di erence method was used to cal?culate the heat transfer process. Fluent software was used to simulate the fluid?solid coupling heat transfer, and both the trend and regularity of the temperature field in the heat transfer process were identified. The results show that the heating e ciency was much higher than traditional heating methods(when the fluid heat of the roll and tempera?ture distribution of the roll surface was more uniform). Moreover, there was a bigger temperature di erence between the input and the output, and after using reverse flow the temperature di erence decreased. The axial and circum?ferential temperature distributions along the sheet were uniform. Both theoretical calculation results and numerical simulation results of the heat transfer between fluid and roll were compared. The error was 1.8%–12.3%, showing that the theoretical model can both forecast and regulate the temperature of the roll(for magnesium alloy sheets) in the rolling process.

关键词： Magnesium alloy Fluid heating Heat transfer model Numerical simulation of fluid?solid coupling

Effects of climate change on phenology and primary productivity in the desert steppe of Inner Mongolia

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Journal of Arid Land 2015年第2期7卷 251-263页

作者： Fang HAN Qing ZHANG Alexander BUYANTUEV Jian Ming NIU peng tao liu Xing Hua LI Sarula KANG Jing ZHANG Chang Ming CHANG Yun peng LI School of Life Sciences Inner Mongolia University Meteorological Bureau of Inner Mongolia Sino-US Center for Conservation Energy and Sustainability Science in Inner Mongolia (SUCCESS) Department of Geography and Planning the State University of New York

Variations in temperature and precipitation affect local ecosystems. Considerable spatial and temporal heterogeneity exists in arid ecosystems such as desert steppes. In this study, we analyzed the spatiotemporal dy- namics of climate and vegetation phenology in the desert steppe of Inner Mongolia, China using meteorological data （1961-2010） from 11 stations and phenology data （2004-2012） from 6 ecological observation stations. We also estimated the gross primary production for the period of 1982-2009 and found that the annual mean tem- perature increased at a rate of 0.47~C/decade during 1961-2010, with the last 10 years being consistently warmer than the 50 years as an average. The most significant warming occurred in winters. Annual precipitation slightly decreased during the 50-year period, with summer precipitation experiencing the highest drop in the last 10 years, and spring precipitation, a rise. Spatially, annual precipitation increased significantly in the northeastern and eastern central areas next to the typical steppe. From 2004 to 2012, vegetation green-up and senescence date advanced in the study area, shortening the growing season. Consequently, the primary productivity of the desert steppe de- creased along the precipitation gradient from southeast to northwest. Temporally, productivity increased during the period of 1982-1999 and significantly decreased after 2000. Overall, the Last decade witnessed the most dramatic climatic changes that were likely to negatively affect the desert steppe ecosystem. The decreased primary produc- tivity, in particular, decreases ecosystem resilience and impairs the livelihood of local farmers and herdsmen.

关键词： desert steppe green-up gross primary productivity phenology precipitation temperature

New perspectives in free nitrous acid (FNA) uses for sustainable wastewater management

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Frontiers of Environmental Science & Engineering 2024年第2期18卷 161-168页

作者： Zhiqiang Zuo Min Zheng tao liu Yongzhen peng Zhiguo Yuan National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology Engineering Research Center of BeijingBeijing University of TechnologyBeijing 100124China Australian Centre for Water and Environmental Biotechnology The University of QueenslandSt.LuciaQLD 4072Australia Water Research Centre School of Civil and Environmental EngineeringUniversity of New South WalesSydneyNew South Wales 2052Australia Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 999077China School of Energy and Environment City University of Hong KongHong Kong 999077China

The biocidal effects of free nitrous acid (FNA) have found applications in multiple units in an urban wastewater system, including sewer networks, wastewater treatment processes, and sludge treatment processes. However, these applications are associated with chemical costs as both nitrite and acid are needed to produce FNA at the required levels. The recent discovery of novel acid-tolerant ammonia oxidizers offers the possibility to produce FNA from domestic wastewater, enabling the development of next-generation FNA-based technologies capable of achieving self-sustaining FNA production. In this study, we focus on the concept of in situ FNA generation facilitated by acid-tolerant ammonia oxidizers and highlight the multiple benefits it creates, after a brief review of the historical development of FNA-based technologies. We will discuss how wastewater systems can be made more energy-efficient and sustainable by leveraging the potential of acid-tolerant ammonia oxidizers.

关键词： Free nitrous acid Acid-toler antammonia oxidizer In situ generationl Wastewater management

Decreased Nrf2 protein level and low sperm quality in intractable spermatocystitis

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Asian Journal of Andrology 2024年第2期26卷 189-194页

作者： Shi-Ze Wang Jian-Nan liu Fen-Fang Zhou Ye-Jin-peng Wang peng Zhang Song-tao Cheng Department of Urology Sichuan Provincial People's HospitalUniversity of Electronic Science and Technology of ChinaChengdu 610072China Department of Urology Zhongnan Hospital of Wuhan UniversityWuhan 430071China Department of Health Management and Clinical Medicine School of Medicine and HealthWuhan PolytechnicUniversityWuhan 430071China

To investigate the molecular etiology of low sperm quality in patients with intractable spermatocystitis,spermatozoa samples from patients with persistent hematospermia undergoing transurethral seminal vesiculoscopy and healthy volunteers were utilized.Spermatozoa samples were collected from the seminal vesicles through transurethral seminal vesiculoscopy or by masturbation ejaculation.Sperm quality was analyzed by a WLJY-9000 color semen analysis system.Measurement of tumor necrosis factor alpha(TNFa)and interleukin-6(IL-6)in the seminal plasma was performed using enzyme-linked immunosorbent assay(ELISA).Measurement of H_(2)O_(2)in the seminal plasma was performed with a hydrogen peroxide kit.The protein levels of nuclear factor erythroid 2-related factor 2(Nrf2)and phosphorylated-Nrf2(p-Nrf2)were measured by western blot analysis and immunofluorescence assays.Low sperm quality parameters and increased levels of inflammatory cytokines(TNFa,IL-6,and H_(2)O_(2))in the seminal plasma were detected among the semen samples from the patients with persistent hematospermia.Nrf2 and p-Nrf2 were strongly expressed in the nucleus and periphery of human sperm cells,according to the results of the immunofluorescence assays.The protein levels of Nrf2 and p-Nrf2 were significantly lower in the spermatozoa samples from patients with persistent hematospermia than in those from healthy volunteers with normal sperm motility.The results suggested that Nrf2 signaling might play a role in the low sperm quality of patients with intractable spermatocystitis.

关键词： H_(2)O_(2) Nrf2 sperm quality spermatocystitis

Comparison of cytokine levels in prostatic secretion between the Ⅲa and Ⅲb subtypes of prostatitis

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Asian Journal of Andrology 2024年第1期26卷 77-84页

作者： Cheng-Lin Han Yu-Xuan Deng peng Hu Bin-tao Hu tao Wang Ji-Hong liu Ming-Chao Li Department of Urology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430000China

Chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS),also known as National Institutes of Health(NIH)type Ⅲ prostatitis,is a common disorder with an unclear etiology and no known curative treatments.Based on the presence or absence of leukocytes in expressed prostatic secretion(EPS),CP/CPPS is classifiedfurther into Illa(inflammatory)and Illb(noninflammatory)subtypes.However,the severity of symptoms is not entirely consistent with the white blood cell(WBC)count.Following the preliminary finding of a link between inflammatory cytokines and CP/CPPS,we performed this clinical study with the aim of identifying cytokines that are differentially expressed according to whether the prostatitis subtype is Ⅲa or Ⅲb.We found that granulocyte colony-stimulating factor(G-CSF),interleukin-18(IL-18),and monocyte chemoattractant protein-1(MCP-1)levels were significantly elevated and interferon-inducible protein-10(IP-10)and platelet-derived growth factor-BB(PDGF-BB)levels were downregulated in the EPS of patients with type Ⅲa prostatitis.In a word,it is a meaningful study in which we investigate the levels of various cytokines in EPS according to whether prostatitis is the Ⅲa or Ⅲb subtype.The combination of G-CSF,IL-18,MCP-1,IP-10,and PDGF-BB expression levels could form a basis for classification,diagnosis,and therapeutic targets in clinical P/CPPS.

关键词： chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS) cytokines NIH-Ⅲa NIH-ⅢB

Magnetic nanoparticle-modified hollow double-shell SiC@C@FeCo with excellent electromagnetic wave absorption

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Nano Research 2024年第4期17卷 3164-3174页

作者： Guiyu peng Jintang Zhou Jiaqi tao Weize Wang Jun liu Junru Yao Yijie liu Zhengjun Yao College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211100China Key Laboratory of Material Preparation and Protection for Harsh Environment(Nanjing University of Aeronautics and Astronautics) Ministry of Industry and Information TechnologyNanjing 211100China

Integrated micro and nanostructures,heterogeneous components,defects,and interfaces is the way to develop high-performance microwave absorbing materials.However,there still needs to be more precise experimental routes and effective validation.In this work,by a continuous process of vacuum sintering,hydrothermal,and carbon thermal reduction,magnetic FeCo nanoparticles were successfully embedded on the hollow double-shell mesoporous SiC@C surface,thus solving the challenges of a single component loss mechanism.The hollow double-shell nanostructure introduces air to enhance impedance matching while significantly reducing the density of the material.The extensive defects and heterogeneous grain boundaries effectively enhance the polarization loss capacity.The magnetic loss mechanism introduced by the magnetic particles effectively improves the impedance matching properties of the material.The synergy of these multiple advantages has enabled the SCFC_(2)-8(here SiC@C@FeCo is abbreviated to SCFC,2 represents the initial metal ion content,and 8 represents the hydrothermal time)sample to achieve an adequate absorption bandwidth of 6.09 GHz at 2.0 mm.With a minimum reflection loss of-60.56 dB,the absorption bandwidth can cover the entire C,X,and Ku bands by adjusting the matching thickness(1.3–4.0 mm).This work provides a valuable paradigm for the deeper exploitation of microwave absorption potential and guides the development of other high-performance materials.

关键词： SiC@C@FeCo(SCFC)composites core–shell hollow structure microwave absorption

Effective Capacity of URLLC over Parallel Fading Channels with Imperfect Channel State Information

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China Communications 2024年第5期21卷 45-63页

作者： peng Hongsen tao Meixia Department of Electronic Engineering and the Cooperative Medianet Innovation Center Shanghai Jiao Tong UniversityShanghai 200240China

This paper investigates the effective capacity of a point-to-point ultra-reliable low latency communication(URLLC)transmission over multiple parallel sub-channels at finite blocklength(FBL)with imperfect channel state information(CSI).Based on reasonable assumptions and approximations,we derive the effective capacity as a function of the pilot length,decoding error probability,transmit power and the sub-channel number.Then we reveal significant impact of the above parameters on the effective capacity.A closed-form lower bound of the effective capacity is derived and an alternating optimization based algorithm is proposed to find the optimal pilot length and decoding error probability.Simulation results validate our theoretical analysis and show that the closedform lower bound is very tight.In addition,through the simulations of the optimized effective capacity,insights for pilot length and decoding error probability optimization are provided to evaluate the optimal parameters in realistic systems.

关键词： effective capacity finite blocklength regime imperfect CSI parallel fading channels URLLC

Differences in and factors controlling organic matter enrichment in the Ziliujing Formation shale in the Sichuan Basin

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Petroleum Science 2024年第1期21卷 77-86页

作者： peng Li Zhong-Bao liu He Bi tao Jiang Rui-Kang Bian peng-Wei Wang Xiao-Yu Shang State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Efficient Development Beijing102206China Key Laboratory of Shale Oil/Gas Exploration and Production Technology SINOPECBeijing102206China Petroleum Exploration and Production Research Institute SINOPECBeijing102206China Research Institute of Petroleum Exploration and Development PetroChinaBeijing100083China Chinese Academy of Geological Sciences Beijing100037China No.4 Oil Production Plant in Daqing Oilfield Co Ltd. Daqing163511HeilongjiangChina

Lacustrine shale oil and gas are important fields for unconventional exploration and development in China,and organic-rich shale deposition lays down the critical foundation for hydrocarbon generation.There are two sets of shale,the Dongyuemiao and Da’anzhai Members,in the Ziliujing Formation in the Sichuan Basin.To identify the differential enrichment characteristics of organic matter and clarify its controlling factors,geochemical analyses of organic and inorganic geochemical analyses were performed.The results showed that the total organic carbon content of the Dongyuemiao shale(1.36%)is slightly higher than that of the Da’anzhai shale(0.95%).The enrichment of organic matter in the two shales resulted from the comprehensive controls of paleoproductivity,paleoenvironment,and terrigenous input,but different factors have different effects.In addition,driven by climate,the change in the sulfate concentration in the bottom water further led to the different intensities of bacterial sulfate reduction in early diagenesis.This made a great difference regarding organic matter accumulation in the two members.In general,climate may have played a dominant role in organic matter enrichment in the two sets of shale.

关键词： Lacustrine shale Ziliujing Formation Sichuan Basin Enrichment mechanism of organic matter