检索结果-南通市图书馆

journal of Rare Earths 2020年第10期38卷 1053-1059,I0001页

作者： Yingqiu gu Xiaoya Chen Shuang Zhao Yuting Zhang jiangsu Key Laboratory of green Synthetic Chemistry for Functional Materials School of Chemistry&Materials ScienceJiangsu Normal UniversityXuzhou 221116China

FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation *** as-prepared materials were characterized by various techniques including powder X-ray diffraction(XRD),N2 adsorption/desorption and high-resolution transmission electron microscopy(HRTEM).Catalyst with the highest iron content(90 FeCe) shows the best activity for the hydrogen generation via ammonia decomposition.83% NH3 conversion is achieved at 550℃ and nearly full conversion of NH3 is realized at 600℃ with a gHSV of 24000 cm3/(gcat·h).The large content and small size crystal particles of iron species are responsible for the good catalytic *** reduction by hydrogen(H2-TPR) was performed to investigate the interaction between cerium and iron *** is found that slight cerium can exert strong interaction with iron compound thus effectively prevent the self-aggregation of active iron species,so as to improve the catalytic activity for ammonia decomposition.

关键词： FeCe nanocomposite Catalytic ammonia decomposition High iron content Hydrogen generation Rare earths

Anthropogenic land use substantially increases riverine CO_(2) emissions

在线全文

学校读者我要写书评

暂无评论

journal of Environmental Sciences 2022年第8期34卷 158-170页

作者： Shijie gu Siyue Li Isaac R.Santos School of River and Ocean Engineering Chongqing Jiaotong UniversityChongqing 400074China Key Laboratory of Reservoir Aquatic Environment Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China Chongqing School University of Chinese Academy of SciencesChongqing 400714China Research Center for Environmental Ecology and Engineering Institute of Changjiang Water Environment and Ecological SecuritySchool of Environmental Ecology and Biological EngineeringKey Laboratory for Green Chemical Process of Ministry of EducationKey Laboratory of Novel Reactor and Green Chemical Technology of Hubei ProvinceEngineering Research Center of Phosphorus Resources Development and Utilization of Ministry of EducationWuhan Institute of TechnologyWuhan 430205China Department of Marine Sciences University of GothenburgGothenburg 41296Sweden National Marine Science Centre Southern Cross UniversityCoffs HarbourNSW 2450Australia

Carbon dioxide(CO_(2)) emissions from inland waters to the atmosphere are a pivotal component of the global carbon budget. Anthropogenic land use can influence riverine CO_(2) emissions, but empirical data exploring cause-effect relationships remain limited. Here, we investigated CO_(2) partial pressures(pCO_(2)) and degassing in a monsoonal river(Yue River)within the Han River draining to the Yangtze in China. Almost 90% of river samples were supersaturated in CO_(2) with a mean ± standard deviation of 1474 ± 1614 μatm, leading to emissions of 557-971 mmol/m^(2)/day from river water to the atmosphere. Annual CO_(2) emissions were 1.6-2.8 times greater than the longitudinal exports of riverine dissolved inorganic and organic carbon. pCO_(2) was positively correlated to anthropogenic land use(urban and farmland), and negatively correlated to forest cover. p CO_(2) also had significant and positive relationships with total dissolved nitrogen and total dissolved phosphorus. Stepwise multiple regression models were developed to predict p CO_(2) . Farmland and urban land released nutrients and organic matter to the river system, driving riverine p CO_(2) enrichment due to enhanced respiration in these heterotrophic rivers. Overall, we show the crucial role of land use driving riverine pCO_(2) , which should be considered in future large-scale estimates of CO_(2) emissions from streams. Land use change can thus modify the carbon balance of urban-river systems by enhancing river emissions, and reforestation helps carbon neutral in rivers.

关键词： River carbon Inland waters greenhouse gases Climate change Water quality Headwater streams

Open surgery in the era of minimally invasive surgery

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Cancer Research 2022年第1期34卷 63-65页

作者： Zichen Zhao jin gu Peking University Wujieping Urology Center Peking University Shougang HospitalBeijing 100144China Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Center of Gastrointestinal CancerPeking University Cancer Hospital&InstituteBeijing 100142China Peking-Tsinghua Center for Life Science Peking University International Cancer CenterBeijing 100142China Department of gastrointestinal Surgery Peking University Shougang HospitalBeijing 100144China Center for Precision Diagnosis and Treatment of Colorectal Cancer and Inflammatory Diseases Beijing 100144China

The benefits and popularity of minimally invasive surgery are undeniable around the ***,open surgery is necessary and learning open surgery skills is still a *** surgery allows for better exposure to the surgical field and provides tactile sensation to facilitate the stereo visual assessment to precisely remove the *** surgery is still the key to surgical training,and the skills learned from open surgeries remain crucial for unforeseen circumstances and certain conditions like emergencies,challenge cases,or patients with compromised status.

关键词： Open surgery minimally invasive surgery laparoscopic surgery

Explosion damage effects of aviation kerosene storage tank under strong ignition

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第7期37卷 27-38页

作者： Shixiang Song Cheng Wang Boyang Qiao gongtian gu State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

In order to study the blast damage effects of aviation kerosene storage tanks,the out-field explosion experiments of 8 m3fixed-roof tanks were carried *** fragments,shock wave and fireball thermal radiation of the tank in the presence of bottom oil,half oil and full oil,as well as empty tank,were investigated under internal explosion by various TNT charge contents(1.8 kg,3.5 kg and 6.2 kg).The results showed that the tank roof was the only fragment produced,and the damage forms could be divided into three *** increase of TNT charge content and oil volume enlarged the deformation of the tank,while the hole ratio presented a trend of increase first and then *** H_r,maxand V_(max)values positively increased as increasing the TNT charge content and oil volume(from empty to half oil),but decreased in full *** Pmaxvalues had a progressive increase with the increment of TNT charge content,but not the case with the increase in oil *** development of fireball was divided into three stages:tank roof‘towed'flame,jet flow flame tumbling and rising,and jet flow flame *** Dmaxand Hf,maxvalues both increased as increasing TNT charge content and oil *** oscillation phenomenon of fireball temperature was observed in the cooling *** average temperature of fireball surface was positively correlated with TNT charge content,and negatively correlated with oil volumes.

关键词： Aviation kerosene Storage tank Internal explosion Shock wave Fireball

DBN-gABP model for estimation of aircraft wake vortex parameters using Lidar data

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Aeronautics 2024年第9期37卷 347-368页

作者： Zhiqiang WEI Tong LU Runping gu Fei LIU College of Air Traffic Management Civil Aviation University of ChinaTianjin 300300China

Aircraft wake turbulence is an inherent outcome of aircraft flight,presenting a substan-tial challenge to air traffic control,aviation safety and operational *** upon data obtained from coherent Doppler Lidar detection,and combining Dynamic Bayesian Networks(DBN)with genetic Algorithm-optimized Backpropagation Neural Networks(gA-BPNN),this paper proposes a model for the inversion of wake vortex *** the wake vortex flow field simulation analysis,the wind and turbulent environment were initially superimposed onto the simulated wake velocity ***,Lidar-detected echoes of the velocity field are simulated to obtain a data set similar to the actual situation for model *** the case study validation,real measured data underwent preprocessing and were then input into the established *** allowed us to construct the wake vortex characteristic parameter inversion *** final results demonstrated that our model achieved parameter inversion with only minor *** a practical example,our model in this paper significantly reduced the mean square error of the inverted velocity field when compared to the traditional *** study holds significant promise for real-time monitoring of wake vortices at airports,and is proved a crucial step in developing wake vortex interval standards.

关键词： Air traffic control Wake vortex flow field simulation Lidar echo simulation DBNmodel gA-BP model Wakevortex characteristic parameter inversion model

Fatigue life research and experimental verification of superalloy thin-walled structures subjected to thermal-acoustic loads

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Aeronautics 2020年第2期33卷 598-608页

作者： jian WANg Fengtong ZHAO Yundong SHA Song gu Department of Aircraft Maintenance Engineering Chengdu Aeronautic PolytechnicChengdu 610100China Liaoning Key Laboratory of Advanced Test Technology for Aeronautical Propulsion System Shenyang Aerospace UniversityShenyang 110136China

Rapid alternating stress is formed in structure subjected to harsh thermal-acoustic loads,which will affect fatigue performance and reduce fatigue life ***,fatigue experiment of superalloy thin-walled structure was carried out to obtain fatigue damage location and failure time of the experiment specimen,and S-iN curves of superalloy thin-walled structure at 723 K were ***,dynamic response simulation of superalloy thin-walled structure under the same load as experiment was implemented,and fatigue life was estimated based on the fatigue life prediction model which mainly included:improved rain-flow counting method,Morrow average stress model and Miner linear cumulative damage ***,comparisons between simulation solutions and experimental results achieved a consistency,which verified the validity of the Fatigue Life Prediction Model(FLPM).Moreover,taking a rectangle plate as the analysis object,the distributions of Fain-low circulation blocks and damage levels of the structure were discussed ***,current research indicates that in pre-buckling the structure is in softened area and fatigue life decreases with the increase of temperature;in post-buckling the structure is in hardened area and fatigue life increases with the increase of temperature within a certain range.

关键词： Experimental verification Fatigue life Improved rain-flow counting method Rain-flow cycle matrix Rain-flow damage matrix Thermal-acoustic load Thin-walled structures

Simulation and assessment of manufacturing ethylene carbonate from ethylene oxide in multiple process routes

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Chemical Engineering 2021年第3期34卷 135-144页

作者： Xincheng gu Xiaochun Zhang Xiangping Zhang Chun Deng Beijing Key Laboratory of Ionic Liquid Clean Process Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Heavy Oil Processing College of Chemical Engineering and EnvironmentChina University of Petroleum-BeijingBeijing 102249China

Ethylene oxide(EO)is an important raw material for producing ethylene carbonate(EC).However,the traditional method for the separation of EO from mixture gas by water in the refining process is high energy *** this paper,two processes of manufacturing EC from EO mixture gas were studied by process *** processes for producing EC from EO mixture as raw materials without EO purification,called the OSAC process and the Modified OSAC process,were developed and assessed *** processes use EC as the absorbent to capture EO,avoiding the separation process of EO from *** comparisons,the EC producing process containing EO absorption by water,EO refinement and carbonylation process were also modeled,which was called the ERC *** schemes were designed for the EO absorber using EC as *** with the initial absorber scheme,the optimal liquid–vapor ratio is reduced from 1.66 to 1.45(mass).Moreover,the mass distribution analysis for the three processes were carried out in the form of the material *** was found that,compared with the ERC process,the energy consumption of the OSAC and the Modified OSAC process is reduced by 56.89%and 30.03%,*** work will provide helpful information for the industrialization of the OSAC process.

关键词： Ethylene oxide Separation Ethylene carbonate Process simulation

Suppressing nonlinear aeroelastic response of laminated composite panels in supersonic airflows using a nonlinear energy sink

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Aeronautics 2021年第2期34卷 376-385页

作者： jian ZHOU Minglong XU Zhichun YANg Yingsong gu State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi'an Jiaotong UniversityXi'an 710049China School of Aeronautics Northwestern Polyteclmical UniversityXi'an 710072China

This paper proposes using a Nonlinear Energy Sink(NES) to suppress the nonlinear aeroelastic response of laminated composite panels in supersonic airflows. Relevant aeroelastic equations are established using Hamilton’s principle and a finite element approach, drawing upon Von Karman’s large deflection theory and first order piston theory. The idea of the NES suppression region is proposed and the effects of NES parameters on the NES suppression region are studied in detail. The results show that the nonlinear aeroelastic responses of the panel can be completely suppressed by the Transient Resonance Capture(TRC);the appropriate NES parameter values can increase the critical dynamic pressure for flutter and suppress the nonlinear aeroelastic response effectively. Increasing the mass ratio of the NES can improve the NES suppression region;the nonlinear stiffness coefficient and damping of the NES within a specific range can suppress the nonlinear aeroelastic response. The most effective installation position for a NES is in a specific region behind the center-line of the panel in the direction of the airflow.

关键词： Aeroelasticity Laminated composite panel Nonlinear dynamics Nonlinear energy sink Panel flutter Passive suppression

Petroleum System of the Sufyan Depression at the Eastern Margin of a Huge Strike-slip Fault Zone in Central Africa

在线全文

学校读者我要写书评

暂无评论

Acta geologica Sinica(English Edition) 2009年第6期83卷 1182-1187页

作者： ZHANg Yamin gu Qin School of Earth Sciences and Resources Management Chang＇an University Xi＇an Shaanxi 710054 China Key Laboratory of Western China＇s Mineral Resources and geological Engineering Ministry of Education Chang＇an University Xi＇an Shaanxi 710054 China Exploration and Development Scientific Research Institute of Zhongyuan Oil Field Company Sinopec Henan 457001 China

The present paper mainly studies the petroleum system of the Sufyan Depression in the Muglad Basin of central Africa and analyzes its control of hydrocarbon accumulation. On the basis of comprehensive analysis of effective source rock, reservoir bed types and source-reservoir-seal assemblages, petroleum system theory has been used to classify the petroleum system of the Sufyan Depression. Vertically, the Sufyan Depression consists of two subsystems. One is an Abu gabra subsystem as a self generating, accumulating and sealing assemblage. The other subsystem is composed of an Abu gabra source rock, Bentiu channel sandstone reservoir and Darfur group shale seal, which is a prolific assemblage in this area. Laterally, the Sufyan Depression is divided into eastern and western parts with separate hydrocarbon generation centers more than 10 000 m deep. The potential of the petroleum system is tremendous. Recently, there has been a great breakthrough in exploration. The Sufyan C-1 well drilled in the central structural belt obtained high-yielding oil flow exceeding 100 tons per day and controlled geologic reserves of tens of millions of tons. The total resource potential of the Sufyan Depression is considerable. The central structural belt is most favorable as an exploration and development prospect.

关键词： effective hydrocarbon source rock petroleum system half-graben (graben) Sufyan Depression Muglad Basin

Precise output loads control of load-diffusion components with topology optimization

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Aeronautics 2020年第3期33卷 933-946页

作者： Yinfeng CAO Xiaojun gu jihong ZHU Weihong ZHANg State IjR Center of Aerospace Design and Additive Manufacturing Northwestern Polytechnical UniversityXi’an 710072China Institute of Intelligence Material and Structure Unmanned System TechnologiesNorthwestern Polytechnical UniversityXi’an 710072China MIIT Lab of Metal Additive Manufacturing and Innovative Design Northwestern Polytechnical UniversityXi’an 710072China

The purpose of this paper is to present a novel topology optimization approach to control precisely the output loads under static loads and harmonic *** introduce the Artificial Bar Element(ABE)at the designated output positions,where the output loads are equivalently measured and constrained with the nodal displacements of *** model is then formulated considering the output load constraints as well as the minimization of strain energy and dynamic displacement responses respectively under the static and dynamic *** influences of the ABEs stiffness,different material usages of the design domain,widths of the output loads constraint intervals and variation ratios of output loads are discussed in *** proposed method is verified with several numerical examples with clear and reasonable load transfer paths.

关键词： Artificial bar elements Dynamic response Kreisselmeier-Steinhauser(KS)function Precise control of output loads Topology optimization