检索结果-南通市图书馆

Radiation model of a xenon flash lamp in a laser amplifier pump cavity

在线全文

学校读者我要写书评

暂无评论

High Power Laser Science and Engineering 2015年第4期3卷 31-37页

作者： Yongzhong Wu Jianqiang Zhu zhixiang zhang Yangshuai Li National Laboratory on High Power Laser and Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences University of Chinese Academy of Sciences

Understanding the radiation model of a flash lamp is essential for the reflector design of a laser amplifier. Reflector design often involves several simplifying assumptions, like a point or Lambertian source; either of these assumptions may lead to significant errors in the output distribution. In practice, source non-idealities usually result in sacrificing the amplifier's gain coefficient. We propose a novel test technique for attaining the xenon flash lamp absolute spectral intensity at various angles of view, and then accurately predict radiation distributions and generate the reflector shape. It is shown that due to the absorption of emitted radiation by the lamp itself, the behavior of the radiation model at various wavelengths is different. Numerical results of xenon plasma absorption coefficient were compared with the measured data. A reasonable agreement was obtained for the absorption coefficient parameters. Thus, this work provides a useful analytical tool for the engineering design of laser amplifier reflectors using xenon flash lamps as pumps.

关键词： absorption coefficient current density radiation model xenon flash lamp xenon plasma

Performance of steel bridge deck pavement structure with ultra high performance concrete based on resin bonding

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2021年第4期15卷 895-904页

作者： Hui zhang zhixiang zhang Peiwei GAO Lei CUI Youqiang PAN Kuan LI Special Pavement Technology Center Jiangsu SinoRoad Engineering Research InstituteNanjing211805China College of Civil Avlation Nanjing University of Aeronautics and AstronauticsNanjing210016China

This research investigated a pavement system on steel bridge decks that use epoxy resin(EP)bonded ultra-high performance concrete(UHPC).Through FEM analysis and static and dynamic bending fatigue tests of the composite structure,the influences of the interface of the pavement layer,reinforcement,and different paving materials on the structural performance were compared and *** results show that the resin bonded UHPC pavement structure can reduce the weld strain in the steel plate by about 32%and the relative deflection between ribs by about 52%under standard axial load conditions compared to traditional *** EP bonding layer can nearly double the drawing strength of the pavement interface from 1.3 MPa,and improve the bending resistance of the UHPC structure on steel bridge decks by about 50%;the bending resistance of reinforced UHPC structures is twice that of unreinforced UHPC structure,and the dynamic deflection of the UHPC pavement structure increases exponentially with increasing fatigue *** fatigue life is about 1.2×10^(7) cycles under a fixed force of 9 kN and a dynamic deflection of 0.35 mm,which meets the requirements for fatigue performance of pavements on steel bridge decks under traffic conditions of large flow and heavy load.

关键词： steel bridge deck pavement ultra-high-performance concrete epoxy resin composite structure bending fatigue performance

The spatial distribution of threats to plant species with extremely small populations

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2017年第1期11卷 127-136页

作者： Chunjing WANG Jing zhang Jizhong WAN Hong QU Xianyun MU zhixiang zhang School of Nature Conservation Beijing Forestry University Beijing 100083 China

Many biological conservationists take actions to conserve plant species with extremely small populations （PSESP） in China; however, there have been few studies on the spatial distribution of threats to PSESP. Hence, we selected distribution data of PSESP and made a map of the spatial distribution of threats to PSESP in China. First, we used the weight assignment method to evaluate the threat risk to PSESP at both country and county scales. Second, we used a geographic information system to map the spatial distribution of threats to PSESP, and explored the threat factors based on linear regression analysis. Finally, we suggested some effective conservation options. We found that the PSESP with high values of protection, such as the plants with high scientific research values and ornamental plants, were threatened by over-exploitation and utilization, habitat fragmentation, and a small sized wild population in broad-leaved forests and bush fallows. We also identified some risk hotspots for PSESP in China. Regions with low elevation should be given priority for ex- and in-situ conservation. Moreover, climate change should be considered for conservation of PSESP. To avoid intensive over-exploitation or utilization and habitat fragmentation, in-situ conservation should be practiced in regions with high temperatures and low temperature seasonality, particularly in the high risk hotspots for PSESP that we proposed. Ex-situ conservation should be applied in these same regions, and over-exploitation and utilization of natural resources should be prevented. It is our goal to apply the concept of PSESP to the global scale in the future.

关键词： threatened plant species extremely small populations climate protection value human activities China

Catalytic activity of porous manganese oxides for benzene oxidation improved via citric acid solution combustion synthesis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2020年第12期32卷 196-204页

作者： Hao Guo zhixiang zhang Zhi Jiang Mingxia Chen Hisahiro Einaga Wenfeng Shangguan Research Center for Combustion and Environmental Technology Shanghai Jiao Tong UniversityShanghai 200240China Department of Energy and Material Sciences Faculty of Engineering SciencesKyushu UniversityFukuoka 816-8580Japan

Various manganese oxides(MnOx) prepared via citric acid solution combustion synthesis were applied for catalytic oxidation of benzene. The results showed the ratios of citric acid/manganese nitrate in synthesizing process positively affected the physicochemical properties of MnOx, e.g., BET(Brunauer-Emmett-Teller) surface area, porous structure, reducibility and so on, which were in close relationship with their catalytic performance. Of all the catalysts, the sample prepared at a citric acid/manganese nitrate ratio of 2:1(C2M1) displayed the best catalytic activity with T(90)(the temperature when 90% of benzene was catalytically oxidized) of 212 ℃. Further investigation showed that C2M1 was Mn2O3 with abundant nano-pores, the largest surface area and the proper ratio of surface Mn^4+/Mn^3+, resulting in preferable low-temperature reducibility and abundant surface active adsorbed oxygen species. The analysis results of the in-situ Fourier transform infrared spectroscopy(in-situ FTIR) revealed that the benzene was successively oxidized to phenolate, o-benzoquinone, small molecules(such as maleates, acetates, and vinyl), and finally transformed to CO2 and H2O.

关键词： Catalytic activity Benzene oxidation Porous manganese oxides Citric acid Solution combustion

Effect of alumina and zirconia as binders on the activity of Fe-BEA for NH3-SCR of NO

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2018年第1期12卷 169-175页

作者： Jin Shil Zihao zhang Mingxia Chen zhixiang zhang Wenfeng Shangguan Shunchao Gu Hirano Shin-ichi Research Center for Combustion and Environment Technology Shanghai Jiao Tong University Shanghai 200240 China School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China Hirano Institute for Materials Innovation Shanghai Jiao Tong University Shanghai 200240 China

Fe-BEA catalysts are active for the NH3-SCR of NO. For industrial application, a binder should be added to the Fe-BEA catalysts to make them tightly adhere to the monoliths. The addition of alumina and zirconia as binders to the Fe-BEA led to a different effect on NO conversion. The catalytic activity of the mixed samples was evaluated by the temperature programmed procedure in a flow-reactor sys!em, and themechaism was. analyzedvia SEM, BET, andXPS. Itwas found that larger ironparticles were tbrmed by the migration orparent tron pamcles in the Fe-BEA catalyst with alumina. This led to the increase of Fe3＋ magnitude and iron cluster, enhancing the abilities of NO oxidation and storage. Accordingly, the SCR activity increased slightly in low temperature but decreased sharply in high temperature. For the Fe-BEA with zirconia sample, NO oxidation and storage abilities decreased due to the less iron clusters. The increase of Fe ＋ magnitude resulted in higher catalytic oxidation ability, which gave rise to little change in the SCR activity compared with the Fe-BEA.

关键词： NH3-SCR NO Fe-BEA Binder Alumina Zirconia

Preparation and promising optoelectronic applications of lead halide perovskite patterned structures:A review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carbon Energy 2023年第10期5卷 91-115页

作者： Shangui Lan Baojun Pan Ying Liu zhixiang zhang Lijie zhang Bin Yu Yanjun Fang Peijian Wang State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhouZhejiangChina ZJU‐Hangzhou Global Scientific and Technological Innovation Center Future Science Research InstituteZhejiang UniversityHangzhouZhejiangChina Key Laboratory of Carbon Materials of Zhejiang Province Institute of New Materials and Industrial TechnologiesCollege of Chemistry and Materials EngineeringWenzhou UniversityWenzhouZhejiangChina School of Micro‐Nano Electronics Zhejiang UniversityHangzhouZhejiangChina

Lead halide perovskites have received considerable attention from researchers over the past several years due to their superior optical and optoelectronic properties,because of which they can be a versatile platform for fundamental science research and *** structures based on lead halide perovskites have much more novel properties compared with their more commonly seen bulk-,micro-,and nano-crystals,such as improvement in antireflection,light-scattering effects,and light absorption,as a result of their adjustability of spatial ***,there are many challenges yet to be resolved in this field,such as insufficient patterned resolution,imperfect crystal quality,complicated preparation process,and so *** pave the way to solve these problems,we provide a systematic presentation of current methods for fabricating lead halide perovskite patterned structures,including thermal imprint,use of etching films,two-step vapor-phase growth,template-confined solution growth,and seed-assisted ***,the advantages and disadvantages of these methods are elaborated in *** addition,thanks to the extraordinary properties of lead halide perovskite patterned structures,a variety of potential applications in optics and optoelectronics of these structures are ***,we put forward existing challenges and prospects in this exciting field.

关键词： fabrication lead halide perovskites optics optoelectronics patterned structures photovoltaics

RE-NiO_(x)(RE=Ce,Y,La)composite oxides coupled plasma catalysis for benzene oxidation and by-product ozone removal

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2023年第6期41卷 789-800,I0001页

作者： Yikun zhang Zhidong Wei Yong Zhu Shanlong Tao Mingxia Chen zhixiang zhang Zhi Jiang Wenfeng Shangguan Research Center for Combustion and Environment Technology School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Plasma-coupled catalysis is a promising volatile organic co mpounds(VOCs) removal technology because of its interactional principles of plasma decomposition and catalytic ***,the problem of harmful by-products is still in trouble.A series of rare earth doped RE-NiO_(x)(RE=Ce,Y,La) composite oxides were synthesized by metal organic frameworks(MOFs)-derived method for coupled plasma oxidation of benzene and by-product ozone *** with plasma alone,the 1%La-NiO_(x)catalyst shows the best enhancement of 50% for benzene conversion with complete removal of a maximum of 800 ppm *** energy consumption for 90% benzene removal efficiency(η90%) is also reduced from 3600 to 1200 J/*** re sults of RE-NiO_(x) catalysts indicate that the doping of La causes interaction and synergistic effect between La and Ni,and the surface oxygen and lattice oxygen with defects play crucial roles in benzene oxidation and ozone decomposition,*** addition,the decomposition mechanism of benzene and ozone under plasma is *** is responsible for the indiscriminate bond breaking in benzene and oxygen to form a variety of organic intermediates and ozone,while the La-NiO_(x) catalyst selectively oxidizes the intermediates to CO_(x)/H2O and decomposes the ozone into oxygen.

关键词： Plasma catalysis Benzene removal By-product ozone control Rare earths doping La-NiO_(x)composite oxide

Thinner 2D α-MoO_(3) makes setting up memristors easier

在线全文

学校读者我要写书评

暂无评论

Journal of Materiomics 2024年第6期10卷 1279-1289页

作者： Yukun Hong Shangui Lan Baojun Pan zhixiang zhang Bingbing Chen Lijie zhang Peijian Wang Key Laboratory of Carbon Materials of Zhejiang Province College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou325035ZhejiangChina Institute of New Materials&Industrial Technologies Wenzhou UniversityWenzhou 325024China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou311215China Macao Institute of Materials Science and Engineering(MIMSE) MUST-SUDA Joint Research Center for Advanced Functional MaterialsMacao University of Science and TechnologyTaipa999078MacaoChina Department of Energy Science and Engineering Nanjing Tech UniversityNanjing210009China

Two-dimensional(2D)metal oxide α-MoO_(3) shows great potentials because of its very high dielectric constant,air stability and anisotropic phonon ***,a method to produce ultrathin single crystallineα-MoO_(3) with high transferability for functional device architecture is ***,we report on the controllable synthesis of ultrathinα-MoO_(3) single crystals via chemical vapor deposition(CVD)assisted by plasma *** also carried out systematic computational work to explicate the mechanism for the slantly-oriented growth of thin nanosheets on plasma-pretreated *** method possesses certain universality to synthesize other ultrathin oxide materials,such as Bi_(2)O_(3) and Sb_(2)O_(3) ***-grownα-MoO_(3) presents a high dielectric constant(≈40),ultrathin thickness(≈3 nm)and high *** withα-MoO_(3) as the functional layers show excellent performance featuring high on/off ratio of approximately 104,much lower set voltage around 0.5 V,and highly repetitive voltage sweep *** power consumption of MoO_(3) memristors is significantly reduced,resulted from reduced thickness of the MoO_(3) *** crystal ultrathinα-MoO_(3) shows great potentials in post-Moore memristor and the synthesis of CVD assisted by plasma pretreatment approach points to a new route for materials growth.

关键词： Ultrathin molybdenum trioxide Thickness controlling High transferability Memristor Low power consumption

Effect of superabsorbent polymer on mechanical properties of cement stabilized base and its mechanism

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transportation Safety and Environment 2020年第1期2卷 58-68页

作者： Yongsheng Guan zhixiang zhang Xiaorui zhang Junqing Zhu Wen Zhou Qi Huang Yuqing zhang Jiangsu Sinoroad Engineering Research Institute Co.LTD 99-196 Taizhong RdNanjing 211805China School of Transportation Engineering Southeast University#2 SipailouNanjing 210096China National Engineering Laboratory of Highway Maintenance Technology Changsha University of Science&TechnologyChangsha 410114China Aston Institute of Materials Research Engineering Systems&Management GroupAston UniversityBirminghamB47ETUK

Superabsorbent polymers(SAPs)are cross-linked polymers that can absorb and retain large amounts of *** recent years,a growing interest was seen in applying SAPs in concrete to improve its performance due to its efficiency in mitigating *** paper presents findings in a study on effect of SAPs on performance of cement-treated base(CTB),using the experience of internal curing of *** specimens with and without SAPs were prepared and tested in the *** conducted include mechanical property testing,dry shrinkage testing,differential thermal analysis,mercury intrusion porosimetry and scanning electron microscope *** was found that 7-day and 28-day unconfined compressive strength of CTB specimens with SAPs was higher than regular CTB specimens.28d compressive strength of CTB specimens with SAPs made by Static pressure method was 5.87 MPa,which is 27%higher than that of regular CTB *** shrinkage of CTB specimens with SAPs was decreased by 52.5%comparing with regular CTB *** the microstructure analysis it was found that CTB specimens with SAPs could produce more hydration products,which is also the reason for the strength improvement.

关键词： superabsorbent polymer cement-stabilized base internal curing mechanical property drying shrinkage