检索结果-南通市图书馆

Fabrication of high nitrogen austenitic stainless steels with excellent mechanical and pitting corrosion properties

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2009年第4期16卷 387-392页

作者： hua-bing Li Zhou-hua jiang Yang Cao Zu-rui Zhang School of Materials and Metallurgy Northeastern University Shenyang 110004 China

A series of high nitrogen austenitic stainless steels were successfully developed with a pressurized electroslag remelting furnace. Nitride additives and deoxidizer were packed into the stainless steel pipes, and then the stainless steel pipes were welded on the surface of an electrode with low nitrogen content to prepare a compound electrode. Using Si3N4 as a nitrogen alloying source, the silicon contents in the ingots were prone to be out of the specification range, the electric current fluctuated greatly and the surface qualities of the ingots were poor. The surface qualities of the ingots were improved with FeCrN as a nitrogen alloying source. The sound and compact macrostructure ingot with the maximum nitrogen content of 1.21wt% can be obtained. The 18Cr18Mn2Mo0.9N high nitrogen austenitic stainless steel exhibits high strength and good ductility at room temperature. The steel shows typical ductile-brittle transition behavior and excellent pitting corrosion resistance properties.

关键词： high nitrogen austenitic stainless steels electroslag remelting nitrogen alloying ductile-brittle transition pitting corrosion resistance

Effect of Carbon and Nitrogen Availability on Metabolism of Amino Acids in Germinating Spores of Arbuscular Mycorrhizal Fungi

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2011年第4期21卷 432-442页

作者： JIN Hai-Ru jiang Dong-hua ZHANG Ping-hua College of Chemistry and Life Science Zhejiang Normal University Jinhua 321004 (China)

The effects of carbon （C） and nitrogen （N） sources on N utilization and biosynthesis of amino acids were examined in the germinating spores of the arbuscular mycorrhizal （AM） fungus Glomus intraradices Schenck ＆ Smith after exposure to various N substrates, CO2, glucose, and/or root exudates. The N uptake and de novo biosynthesis of amino acids were analyzed using stable isotopic labeling with mass spectrometric detection. High-performance liquid chromatography-based analysis was used to measure amino acid levels. In the absence of exogenous N sources and in the presence of 25 mL L^-1 CO2, the germinating AM fungal spores utilized internal N storage as well as C skeletons derived from the degradation of storage lipids to biosynthesize the free amino acids, in which serine and glycine were produced predominantly. The concentrations of internal amino acids increased gradually as the germination time increased from 0 to 1 or 2 weeks. However, asparagine and glutamine declined to the low levels; both degraded to provide the biosynthesis of other amino acids with C and N donors. The availability of exogenous inorganic N （ammonium and nitrate） and organic N （urea, arginine, and glutamine） to the AM fungal spores using only CO2 for germination generated more than 5 times more internal free amino acids than those in the absence of exogenous N. A supply of exogenous nitrate to the AM fungal spores with only CO2 gave rise to more than 10 times more asparagine than that without exogenous N. In contrast, the extra supply of exogenous glucose to the AM fungal spores generated a significant enhancement in the uptake of exogenous N sources, with more than 3 times more free amino acids being produced than those supplied with only exogenous CO2. Meanwhile, arginine was the most abundant free amino acid produced and it was incorporated into the proteins of AM funsal spores to serve as an N storage compound.

关键词： biosynthesis exogenous C and N sources isotopic labeling N uptake N storage compound

Deriving Internal Energy by Virtue of Generalized Feynman-Hellmann Theorem for Mixed States

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第6X期44卷 1041-1044页

作者： FAN Hong-Yi jiang Zhong-hua Department of Physics Shanghai Jiao Tong University Shanghai 200030 China Department of Materials Science and Engineering University of Science and Technology of China Hefei 230026 China Special Class for Gifted Young University of Science and Technology of China Hefei 230026 China

We show how to directly use the generalized Feynman-Hellmann theorem, which is suitable for mixed state ensemble average, to derive the internal energy of Hamiltonian systems. A concrete example, which is a two couple... 详细信息

关键词： generalized Feynman-Hellmann theorem internal energy mixed state

Ultra-Pure Ferritic Stainless Steels-Grade,Refining Operation,and Application

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2007年第4期14卷 24-30页

作者： YOU Xiang-mi jiang Zhou-hua LI hua-bing School of Materials and Metallurgy Northeastern University Shenyang 110004 Liaoning China

The grades of ultra-pure ferritic stainless steels, especially the grades used in automobile exhaust system, were reviewed. The dependence of properties on alloying elements, the refining facilities, and the mechanism of the reactions in steel melts were described in detail. Vacuum, strong stirring, and powder injection proved to be effective technologies in the melting of ultra-pure ferritic stainless steels. The application of the ferritic grades was also briefly introduced.

关键词： ultra-pure ferritic stainless steel interstitial element stabilizing element automobile exhaust system SS-VOD VOD-PB VCR

在线全文

学校读者我要写书评

暂无评论

锁定接骨板在肱骨近端骨折治疗中的应用

实用骨科杂志 2008年第7期14卷 393-395页

作者：王邦荣郑华江应江炜马维虎徐荣明浙江省宁波市第六医院骨科浙江宁波315040

目的探讨肱骨近端锁定接骨板在肱骨近端骨折治疗中的应用和临床疗效。方法自2005年8月至2006年10月,应用锁定接骨板治疗36例肱骨近端骨折患者,其中男性13例,女性23例;年龄35-70岁,平均50.5岁。根据Neer分类,二部分骨折13例,三部分骨折15... 详细信息

目的探讨肱骨近端锁定接骨板在肱骨近端骨折治疗中的应用和临床疗效。方法自2005年8月至2006年10月,应用锁定接骨板治疗36例肱骨近端骨折患者,其中男性13例,女性23例;年龄35-70岁,平均50.5岁。根据Neer分类,二部分骨折13例,三部分骨折15例,四部分骨折8例。结果随访12-15个月,平均13.3个月,骨折平均愈合时间7.6周。根据Constant评分,优良率为88.9%。结论锁定接骨板治疗肱骨近端骨折具有操作简单、固定稳定、骨折愈合率高、并发症少等优点,尤其适合肱骨近端复杂骨折的治疗。

关键词：肱骨近端骨折锁定接骨板治疗

Experimental Study on a New Dual-Layer Granular Bed Filter for Removing Particulates

在线全文

学校读者我要写书评

暂无评论

Journal of China University of Mining and Technology 2007年第2期17卷 201-204页

作者： YANG Guo-hua ZHOU jiang-hua Maritime College Ningbo University Ningbo Zhejiang 315211 China

A new dual-layer granular bed filter for hot gas cleanup was invented and studied experimentally. Fine sand,0.5-1 mm grain size and about 1350 kg/m3 bulk density,was used as the lower layer of the filter. Expanded perlite par-ticles,2-5 mm grain size and about 70 kg/m3 bulk density,was used for the upper layer of the filter in this study. It was confirmed that the sizes and densities of these two media matched well; the binary media remained in complete segre-gation during regeneration by fluidization. Test results show that the filtration of the expanded perlite particle layer was characterized as "deep bed filtration." Filtration of the fine sand layer was "surface cake filtration." The expanded per-lite particle layer contributed about 90% to the bed dust capacity,but only about 20% to the total bed pressure drop,which increased the bed dust capacity ten fold compared to a single-layer bed of the same sand and the same total bed pressure drop. The dust cake on the surface of the fine sand layer raised the collection efficiencies to over 99.99%.

关键词： filtration granular bed filter particulate

Experimental study on the influence of content and fineness of fly ash on the mechanical properties of grouting slurries

在线全文

学校读者我要写书评

暂无评论

Deep Underground Science and Engineering 2024年第4期3卷 467-480页

作者： hua jiang Handong Zhang Xiaoyan Zhang Jinxun Zhang Yusheng jiang School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijingChina Beijing Urban Construction Group Co. Ltd.BeijingChina

Excavation gaps around the front shield can be generated during shield construction,resulting in significant ground *** synchronous grouting slurries are unsuitable forfilling these gaps during tunneling under existing subway *** address this issue,experiments are conducted on mix characteristics and hardening properties of slurries with variations infineness and contents ofﬂy *** experimental and computed tomography scan results yield the followingfindings:(1)ﬂy ash with highfineness can effectively reduce the early strength of slurries and enhance their *** improves thefilling effect on micropores in the slurry and ultimately enhances thefinal hardening strength.(2)Fineness ofﬂy ash controls the process of slurry *** higher thefineness ofﬂy ash,the more visible the exothermic hydration of slurry and the earlier the highest temperature peak appears.(3)Fly ash with highfineness can effectively increase the density and consolidation rate of slurries,resulting in greater improvement in slurry strength,particularly when the ratio ofﬂy ash to cement(mf/mc)is 0.75.(4)Fly ash with highfineness can effectively decrease the likelihood of appearance of pores in the slurry,optimize the pore structure,and enhance the strength of slurries after consolidation.

关键词： content CT scan environmentally friendly fineness fly ash homogeneity hydration mechanism

Relationship between real meridional volume transport and Sverdrup transport in the North Subtropical Pacific

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第14期51卷 1757-1760页

作者： jiang hua WANG Hui ZHU jiang TAN Benkui Institute of Climate System Chinese Academy of Meteorological Sciences Beijing 100081 China Chinese Academy of Meteorological Sciences Beijing 100081 China Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Department of Atmospheric Science School of Physics Peking University Beijing 100871 China

The oceanic meridional volume trans-port (MVT) in the North Subtropical Pacific is calcu-lated directly from an observed velocity field (realMVT) and indirectly from wind stress based on Sver-drup balance, respectively. It is confirmed that theSverdrup MVT is a good approximation to the realMVT for the North Subtropical Pacific except in thewestern boundary region, where the difference isexpected because of frictional and nonlinear *** time evolution of the MVT derived from a revisedSverdrup balance, in which a time delay due to thepropagation of the first baroclinic Rossby wave isconsidered, is well correlated with that of the realMVT on decadal time scale, especially near thewestern boundary region. It is suggested that theSverdrup balance can be used to study not only themean climatology of the oceanic circulation, but alsothe time-dependent oceanic circulation of the NorthSubtropical Pacific when the Rossby wave propaga-tion is taken into account.

关键词：斯维尔德鲁普运输时延 MVT 亚热带太平洋

An Uncertainty Analysis of the Newmark Displacement Model for Earthquake-Induced Landslides in the Jiuzhaigou National Geopark

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年第6期35卷 1998-2012页

作者： Guochao Fu hua Pan jiang Cheng Institute of Geophysics China Earthquake AdministrationBeijing100081China

In this paper,we present an approach to generating probabilistic hazard maps for earthquake-induced landslides using the Newmark Displacement Model(NDM).This model takes the uncertainties associated with the slope properties(e.g.,soil shear strengths,groundwater table location)into consideration,which is coupled with the hydrological model based on geomorphological,geological,geotechnical,seismological,and rainfall *** and fluctuations in the input parameters of the NDM are considered by treating these quantities asβ-PERT distributions through Monte Carlo techniques,which allows probability value of the NDM to be cast into hazard ***,incorporating Monte Carlo techniques can avoid using conservative input parameters in a deterministic approach to capture these *** the 2017 Jiuzhaigou M_(w)6.5 Earthquake in Sichuan Province,Western China as an example,earthquake-induced landslides probability distribution map is generated with the most appropriate displacement threshold(λ=1 cm).Our results show good performances for realistic landslide hazard assessment,which can serve as a basis for providing a reference for the prediction of earthquake-induced landslide probability and rapid landslide hazard assessment after a strong earthquake.

关键词： earthquakes landslides Monte Carlo Beta-PERT distribution Newmark Displacement Model Tibet Plateau