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Soil Microbial Activities in Beech Forests Under Natural Incubation Conditions as Affected by Global Warming

Pedosphere 2014年第6期24卷 709-721页

作者： S.LU q.wang S.KATAhATA M.NARAMOTO h.MIZUNAGA Graduate School of Science and Technology Shizuoka University Graduate School of Agriculture Shizuoka University

Microbial activity in soil is known to be controlled by various factors. however, the operating mechanisms have not yet been clearly identified, particularly under climate change conditions, although they are crucial for understanding carbon dynamics in terrestrial ecosystems. In this study, a natural incubation experiment was carried out using intact soil cores transferred from high altitude(1 500 m) to low(900 m) altitude to mimic climate change scenarios in a typical cold-temperate mountainous area in Japan. Soil microbial activities, indicated by substrate-induced respiration(SIR) and metabolic quotient(q CO2), together with soil physicalchemical properties(abiotic factors) and soil functional enzyme and microbial properties(biotic factors), were investigated throughout the growing season in 2013. Results of principal component analysis(PCA) indicated that soil microbial biomass carbon(MBC) andβ-glucosidase activity were the most important factors characterizing the responses of soil microbes to global warming. Although there was a statistical difference of 2.82 ℃ between the two altitudes, such variations in soil physical-chemical properties did not show any remarkable effect on soil microbial activities, suggesting that they might indirectly impact carbon dynamics through biotic factors such as soil functional enzymes. It was also found that the biotic factors mainly controlled soil microbial activities at elevated temperature,which might trigger the inner soil dynamics to respond to the changing environment. Future studies should hence take more biotic variables into account for accurately projecting the responses of soil metabolic activities to climate change.

关键词： biotic factors carbon dynamics metabolic quotient microbial biomass soil enzymes soil respiration

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LOW CYCLE FATIGUE AND DEFORMATION BEhAVIOR IN AN 8090 Al-Li ALLOY

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Acta Metallurgica Sinica(English Letters) 1998年第1期11卷 1-11页

作者： S.h.Ai Y.q.Wu Z.G.wang Y.Zhang Chinese Acad of Sciences Shenyang China

Low cycle fatigue (LCF)tests under different total strain amplitudes have been conducted in order to ascertain the effect of precipitate sizes on LCF behavior of 8090 Al-Li alloy. A constant strain rate of 3×10-3s-1 and symmetrical triangular waveform were employed for all tests. It is found that the cyclic stress response of the alloy varied with the precipitate sizes and strain amplitudes. The materials in all conditions cyclically handen at first and the higher the strain amplitude, the greater the amount of hardening. The low cyclic flow stress is the highest in the peakaged condition. TEM and SEM observations demonstrated that cyclic stress-strain behavior and fracture mode of Al-Li alloy are closely related to an increase in the dislocation density and interaction between the precipitates and dislocations, sizes of δ particles and pricipitate free zone (PFZ) at grain boundaries.

关键词： Al-Li alloy low cycle fatigue aged condition

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DEFORMATION-INDUCED α2→γ TRANSFORMATION IN A hOT DEFORMED Ti-45A1-10Nb ALLOY

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Acta Metallurgica Sinica(English Letters) 1998年第1期11卷 19-24页

作者： J.G.wang L.CZhang G.L.Chen h.q.Ye Univ of Science and Technology Beijing Beijing China

high-resolution transmission electron microscope (hRTEM) was employed to investigate the deformation-induced α2→γ phase transformation phenomenon in a hot deformed Ti-45Al-10Nb alloy. Such a tronsformation can be nucleated either at α2/γ interfaces or at stacking faults on the basal planes of the α2 phase. The growth of deformation-induced γplate is accomplished by the motion of α/6 Shockley partials on alternate basal planes (0001)α2, and the α/6 Shockley partials move in coordination rather than sweep on (0001)α2 plane one by one. It appears that no atom transportation is involved in this stress-induced α2→γ transfromation.

关键词： intermetallic compound titanium aluminide Ti-45Al-10Nb alloy stress-induced phase transformation interface hRTEM

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ThE INVESTIGATION ON PLASMA ARC TREATMENT OF ChROMIUM PLATED ALLOY STRUCTURE STEEL

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 289-294页

作者： X.M.Fan J.W.huang K.h.wang q.Liu DepartmentofMaterialsScienceandEngineering NanjingUniversityofScienceandTechnologyNanjing210094China

The technology of plasma arc was used to modify the interface adhesion between c hromium coating and steel substrate. The interface microstructure was studied as a function of plasma arc processing parameters. Microstructure analysis was per formed by optical microscopy, scanning electron microscopy and electron probe. T he microhardness distribution along the depth of a cross-section of the chromium coating and the substrate was measured. The results show the energy density of transferred plasma arc is obviously higher than plasma non-transferred arc. The molten interface was obtained by plasma transferred arc. Interfaces between chro mium coating and steel substrate can be divided by plasma non-transferred arc in to three classes: non-molten, a little molten and molten. Good interface bonding was obtained by proper process parameters. The microhardness of chromium coatin g decreases with increasing energy density of plasma arc.

关键词： plasma transferred arc plasma non-transferred arc coating hard-

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Universal basis underlying temperature, pressure and size induced dynamical evolution in metallic glass-forming liquids

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Chinese Physics B 2024年第1期33卷 134-142页

作者：张华平范蓓蓓吴佳琦李茂枝 Department of Physics Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano DevicesRenmin University of ChinaBeijing 100872China Songshan Lake Materials Laboratory Dongguan 523808China Key Laboratory of quantum State Construction and Manipulation Renmin University of ChinaBeijing 100872China

The dramatic temperature-dependence of liquids dynamics has attracted considerable scientific interests and efforts in the past decades, but the physics of which remains elusive. In addition to temperature, some other parameters, such as pressure, loading and size, can also tune the liquid dynamics and induce glass transition, which makes the situation more complicated. here, we performed molecular dynamics simulations for Ni_(50)Zr_(50) bulk liquid and nanodroplet to study the dynamics evolution in the complex multivariate phase space, especially along the isotherm with the change of pressure or droplet size. It is found that the short-time Debye–Waller factor universally determines the long-time relaxation dynamics no matter how the temperature, pressure or size changes. The basic correlation even holds at the local atomic scale. This finding provides general understanding of the microscopic mechanism of dynamic arrest and dynamic heterogeneity.

关键词： metallic glass-forming liquids structure relaxation dynamical heterogeneity Debye–Waller factor

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EFFECT OF LASER INPUT ENERGY ON AuSn_x INTERMETALLIC COMPOUNDS FORMATION IN SOLDER JOINTS WITh DIFFER-ENT ThICKNESS OF Au SURFACE FINISh ON PADS

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Acta Metallurgica Sinica(English Letters) 2008年第3期21卷 183-190页

作者： W. Liu C.q. wang Y.h. Tian M.Y. Li Department of Electronics Packaging Technology State Key Lab of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China Shenzhen Graduate School of harbin Institute of Technology Shenzhen 518055 China

Formation of AuSnx intermetallic compounds （IMCs） in laser reflowed solder joints was investigated. The results showed that few IMCs formed at the solder/0. 1μm Au interface. Needlelike AuSn4 IMCs were observed at the solder/0.5μm Au interface. In Sn-2.0Ag-O,75Cu-3,0Bi and Sn-3.5Ag-O.75Cu solder joints, when the laser input energy was increased, AuSn4 IMCs changed .from a layer to needlelike or dendritic distribution at the solder/0.9μm Au interface. As for the solder joints with 4.0 μm thickness of Au surface finish on pads, AuSn4 , AuSnx, AuSn IMCs, and Au2Sn phases formed at the interface. Moreover, the content of AuSnx IMCs, such as, AuSn4 and AuSn2, which contained high Sn concentration, would become larger as the laser input energy increased. In the Sn-37Pb solder joints with 0.9 μm or 4.0 μm thickness of the Au surface finish on pads, AuSn4 IMCs were in netlike distribution. The interspaces between them were filled with Pb-rich phases.

关键词： Laser soldering Inlermetallics Au films

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Microstructure and mechanical properties of Mg-to-Al dissimilar welded joints with an Ag interlayer using ultrasonic spot welding

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Journal of Magnesium and Alloys 2020年第2期8卷 552-563页

作者： h.Peng D.L.Chen X.F.Bai P.q.wang D.Y.Li X.q.Jiang College of Engineering and Technology Southwest UniversityTiansheng Road 2Beibei DistrictChongqing 400715China Department of Mechanical and Industrial Engineering Ryerson University350 Victoria StreetTorontoOntario M5B 2K3Canada School of Materials and Energy Southwest UniversityTiansheng Road 2Beibei DistrictChongqing 400715China Department of Chemical and Materials Engineering University of AlbertaEdmontonAlberta T6G 1H9Canada

Lightweight ZEK100-0 Mg alloy and A16022-T43 Al alloy with an Ag interlayer were joined via ultrasonic spot welding(USW),focusing on the microstructural change and tensile lap shear strength of the welded joints in relation to welding ***/Al interface was superseded by Mg/Ag and Al/Ag interfaces,and unfavorable Mg门A-intermetallic compound was *** foil was observed to be intact in the nugget center,while it was broken or dissolved at the nugget edge at high welding energy *** diffusion layer at the Mg/Ag interface consisted of two distinctive sub-layers:Mg3Ag intermetallic compound adjoining Ag foil,and Mg3Ag-l-Mg eutectic structure adjacent to *** a thin diffusion layer consisting mainly of Ag3Al occurred al lhe Al/Ag *** tensile lap shear strength first increased,reached its peak value,and then decreased with increasing welding *** shear strength achieved in the present study was〜31%higher than that of the joint without *** failure occurred at all energy levels,with Ag foil particles or fragments being stuck on both Mg and Al sides due to its intense interaction with Mg and Al via accelerated diffusion during *** results obtained pave the way for the challenging dissimilar welding between Mg and Al alloys.

关键词： Magnesium alloy Aluminum alloy Ultrasonic spot welding Ag interlayer Microstructure Tensile lap shear strength

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畅通英语（第三版）基础教程 3版

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2014年

作者： h.q. Mitchell, J. Scott[]

本书包括12个单元，每单元包括3课内容，前两课注重词汇、会话、语法的学习和练习，第三课注重阅读、听力、口语和写作的综合训练。

ISBN: (纸本)9787040394276

本书包括12个单元，每单元包括3课内容，前两课注重词汇、会话、语法的学习和练习，第三课注重阅读、听力、口语和写作的综合训练。

关键词：英语

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The physical presence of gallstone modulates ex vivo cholesterol crystallization pathways of human bile

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Gastroenterology Report 2019年第1期7卷 32-41,I0002页

作者： Piero Portincasa Karel Jvan Erpecum Agostino Di Ciaula David q-h.wang Division of Internal Medicine Department of Biomedical Sciences and Human OncologyUniversity Medical SchoolBariItaly Department of Gastroenterology University Medical CenterUtrechtThe Netherlands Division of Internal Medicine Hospital of BisceglieASL BATBisceglieItaly Department of Medicine Division of Gastroenterology and Liver DiseasesMarion Bessin Liver Research CenterAlbert Einstein College of MedicineBronxNYUSA

Background:Cholesterol crystallization is an essential step toward gallstone *** model bile studies showed that competition occurs between the gallstone surface and the surrounding aqueous phase for cholesterol molecules available for crystallization,this has not been investigated in human ***:Fresh gallbladder bile was obtained during laparoscopic cholecystectomy from 13 patients with cholesterol(n紏10)or pigment(n紏3)*** cholesterol gallstones were collected from another two *** native and ultrafiltered bile with or without added gallstones was analysed by polarized light microscopy for the presence of arc-like and needle-like anhydrous cholesterol crystals and classic cholesterol monohydrate *** of the added stones was evaluated before and after 21 days of bile ***:In unfiltered bile,the presence of stones was associated with a trend towards less anhydrous cholesterol crystals,but significantly more aggregated cholesterol monohydrate *** ultrafiltered bile,the presence of stones tended to inhibit the formation of arc-like or needle-like crystals and was associated with significantly greater amounts of both platelike and aggregated cholesterol monohydrate *** 21 days of the incubation,stone weight was decreased in both unfiltered(–4.561.6%,P紏0.046)and ultrafiltered bile(–6.561.5%,P紏0.002).Bile from pigment-stone patients was clear in the absence of stones,but showed early appearance of plate-like and aggregated cholesterol monohydrate crystals in all samples to which cholesterol gallstones were ***:The physical presence of cholesterol gallstones in both native and filtered bile greatly influences cholesterol crystallization *** cholesterol monohydrate crystals increase,anhydrous cholesterol crystals tend to be *** of solid cholesterol crystals from the gallstone surface may explain these findings.

关键词： Bile cholesterol crystals cholesterol stones pigment stones polarizing light microscopy supersaturated bile

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Current diffusion and efficiency droop in vertical light emitting diodes

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Chinese Physics B 2019年第1期28卷 561-569页

作者： R q Wan T Li Z q Liu X Y Yi J X wang J h Li W h Zhu J M Li L C wang State Key Laboratory of high Performance Complex Manufacturing College of Mechanical and Electrical EngineeringCentral South University Semiconductor Lighting Technology Research and Development Center Institute of SemiconductorsChinese Academy of Sciences College of Materials Science and Opto-Electronic Technology University of Chinese Academy of Sciences

Current diffusion is an old issue, nevertheless, the relationship between the current diffusion and the efficiency of light emitting diodes(LEDs) needs to be further quantitatively clarified. By incorporating current crowding effect(CCE) into the conventional ABC model, we have theoretically and directly correlated the current diffusion and the internal quantum efficiency(IqE), light extraction efficiency(LEE), and external quantum efficiency(EqE) droop of the lateral ***, questions still exist for the vertical LEDs(V-LEDs). here firstly the current diffusion length L_s(I) and L_s(II) have been clarified. Based on this, the influence of CCE on the EqE, IqE, and LEE of V-LEDs were investigated. Specifically to our V-LEDs with moderate series resistivity, L_s(III) was developed by combining L_s(I) and L_s(II), and the CCE effect on the performance of V-LEDs was investigated. The wall-plug efficiency(WPE) of V-LEDs ware investigated finally. Our works provide a deep understanding of the current diffusion status and the correlated efficiency droop in V-LEDs, thus would benefit the V-LEDs' chip design and further efficiency improvement.

关键词： efficiency droop vertical light emitting diodes current crowding effect current blocking layer

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