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Effects of Active Gases on Droplet Transfer and Weld Morphology in Pulsed-Current NG-GMAW of Mild Steel

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Chinese Journal of Mechanical Engineering 2021年第4期34卷 249-261页

作者： Guoqiang Liu xinhua tang Qi Xu Fenggui Lu Haichao Cui Shanghai Key Laboratory of Materials Laser Processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration Shanghai 200240China

The current research of narrow-gap gas metal arc welding(NG-GMAW)primarily focuses on improving the sidewall fusion and avoiding the lack-of-fusion ***,the high cost and operation difficulty of the methods limit the industrial *** this study,small amount of active gases CO_(2) and O_(2) were added into pure argon inert shielding gas to improve the weld formation of pulsed-current narrow-gap gas metal arc welding(NG-GMAW)of mild *** effects on droplet transfer and arc behavior were investigated.A high-speed visual sensing system was utilized to observe the metal transfer process and arc *** the proportion of CO_(2),being added into the pure argon shielding gas,changes from 5%to 25%,the metal transfer mode changes from pulsed spray streaming transfer to pulsed projected spray transfer,while it remains the pulsed spray streaming transfer when 2%to 10%O_(2) is *** CO2 and O_(2) are favorable to stabilizing arc and welding process.O_(2) is even more effective than CO_(2).However,O_(2) is more likely to cause slags on the weld surface,while CO_(2) can improve the weld appearance in some *** weld surface concavity in NG-GMAW is greatly influenced by the addition of active gas,but the weld width and weld penetration almost keep *** study proposes a new method which is beneficial to improving the weld bead formation and welding process stability.

关键词： Metal transfer Active gases Pulsed-current NG-GMAW Weld morphology

Raman Scattering and t-Phase Lattice Vibration of 3% (mole fraction) Y_2O_3-ZrO_2

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Journal of Materials Science & Technology 2004年第5期20卷 485-489页

作者： Xinglun tang and xinhua ZHENGSchool of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China Sch. of Mat. Sci. and Eng. Beijing Inst. of Technol. Beijing 100081 China

The Raman spectra of 3% (mole fraction) Y2O3-ZrO2 (3Y) are obtained at different temperature from 77 K to 853 K. The results show that 260 cm-1 Eg and 460 cm-1 Eg modes on the spectra shift toward lower wave number with the increase of temperature; meanwhile, the continuity of the Half Width at Half Maximum (HWHM) and wave number (frequency) of Raman bands are broken and t-phase only partially transforms to m-phase at 523 K. Based on the experimental results, this paper discusses the t-phase lattice vibration of 3Y and presents the images of vibration displacement of six Raman-active modes for t-phase of ZrO2. The analysis indicates that there are diversities existing in the displacement of the atomic vibration of Raman-active modes because of their different symmetries at various temperature, which leads to the different change tendencies of Raman bands. Furthermore, the abrupt changes of some Raman-active modes indicating the atomic displacement are assumed to be the condensations of phonon modes in the t→m phase transition.

关键词： Raman scattering Zirconia Phase transition Condensation of phonon

Enhanced U(Ⅵ) bioreduction by alginate-immobilized uranium-reducing bacteria in the presence of carbon nanotubes and anthraquinone-2,6-disulfonate

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Journal of Environmental Sciences 2015年第5期27卷 68-73页

作者： Weida Wang Yali Feng xinhua tang Haoran Li Zhuwei Du Aifei Yi Xu Zhang Civil and Environmental Engineering School University of Science and Technology Beijing National Key State Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences National University of Singapore Department of Civil and Environmental EngineeringCentre for Water Research

Uranium-reducing bacteria were immobilized with sodium alginate, anthraquinone-2,6-disulfonate（AQDS）, and carbon nanotubes（CNTs）. The effects of different AQDS-CNTs contents, U（Ⅳ） concentrations, and metal ions on U（Ⅳ） reduction by immobilized beads were examined. Over 97.5% U（Ⅵ）（20 mg/L） was removed in 8 hr when the beads were added to 0.7% AQDS-CNTs, which was higher than that without AQDS-CNTs. This result may be attributed to the enhanced electron transfer by AQDS and CNTs. The reduction of U（Ⅵ） occurred at initial U（Ⅵ） concentrations of 10 to 100 mg/L and increased with increasing AQDS-CNT content from 0.1% to 1%. The presence of Fe（Ⅲ）, Cu（Ⅱ） and Mn（Ⅱ）slightly increased U（Ⅵ） reduction, whereas Cr（Ⅵ）, Ni（Ⅱ）, Pb（Ⅱ）, and Zn（Ⅱ） significantly inhibited U（Ⅵ） reduction. After eight successive incubation-washing cycles or 8 hr of retention time（HRT） for 48 hr of continuous operation, the removal efficiency of uranium was above 90% and 92%, respectively. The results indicate that the AQDS-CNT/AL/cell beads are suitable for the treatment of uranium-containing wastewaters.

关键词： Uranium Carbon nanotubes(CNTs) Redox mediator Anthraquinone-2 6-disulfonate(AQDS) Immobilization

Determination of trace Pb(II), Cd(II) and Zn(II) using differential pulse stripping voltammetry without Hg modification

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Science China Chemistry 2013年第12期56卷 1749-1756页

作者： LIN Qi LIN HongMei ZHANG YuanHui RONG MingCong KE HuiXian tang xinhua CHEN Xi Key Lab of Global Change and Marine-Atmospheric Chemistry SOA Third Institute of Oceanography SOA Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen Standard Scientific Instrument Co. Ltd.

In this work,we reported a simultaneous determination approach for Pb(II),Cd(II)and Zn(II)atμg L 1concentration levels using differential pulse stripping voltammetry on a bismuth film electrode(BiFE).The BiFE could be prepared in situ when the sample solution contained a suitable amount of Bi(NO)3,and its analytical performance was evaluated for the simultaneous determination of Pb(II),Cd(II)and Zn(II)in *** determination limits were found to be 0.19μg L 1for Zn(II),and0.28μg L 1for Pb(II)and Cd(II),with a preconcentration time of 300 *** BiFE approach was successfully applied to determine Pb(II),Cd(II)and Zn(II)in tea leaf and infusion samples,and the results were in agreement with those obtained using an atomic absorption spectrometry *** Hg usage,the in situ preparation for BiFE supplied a green and acceptability sensitive method for the determination of the heavy metal ions.

关键词： bismuth film electrode differential pulse stripping voltammetry tea leaves tea infusion

Power and Strategy in the Techno-Politik Era

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Peace 2021年第2期 59-79页

作者： tang xinhua Institute of Contemporary International Relations

Today’s world is in a major historical converging period of a new round of deepening scientific-technological revolution and industrial change,and the profound evolution of the world’s great *** mass breakthroughs and integrated developments of new technologies are pushing human society into a brand new *** new scientific-technological revolution is profoundly reshaping the connotation and form of international *** power based on technology has become the pillar of supporting international power in other areas,and the competition and order-building around technological power will be the core of international strategic competition in the 21 st century,which will push international politics from the geopolitical era to the techno-political era and give birth to techno-political *** new strategic thinking and ideological reshaping of the United States become increasingly *** the framework of technological multilateralism,the United States is planning to develop technology alliances,building"hierarchical pyramid"structure of technological hegemony system,competing for control of new strategic space,and restructuring strategic deterrence capability and deterrence *** the context of techno-political strategy,systematic changes are taking place in international strategic thinking,theory,system,method and path,and a multi-domain integration of international strategic theoretical system needs to be constructed.

关键词： deepening breakthrough strategic

*** Clean Energy and Environmental Protection Drives Sustainable Global Development

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China Today 2015年第10期64卷 44-47页

作者： tang xinhua the China Institutes of Contemporary International Relations

COOPERATION between China and the *** clean energy and environmental protection is currently undergoing orderly progress under a new framework inaugurating a concerted model for addressing global climate change.

关键词： China-U.S.Cooperationon Clean Energy and Environmental Protection Drives Sustainable Global Development

For a Cleaner and Sustainable Future--China-U.S. cooperation on clean energy and environmental protection inaugurates a concerted model for addressing global climate change

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Beijing Review 2015年第39期58卷 30-31页

作者： tang xinhua

LP Amina is a North Carolina-based envi- ronmental engineering firm that provides DroDrietarv solutions for emission reduc-tions in coal- and gas-fired power plants. It developed a technology that prevents larger coal-dust particles from entering boilers, and so reduces the discharge of nitrogen oxides by 15 percent thereby significantly mitigating pol- lution from coal-fired power plants, while also increasing employment in the manufacturing indusby. The China-U.＆ Clean Energy Research Center （CERC） was founded in 2011.

关键词：清洁能源可持续发展气候变化环保合作燃煤发电厂北卡罗来纳州氮氧化物排放环境工程

新型基础设施在国家治理现代化建设中的功能研究

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中国科学院院刊 2021年第1期36卷 79-85页

作者：唐新华中国现代国际关系研究院科技发展研究中心北京100081

当今世界正处在百年未有之大变局和新科技革命深入发展的历史交汇期,党的十九届五中全会为国家治理现代化制定了总体远景规划,其中新型基础设施是实现国家治理现代化建设的重要基础。如何在推进新型基础设施建设中科学地协调科技、产业... 详细信息

当今世界正处在百年未有之大变局和新科技革命深入发展的历史交汇期,党的十九届五中全会为国家治理现代化制定了总体远景规划,其中新型基础设施是实现国家治理现代化建设的重要基础。如何在推进新型基础设施建设中科学地协调科技、产业、国家治理和国际战略等多种要素,从而激发出系统性、可持续的创新与发展效能是抓住当前新科技革命重大历史发展机遇的关键。文章以新型基础设施涉及的若干科技产业发展趋势判断为起点,研究了新型基础设施在构建现代化国家治理体系中的功能与作用,为国家治理现代化建设中的科技、产业与战略的协调发展路径提供了理论参考。

关键词：新型基础设施国家治理现代化新科技革命产业革命

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南水北调西线工程对长江上游水库发电的影响

水力发电学报 2010年第4期29卷 118-126,139页

作者：金勇唐新华清华大学水利水电工程系水沙科学与水利工程国家重点实验室北京100084

南水北调西线工程规划一、二期工程合并后,新一期调水工程从雅砻江、大渡河共调水80亿m3,二期工程从通天河调水80亿m3。本文对南水北调西线调水影响下的长江上游水库群运行作了分析,考虑了受西线影响的52座大型水库。调水使水库梯级的... 详细信息

南水北调西线工程规划一、二期工程合并后,新一期调水工程从雅砻江、大渡河共调水80亿m3,二期工程从通天河调水80亿m3。本文对南水北调西线调水影响下的长江上游水库群运行作了分析,考虑了受西线影响的52座大型水库。调水使水库梯级的发电量明显减少,雅砻江水系减少比例最大;调水对调节库容大的水库影响较大,龙头水库的运行状况对其水系发电和径流的影响显著,汛末不能蓄满时其水系电量损失更大;对受调水影响水库群的弃水作了分析,弃水主要发生于汛期,大渡河弃水最多,受调水影响最小;调水对减少水库群弃水有益,但调水后水库群发电损失较大。调水对三峡枢纽发电影响不大,长江上游所有规划水库修建后,西线调水160亿m3,三峡平均每年损失电量31.9亿度,约减少3.6%。此外又考虑了滇中调水工程,所有调水工程运行后,长江上游水库群年均电量总损失为870亿度。

关键词：南水北调西线工程水电开发三峡枢纽弃水分析滇中调水工程