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Estimating the effects of meteorology on PM_(2.5) reduction during the 2008 Summer Olympic Games in Beijing, China

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Frontiers of Environmental Science & Engineering 2011年第3期5卷 331-341页

作者： Liu YANG ye wu Jerry M.DAVIS Jiming HAO School of Environment Tsinghua UniversityBeijing 100084China Office of Air Quality Planning and Standards Health and Environmental Impacts DivisionUS Environmental Protection AgencyRaleighNC 27513USA

Particulate pollution was a critical challenge to the promise of good air quality during the 2008 Beijing Olympic Games,which took place from August 8th to *** ensure good air quality for the Games,several temporary emission control measures were implemented in Beijing and surrounding *** particulate matter concentration decreased significantly during the Olympic period;however,it is difficult to distinguish the effectiveness of those control measures since meteorology also affects ambient PM_(2.5) *** this work,a multiple linear regression model based on continuous field monitoring at a roadside site was conducted to evaluate the effects of meteorology and emission control measures on the reduction of PM_(2.5) during the 2008 Olympic *** hourly data set was divided into two time periods,the no control period,June 22nd to July 4th,and the control period,July 28th to August *** response variable was PM_(2.5) and the meteorology covariates used in the model were hourly temperature,dew point temperature,wind speed and *** direction was not a significant predictor of PM_(2.5) levels in either the control or the no control *** the meteorologically-based regression coefficients from the two time periods,meteorology was found to contribute to at least a 16%reduction in PM_(2.5) levels in the roadside microenvironment;while the pollution control measures contributed to at least a 43%reduction in PM_(2.5) levels.

关键词： meteorology emission control measures Beijing Olympic Games PM_(2.5) linear statistical models

Influence of cooling rate on magneto-structural transition and magnetocaloric effect of Ni_(30)Cu)8Co_(12)Mn_(37)Ga_(13) alloy

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Journal of Iron and Steel Research International 2017年第7期24卷 711-717页

作者： Zhu-jun Jiang Yu-ye wu Jing-min Wang Cheng-bao Jiang School of Materials Science and Engineering Beihang University School of Physics and Nuclear Energy Engineering Beihang University

The influence of heat treatment with different cooling rates on phase transition behaviors and magnetocaloric effect is systematically *** in atomic order is induced by changing cooling rates,where ordered phase is obtained in the furnace cooled（FC）sample while disordered phase is reserved in the water quenched（WQ）*** coupled magneto-structural transition is detected in both samples but the characteristic temperature significantly shifts to lower temperatures with increasing atomic *** magnetic entropy change（ΔS_（mag））derived from magnetic field induced martensitic transformation is confirmed for both samples,and can be remarkably enhanced by the atomic *** largestΔS_（mag） of 20.9J/（kg·K）is obtained at 307.5Kunder 5Tin the FC sample.

关键词： Ferromagnetic shape memory alloy Heat treatment Martensitic transformation Magnetocaloric effect Cooling rate Magneto-structural transition

Thermoelectric performance of p-type zone-melted Se-doped Bi_(0.5)Sb_(1.5)Te_3 alloys

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Rare Metals 2018年第4期37卷 308-315页

作者： Ren-Shuang Zhai ye-Hao wu Tie-Jun Zhu Xin-Bing Zhao State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University

For zone-melted （ZM） bismuth telluride-based alloys, which are widely commercially available for solidstate cooling and low-temperature power generation around room temperature, introducing point defects is the chief approach to improve their thermoelectric performance. Herein, we report the multiple effects of Se doping on thermoelectric performance of p-type Bi0.5Sb1,5Te3-xSex ＋ 3 wt% Te ZM ingots, which increases carrier concentration, reduces lattice thermal conductivity and deteriorates the carrier mobility. As a result, the peak figure of merit （ZT） is shifted to a higher temperature and a high ZT 1.2 at 350 K is obtained, due to the reduced thermal conductivity and suppressed intrinsic conduction. Further, decreasing Sb content is followed to optimize the room temperature performance and a ZT - 1.1 at 300 K is obtained. These results are significant for designing and optimizing the thermoelectric performance of commercial Bi0.5Sb1.5Te3＋ 3 wt% Te ZM alloys.

关键词： Thermoelectric materials Bismuth telluride Zone melting Se doping Bi0.5Sb1.5Te3

Enhancing room-temperature thermoelectric performance of n-type Bi_(2)Te_(3)-based alloys via sulfur alloying

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Rare Metals 2021年第3期40卷 513-520页

作者： Feng Liu ye-Hao wu Qi Zhang Tie-Jun Zhu Xin-Bing Zhao State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China

Bismuth-telluride-based alloys are the best thermoelectric materials used in commercial solid-state refrigeration near room ***,for n-type polycrystalline alloys,their thermoelectric figure of merit(zT) values at room temperature are often less than1.0,due to the high electron concentration originating from the donor-like effect induced by the mechanical deformation ***,carrier concentration for better performance near room temperature was optimized through manipulating intrinsic point defects by sulfur *** alloying significantly decreases antisite defects concentration and suppresses donor-like effect,resulting in optimized carrier concentration and reduced electronic thermal *** hot deformation process was also applied to improve carrier mobility due to the enhanced *** a result,a high zT value of 1 at 300 K and peak zT value of 1.1 at 350 K were obtained for the twice hot-deformed Bi_(2) Te_(2.7)Se_(0.21)S_(0.09) sample,which verifies sulfur alloying is an effective method to improve thermoelectric performance of n-type polycrystalline Bi2 Te3-based alloys near room temperature.

关键词： Bismuth telluride Thermoelectric Point defect Sulfur alloying Hot deformation

Unactivated C(sp^(3))–H functionalization via vinyl cations

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Science China Chemistry 2022年第1期65卷 20-30页

作者： Xi-Jia Liu Yin Xu Conghui Tang Peng-Cheng Qian Long-wu ye Key Laboratory of Environmental Functional Materials Technology and Application of Wenzhou City College of Chemistry&Materials EngineeringInstitute of New Materials&Industry TechnologyWenzhou UniversityWenzhou 325035China Key Laboratory of Chemical Biology of Fujian Province State Key Laboratory of Physical Chemistry of Solid SurfacesCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Direct functionalization of inert C(sp^(3))–H bonds is a topic of immense contemporary interest and exceptional value in organic *** recent research has established a novel and practical protocol which features the engagement of vinyl cation species to functionalize C(sp^(3))–H *** discussion of the topic is arranged by the strategies to generate the reactive intermediates,including ionization of vinyl triflates,addition of electrophiles to alkynes,tandem cyclization of enynes or diynes,and decomposition ofβ-hydroxy-α-diazo *** review closes with a personal perspective on the dynamic research area of unactivated C(sp^(3))–H functionalization via vinyl ***,it will provide timely illumination and beneficial guidance for organic chemists who are interested in this *** continued development of the field is strongly anticipated in the future.

关键词： C(sp^(3))-H functionalization vinyl cation homogeneous catalysis cyclization

Facile Synthesis of α-Haloketones by Aerobic Oxidation of Olefins Using KX as Nonhazardous Halogen Source

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Chinese Journal of Chemistry 2020年第2期38卷 173-177页

作者： Zhibin Luo Yunge Meng Xinchi Gong Jie wu Yulan Zhang Long-wu ye Chunyin Zhu School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiangJiangsu 212013China State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen UniversityXiamenFujian 361005China

Summary of main observation and conclusion An operationally simple and safe synthesis of a-haloketones using KBr and KCI as nonhazardous halogen sources is *** involves an iron-catalysed reaction of alkenes with KBr/KCl using O2 as terminal oxidant under the irradiation of *** strategy avoids the risks associated with handling halo-contained electrophiles(Cl2,Br2/NCS,NBS).The process is tolerant to several functional groups,and extended to a range of substituted styrenes in up to 89%yield.A radical reaction pathway is proposed based on control experiments and spectroscopy studies.

关键词： substituted styrene conclusion

Simulation of Thermal Insulation of Top-Surface Slag Layers in Continuous Casting Mold

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Journal of Iron and Steel Research International 2011年第10期18卷 29-33页

作者： WANG Qiang wu ye-ming QIU Sheng-tao ZHAO Pei National Engineering Research Center of Continuous Casting Technology Central Iron and Steel Research Institute Beijing 100081 China

A computational model of thermal behavior of the top-surface slag layers in continuous casting mold was applied to interpret the thermal insulation of mold powder. The temperature drop of liquid steel caused by heat re moral at the interface of molten steel and slag in mold was proposed to evaluate the thermal insulation of mold slag. The calculation results show that slag consumption is one of important factor influencing the temperature drop, while the casting speed has no obvious effect on it. With the increase of slag consumption, the temperature drop is increased.

关键词： thermal insulation temperature distribution heat flux temperature drop

Efficient and Divergent Synthesis of Medium-Sized Lactams through Zinc-Catalyzed Oxidative Cyclization of Indoly Ynamides

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Chinese Journal of Chemistry 2020年第3期38卷 263-268页

作者： Hang-Hao Li Si-Han ye Yang-Bo Chen Wen-Feng Luo Peng-Cheng Qian Long-wu ye State Key Laboratory of Physical Chemistry of Solid Surfaces and Key Laboratory for Chemical Biology of Fujian Province College of Chemistry and Chemical EngineeringXiamen UniversityXiamenFujian 361005Chino Institute of New Materials&Industry Technology College of Chemistry&Materials EngineeringWenzhou UniversityWenzhouZhejiang 325035China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

An efficient zinc-catalyzed oxidative cyclization of readily available indoly ynamides has been developed,enabling rapid and practical access to a diverse array of valuable medium-sized lactams in mostly good to excellent yields with wide substrate *** addition,such an asymmetric synthesis has also been explored by employing the chiral substrate.

关键词： oxidative readily sized

Ring strain strategy for the control of regioselectivity. Goldcatalyzed anti-Markovnikov cycloisomerization initiated tandem reactions of alkynes

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Science Bulletin 2017年第5期62卷 352-357页

作者： Chao Shu Long Li Tong-De Tan Ding-Qiang Yuan Long-wu ye State Key Laboratory of Physical Chemistry of Solid Surfaces and The Key Laboratory for Chemical Biology of Fujian Province College of Chemistry and Chemical EngineeringXiamen University State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of Sciences

Gold-catalyzed nucleophilic addition to terminal alkynes has received considerable interest in the past decade, as this chemistry offers a highly efficient and regioselective way for CAC, CAH and CAX bond formation. However, such a nucleophilic addition mainly involves a Markovnikov addition. In this short review, the recent progress of the gold-catalyzed 5-endo-dig cycloisomerization-initiated tandem reactions by utilizing the steric strain in ring formation to achieve an anti-Markovnikov regioselectivity was reviewed, including the scope of reactions, mechanism and synthetic applications.

关键词： Gold Heterocycles Ring strain Cyclization Tandem reaction