检索结果-南通市图书馆

维普期刊数据库博看期刊

Theoretical study on the reaction mechanism of ozone addition to the double bonds of keto-limonene

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2012年第1期24卷 147-151页

作者： Lei Jiang yisheng xu Baohui Yin Zhipeng Bai College of Environmental Sciences and Engineering Peking UniversityBeijing 100871China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China

The reaction mechanism of ozone （O 3） addition to the double bonds of gas phase keto-limonene was investigated using ab initio *** different possibilities for O 3 addition to the double bond were considered and two corresponding van der Waals complexes （Complex 1 and Complex 2） were found for 1-endo and *** rate constants were calculated using the transition state theory at the CCSD（T）/6-31G（d）＋ CF//B3LYP/6-31G（d,p） *** high-pressure limit of the total rate constant at 298 K was 3.51×10-16 cm 3/（molecule·sec）,which was in a good agreement with the experimental data.

关键词： keto-limonene O3 transition state theory

超临界二氧化碳介质中晶圆清洗与选择性刻蚀研究进展

在线全文

学校读者我要写书评

暂无评论

化工学报 2024年第1期75卷 110-119页

作者：张泽欣郑伟中徐益升胡冬冬卓欣宇宗原孙伟振赵玲华东理工大学化学工程联合国家重点实验室上海200237

随着集成电路特征尺寸的逐渐减小,器件结构会要求更高的纵横比,常规湿法清洗由于表面张力很难进入晶圆深沟槽结构内部,不能满足更细线条工艺要求和高深宽比结构,直接影响沟槽内的污染物去除效果;常规湿法刻蚀各向异性差、结构坍塌严重... 详细信息

随着集成电路特征尺寸的逐渐减小,器件结构会要求更高的纵横比,常规湿法清洗由于表面张力很难进入晶圆深沟槽结构内部,不能满足更细线条工艺要求和高深宽比结构,直接影响沟槽内的污染物去除效果;常规湿法刻蚀各向异性差、结构坍塌严重、深沟槽刻蚀效果不明显;而等离子体干法刻蚀则存在刻蚀速率慢、光刻胶脱落和黏附、结构损伤、废气处理等一系列问题。超临界清洗和刻蚀技术是最具有前景的环境友好、无损伤技术,能够耦合刻蚀、清洗与干燥工艺为一体,且可以循环使用,安全环保,是晶圆制造过程中常规清洗和刻蚀的首选替代技术。综述了超临界二氧化碳中晶圆清洗与选择性刻蚀的研究进展,重点介绍了超临界二氧化碳共溶剂、微乳液体系在光刻胶剥离以及含硅基底选择性蚀刻中的应用,展望了超临界二氧化碳晶圆清洗和刻蚀存在的问题和发展趋势。

关键词：晶圆清洗晶圆刻蚀超临界二氧化碳超临界流体微乳液

聚苯乙烯/碳纳米管/纳米黏土导电复合材料的制备及性能

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

工程塑料应用 2024年第2期52卷 1-8页

作者：张汉杰王秋峰魏浩然王杰徐益升范传杰华东理工大学化工学院上海200237 南通君江材料科技有限公司江苏南通226000

为了考察纳米黏土(NC)的引入对碳纳米管(CNTs)在聚苯乙烯(PS)树脂基体中分散的影响,使用NC作为非导电填料,通过熔融共混工艺制备了PS/CNTs/NC导电复合材料,探讨了NC与CNTs的含量及密炼时间对PS/CNTs/NC复合材料导电性能和力学性能的影... 详细信息

为了考察纳米黏土(NC)的引入对碳纳米管(CNTs)在聚苯乙烯(PS)树脂基体中分散的影响,使用NC作为非导电填料,通过熔融共混工艺制备了PS/CNTs/NC导电复合材料,探讨了NC与CNTs的含量及密炼时间对PS/CNTs/NC复合材料导电性能和力学性能的影响规律。扫描电子显微镜分析表明NC的加入减少了CNTs在PS基体中的团聚现象,并促使CNTs在较低添加量下形成了导电网状结构。复合材料的电阻率表征结果表明,在相同的CNTs含量下随着复合材料中NC含量的增加,体系电阻率呈现出逐渐减小趋势,并且在低CNTs添加量下,NC的引入促使体系电阻率降低的现象更明显,随着密炼时间的增加,体系电阻率呈现进一步减小的现象;力学性能表征结果表明,PS/CNTs/NC复合材料的拉伸性能总体上随着CNTs和NC含量的增加而增大,并且随着密炼时间的增加,复合材料拉伸强度最高可增加50.2%。NC与CNTs的质量比为1∶1时,可获得具有良好导电性能的复合材料。

关键词：导电聚合物复合材料聚苯乙烯碳纳米管导电网络

Visible-light-induced hydrogenation of biomass-based aldehydes by graphitic carbon nitride supported metal catalysts

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2021年第5期6卷 715-724页

作者： Shenghong Dong Mingzhe Chen Jiarui Zhang Jinzhu Chen yisheng xu State Key Laboratory of Chemical Engineering East China University of Science and Technology130 Meilong RoadShanghai200237China Department of Chemistry College of Chemistry and Materials ScienceJinan UniversityNo.855 East Xingye AvenuePanyu DistrictGuangzhou511443China Key Laboratory of Biomass Chemical Engineering of Ministry of Education Department of Chemical and Biological EngineeringZhejiang University38 Zheda RoadHangzhou310027China

The plasmonic photocatalyst of Pd supported on graphitic carbon nitride(Pd/g-C3N4)exhibits excellent catalytic activity in photo-induced hydrogenation of biomass-based aldehydes with environmental benign reagents of formic acid(HCOOH)as proton source and triethylamine(TEA)as sacrificial electron *** chemical and configurational properties of the Pd/g-C3N4 were systematically analyzed with XRD,TEM and *** optimized conditions,27%yield of furfuryl alcohol with the corresponding turnover frequency(TOF)around 3.72 h^(-1) were obtained from furfural and TEA-HCOOH under visible-light irradiation by using Pd/*** research additionally reveals that Pd atom is the true catalytic active site for the hydrogenation and the photo-promoted reduction mainly occurs through noble metal nanoparticles(NPs)-induced effect of surface plasmon resonance(SPR).The photo-catalytic system of Pd/g-C3N4 thus demonstrates a green and effective method for the hydrogenation of biomass-based aldehydes with sustainable solar energy as a driven force.

关键词： Biomass Graphitic carbon nitride Green chemistry Hydrogenation Photocatalysis

Interactions of sulfuric acid with common atmospheric bases and organic acids: Thermodynamics and implications to new particle formation

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2020年第9期32卷 130-140页

作者： Yunfeng Li Haijie Zhang Qingzhu Zhang yisheng xu Alexey B.Nadykto Environment Research Institute Shandong UniversityQingdao 266237China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental ScienceBeijing 100012China Department of Applied Mathematics Moscow State University of Technology“Stankin”Moscow 127994Russia

Interactions of the three common atmospheric bases,dimethylamine((CH3)2 NH),methylamine(CH3 NH2),ammonia(NH3),all considered to be efficient stabilizers of binary clusters in the Earth’s atmosphere,with H2 SO4,the key atmospheric precursor,and 14 common atmospheric organic acids(COAs)(formic,acetic,oxalic,malonic,succinic,glutaric acid,adipic,benzoic,phenylacetic,pyruvic,maleic acid,malic,tartaric and pinonic acids)have been studied using the density functional theory(DFT)and composite high-accuracy G3 MP2 *** thermodynamic stability of mixed(COA)(H2 SO4),(COA)(B1),(COA)(B2)and(COA)(B3)dimers and(COA)(H2 SO4)(B1),(COA)(H2 SO4)(B2)and(COA)(H2 SO4)(B3)trimers,where B1,B2 and B3 refer to(CH3)2 NH,CH3 NH2 and NH3,respectively,have been investigated and their impacts on the thermodynamic stability of clusters containing H2 SO4 have been *** investigation shows that interactions of H2 SO4 with GOA,(CH3)2 NH,CH3 NH2 and NH3 lead to the formation of more stable mixed dimers and trimers than(H2 SO4)2 and(H2 SO4)2(base),respectively,and emphasize the importance of common organic species for early stages of atmospheric *** also show that although amines are generally confirmed to be more active than NH3 as stabilizers of binary clusters,in some cases mixed trimers containing NH3 are more stable thermodynamically than those containing CH3 *** study indicates an important role of COA,which coexist and interact with that H2 SO4 and common atmospheric bases in the Earth atmosphere,in formation of stable prenucleation clusters and suggests that the impacts of COA on new particle formation(NPF)should be studied in further details.

关键词： bases particle atmospheric

Formation mechanism of typical aromatic sulfuric anhydrides and their potential role in atmospheric nucleation process

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第1期123卷 54-64页

作者： Haijie Zhang Rui Gao Hong Li Yunfeng Li yisheng xu Fahe Chai State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China

Sulfuric anhydrides,generated from the cycloaddition reaction of SO3with carboxylic acids,have been revealed to be potential participants in the nucleation process of new particle formation(NPF).Hence the reaction mechanisms of typical aromatic acids(benzoic acid(BA),phenylacetic acid(PAA),phthalic acid(PA),isophthalic acid(mPA),and terephthalic acid(PTA))with SO3to generate the corresponding aromatic sulfuric anhydrides were investigated by density functional theory calculations at the level of M06-2X/6-311++G(3df,3pd).As a result,these reactions were found to be feasible in the gas phase with barriers of 0.34,0.30,0.18,0.08 and 0.12 kcal/mol to generate corresponding aromatic sulfuric anhydrides,*** thermodynamic stabilities of clusters containing aromatic sulfuric anhydrides and atmospheric nucleation precursors(sulfuric acid,ammonia and dimethylamine)were further analyzed to identify the potential role of aromatic sulfuric anhydrides in *** the thermodynamic stability of a cluster depends on both the number and strength of hydrogen bonds,the greater stability of the interactions between atmospheric nucleation precursors and aromatic sulfuric anhydrides than with aromatic acids make aromatic sulfuric anhydrides potential participators in the nucleation process of ***,compared with BA,the addition of a-CH_(2)-functional group in PAA has little influence on the reaction barrier with SO3but an inhibitive effect on the thermodynamic stability of *** position of the two-COOH functional groups in PA,m PA and PTA does not have a consistent impact on the reaction barrier with SO3or the thermodynamic stability.

关键词： New particle formation(NPF) Sulfuric anhydride Reaction mechanism Atmospheric clusters Thermodynamic stability

Highly dispersed CeO_(2-x)nanoparticles with rich oxygen vacancies enhance photocatalytic performance of g-C_(3)N_(4)toward methyl orange degradation under visible light irradiation

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2022年第8期40卷 1255-1263页

作者： xuejun xu Tianhua Huang yisheng xu Huawen Hu Shuang Liao Xiaohong Hu Dongchu Chen Min Zhang School of Materials Science and Hydrogen Energy Foshan UniversityFoshan 528000China Guangdong Key Laboratory for Hydrogen Energy Technologies Foshan 528000China

CeO_(2)/g-C_(3)N_(4)photocatalysts have attracted tremendous attention in the photocatalytic degradation of organic *** design and construction of highly active CeO_(2)/g-C_(3)N_(4)photocatalysts without harsh conditions are still ***,highly dispersed CeO_(2-x)nanoparticles with rich oxygen vacancies were successfully precipitated on the surface of g-C_(3)N_(4)under mild *** fabricated CeO_(2-x)/g-C_(3)N_(4)exhibits remarkable activity and stability for photocatalytic degradation of MO *** optimal rate constant of MO degradation over CeO_(2-x)/g-C_(3)N_(4)is about 0.031 min^(-1),which is three times higher than that of g-C_(3)N_(4).A negligible activity decrease is observed after three cycling *** enhanced catalytic performance can be ascribed to the excellent dispersion of CeO_(2-x)with rich oxygen vacancies that benefit O_(2)adsorption and visible light *** addition,the proper band alignment between CeO_(2-x)and gC_(3)N_(4)is conducive to the highly efficient separation of photogenerated electron-hole pairs.

关键词： CeO_(2-x) G-C_(3)N_(4) Heterojunctions Oxygen vacancies Rare earths

Influence of zirconium addition on the microstructure and magnetic properties of nanocomposite Nd_(10.1)Fe_(78.2-x)Co_5Zr_xB_(6.7) permanent magnets

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2007年第3期26卷 218-221页

作者： FENG Shanshan NI Jiansen WANG Zhanyong WU yisheng ZHOU Bangxin xu Hui Institute of Materials Science Shanghai University Shanghai 20007 China

Nanocomposite Nd10.1Fe78.2-xCo5ZrxB6.7 （x= 0, 1.5, 2.5, 2.7, 3, 4） permanent magnets were prepared by melt-spun and annealing. The microstructure and magnetic properties of the permanent magnets were investigated. The resuits reveal that the addition of Zr element significantly reduces the grain size and improves the thermal stability of the amorphous phase. A fme nanocomposite microstructure with an average grain size of about 35 nm can be developed at a wheel speed of 16 m·s^-1 with the content of Zr up to 2.7 at.%. After optimal annealing （710℃ x 4 min）, the magnetic properties of the ***6.7 bonded magnets were achieved as follows： Br= 0.72 T, jHc = 769 kA·m^-1, and （BH）max = 85.0 kJ·m^-3.

关键词： magnetic properties Nd-Fe-B nanocomposite rare earths bonded magnet

Transient species in the ozonolysis of tetramethylethene

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2020年第9期32卷 210-216页

作者： Xiaolu Yang Jianguo Deng Dong Li Jianhua Chen yisheng xu Kai Zhang Xiaona Shang Qing Cao State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China School of Environment Tsinghua UniversityBeijing 100084China

The reaction of alkenes with ozone has great effect on atmospheric oxidation,its transient species can produce OH radicals and contribute to the formation of secondary organic aerosols(SOA).In the present study,the reaction of tetramethylethene(TME) with ozone was investigated using self-assembled low temperature matrix isolation *** TME and ozone were co-deposited on a salt plate at 15 K,and then slowly warmed up the *** first transient species primary ozonide(POZ) was detected,indicating that the reaction followed Criegee *** POZ began to decompose at 180 ***,secondary ozonide(SOZ) was not observed according to Criegee ***,Criegee Intermediate(CI) did not react with inert carbonyl of acetone,but with remaining TME formed tetra-methyl epoxide(EPO).

关键词： ozone transient slowly