13 research outputs found

    Pollution Characteristics and Ecological Risk of PBDEs in Water and Sediment from an Electronic Waste Dismantling Area in Taizhou

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    以台州某电子垃圾拆解工业园为圆心,在半径为16 km的范围内,由近及远设计了C(3 km)、S(5~10 km)和R(10~16km)三圈共30个采样点,研究了该区域水及沉积物中多溴联苯醚(PBDEs)的污染特征与生态风险.结果表明,水中PBDEs含量为9.4~57.2 ng·L~(-1),平均值为25.9 ng·L~(-1);沉积物中PBDEs含量为3.7~38 775 ng·g~(-1),平均值为2 779 ng·g~(-1);BDE-209均为主要成分.水及沉积物中PBDEs含量的空间分布态势均为:C圈>S圈>R圈,沉积物中PBDEs含量和离工业园区中心的距离呈极显著负相关(P S > R. Furthermore,the concentrations of PBDEs in sediments showed significant negative correlation against the distance from the industrial park( P < 0. 01). Compared with other regions around the world,the PBDEs contamination was more serious in the area,which indicated that e-waste dismantling activity was one of the significant sources for PBDEs pollution. It was estimated that a total of 30. 7 t PBDEs( including 28. 9 t BDE-209) was discharged into surrounding environment as a result of dismantling industrial activities in last 40 years. A preliminary ecological risk assessment for PBDEs in water and sediments was conducted by hazard quotient method. The results demonstrated that the Penta-BDEs in the center of e-waste dismantling area( a radius of 1. 5 km) was at particularly high risk level and could cause serious influence on the ecological safety and human health.环境保护公益性行业科研专项(201309047

    Pentagon-Fused Hollow Fullerene in C-78 Family Retrieved by Chlorination

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    通讯作者地址: Xie, SY (通讯作者), Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 3. Wuhan Univ, Dept Chem, Minist Educ, Key Lab Analyt Chem Biol & Med, Wuhan 430072, Peoples R ChinaC-78 is one of the most widely investigated higher fullerenes. Among its huge isomer family, only one non-IPR (IPR = isolated pentagon ring) cage, the C-2-symmetric C-#22010(78), was previously stabilized by endohedral derivatization. Here we report a new C-1-symmetric non-IPR hollow isomer, C-#23863(78), which was captured as (C78Cl8)-C-#23863 and then subjected to a regioselective substitution reaction with benzyl hydroperoxide to form C-#23863(78)(OOCH2C6H5)Cl-7. The structural connectivity of C-#23863(78), which contains a pair of fused pentagons, was confirmed by single-crystal X-ray diffraction analysis of the C-#23863(78)(OOCH2C6H5)Cl-7 molecule, which shares the same fullerene core with (C78Cl8)-C-#23863, support for the structure is provided by comparable IR measurements and computation. Theoretical studies suggest that the differences in C-Cl bond length, intermediate stability, and steric effects of the involved molecules account for the chemical regioselectivity of the substitution reaction.NNSF of China 20525103,20721001 ,20625516 973 Program 2007CB81530

    Chlorofullerenes featuring triple sequentially fused pentagons

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    通讯作者地址: Tan,YZ(通讯作者),Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 电子邮件地址: [email protected], [email protected] triple sequentially fused pentagons (TSFP) motif is one of the basic subunits that could be used for constructing fullerenes, but it violates the isolated pentagon rule (IPR) and has not been found in carbon cages to date. The properties of TSFP-incorporating fullerenes are thus poorly explored both theoretically and experimentally. Reported herein are four chlorinated derivatives of three different fullerene cages, all with the TSFP motif. X-ray crystallographic analyses indicate that the molecular strain inherent to the pentagon adjacency of a TSFP is significantly relieved upon exohedral chlorination, leaving one of the four pentagon fusion sites unsaturated and rendering the present derivatives chiral. This unique reactivity, in stark contrast to that of previously reported non-IPR fullerenes containing double fused pentagons or triple directly fused pentagons, can be rationalized by density functional theory calculations, and are expected to stimulate further studies of these new members of the fullerene family, both theoretically and experimentally.NNSF of China 20525103,20531050,20721001,20423002 20673088 973 Program 2007CB81530

    Two I-h-symmetry-breaking C-60 isomers stabilized by chlorination

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    通讯作者地址: Xie, SY (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] abiding surprise in fullerene science is that I-h-symmetric buckminsterfullerene C-60 (ref. 1) (I-h-C-60 or C-#1,812(60), the nomenclature specified by symmetry or by Fowler's spiral algorithm(2)) remains the sole C-60 species experimentally available. Setting it apart from the other 1,811 topological isomers (isobuckminsterfullerenes) is its exclusive conformity with the isolated-pentagon rule(3), which states that stable fullerenes have isolated pentagons. Although gas-phase existence of isobuckminsterfullerenes has long been suspected(4-7), synthetic efforts have yet to yield successful results. Here, we report the realization of two isobuckminsterfullerenes by means of chlorination of the respective C-2v-and C-s-symmetric C-60 cages. These chlorinated species, (C60Cl8)-C-#1,809(1) and (C60Cl12)-C-#1,804(2), were isolated in experimentally useful yields. Structural characterization by crystallography unambiguously established the unique pentagon-pentagon ring fusions. These distinct structural features are directly responsible for the regioselectivity observed in subsequent substitution of chlorines, and also render these unprecedented derivatives of C60 isomers important for resolving the long-standing puzzle of fullerene formation by the Stone-Wales transformation scheme(8-11).NNSF of China,20525103 ,20531050 ,20721001 , 20571062 ,20425312 973 Program 2007CB81530

    &gamma;-辐照高聚物的正电子湮没寿命谱研究

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    喷灌与地面灌溉条件下冬小麦籽粒灌浆过程特性分析

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    为比较喷灌和地面灌溉条件下冬小麦籽粒灌浆过程特性的差异,进而探讨喷灌对作物产量形成的影响机制,该研究以百农矮抗58为试验材料,采用大田试验的方法,应用Richards模型对喷灌和地面灌溉条件下冬小麦强势粒、弱势粒的籽粒灌浆过程进行了模拟。建立在Richards模型基础上的籽粒生长分析显示:与地面灌溉相比,喷灌处理使冬小麦强势粒、弱势粒的千粒质量均显著性提高。灌浆特征参数的比较表明,喷灌处理使冬小麦强势粒、弱势粒的起始势增强,到达最大灌浆速率的时间提前,平均灌浆速率和最大灌浆速率均增大。阶段灌浆特征参数的比国家自然科学(50909043);农业部作物需水与调控重点开放实验室开放(CWRR200905);河南科技学院青年骨干教师资助计划项目(060101

    ~(16)O+~(24)Mg反应全熔合激发函数的类共振结构

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    本工作用位置灵敏的△E-E望远镜系统,入射能量步长为1.0MeV,测量了55~90MeV~(16)O+~(24)Mg反应全熔合激发函数.实验结果表明,这个反应的全熔合激发函数不是平滑的,存在着宽结构.峰位在E_CM=34.2、37.8、40.6、43.8和46.6MeV.当E_CM>48MeV时,激发函数的结构消失了。The complete fusion excitation function for the 16O+24Mg reaction has been measured in the energy range of 55~90MeVwith the step of 1.0MeV using a position sensitive△E-E telescopy system. It shows that the fusion excitation function is not smooth and exhibits gross structure. Peaks are at ECM=34. 2, 37. 8,40. 6,43. 8 and 46. 6MeV. The resonancestructure of the excitation function vanishes when ECM is>48.0MeV.中国科学院七五重大课题,中国科学院科学基
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