西昌经久工业园区环境现状监测研究

以国标法为检测标准,对西昌经久工业园区区域地表水、环境空气主要污染指标进行检测与监测。通过现场监测、室内分析和数据处理表明:西昌经久工业园区区域地表水、环境空气主要污染指标达到国家环境要求。     

ARGO-YBJ detector simulation using GEANT4

‘G4argo＇, a GEANT4-based simulation package for the ARGO-YBJ detector, is described in this paper. C4argo incorporates in the simulation the true RPC time resolution and another 0.5 ns time uncertainty which is introduced from the offline calibration of TDC. In addition, the correct RPC geometry and the true materials for the ARGO-YBJ experimental hall are implemented. As a result, G4argo simulation shows a very good agreement with real data.     

Surface-enhanced Raman scattering substrates of high-density and high-homogeneity hot spots by magneto-metal nanoprobe assembling

Binary naoparticles composed of a superparamagnetic Fe(3)O(4) core and an Au nanoshell were prepared via a high-temperature hydrolysis reaction followed by seed-mediated growth. The nanoprobes render simultaneous dual functions of both fast magnetic response and local surface plasmon resonance. Using these nanoprobes, analyte molecules can be easily biologically captured, magnetically concentrated, and analyzed by surface-enhanced Raman scattering (SERS). Particularly, the complex particles were assembled under magnetic force direction into a SERS substrate. It was found to possess both a high enhancement factor (10(6)) and high homogeneity of "hot spot" distribution (fluctuation less than 20% for a 1 μm(2) area) with 4-aminothiophenol as the analyte.     

Influence of Different Substrates on Laser Induced Damage Thresholds at 1064nm of Ta2O5 Films

Ta2O5 films are prepared on Si, BK7, fused silica, antireflection （AR） and high reflector （HR） substrates by electron beam evaporation method, respectively. Both the optical property and laser induced damage thresholds （LIDTs） at 1064 nm of Ta2O5 films on different substrates are investigated before and after annealing at 673 K for 12 h. It is shown that annealing increases the refractive index and decreases the extinction index, and improves the O/Ta ratio of the Ta2O5 films from 2.42 to 2.50. Moreover, the results show that the LIDTs of the Ta2O5 films are mainly correlated with three parameters： substrate property, substoichiometry defect in the films and impurity defect at the interface between the substrate and the films. Details of the laser induced damage models in different cases are discussed.     

Si1-xGex合金半导体中CiCs和CiOi缺陷随Ge含量的变化

采用从头计算(ab initio)的方法对Si和Si1-xGex合金半导体材料中CiCs 缺陷的性质进行探讨,同时也对比调查了CiOi 缺陷在Si和Si1-xGex合金中的性质. 在不同Ge含量的Si1-xGex合金中CiCs和CiOi缺陷的结构都具有较好的稳定性;从能量学角度,Ge原子不能与C或O原子直接成键. CiCs缺陷的A型和B型结构在Si1-xGex合金中表现出的行为基本类似,但是A型结构随着Ge含量的增加形成能逐渐减小,结构越来越稳定,而B型结构的形成能先有所下降后逐渐增加;A型和B型结构的能量差值随着Ge含量的增加先在小范围内变化后迅速下降. CiOi缺陷形成能的变化特征较为复杂. 纯Si体系在1000K及以上温度的等温退火过程中,CiCs缺陷的A型结构会向B型结构转变;Si1-xGex合金在进行等温退火时CiCs缺陷的A型结构的变化特征与退火温度、Ge含量和Ge取代的位置等因素有关.     

Highly regioselective photodimerization of 1,4-dihydropyridines: An efficient synthesis of novel 3,6-diazatetraasteranes

Conventional photocycloaddition of 1,4-dihydropyridines does not afford novel head-to-head 3,6-diazatetraasteranes. Herein, we describe a highly regioselective method to synthesize 3,6-diazatetraasteranes via an intramolecular photodimerization of 1,4-dihydropyridines. First, the 1,4-dihydropyridines were tethered by phthaloyl to direct a proximate parallel arrangement in head-to-head orientation by the rotation of CC single bonds in solution. An intramolecular [2 + 2] photocycloaddition proceeded subsequently to give desired 3,6-diazatetraasteranes in high yield (92–97%) and excellent regioselectivity. Furthermore, two different 1,4-dihydropyridines can also be regiocontrolled by this strategy and produce polysubstituted 3,6-diazatetraasteranes via a cross-photodimerization in a concise and efficient way. In addition, this approach can provide direct access to other polysubstituted polyhedron scaffolds from 1,4-dihydropyridine analogues.     

Blue organic light-emitting supramolecular microfibers: the self-assembly of a 1,2,4-triazolo[1,5-a]pyrimidine derivative

The design and synthesis of 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-2-thioaceto-(2-fluorobenzyl) hydrazone (TPTH), which self-assembled into supramolecular microfibers with blue organic light-emitting properties, is reported. This is the first occurrence of the molecular self-assembly of 1,2,4-triazolo[1,5-a]pyrimidine derivatives.     

新型含硫(氧)肟醚衍生物的合成、杀虫活性及其结构活性关系研究

通过1-芳基含硫(氧)酮肟与相应的拟除虫菊醇卤化物在氢氧化钠和相转移催化剂条件下反应或1-芳基含硫(氧)酮肟与相应的拟除虫菊醇卤化物的三乙基季胺盐在氢氧化钠条件下反应, 合成了1-芳基含硫(氧)酮O-苄基肟醚C1～C96共96个化合物. 它们的结构经质谱, 1H NMR, IR和元素分析确证. 生物活性测定结果表明, 该类化合物对鳞翅目和同翅目害虫表现出显著活性, C74和C93对粘虫、叶蝉的活性[LC50/(mg•L－1)]分别为1.4, 0.63和0.31, 1.2. 优于对照药氰戊菊酯.