UV-induced photodecomposition of 2, 2′, 4, 4′, 6, 6′-hexanitrostillbene (HNS)

HNS (2, 2′, 4, 4′, 6, 6′-hexanitrostillbene) is a heat-resistant photosensitive explosive widely used in the booster charge. Investigation of the photodecomposition mechanism may provide important information for controlling and enhancing the detonation performance, also for the lifetime prediction. The UV-induced photodecomposition of HNS has been subjected to experimental studies. The UV-Vis spectra, X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance spectra (EPR) demonstrate the formation of NO₂ free radicals and nitroso derivatives of HNS upon UV irradiation, which proves well known facts that C-NO₂ breaking and removal of oxygen from the nitro group take part in the photodecomposition of HNS.     

反相高效液相色谱法测定4, 4'-联苯二甲酸

建立了应用反相高效液相色谱测定4,4’-联苯二甲酸的方法。色谱柱采用Symmetry C18柱(150mm*4.6mm,5μm),在25℃,以乙腈和纯水为流动相等度洗脱,检测波长287.5nm,对4,4-联苯二甲酸进行分离与鉴定,样品在0.040 g/L-0.200 g/L浓度范围内与峰面积呈良好的线性关系(相关系数0.9992),测试相对偏差0.11%(n=6),平均回收率99.6%。     

4D技术,感官世界的盛宴

随着影音娱乐技术的发展和娱乐市场的需求,3D电影这种单单从视觉上吸引眼球的方式仿佛已经不能够满足现代人的审美,于是4D影院呼之欲出,不仅将震动、坠落、吹风、喷水、挠痒等特技引入3D影院,而且还根据影片的情     

4D技术,感官世界的盛宴

随着影音娱乐技术的发展和娱乐市场的需求,3D电影这种单单从视觉上吸引眼球的方式仿佛已经不能够满足现代人的审美,于是4D影院呼之欲出,不仅将震动、坠落、吹风、喷水、挠痒等特技引入3D影院,而且还根据影片的情     

CF4,CH4制备氟化非晶碳薄膜工艺研究

以CF4和CH4为源气体,用等离子体增强化学气相沉积(PECVD)方法制备了不同工艺条件下的氟化非晶碳(a-C∶F)薄膜.发现薄膜的沉积速率和射频功率几乎成正比关系,薄膜中氟的存在是导致薄膜具有紫外吸收特性的根本原因;用傅立叶变换红外光谱(FTIR)分析可知薄膜中有C-F基团的存在,使得薄膜的介电常数降低;合理控制沉积条件,可获得理想的电介质薄膜.     

Temperature dependence of the electrical conductivity in 4, 4′ bis(2-thenylideneamino)biphenyl and 4, 4′ bis(thenyldiphenyl-phosphinylmethyleneamino)biphenyl compounds

Correlation of the molecular structure and utilizing measurements of the electrical conductivity, activation energy of conduction of 4,4 bis(2-thenylideneamino)biphenyl (SB) and 4,4 bis(thenyl-diphenylphosphinylmethyleneamino)biphenyl (OPSB) compounds have been carried out. The results of the activation energies, obtained from the electrical conductivity measurements, as well as the energy gaps calculated from ultraviolet (u.v.) and visible spectra in the solid state indicate that the investigated compounds behave like semiconducting materials. The delocalized -electrons in addition to the lone pairs of electrons on the nitrogen atoms of the two compounds as well as the donor effect of diphenylphosphinyl groups of OPSB compound were considered as the main sources participating in the conduction processes.     

Study of 4, 4′-methylenebis-cyclohexanamine as a high temperature-resistant shale inhibitor

In order to develop high-performance water-based drilling fluid with the aim of meeting the increasing requirement of drilling industry, highly inhibitive and high-temperature-resistant shale inhibitors are essential. In this study, 4, 4′-methylenebis-cyclohexanamine was introduced as a potential shale inhibitor. The inhibitive properties of the amine compound in comparison with currently available polyether diamine inhibitor were evaluated using bentonite inhibition test, shale cuttings hot-rolling dispersion test, linear swelling test, and pressure transmission test. The inhibitive mechanism was investigated with zeta potential measurement, X-ray diffraction analysis, and contact angle measurement. The results indicated that 4, 4′-methylenebis-cyclohexanamine can inhibit shale hydration and dispersion effectively, and prevent pressure transmission to a certain extent, performing better than that of polyether diamine. Furthermore, the new diamine provides reliable thermal stability as high as 220 °C, preserving the benefits of high-temperature wells application. This novel diamine inhibits shale hydration and dispersion with the combination of chemical inhibition and physical plugging. The intercalation into the interlayer of clay with monolayer collapses the hydrated clay structure and expels the water molecules. After adsorption, clay surface became more hydrophobic, which prevents the imbibition of water. The variation of solubility separates the compound from the solution, which can plug the micro-pores of shale and prevent fluid invasion.     

ICP-MS法测定氢氧化钽中Mg,Fe,Cr,Zn 4种杂质

研究了直接采用ICP-MS的等离子体屏蔽技术(PS)测定高纯氢氧化钽中Mg,Fe,Cr,Zn 4种杂质元素的分析方法.实验了的仪器工作参数,用Co做内标补偿基体效应,方法的回收率在80%～130%之间,相对标准偏差均低于18.40%,检出限为0.01 ng/ml～0.56 ng/ml,测定结果与ICP-AES测定结果基本一致.     

锌合金ZZnAl4—1中Mg,Fe,Pb,Sn的光谱分析方法

本文法提供了将样品采用稀硝酸溶解，蒸干，在４００℃温度下灼烧成硝酸盐氧化物，研磨成细粉，以光谱纯碳粉作缓冲剂，用电弧激发试样进行分析，其准确度：Ｍｇ±４．４％，Ｆｅ±７．４％，Ｐｂ±２．７％，Ｓｎ±３．１％，现已用于生产分析。     

一种622Mbps,4∶1,SDH/SONET合路器

本文介绍了一种 6 2 2Mbps,4 :1 ,SDH SONET合路器 ,具有LVDS输入 ,PLL时钟合成。     

一种622Mbps,4:1,SDH/SONET合路器

本文介绍了一种622Mbps,4I,SDH/SONET合路器,具有LVDS输入,PLL时钟合成.     

Thermal properties and radiation damage in NaNH4XO4·2H2O single crystals (XO4=SO4,SeO4)

Differential thermal analysis (DTA) studies of NaNH₄SO₄·2H₂O, NaND₄SO₄·2H₂O, and NaNH₄SeO₄·2H₂O single crystals were performed in the temperature range of the ferroelectric-paraelectric phase transition and of the dehydration process. The first-order phase transition at the Curie point was confirmed for NaNH₄SO₄·2H₂O, whereas the transition in the isomorphous NaNH₄SeO₄·2H₂O at the Curie temperature was found to be similar to a contineous (second order) with considerable higher transition enthalpy. Dehydration process of the crystals studied was found to proceed in two stages, with maximum dehydration rates at 355 and 400K. A linear decrease in thermal energy related to the long-range ordering in NaNH₄SO₄·2H₂O crystals was observed with the dose of -cobalt-60 irradiation and discussed with respect to the radiation induced decrease in spontaneous polarization.     

Cathodoluminescence of Cd4SiS6 , Cd4SiSe6 , and Si-Doped CdS, CdSe, and CdTe Crystals

CdS, CdSe, and CdTe single crystals were vapor-phase-doped with the corresponding silicon chalcogenides under nearly equilibrium conditions. Cathodoluminescence studies revealed that the Si dopant produced new luminescence centers in the crystals. The cathodoluminescence spectra of Cd₄SiS₆and Cd₄SiSe₆crystals were measured. Metastable, sphalerite CdSSi and CdSeSi films were grown under highly nonequilibrium conditions. The maximum of edge emission in their spectra was redshifted as compared to the stable materials. The CdSSi and CdSeSi crystals were shown to be photosensitive.     

La(BO3,PO4):Ce,Tb,Gd的发光研究

以BPO4和稀土氧化物为原料制备了铈、铽、钇共掺杂的硼磷酸镧绿色荧光粉,研究了基质中Gd^3 、Ce^3 、Tb^3 的发光特性及它们之间的相互作用。在该基质中存在Ce^3 →Gd^3 、Gd^3 →Tb^3 、Ce^3 →Tb^3 的能量传递;当钆加入到铈、铽共掺杂的硼磷酸镧基质中会导致铈离子的发射减弱,铽离子^5D4→^7F1的发射显著增强,而^5D3→^7F1的发射没有明显变化,故有利于提高荧光粉的发光强度和绿色发射纯度。用硼磷酸钆作基质比用硼磷酸镧更能提高荧光粉的发光强度、发光纯度以及发光色坐标x的值,所以La(BO3,PO4):Ce,Tb,Gd和Gd(BO3,PO4):Ce,Tb均是理想的绿色发射材料。     

Crystal Structure,Luminescence, and Thermodynamic Properties of Pb10 – xEux(GeO4)2 + x(VO4)4 – x (x = 0.1, 0.2, 0.3) Substituted Apatites

Inorganic Materials - Pb10 – xEux(GeO4)2 + x(VO4)4 – x (x = 0.1, 0.2, 0.3) Eu-substituted lead germanatovanadates with the apatite structure have been prepared by solid-state reactions,...     

La(BO_3,PO_4):Ce,Tb,Gd的发光研究

以 BPO4和稀土氧化物为原料制备了铈、铽、钆共掺杂的硼磷酸镧绿色荧光粉,研究了基质中 Gd3＋、 Ce3＋、 Tb3＋的发光特性及它们之间的相互作用。在该基质中存在 Ce3＋→ Gd3＋、Gd3＋→ Tb3＋、 Ce3＋→ Tb3＋的能量传递;当钆加入到铈、铽共掺杂的硼磷酸镧基质中会导致铈离子的发射减弱,铽离子 5D4→ 7FJ的发射显著增强,而 5D3→ 7FJ的发射没有明显变化,故有利于提高荧光粉的发光强度和绿色发射纯度。用硼磷酸钆作基质比用硼磷酸镧更能提高荧光粉的发光强度、发光纯度以及发光色坐标 x的值,所以 La(BO3,PO4):Ce,Tb,Gd和 Gd(BO3,PO4):Ce,Tb均是理想的绿色发射材料。     

X-ray crystallographic data on aluminum silicon carbide, α-Al4SiC4 and Al4Si2C5

Single-crystal and powder X-ray crystallographic data on -Al₄SiC₄ and Al₄Si₂C₅ are given, and their respective space groups are P6₃ mc and R¯3m. Powder X-ray diffraction lines are individually indexed in the 2-range from 5° to 110°. The unit cell dimensions obtained from a least-square computer program are a=3.2771 Å (±0.0001 Å), c= 21.676 Å (±0.002) for -Al₄SiC₄ and a=3.2512 Å (±0.0002 Å), c=40.1078 Å (±0.0027 Å) for Al₄Si₂C₅. In addition, it is proposed that the crystal structures of -Al₄SiC₄ and Al₄Si₂C₅ may be formed by substituting SiC-layers for AIN-layers in the Al₅C₃N and Al₆C₃N₂ structures.     

AC and DC Conductivity Studies on Lead-Free Ceramics: Sr1–xCaxBi4Ti4O15(x = 0, 0.2, 0.4, 0.6, 0.8)

Sr_1–xCa_xBi₄Ti₄O₁₅ [x = 0, 0.2, 0.4, 0.6, 0.8] ceramics are synthesized by solid-state reactive technique. Structural analyses are done by x-ray diffraction data. Morphological studies were carried out by scanning electron microscope, and the data showed plate-like structures. To understand the conductivity mechanism, frequency and temperature dependency of AC and DC conductivity studies are carried out. The conductivity measurements are done using an impedance analyzer (Wayn–Kerr) in the temperature range 100–600°C. The frequency-dependent AC conductivity at different temperatures indicates that the conduction process follows the universal power law, and the hopping frequency shifts toward higher frequency side with increase in temperature, below which the conductivity is frequency independent. The variation of DC conductivity confirms that the ceramics exhibit negative temperature coefficient of resistance behavior at high temperature. DC conductivity values do not show any linearity with doping concentration; for a particular composition SCBT06, the DC conductivity was low.