两种体系核空气净化系统性能评价试验方法的融合应用

国内开展核空气净化系统性能评价的行业标准是在参考美国、法国两种体系标准的基础上,结合国内的工程实践经验起草的;实际应用中,一般情况下只是采用单一体系内的试验方法开展性能评价试验;本工作结合应用实践提出,将两种标准体系的试验方法灵活地进行融合应用或互相补充,可更好地适应核设施核空气净化系统的特征,对核设施管理的要求和对人员防护的需要等都是必要的和可行的。     

低压离子色谱柱后偶合化学发光测定蔬菜中碘离子

以NaNO3作洗脱液,碘离子经低压离子色谱柱分离与KIO4反应后,再与鲁米诺发生化学发光。经试验测定碘离子浓度在8.0×10-5~5.0×10-8g/mL范围内与发光强度呈良好的线性关系;检出限为8.0×10-9g/mL(3σ);相对标准偏差为0.8%。     

Capillary supercritical fluid chromatographic analysis of shark liver oils

The liver oils of six different shark species have been analyzed by supercritical fluid chromatography (SFC). The liver oils were from the species Pseudotriakis microdon (False catshark), Centroscymnus coelepsis (Portuguese dogfish), Centrophorus squanosus (Leafscalp gulper shark), Deanea calceus (Birdbeak dogfish), Etmopterus princips (Greater lantern shark), and Centroscymnus crepidater (Longnose velvet dogfish). The method was capable of direct quantitation of squalene and cholesterol, while quantitation of triacylglycerols, cholesterol esters, and diacylglycerol ethers required thin-layer chromatographic fractionation prior to SFC analysis. The iodine values of the liver oil samples gave a linear correlation when plotted against the squalene content found by SFC. The variation of squalene content within one shark species is large, and there are large differences in squalene content from species to species. The squalene contents varied between 0.22 and 82.54 wt%. The identity of the glycerol ethers was investigated by SFC of the unsaponifiable matter. The major glycerol ethers contained chimyl, batyl, and selachyl alcohol.     

浅埋近距离煤层群工作面上隅角贫氧致因及综防技术

我国神东、平朔、大同煤田赋存着大量浅埋近距离煤层群,浅埋近距离煤层群具有煤层埋藏浅、煤层间距近等特点,在开采扰动下,层间易产生裂隙形成漏风通道,当地表空气进入上覆采空区,易引起上覆采空区遗煤自燃,间接影响下层煤开采过程中工作面上隅角的氧气浓度,造成贫氧现象。为了探究浅埋近距离煤层群工作面上隅角贫氧致因,提出防治贫氧的措施,以大恒煤矿91103综采工作面为研究背景,采用理论分析、CDEM数值模拟以及SF6示踪气体漏风测试等方法进行了研究。结果表明:地面裂缝、沉积现象明显;模拟煤岩损伤、破裂过程、裂隙发育,得出地表与上覆采空区、工作面贯通模型;利用连续定量释放SF6示踪气体在工作面进行漏风测定,测定结果验证了数值模拟中地表、上覆采空区以及工作面的贯通。工作面上隅角贫氧是由于浅埋赋存煤体破碎析出的低氧气体、采空区氧化衍生气体以及防灭火注入的惰性气体,在通风负压和大气压力的双重作用下,通过漏风通道进入工作面,加之U型通风方式的通风特点等多种因素共同造成的,其中工作面与地表贯通造成漏风严重是上隅角贫氧的主要致因。基于对贫氧致因的研究,大恒煤矿采用了井上下堵漏、安设风帘、埋管抽采、风机配合风筒等综合性防治措施,有效解决了工作面上隅角贫氧对安全生产的制约和影响,确保了工作面上隅角氧气浓度始终处于正常水平。     

Rapid and direct lodine value and saponification number determination of fats and oils by attenuated total reflectance/fourier transform infrared spectroscopy

A simple, rapid and reproducible method of determining the iodine value (IV) and saponification number (SN) for fats and oils was developed with an attenuated total reflectance/Fourier transform infrared spectrometer and commercially available triglycerides as calibration standards. Partial least squares was used to determine the spectral regions correlating with the known chemical IV and SN values, and the calibration set was augmented with additional standards generated by spectral co-adding techniques. The calibration model obtained was used to analyze commercially available fats and oils with a wide range of IV and SN values, and the results were compared to the values obtained by American Oil Chemists’ Society methods. With the spectrometer calibrated and programmed, IV and SN results could be obtained within 2–3 min per sample, a major improvement over conventional wet chemical methods.     

水质深度处理用活性炭的选择问题

该文从活性炭吸附容量及吸附速度与粒度的关系,以及吸附容量的条件出发,验证了活性炭的粒度与吸附水中有机物的负相关关系;碘值与亚甲蓝值之和与水处理的动态吸附容量的相关关系,从而指出在评价活性炭的吸附性能时,需要考虑其粒度对有机物去除的影响;要用碘值及亚甲蓝值之和,而不是将它们分开去评价活性炭吸附水中有机物的相关性。     

（C5H7N2O2）4（SiMo12O40）的合成、结构及催化氧化碘离子研究

采用常规水溶液法合成了一种新型的有机-无机杂化多金属氧酸盐（C₅H₇N₂O₂）₄（SiMo₁₂O₄₀）（简称SiMo-12）。采用红外光谱（IR）、热重分析（TG）、单晶和粉末X射线衍射（XRD）、元素分析等对SiMo-12进行了表征。以过氧化氢为氧化剂,运用SiMo-12催化碘离子氧化,考察了催化剂用量、氧化剂用量、pH、温度等因素对反应速率的影响。结果表明：该化合物属三斜晶系,P-1空间群,晶胞参数a=1.097 58（4） nm、b=1.144 88（4） nm、c=1.252 66（4） nm、α=64.665（1）°、β=64.804（1）°、γ=83.441（1）°、V=1.282 89（8） nm³、Z=1、R=0.034 0、wR₂=0.079 9。化合物由4个1-咪唑乙酸和一个经典的Keggin型[SiMo₁₂O₄₀]^4-单元组成,有机配体和多金属氧酸阴离子之间通过静电作用、质子转移以及氢键作用沿x轴形成一维链,链与链之间相互平行形成平行于xy面的二维层,层与层之间再通过氢键连接而得到三维网状结构。SiMo-12在催化碘离子氧化中表现出较为优异的催化活性,在c（SiMo-12）=2.0×10^-4 mol/L、c（过氧化氢）=2.0×10^-3 mol/L、pH=1.4、50 ℃条件下反应速率达到2.641 6×10^-5 mol/（L·s）,比未加催化剂时的反应速率提高了1 565倍。     

5-（2-噻吩）-2-对-甲苯基噁唑的合成

以2-溴-1-（2-噻吩）-1-乙酮和对-甲基苯甲胺为原料,在复合催化剂碘与叔丁基过氧化氢的作用下,通过氧化环合反应合成了5-（2-噻吩）-2-对-甲苯基噁唑。产物结构经FTIR,NMR 和MS检测。结果显示：合成产物的最佳条件为：2-溴-1-（2-噻吩）-1-乙酮1 mmol、对-甲基苯甲胺1.3 mmol、碘0.2 mmol、质量分数55%的叔丁基过氧化氢1.2mmol、碳酸氢钠1.0 mmol,室温下反应12 h,产物收率为89.7 %。抑菌圈测定结果显示该产物对大肠杆菌具有强的抑菌能力。     

氟硅酸中碘回收的氧化解吸实验研究

将氟硅酸中的碘氧化为I_2后采用热空气吹出,回收氟硅酸中的碘。对影响碘的氧化解吸的因素进行系统地分析,重点研究氧化剂次氯酸钠的用量、水浴温度、吸收时间等对碘分离率的影响。通过实验分析得出,碘的最佳解吸工艺条件为:氧化剂次氯酸钠用量1.2 mL/L,水浴温度80℃,气液混合时间12 min;在优惠工艺条件下碘分离率可达到74%以上。     

In situ observation of oxygen deficiency occurring during electron irradiation in high Tc superconductor YBa2Cu3Oy

The decreasing process of oxygen in YBa₂Cu₃O _y is investigated through high resolution electron microscopy (HREM) and convergent beam electron diffraction (CBED). Measurements of the axial length in HREM images show that oxygen content y decreases faster near a twin boundary than at the inner part of a twin lamella. The transformation from an orthorhombic to a tetragonal phase starts at a twin boundary and the transformed region propagates to an inner region of lamella. Lattice strains are observed near boundaries between transformed and non-transformed regions. The transformation is almost complete within 30 s during observation of HREM images at 400 kV and at room temperature. A value of y was quantitatively measured by analysing observed intensities of energy-filtered CBED patterns with the dynamical theory. The value of y decreases from 6.9 to 6.5 when 200 kV electrons are irradiated for 160 s in a microscope at 108 K. More precise analysis of the intensities provides information on charge distribution along the c -axis as well as local oxygen content at a spatial resolution of several nanometres.