Spectra of the ammonium radical: the schüler bands

The main bands of the Schüler system of ND₄ and NH₄ have been observed at high resolution. On the basis of these spectra, Watson, in a separate paper, has analysed the ND₄ main band showing that it represents a²F₂ → ² A₁ transition of a tetrahedral molecule. The observed wavenumber data for both ND₄ and NH₄ are presented; the latter have not yet been analysed. Isotopic bands for¹⁵ND₄,¹⁴ND₃H,¹⁴ND₂H₂,¹⁴NDH₃ have also been obtained and as previously pointed out confirm the assumed carrier of the spectrum. The much weaker bands accompanying the main Schüler band on the short and long wavelength sides are photographed at medium resolution. The interpretation of these bands in terms of the vibrational levels of upper and lower states is briefly discussed.     

Gas-Phase OH Oxidation of Monoterpenes: Gaseous and Particulate Products

Smog chamber experiments have beenconducted in which cyclic monoterpenes were oxidisedin the gas phase by OH. The evolved secondary organicaerosol (SOA) was analysed by LC-MSⁿ and thegas-phase products were analysed by FT-IR. Theconcentrations of the identified compoundscorresponded to carbon mass balances in the range of40%–90%. The identified compounds in the particularphase corresponded to 0.5%–4.2% of the reactedcarbon. The most abundant compounds in SOA fromterpenes with an endocyclic C=C double bond wereC₁₀-keto-aldehydes, C₁₀-keto-carboxylicacids, C₁₀-hydroxy-keto-carboxylic acids, andC₁₀-hydroxy-keto-aldehydes (pinonaldehyde,pinonic acid, hydroxy-pinonic acid isomers, andhydroxy-pinonaldehyde isomers from -pinene;3-caronaldehyde, 3-caronic acid, hydroxy-3-caronicacid isomers, and hydroxy-3-caronaldehyde isomers from3-carene). The most abundant compounds in SOA fromterpenes with an exocyclic C=C double bond wereC₉-ketones, C₉-dicarboxylic acids, andC₁₀-hydroxy-keto-carboxylic acids (nopinone,pinic acid, and hydroxy-pinonic acid isomers from-pinene; sabinaketone, sabinic acid andhydroxy-sabinonic acid isomers from sabinene).Decarboxylated analogues of most of the compounds werepresent in SOA in minor concentrations, such asC₉-keto-carboxylic acids (norpinonic acid,nor-3-caronic acid) and C₈-dicarboxylic acids(norpinic acid, nor-3-caric acid, norsabinic acid). InSOA from limonene, which contains an endocyclic aswell as an exocyclic C=C double bond, the mostabundant compounds were a C₁₀-keto-aldehyde andits oxo-derivative (limononaldehyde and keto-limononaldehyde) together with hydroxy-derivatives of aC₁₀-keto-carboxylic acid (isomers ofhydroxy-limononic acid). Also aC₁₀-keto-carboxylic acid (limononic acid) waspresent together with minor concentrations of aC₉-dicarboxylic acids (limonic acid), itsoxo-derivative (keto-limonic acid), and itsdecarboxylated analogue (norlimonic acid). Mechanisticpathways for the formation of these products, some ofwhich are identified here for the first time, areproposed.     

基于响应面法的鮟鱇活性肽制备工艺

鮟鱇是一种低脂肪高蛋白的优质海洋生物资源, 其氨基酸含量丰富, 蛋白质含量高达75.30%。本实验选用胰蛋白酶, 胃蛋白酶, 木瓜蛋白酶和菠萝蛋白酶水解鮟鱇鱼糜, 比较各酶解产物对1, 1-二苯基-2-三硝基苯肼(DPPH)自由基的清除率, 确定木瓜蛋白酶为最佳用酶。在单因素实验基础上进行响应面优化实验, 确定酶解反应的最佳条件为: 加酶量829.51 U/g, pH值7.37, 酶解温度47.09 ℃, 酶解时间5.86 h, 液固比5.79∶1。在最优条件下验证其DPPH自由基清除率为80.22%±0.63%, 接近预测值80.55%。经响应面法实验制备的鮟鱇活性肽粉末呈淡黄色, 具有较好的抗氧化活性, 其羟自由基清除能力的IC₅₀值为1.69 mg/mL, 可作为潜在的抗氧化剂。     

序贯紧线法在小儿多发性肛瘘术中的临床观察

目的：观察序贯紧线法在小儿多发性肛瘘术中的临床疗效。方法：将78 例多发性肛瘘患儿随机分为治疗组和对照组。在手术过程中,治疗组36例采用序贯紧线法一次性根治,对照组42例采用分期根治术治疗。观察2组的住院时间、治愈时间、术后疼痛程度、治愈情况、肛门功能评分及肛门畸形、肛门狭窄、复发情况。结果：与对照组比较,治疗组住院时间、治愈时间均缩短,差异均有统计学意义（P<0.01）;2组术后疼痛评分、治愈率、肛门功能评分及肛门畸形、肛门狭窄、复发例数比较,差异均无统计学意义（P＞0.05）。结论：序贯紧线法治疗能缩短小儿多发性肛瘘术后的住院时间及愈合时间,具有较好的临床疗效与安全性。     

高原环境因素与自由基反应

高原环境是一个特殊的生态环境系统,其复杂多变的自然地理条件使移居和新进高原环境的人群或生物出现高原反应或发生“高原(山)病”。大气压低、氧分压低、太阳辐射强所导致的氧化应激反应是高原反应或高原病的主要原因之一。本文从高原气候因素与自由基反应,不同海拔高度对不同民族人群自由基反应的影响,相同海拔高度不同人群的自由基反应,海拔高度与机体抗氧化营养物质变化的关系,不同海拔高度紫外线强度与自由基反应及高原环境地球化学异常与自由基反应等6个方面,论述了高原环境因素与不同人群自由基反应的关系,不仅对探讨环境应激反应所产生的自由基反应与世居高原地区人群起源和进化有重要意义,而且对研究移居人群高原反应和高原病的预防、治疗及经济、国防建设具有现实应用价值。     

Ce掺杂羟基铁插层蒙脱石的光催化性能研究

使用离子交换的方式制备了掺杂Ce的羟基铁插层蒙脱石,通过X射线粉末衍射分析(XRD)、红外光谱(FTIR)、X射线电子能谱(XPS)以及BET比表面积分析等测试手段对催化剂进行了表征。在不同实验条件下,使用插层蒙脱石作为异相光助Fenton试剂,考查了催化剂在紫外光条件下降解活性艳蓝的光催化性能。实验结果表明,掺杂Ce能明显提高羟基铁插层蒙脱石的光催化效率。在活性艳蓝(KN-R)初始质量浓度ρ0(KN-R)=75mg/L,pH=3.0,H2O2初始浓度[H2O2]0=4.9mmol/L条件下,t=100min时,掺杂2%Ce的铁插层蒙脱石对活性艳蓝的降解率为99.5%。实验结果结合化学结构的分析表征探讨了Ce对催化效果的影响。     

石英玻璃原料矿的流体包裹体特征

研究不同产地石英玻璃原料矿中包裹体的显微形貌、均一温度及红外光谱特征，矿物加工成高纯石英粉后，在氢气保护高温电炉中溶制成石英玻璃。分析原料矿包裹体特征与石英玻璃气泡、羟基质量的联系，结果表明：高温下不爆破的流体包裹体是形成石英玻璃气泡的主要因素，包裹体中的水发子溶解于SiO2熔体中形成石英玻璃的残余羟基。     

Photooxidation of Methacrolein in Fe(Ⅲ)-Oxalate Aqueous System and Its Atmospheric Implication

Iron and oxalic acids are widely distributed in the atmosphere and easily form ferric oxalate complex (Fe(Ⅲ)-Ox). The tropospheric aqueous-phase could provide a medium to enable the photo-Fenton reaction with Fe(Ⅲ)-Ox under solar irradiation. Although the photolysis mechanisms of Fe(Ⅲ)-Ox have been investigated extensively, information about the oxidation of volatile organic compounds (VOC), specifically the potential for Secondary Organic Aerosol (SOA) formation in the Fe(Ⅲ)-Ox system, is lacking. In this study, a ubiquitous VOC methacrolein (MACR) is chosen as a model VOC, and the oxidation of MACR with Fe(Ⅲ)-Ox is investigated under typical atmospheric water conditions. The effects of oxalate concentration, Fe(Ⅲ) concentration, MACR concentration, and pH on the oxidation of MACR are studied in detail. Results show that the oxidation rate of MACR greatly accelerates in the presence of oxalate when compared with only Fe(Ⅲ). The oxidation rate of MACR also accelerates with increasing concentration of oxalate. The effect of Fe(Ⅲ) is found to be more complicated. The oxidation rate of MACR first increases and then decreases with increasing Fe(Ⅲ) concentration. The oxidation rate of MACR increases monotonically with decreasing pH in the common atmospheric water pH range or with decreasing MACR concentration. The production of ferrous and hydrogen peroxide, pH, and aqueous absorbance are monitored throughout the reaction process. The quenching experiments verify that ·OH and (O-·2) are both responsible for the oxidation of MACR. MACR is found to rapidly oxidize into small organic acids with higher boiling points and oligomers with higher molecular weight, which contributes to the yield of SOA. These results suggest that Fe(Ⅲ)-Ox plays an important role in atmospheric oxidation.