深黄被孢霉催化转化十八醇合成不饱和脂肪酸

深黄被孢霉催化转化十八醇合成不饱和脂肪酸在优化转化条件下所得产物分析表明,干细胞中含油脂47.5%,蛋白质31.5%,碳水化合物28.9%.十八醇转化率为67.2%,油脂选择性为30.6%,产率20.6%.油脂中脂肪酸的选择性为:棕榈酸4.00%,棕榈油酸0.81%,硬脂酸0.95%,油酸20.75%,亚油酸1.95%,亚麻酸2.19%.催化转化条件下的研究表明,底物浓度越低,油脂和不饱和脂肪酸的选择性越好,当十八醇质量分数为0.5%时,油脂和不饱和脂肪酸的选择性达到最大值;培养基pH为中性时,获得了最大的油脂选择性和收率;33℃时醇转化率达最大值88%,23℃油脂产率达最大值9.7%.Mg²⁺对不饱和脂肪酸的生成有显著影响,当培养基中[Mg²⁺]=25mmol/L时,获得了最大的油脂选择性(25.7%)和产率(17.6%).     

Δ6 去饱和酶催化合成γ-亚麻酸

报道了含△６去饱和酶的深黄被孢霉菌丝提取物催化亚油酸合成γ－亚麻酸．研究了辅酶、温度、时间等对γ－亚麻酸合成的影响．结果表明,反应温度降低,γ－亚麻酸的产率提高．在１０℃以下．γ－亚麻酸的产率达到最大值;苹果酸盐对该反应有明显促进作用．γ－亚麻酸的产率随体系ｐＨ增加而增加,且在ｐＨ＝７~８时产率较高;该反应需在分子氧存在下进行;ＮＡＤＰＨ,ＡＴＰ和ＣｏＡ是该反应的必需辅酶．在优化的反应条件下,γ－亚麻酸的产量达到０．２１ｍｇ/ｍＬ。     

△6γ去饱和酶催化合成γ—亚麻酸

报道了含△6去饱和酶的深黄被孢霉菌丝提取物催化亚油酸合成γ－亚麻酸，研究了辅酶，温度，时间等对γ－亚麻酸合成的影响。结果表明，反应温度降低，γ－亚麻酸的产率提高，在10℃以下，γ－亚麻酸的产率达到最大值；苹果酸盐对该反应有明显促进,γ－亚麻酸的产率随体系pH增加而增加。且在pH=7-8时产率较高；该反应需在分子氧存在下进行；NADPH，ATP和CoA是该反应的必需辅酶。在优化的反应条件下，γ－亚麻酸的疸这到.21mg/mL。     

负载量对K—Mo／γ—Al2O3合成醇催化剂性能及结构的影响

不同负载量硫化态Ｋ－ＭｏＯ３／Ａｌ２Ｏ３催化剂的合成醇活性结果表明，负载量由ＭｏＯ３／Ａｌ２Ｏ３＝０．０５增加至ＭｏＯ３／Ａｌ２ｏ３＝０．２５时，ＣＯ２总转化率逐渐下降，而醇的选择性由３％增加至５０％，负载量进一步增加至ＭｏＯ３／Ａｌ２Ｏ３／０．４５时，ＣＯ总转化率逐渐升高而低碳醇选择性保护不变。     

有机溶剂中脂肪酶催化酯交换反应的研究

对几种有机溶剂中猪胰脂肪酸催化的酯交换反应进行了研究，详细考察了反应温度、反应时间、反应物摩尔比、反应物中水含量和不同溶剂对反应性能的影响。结果表明：1．反应温度在313K左右时酶显示出最高催化活性。2．在实验条件下，反应进行72h后，转化率不再随反应时间的延长而变化，即反应达到平衡。3．酯／醇摩尔比的增大对反应转化率的影响较小。4．反应系统中水含量为0．5％－1．3％时，酶的催化活性最高。5．酶的催化活性随溶剂极性增大而降低。     

不同热裂解温度下ZSM-5对玉米秸秆催化热裂解烃类选择性影响

为探讨不同热裂解温度下ZSM-5对玉米秸秆催化热裂解特性及烃类选择性的影响,本研究利用TGA对比有无ZSM-5时玉米秸秆的热裂解失重曲线,利用Py-GC/MS对比玉米秸秆在450、500、550和600℃下的热裂解和催化热裂解产物分布。结果表明,ZSM-5的使用可以降低玉米秸秆最高分解速率时对应的热裂解温度,降低温度为23℃。未使用ZSM-5时,热裂解产物种类以及烃类选择性均随热裂解温度的升高不断增加,在600℃时,烃类选择性达到最高,为11.33%;使用ZSM-5后,烃类产率随热裂解温度的升高先增加后减少,在550℃时,烃类选择性达到最高,为29.24%。使用ZSM-5后,玉米秸秆催化热裂解主要产物中出现了甲苯、茚、萘、二甲基萘等烃类,甲苯的最高产率为4.76%,萘的最高产率为3.96%。     

生物质热裂解气中模型化合物萘的催化转化研究

在常压连续流动固定床反应器上, 以Ni-Pt/Al2O3为催化剂, 研究了水蒸气含量及反应温度对萘的催化转化反应性能的影响。实验发现，反应温度的升高不仅可以提高萘的转化率和CO、H2的产率, 而且可以改善CO的选择性, 但H2的选择性和积碳量降低；随着水蒸气含量的升高，萘的转化率、H2的产率以及H2的选择性均得到提高，但CO的产率和选择性、积碳量有所下降。此外, 随水蒸气含量的升高副产物苯的浓度增大，在反应温度为700 ℃左右时苯的浓度出现极大值。     

近临界下HZSM-5催化的甲苯歧化反应

用高压观测池通过可视观测确定了苯、甲苯和对二甲苯等二元系及三元系的临界性质以及甲苯歧化反应混合物临界性质随着反应进程的变化规律；在此基础上，分别研究了近临界区以及高温下以HZSM-5为催化剂的甲苯歧化反应。结果发现，在近临界区甲苯歧化反应的对二甲苯选择性最高，随温度的升高甲苯转化率明显增加，对二甲苯选择性下降。高温下压力对对二甲苯选择性没有影响，转化率随压力升高而提高。     

基于火花放电等离子体部分氧化重整二甲醚制氢研究

应用自制的多级式等离子体富氢气体制备装置，进行了二甲醚部分氧化重整制氢实验。实验结果表明，常温常压下二甲醚的转化率和氢产率随占空比的增大先增大后减小，当占空比为80%时最大值分别为87.6%和39.4%。随着电源电压的增加，放电能量和持续时间逐渐增加，转化率和氢产率逐渐增加。当反应器采用保温措施或对反应物进行加湿时，转化率和氢产率均有明显提高，同时制氢能耗下降，热效率有一定提高。实验过程中附着在电极上的积炭主要是由于氧气不足造成，随空醚比的增大，积炭明显减少。     

HZSM-5型分子筛硅铝比对一步法合成二甲醚的影响

以Cu/Zn/Al(摩尔比为6∶3∶1)甲醇合成催化剂与HZSM-5型分子筛混合，制备了一步法二甲醚合成催化剂。通过改用三种不同Si/Al摩尔比（摩尔比为25、38和50）的HZSM-5型分子筛，考察了催化剂中脱水组分（HZSM-5分子筛）的酸性对二甲醚合成的影响。结果表明，随着催化剂Si/Al摩尔比的降低，分子筛的酸性增强，使得CO单程转化率提高。当催化剂Si/Al＝38时，CO对二甲醚的选择性最高，可达到68.13％，其次是催化剂Si/Al＝50，选择性最差的是Si/Al＝25的催化剂。在553 K、 3 MPa和4 000 h－1的条件下，Si/Al＝25和Si/Al＝38的催化剂CO单程转化率和DME的选择性接近一致。在此条件下，两者的时空产率达到试验的最大值，分别为0.38 gDME/(gcat·h)和0.36 gDME/(gcat·h)，在试验范围内，一步法合成二甲醚催化剂最佳的Si/Al摩尔比为25。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.