席夫碱缓蚀剂对碳钢材料的缓蚀性能

采用失重法和电化学方法研究了2种席夫碱类缓蚀剂N,N′-二水杨醛基-1,2-乙二亚胺(SB-Ⅰ)和水杨醛基吡啶-2-亚胺(SB-Ⅱ)在1mol/L盐酸溶液中对A3碳钢的缓蚀性能。失重实验表明,SB-Ⅰ和SB-Ⅱ在1mol/L盐酸溶液中的浓度为20mmol/L时,缓蚀效率分别达85%和92%。经三电极体系极化曲线和交流阻抗谱测定实验表明,缓蚀性能是由于碳钢材料表面为缓蚀剂分子吸附所致,二者均属阴极型缓蚀剂。     

双苯并咪唑衍生物对N80钢的缓蚀效果

选用1,3-双(2-苯并咪唑基)丙烷(BBP),1,3-双(2-苯并咪唑基)-2-氧杂丙烷(DMDB),N,N-双(2-苯并咪唑亚甲基)胺(IDB),1,3-双(2-苯并咪唑基)-2-硫代丙烷(BBMS)4种结构相似的双苯并咪唑衍生物作为N80油管钢缓蚀剂。采用失重法和电化学极化测试分别考察了不同缓蚀剂的缓蚀性能及其与KI复配后在pH=4.5的饱和CO2溶液中对N80钢的缓蚀效果。结果表明,此系列双苯并咪唑衍生物在投加量较小的情况下即对N80钢均具有较好的缓蚀效果,且此系列缓蚀剂既抑制了阳极过程,又抑制了阴极过程,为混合型缓蚀剂。当1,3-双(2-苯并咪唑基)-2-硫代丙烷(BBMS)与KI复配后,缓蚀机理没有发生改变,且缓蚀率明显提高,其浓度均为2mmol/L时,缓蚀率高达95.09%。     

席夫碱缓蚀剂的合成及其对碳钢材料缓蚀性能

采用失重法和电化学方法研究了2种席夫碱类缓蚀剂N,N′-二水杨醛基-1,2-乙二亚胺（SB-Ⅰ）和水杨醛基吡啶-2-亚胺(SB-Ⅱ)在1 mol/L盐酸溶液中对A3碳钢的缓蚀性能。 失重实验表明,SB-Ⅰ和SB-Ⅱ在1 mol/L盐酸溶液中的浓度为20 mmol/L时,缓蚀效率分别达85%和92%。 经三电极体系极化曲线和交流阻抗谱测定实验表明,缓蚀性能是由于碳钢材料表面为缓蚀剂分子吸附所致,二者均属阴极型缓蚀剂。     

离子液体[Bmim]Cl在H2SO4中对Q235钢的缓蚀实验和理论分析

探究1-丁基-3-甲基-咪唑氯盐([Bmim]Cl)在H_2SO_4介质中对Q235钢的缓蚀性能,解决酸性环境在金属表面造成的腐蚀危害。采用静态缓蚀失重法、电化学法分析了不同浓度[Bmim]Cl对Q235钢的缓蚀性能。Q235钢表面形貌特征以及吸附行为分别采用了扫描电子显微镜(SEM)及吸附等温模型进行了分析。采用理论模拟计算分析了缓蚀剂分子在碳钢表面的缓蚀机理。结果表明,[Bmim]Cl为阴极主导的混合型缓蚀剂,随[Bmim]Cl浓度的增加,缓蚀效果越好,当[Bmim]Cl浓度为0.6 mol·L~(-1)时,缓蚀效率可达91%以上,等温吸附模型证明缓蚀剂分子可自发吸附在金属表面,符合Langmuir等温线。[Bmim]Cl通过化学键与Q235钢表面结合形成了以咪唑杂环为吸附中心、稳定化学吸附的单分子吸附层,且[Bmim]~+平行吸附于表面达到防腐蚀效果。[Bmim]Cl是一种性能优异的防腐蚀剂,能有效预防Q235钢在H_2SO_4介质中的腐蚀。     

诺氟沙星-铜（Ⅱ）-吡啶衍生物配合物的合成、表征及生物活性

诺氟沙星(NFA)(图1)(1-乙基-6-氟-1,4-二氢-4-氧代-7-(1-哌嗪基)-3-喹啉羧酸)是一种典型的喹诺酮类抗菌化合物,主要通过抑制DNA旋转酶和拓扑异构酶II使脱氧核糖核酸、核糖核酸及蛋白质的合成受到干扰,使细胞不能再进行分裂,而起杀菌作用,具有广谱抗菌性[1]。喹诺酮类药物是一类     

环糊精包合有机磷酸作为缓蚀剂的理论研究

采用分子模拟对三种有机磷酸(5-单磷酸腺苷(A)、羟基乙叉二磷酸(B)、2-磷酸基-1, 2, 4-三羧酸丁烷(C))及其与阳离子改性的β-环糊精(HPTEA-β-CD)形成的包合物作为缓蚀剂进行了理论研究,并通过失重法进行了实验验证.量子化学的计算结果表明,三种有机磷酸分子的反应活性主要集中在N、O、P等原子上,其中C分子的反应活性更强.同时采用分子动力学模拟HPTEA-β-CD包合A、B、C分子作为缓蚀剂在Fe(001)表面上的平衡吸附,结果表明C-HPTEA-β-CD的缓蚀效率最强.通过失重法分析,三种缓蚀剂对q²35碳钢均有良好的缓蚀性,其中C-HPTEA-β-CD的缓蚀效率最高,达到了91.50%,实验结果与理论计算的分析一致.     

高效液相色谱法测定药物制剂中诺氟沙星

诺氟沙星(Norfloxacin,简称 NFCX)的化学名为 1-乙基-6-氟-1,4-二氢-4-氧代-7-(1-哌嗪基)-3-喹啉羧酸,是一种氟喹诺酮类抗菌药,具有广谱的抗菌作用.鉴于其在医药上的应用价值,NFCX 含量的测定一直为人们所关注.目前该药的测定,中国药典采用非水滴定法[1],其方法操作繁琐,高浓度的乙酸对人体也有害.另外还有紫外分光光度法[2,3]、一阶导数紫外分光光度法[4,5]、火焰原子吸收光谱法[6]、流动注射在线过滤稀释原子吸收光谱法[7]等.也有用高效液相色谱法(HPLC)[8-10]测定,但这些方法多采用反相液相色谱法,使用多相混合流动相,试剂用量大,线性范围小.     

诺氟沙星-铜(Ⅱ)-TBZ/HPB配合物的合成、抗菌活性及与DNA作用

合成了2个新的配合物:[Cu(NFA)(TBZ)(H2O)](NO3).(H2O)0.5(1)和[Cu(NFA)(HPB)(H2O)]NO3(2)[NFA=1-乙基-6-氟-1,4-二氢-4-氧代-7-(哌嗪-1-基)-3-喹啉羧酸(诺氟沙星),TBZ=2-(噻唑-4′-基)苯并咪唑,HPB=2-(吡啶-2-基)-苯并咪唑]。用元素分析、摩尔电导率、红外光谱和紫外可见光谱等方法对配合物进行了表征;通过二倍稀释法研究了配合物对枯草杆菌、大肠杆菌和沙门氏菌的抑制作用;用电子吸收光谱、荧光光谱和粘度测定等方法研究了配合物与CT-DNA的作用。结果表明,这2种配合物均具有良好的抗菌活性,能以插入方式与CT-DNA结合,且抗菌活性与DNA结合能力大小一致:配合物21。     

丁酸氯维地平降解杂质的合成

以4-(2,3-二氯苯基)-1,4-二氢-2,6-二甲基-3,5-吡啶二羧酸(2-氰基乙基)（甲基）酯(5)为起始原料,合成了丁酸氯维地平的5种降解杂质：4-(2,3-二氯苯基)-1,4-二氢-2,6-二甲基-3,5-吡啶二羧酸单甲酯(A), 4-(2,3-二氯苯基)-1,4-二氢-2,6-二甲基-3-吡啶羧酸甲酯(B), 4-(2,3-二氯苯基)-2,6-二甲基-3,5-吡啶二羧酸单甲酯(C), 4-(2,3-二氯苯基)-2,6-二甲基-3,5-吡啶二羧酸（丁酰氧基甲基）（甲基）酯(D)和4-(2,3-二氯苯基)-2,6-二甲基-3-吡啶羧酸甲酯(E)。其中A由5水解制得;B由A脱羧制得;C由5氧化后再经水解制得;D由C和丁酸氯甲酯缩合制得;E由C脱羧制得,化合物结构经¹H NMR和MS（ESI）确证。     

蛋氨酸衍生物的合成及其缓蚀性能研究

本文合成了一种新型蛋氨酸衍生物酸洗缓蚀剂,运用红外光谱及核磁共振氢谱对其结构进行了鉴定。采用失重法和电化学法研究了在0. 5mol·L~(-1)硫酸介质中其对碳钢试片的缓蚀性能,并通过吸附等温模型对缓蚀机理进行初步的探讨。结果表明,蛋氨酸衍生物的缓蚀效率约为90%,整体用量适中,是一种有望得到良好应用的绿色缓蚀剂。电化学分析表明,蛋氨酸衍生物为混合型缓蚀剂,其通过增大金属表面的电荷转移电阻而降低电化学腐蚀速率。     

Furyl- and thienyl-silatranes and germatranes

We review our research on the synthesis and study of the physical and biological properties of furyl- and thienylgermatranes and -silatranes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 725–732, June, 1992.     

Review and patents and literature

The use of the insect cell/baculovirus expression system for producing recombinant proteins of bacterial, plant, insect, and mammalian origin has become widespread. The popularity of this eukaryotic expression system is due to many factors, including (1) potentially high protein expression levels, (2) ease and speed of genetic engineering, (3) ability to accommodate large DNA inserts, (4) protein processing similar to higher eukaryotic cells (e.g., mammalian cells), and (5) ease of insect cell growth (e.g., suspension growth). The following review of the literature discusses two engineering aspects of recombinant protein synthesis by insect cell cultures: bioreactor scale-up and insect cell line selection. Following this review patent abstracts and additional literature pertaining to expression of recombinant proteins in insect cell culture are listed.     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...     

微量元素与疾病诊断治疗的研究现状及展望

对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述，包括：微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。     

Preparation and photolysis of poly-p-ethylacrylophenone and poly-p-chloroacrylophenone and their copolymers with styrene and methyl methacrylate

Poly-p-ethylacrylophenone (PPEtAP) and poly-p-chloroacrylophenone (PPClAP) and their copolymers with styrene (PEtAP/S) and (PClAP/S) and with methyl methacrylate (PEtAP/MMA) and (PClAP/MMA) were prepared. Quantum yields of main-chain scissions at 366 nm at room temperature in benzene solution are of the same order as those of the unsubstituted polyacrylophenone and its copolymers. Substitution with chlorine and ethyl group in the para position compared to the unsubstituted polyacrylophenone and its copolymers leads to an increase of the lifetime for the n–π^* excited triplet state, as is evident from the measured quenching constants of photolysis. The low-temperature emission spectra of the copolymers are similar to the spectra of the model compounds in a polymer film. For the homopolymer, however, the character of the emission spectrum changes considerably.     

Concentrations and distributions of trace and minor elements in Chinese and Canadian coals and ashes

A total of 35 trace and minor elements including some of environmental significance were determined in each of a selection of 15 Chinese and 6 Canadian thermal coals and their ashes by using the SLOWPOKE-2 nuclear reactor facility of the University of Toronto. The concentrations and distributions of these constituents among the coals and their combustion products (viz. ash and volatile matter) are presented together with an interpretation of their significance in relation to the large scale combustion of these coals as thermal fuels in industrialized countries such as China and Canada. The detailed results showed wide variations in trace impurity concentrations (up to a factor of 100 and more) among the coals studied with few large differences between those of Chinese and Canadian origin except that the rare earths, Sc, Th, U, I, and Se were much higher in the former, other halogens, As and Na were lower. Values for elemental enrichment factors (EF) relative to normal crustal abundances indicated that only As(EF=13), Br(5.7), I(16), S(230), Sb(11) and Se(320) were appreciably enriched in coal. During static ashing at 750°C most of the halogens, S and Se were volatilized whereas most other inorganic constituents were highly retained and concentrated in the ash by factors of 6 to 11.     

Ground- and excited-state aromaticity and antiaromaticity in benzene and cyclobutadiene

The aromaticity and antiaromaticity of the ground state (S 0), lowest triplet state (T 1), and first singlet excited state (S 1) of benzene, and the ground states (S 0), lowest triplet states (T 1), and the first and second singlet excited states (S 1 and S 2) of square and rectangular cyclobutadiene are assessed using various magnetic criteria including nucleus-independent chemical shifts (NICS), proton shieldings, and magnetic susceptibilities calculated using complete-active-space self-consistent field (CASSCF) wave functions constructed from gauge-including atomic orbitals (GIAOs). These magnetic criteria strongly suggest that, in contrast to the well-known aromaticity of the S 0 state of benzene, the T 1 and S 1 states of this molecule are antiaromatic. In square cyclobutadiene, which is shown to be considerably more antiaromatic than rectangular cyclobutadiene, the magnetic properties of the T 1 and S 1 states allow these to be classified as aromatic. According to the computed magnetic criteria, the T 1 state of rectangular cyclobutadiene is still aromatic, but the S 1 state is antiaromatic, just as the S 2 state of square cyclobutadiene; the S 2 state of rectangular cyclobutadiene is nonaromatic. The results demonstrate that the well-known "triplet aromaticity" of cyclic conjugated hydrocarbons represents a particular case of a broader concept of excited-state aromaticity and antiaromaticity. It is shown that while electronic excitation may lead to increased nuclear shieldings in certain low-lying electronic states, in general its main effect can be expected to be nuclear deshielding, which can be substantial for heavier nuclei.