ABO_3，A_2BO_4型复合氧化物催化剂用于CO，CH_4，NH_3完全氧

本文探讨了ＣＯ，ＣＨ＿４和ＮＨ＿３在ＬａＮｉＯ＿３，Ｌａ＿２ＮｉＯ＿４和ＬａＳｒＮｉＯ＿４三个催化剂上的氧化行为，并得出结论：对于ＣＯ氧化，关键步骤在于ＣＯ在催化剂表面上的络合活化。Ｎｉ￣（３＋）含量越高，越利于ＣＯ的络合活化。对于氨氧化，催化反应遵循氧化－还原机理。Ｎｉ￣（３＋）是主要的活性离子，晶格氧是主要活性氧种。对于ＣＨ＿４氧化，催化机理较复杂，只是发现Ａ＿２ＢＯ＿４型氧化物（Ｌａ＿２ＮｉＯ＿４，ＬａＳｒＮｉＯ＿４）比ＡＢＯ＿３型氧化物（ＬａＮｉＯ＿３）较利于ＣＨ＿４的氧化。     

有机化合物结构与性能的关系——激发能的同系线性规律

有机化合物的光谱及激发能存在着良好的同系线性规律。前文曾用HMO法对多联苯体系的同系线性规律进行了讨论,说明了对联多苯的共轭作用比间联多苯强,而后者共轭作用很弱,这可从光谱得到证实。近来,徐光宪等探讨了同系线性规律的量子化学基础,根据多烯中键长交替现象提出了MHMO法。     

关于气相渗透法仪器常数对分子量的依赖性

在热敏电阻装置不同的两种仪器上,对分子量为178—716的九种纯化合物,在苯、氯仿和丁酮中,和几个温度下测定了VPO仪器常数K值,在此分子量范围内,K值是常量。为了研究仪器结构对测试结果的影响,对分子量为1200—3.5×10~4的几个聚合物进行测试,所得结果很接近,并发现达到稳态所需时间和溶剂性质有明显的关系。     

Crystal and molecular structure of two new Schiff bases: Paeonol-ethylenediamine and paeonol-1,3-propylenediamine

Two new Schiff bases were prepared by the condensation reaction of paeonol with ethylenediamine (for compound 1) and 1,3-propylenediamine (for compound 2). The compounds were studied with single crystal X-ray diffraction method. Compound 1 is monoclinic, space group P2₁/c, a = 10.956(15) Å, b = 6.767(10) Å, c = 12.494(18) Å; β = 104.66(2)°, V = 896(2) ų, Z = 2. Compound 2 is triclinic, space group P-1, a = 6.878(2) Å, b = 12.141(4) Å, c = 12.414(4) Å; α = 101.023(6)°, β = 103.415(6)°, γ = 102.337(6)°, V = 952.8(6) ų, Z = 2. The molecular structures of 1 and 2 are similar; the molecule being centrosymmetric in 1 but asymmetric in 2.     

共轭亚麻酸的制备、表征和生物活性研究进展

近年来的研究发现共轭亚麻酸(CLN)具有多种非常有益的生理功能,已成为化学家、药理学家、营养学家争相研究的热点。本文就CLN的制备、表征、分离分析以及生物活性等方面,对国内外的研究进行了综述。CLN的制备包括化学法、生物法和天然产物提取法三大类。CLN的表征方法主要有紫外光谱、红外光谱、核磁共振等方法,以及采用气相色谱法(GC)、高效液相色谱法(HPLC)和毛细管电泳法(CE)等方法对合成的CLN混合物进行分离分析。CLN的生物活性主要有抗癌、降血脂、减肥、抗致癌等。     

Characterization of a pectic polysaccharide from the fruit of <Emphasis Type="Italic">Ziziphus jujuba</Emphasis>

A pectic polysaccharide was isolated from the fruits of Ziziphus jujuba Mill. cv. jinsixiaozao Hort. and its structure was characterized by acid hydrolysis, methylation, and NMR spectroscopies. The purified fraction Ju-B-7 had a molecular mass of over 2000 kDa. Chemical and spectroscopic analyses indicated that Ju-B-7 is composed mainly of α-1,4-linked D-galactopyranosyluronic acid and 1,2-linked L-rhamnose with a molar ratio of 8.1:1. It can significantly stimulate spleen cell proliferation in vitro (P<0.01, 10 μmg/mL). Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 311–312, July–August, 2007.     

金属锂二次电池锂负极改性

本文综述了金属锂二次电池中提高锂负极性能的研究进展。分别介绍了以下改性方法:对金属锂表面进行预处理,使其表面预先形成性能良好的固体电解质界面膜,或直接在其表面制备保护膜;在电解液中加入添加剂对锂电极进行表面改性;采用新型有机溶剂、离子液体、聚合物电解质、玻璃态固体电解质、塑晶固体电解质等电解质体系提高界面相容性;改进金属锂电极的制备工艺,如制备金属锂粉末多孔电极和电沉积锂电极、制备全固态薄膜锂电池以及利用物理方法处理锂电极。并在此基础上对今后的发展趋势进行了展望。     

Development of a Chromatographic Fingerprint of Tobacco Flavor by Use of GC and GC-MS

A new chromatographic fingerprinting method has been established for quality control of tobacco flavor. Three different extraction techniques, simultaneous distillation extraction (SDE), liquid–liquid extraction, and solid-phase microextraction were evaluated for isolation of the components of interest. After comparison of their performance, a combination of SDE and GC-MS was used for simple, reliable, and reproducible development of a chromatographic fingerprint of tobacco flavor. Twelve samples of the flavor from different batches were used to establish the fingerprint. Thirty-nine volatile components of the tobacco flavor samples, accounting for 86.54% of the total content, were identified and quantified. The 12 samples had 28 peaks in common. The method of fingerprint analysis was then validated on the basis of the relative retention times and relative peak areas of the common peaks, sample stability, and similarity analysis. The similarities of the 12 samples of tobacco flavor were >0.80, showing that samples from different batches were, to some extent, consistent. The chromatographic fingerprint developed was successfully used to differentiate tobacco flavor samples from tobacco extract prepared from tobacco leaf, both by similarity comparison and by principal-components projection analysis. The method can be used for quality control of tobacco flavor.     

荧光法对光诱导野生型肌红蛋白和突变体(D44K)去氧的对照研究

用荧光法对光诱导野生型肌红蛋白(Mb)和突变体(D44K)去氧的过程进行对照研究。发现430nm是研究Mb(WT)和Mb(D44K)光照去氧的最佳激发波长。430nm激发时,Mb(D44K)在597.9nm和628.8nm处出现两个荧光发射峰,不同于Mb(WT)仅在597nm处出现一个荧光发射峰。经研究证明,628.8nm处荧光峰是Mb3 -H2O型中的H2O峰。光照也使此峰的荧光强度下降,但比去氧的速率慢。研究发现,597nm处Mb(D44K)的荧光效率比Mb(WT)的荧光效率低。传能实验表明Mb表面44位氨基酸由天冬氨酸突变为赖氨酸后,不影响Mb(D44K)中色氨酸和酪氨酸残基传递给铁卟啉的荧光效率,但使Mb(D44K)中色氨酸和酪氨酸残基的荧光效率变高。     

贵金属甲烷燃烧催化剂*

贵金属催化剂具有较高的甲烷燃烧活性,但是其弱的稳定性抑制了其在VOC脱除以及低浓瓦斯治理等领域的应用,因此提高贵金属甲烷燃烧催化剂的稳定性是目前研究的热点。本文综述了活性组分、载体、助剂和前驱体对贵金属甲烷燃烧催化剂性能的影响;重点介绍了具有较高甲烷燃烧活性的Pd基催化剂受这些因素的影响;结合甲烷燃烧动力学分析了反应组分对催化剂性能的影响;讨论了催化剂失活的机理以及导致研究结论存在较大分歧的原因,提出了避免这些分歧的措施。