热重分析测定脱附活化能分布研究

以脱附过程本征动力学模型为基础,提出了一种采用热重分析技术测定脱附活化能随吸附质分子表面覆盖率分布的方法。该方法通过一条热重分析曲线就可以得到清晰的脱附活化能关于覆盖率的函数表达式。采用所提出的方法,通过不同升温速率下的热重分析实验测定了芴和蒽在活性炭上脱附活化能的线性分布,结果表明覆盖率越高,脱附活化能越低。对芴和蒽,由于覆盖率上升,脱附活化能最大降幅达18.5%和15.1%。     

THE FORMING EQUATION FOR THE LAMELLAR LIQUID CRYSTAL

Based on the characteristics and composition of the lamellar liquid crystal, its forming equation was proposed for the first time. It was found that the predicted location and shape of a liquid crystalline region by the equation match well with experimental results. The predicted size of the region is greater lhan the experimentally determined one. The proposed forming equation for the lamellar liquid crystal provides a new tool lor determining the liquid crystalline region in multicomponent systems. This niav be useful in both basic theoretical research and industrial applications     

分布分数四则运算的新方法

基于代数法建立了溶液中同种物质不同型体分布分数四则运算的新方法。该方法仅需对PL及相关lgK进行少量加、减及以10为底的乘方运算。该方法简便、快速，计算结果的相对误差可预先设置，一般不超过5%。     

聚苯胺尿酸酶电极性能的研究

依据pH对聚苯胺尿酸酶电极最大响应电流的影响, logim～pH图表明尿酸酶电极的催化活性只与其电离基团的碱性形式有关. 扫描电镜的结果表明, 聚苯胺尿酸酶电极的稳定性与其制备方法有关. 电化学法固定的尿酸酶电极具有高的稳定性.     

制动器管裂纹原因分析

重型汽车制动器管在潮湿的环境中使用时发生破裂,采用化学成分分析、力学性能试验、断口分析和金相分析等方法对破裂的制动器管进行分析.结果表明,制动器管的裂纹主要产生于存在加工应力的弯曲部位,应力腐蚀是造成其破裂的主要原因.同时在选材方面提出建议.     

对一种蓝色染料影象的象质评价

本文对黑白胶片经过特殊的蓝色成象工艺加工后形成的影象的质量进行了客观评价。结果表明,用蓝色成象工艺,感光度、特性曲线直线部分的斜率γ、最大密度及调制传递函数在低空间频率的响应等,均较黑白影象有不同程度的改善和提高;分辨率基本相同;粒度有些增高;调制传递函数的高频响应变坏。这种成象工艺用于对空间频率上限要求不高的一些成象体系,如X射线照象是有利的。这与临床诊断的主观评价的结果一致。     

CUT-OFF FILTERS FOR THE NEAR ULTRAVIOLET

Abstract—A series of transmission curves of liquid and solid sheet filter materials in the 280–400 nm range is presented. These filters may be useful as cut-off filters for the near UV.     

THE QUANTUM YIELD FOR BILIRUBIN PHOTOISOMERISATION

Abstract— The difference extinction coefficient, dL₅₀₀, for the photoisomerisation of bilirubin (BR) bound to human serum albumin is determined, by isolation of the product, as 4000 1000 mol_-1 dm₃ cm_-1, This value is used with laser flash photolysis data to calculate the quantum yield for photoisomerisation as 0.2 +- 0.05 which allows the quantitative demonstration of the much higher efficiency of photoisomerisation compared with self sensitised photooxidation. Similar findings were made for BR in organic solvents and suggest that photoisomerising action is the major relaxation path for excited BR under a variety of conditions.     

TRANSITIONAL FIELD BEHAVIOUR FOR THE MATUYAMA-BRUNHES

Paleomagnetic study from Tongjing basalts, Shandong Province, China, provides a record of the transitional field behaviour for the Matuyama-Brunhes. Based on the record the transitional field configurations are studied. The reasons that make the virtual geomagnetic pole (VGP) at the low latitude are researched.     

红外光谱的分形特征

红外光谱可作为一种信号的功率谱,用富里叶分析来研究。同时,红外光谱的吸收峰并不是随频率呈周期性变化的,而是表现出一些混沌特征,因此其分子的振动随时间的变化,可看成一种混沌运动,其运动轨迹可能具有某种分形结构。因此,可用分形理论来研究分子的振动。本文把富里叶分析与分形理论结合起来,从整体的角度对红外光谱的分形特征作一些尝试性的探讨。     

EVIDENCE FOR THE EXISTENCE OF MEMBRANE-ASSOCIATED PHYTOCHROME IN THE CELL

Abstract Comparative fluorescence and photochemical studies of phytochrome in etiolated seedlings of maize and in soluble and membrane-containing fractions isolated from them were camed out. The membrane fractions prepared in the absence of Mg²⁺ from etiolated coleoptiles contained 13% of total photoreversible phytochrome, which was readily solubilized by mild detergents. Its molecular size was indistinguishable from soluble phytochrome and equal to nondegraded maize phytochrome. Low-temperature fluorescence studies with intact tissue found that the position of the emission maximum at 85 K (λ_max) and the extent of the phototransformation of the red-absorbing form (Pr) into the first stable photoproduct, lumi-R, at 85 K (γ₁), varied in different parts of etiolated seedlings: λ_max and γ₁ reached their maximum values in the tips of coleoptiles and roots, 686 nm and 0.30–0.40, whereas the lowest values, 682 nm and ca 0.05, were observed in the root base. These parameters correlated well with those obtained for the pigment in the soluble and membrane-containing fractions: 684 and 680 nm, and 0.33 and 0.06, respectively. The extent of the Pr phototransformation into the far red-absorbing form (Pfr) (γ₂) did not differ much: values of 0.80–0.85 and 0.70–0.75 correlated with the high and low values of γ₁. These variations of the parameters were interpreted in agreement with our previous observations in terms of two phytochrome A species whose relative concentrations vary depending on the experimental conditions—the longer wavelength bulk light-labile species with high γ₁ (Pr″), and the shorter wavelength minor light-stable species with low γ₁ (Pr″). Close similarity between Pr’and the soluble phytochrome and between Pr″ and the membrane-bound phytochrome points to the possible origin of the native Pr’and PrPrime; species, thus providing evidence for the existence of membrane-bound pigment in the cell.     

四(α-高歧化度烷氧基)酞菁合成关键步骤的研究

烷氧基邻苯二腈是酞菁合成的重要中间体,但高歧化度烷氧基邻苯二腈的合成由于副产物多,产率低下而成为此类酞菁应用的"瓶颈".文中对反应副产物进行了分离纯化,并利用红外、气质联用、1HMR和元素分析等测试手段对其进行了表征.且根据测试数据推导出了副产物结构式为1,2,1'2' 四腈基 3,3' 二苯基醚.这一副反应机制的阐明,对于寻求对主反应有利的条件,具有重要的意义.     

胶体颗粒大小的分布——Ⅱ.物理显影中胶体催化剂颗粒大小的分布函数

本文用对数正态分布对物理显影中常用的Au、Ag及Ag_2s胶体催化剂的颗粒大小的实验分布进行了拟合。理论分布与实验分布的比较表明:本实验条件下制备的十二组胶体溶液其颗粒大小都服从了对数正态分布,并且不依赖于胶体的组成、大小及制备方法。因此,它们很可能遵从了同样的成核成长规律。     

大气采样器计量标准的测量不确定度

对大气采样器计量标准的测量不确定度来源如计量标准、流量示值误差、流量重复性、温度计示值误差进行了分析和评定,计算得合成标准不确定度和扩展不确定度分别为0.65%和1.30%.对测量不确定度的合理性进行了验证.     

葡萄糖在KRPB生理缓冲溶液中电还原反应的研究

葡萄糖在ＫＲＰＢ生理缓冲溶液中电还原反应的研究朱庆存，姜力夫，郁章玉，陈常峰，周正宇（曲阜师范大学，电化学研究所，曲阜２７３１６５）关键词：葡萄糖，扩散系数，磷酸盐生理溶液。本文从葡萄糖在铂电极上的电氧化还原峰电流与ｐＨ值的线性关系，扩散系数与葡萄糖...     

光谱透射比标准物质的研究

研制了紫外、可见、近红外光谱区通用光谱透射比较标准物质。以高纯熔融石英为基片材料，镍铬合金的镀膜材料，采用双光楔对称光胶结构以消除同色杂散光的影响，对镀膜进行光胶处理以保证膜层的强度、稳定性及光学中性，采用高精度分光光度测量装置作为定值手段的以保证准确的定值，设计定位保护架以消除多次反射误差。该光度标准适用的光谱范围的200-2600nm，光谱透射比定值不确定度为0.5%。     

准圆周薄层色谱上行展开的研究

圆周薄层色谱能将样品展开为很细的谱线,具有较高的分辨能力,常用于分析一些难分离的物质。这种色谱方法过去只能采用水平展开方法。我们将普通薄层板修饰成特定形状,用最常见的上行展开法获得近似于圆周薄层的色谱。方法不需要特殊展开装置,应用于皂苷、生物碱的分离鉴定取得很好效果。     

有机物燃烧热测定方法的改进

对有机物燃烧热的测定方法进行了改进。改变点火丝的安装方法,采用高性能量热计,改变氧弹内氧气的压力及燃烧样品的用量,确定了新的测定方法。采用新的测定方法测定萘的燃烧热,测定结果的相对误差为0．05％,相对标准偏差为0．077％。     

容量瓶温变试验及其应用

试验了容量瓶经升温，降温后容量的变化。试验表明，容量瓶具有良好的热恢复性；用容量瓶直接配制溶液对溶液浓度影响不大。     

O-羧甲基甲壳素制备条件的研究

甲壳素除了某些特殊溶剂如：２－六氟甲醇、二甲基乙酰胺－氯化锂和三氯醋酸－二氯乙烷可使其溶解外，其它溶剂都难以使其溶解，所以开发其水溶性产品扩大其应用范围势在必行。甲壳素在碱性条件下可与氯乙酸反应，在Ｃ６的－ＯＨ基中导入－ＣＨ２ＣＯＯＨ基［１，２，３］...