SF-环的内射性

研究了SF-环与P-内射环的关系,构造了SF-环成为P-内射环的一系列条件.证明了SF-环R只要满足其中之一:R的每个极大左理想是有限生成的;特殊右零化子的降链条件;对R的每个极大左理想M,l(M)在R中是本质的,那么R就是P-内射环.在此基础上,利用一定条件下SF-环的P-内射性,发展了SF-环的若干新结果,这些结果部分地拓展了有关文献中的结果.     

关于满足ACC的*-λ-半环

从满足ACC的任何偏序集是pre-CPO出发,研究了满足ACC的偏序集上的定向集,并由此给出满足ACC的＊-λ-半环的一些性质.证明了S是满足ACC的＊-λ-半环,则S是局部闭＊-半环和连续＊-半环.进一步得到任何满足ACC的＊-λ-半环是对称＊-λ-半环。     

采用铜铝复合管的翅片管换热器性能试验研究

针对铜铝复合管(ACC管)在空调用翅片管换热器中替代铜管应用进行了试验研究。分别对Ф7.94mm型管的全铜管、过冷段铜铝复合管、全铜铝复合管三种换热器进行了性能比较和成本分析。研究结果表明,在风速和风量不变的情况下,过冷段铜铝复合管换热器能力为8634.22W,高于全铜铝复合管的换热器的8389.36W,低于全铜管换热器的8989.07W。制冷剂侧能力测试中,过冷段铜铝复合管换热器平均值为8.885kW,与全铜铝复合管换热器平均值8.775kW相比高1.24%,与全铜管换热器平均值9.101kW相比低2.37%,与能力测试结果基本一致。与原换热器铜管相比,在相同条件下,铜铝复合管可以降低管材成本29.5%。综上所述,过冷段采用铜铝复合管的换热器能够取代铜管换热器应用在空调中,在不影响其换热性能的基础上,降低成本效果明显。     

超声辅助离子液体分散液液微萃取/高效液相色谱法测定新型抗艾药ACC007

该文提出了一种基于超声辅助离子液体分散液液微萃取/高效液相色谱(HPLC)测定血清及药片中ACC007含量的新方法.在超声辅助下,无需分散剂即可将疏水性离子液体1-辛基-3-甲基咪唑六氟磷酸盐([C8mimPF6])形成的细小液滴分散于样品溶液中,从而有效萃取ACC007,萃取率在94.0％以上.实验对萃取剂种类、萃取...     

Thermodynamics of methane adsorption on the microporous carbon adsorbent ACC

The behavior of the thermodynamic functions (differential molar isosteric heat of adsorption, entropy, enthalpy, and heat capacity) of the adsorption system methane—microporous carbon adsorbent ACC was analyzed at different adsorption equilibrium parameters in the temperature interval from 177.65 to 393 K and in the pressure range from 1 Pa to 6 MPa. The influence of the nonideal character of the gas phase and noninertness of the adsorbent were taken into account, which resulted in the appearance of the temperature dependence of the isosteric heat of adsorption, especially in the region of high pressures of the adsorptive. For the system studied, nonideality of the gas phase exerts the main effect on the thermodynamic functions of the adsorption system. In this interval of the parameters of the adsorption system, the correction to the noninertness of the adsorbent is not higher than 2.5%. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1765–1771, September, 2008.     

中学化学教材“化抽象为具体”图片分析工具设计及应用

将"化抽象为具体"(Abstract Convert to Concrete)的图片称为ACC图,并根据ACC图的认知过程及其影响因素设计化学教材ACC图分析工具,进而通过教材试分析,探讨现行教材ACC图的设计情况,为ACC图的优化提供参考。     

一氧化氮对ACC 氧化酶活性的抑制动力学研究

NO可以通过其辅因子氧化灭活作用抑制ACC氧化酶(ACO)活性,从而降低乙烯释放速率。本文主要研究了NO对ACO抑制作用的化学动力学,揭示了NO对ACO活性的抑制机理。NO溶液与ACC氧化酶的最佳反应时间是30min,底物ACC的最佳浓度为2mmol/L,作为酶促反应的辅因子,抗坏血酸钠和Fe2+的最适浓度分别为60mmol/L和60μmol/L,碳酸氢钠的最适浓度为60mmol/L。Lineweaver-Burk图显示NO是一种非竞争性抑制剂。NO与ACO反应的米氏常数Km为2.54mmol/L,抑制常数Ki为3.22μmol/L。     

In silico structural and functional analysis of Mesorhizobium ACC deaminase

Nodulation is one of the very important processes of legume plants as it is the initiating event of fixing nitrogen. Although ethylene has essential role in normal plant metabolism but it has also negative impact on plants particularly in nodule formation in legume plants. It is also produced due to a variety of biotic or abiotic stresses. 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase is a rhizobial enzyme which cleaves ACC (immediate precursor of ethylene) into α-ketobutyrate and ammonia. As a result, the level of ethylene from the plant cells is decreased and the negative impact of ethylene on nodule formation is reduced. ACC deaminase is widely studied in several plant growth promoting rhizobacterial (PGPR) strains including many legume nodulating bacteria like Mesorhizobium sp. It is an important symbiotic nitrogen fixer belonging to the class – alphaproteobacteria under the order Rhizobiales. ACC deaminase has positive role in Legume-rhizobium symbiosis. Rhizobial ACC deaminase has the potentiality to reduce the adverse effects of ethylene, thereby triggering the nodulation process. The present study describes an in silico comparative structural (secondary structure prediction, homology modeling) and functional analysis of ACC deaminase from Mesorhizobium spp. to explore physico-chemical properties using a number of bio-computational tools. M. loti was selected as a representative species of Mesorhizobium genera for 3D modelling of ACC deaminase protein. Correlation by the phylogenetic relatedness on the basis of both ACC deaminase enzymes and respective acdS genes of different strains of Mesorhizobium has also studied.     

Adsorption of Pentafluorophenol onto Powdered,Granular, and Cloth Activated Carbons

In the present study, the adsorption of pentafluorophenol from aqueous solution onto granular activated carbon, powdered activated carbon, and activated carbon cloth has been investigated from the equilibrium and kinetic points of view. To the best of our knowledge, the removal of pentafluorophenol from aqueous solution onto activated carbon have not been reported in the literature. The experimental equilibrium data, suitably fitted by the Toth, Langmuir-Freundlich, and Redlich-Peterson isotherms, have shown that the cloth and powdered carbons exhibit the highest adsorption capacity. For all the investigated samples, the experimental kinetic data have been satisfactorily interpreted by a pseudo-second-order model. From the fitting results it has been observed that the highest rate constant and initial rate of adsorption is shown by powdered activated carbon.     

STUDY ON MECHANISM OF ETHYLENE CONTROL OF SEX DIFFERENTIATION IN Lagenaria siceraria

The sex expression of Lagenaria siceraria can be modified by phytohormones. This modification is related to "a certain bisexual stage" during floral bud differentiation. ACC (ethylene precursor) and STS (ethylene antagonist) can change the direction of sex differentiation of the floral buds in vitro. STS induces maleness by means of inhibiting ethylene action, directly promoting the development of the primordia of stamens, and then suppressing that of pistils. Hence, it can be deduced that ethylene induces femaleness by directly suppressing the development of the primordia of stamens and then promoting that of pistils. Such a regulation of the development of sexual organs is due to a change in the direction of assimilates to the pistils by ACC and to the stamens by STS. Therefore, ethylene induces femaleness by first limiting the sink strength of the stamens and then increasing that of the pistils.