Preparation and Characterization of Microencapsulated Hexadecane Used for Thermal Energy Storage

Polyurea microcapsules about 2.5μm in diameter containing phase change material for thermal energy storage application were synthesized and characterized by interfacial polycondensation method with toluene-2,4-diisocyanate and ethylenediamine as monomers in an emulsion system. Hexadecane was used as a phase change material and OP, which is nonionic surfactant, and used as an emulsifier. The chemical structure and thermal behavior of the microcapsules were investigated by FTIR and thermal analysis respectively. The results show encapsulated hexadecane has a good potential as a solar energy storage material.     

Theoretical study of the surface energy and electronic structure of pyrite FeS2 (100) using a total-energy pseudopotential method, CASTEP

The geometric and electronic structures of FeS(2) (100) surface have been studied by a quantum-mechanical calculation using a total-energy pseudopotential code, CASTEP. The (100) surface is very stable and does not give any significant geometric relaxation. The electronic structure of FeS(2) (100) surface is characterized by the appearance of new native surface states in the bulk band gap, which correspond to antibonding mixed Fea-Ssp(3) states. These surface states play an important role as mediators of electron transfer on both anodic and cathodic sites in the incipient oxidation of pyrite. Moreover, the (100) surface has small band gaps and shows some metallic character. It is predicted that the rate of cathodic reductive reaction of O(2) in the incipient oxidation of pyrite is much faster than previously considered. The transport of electrons from the anodic sites to the cathodic sites on the (100) surface is faster and hole injection of anodic sites is not the rate-determining step. So we can deduce that the rate-determining step of incipient oxidation for pyrite consists of both electron transfer of pyrite/aqueous O(2) interface and the splitting of H(2)O.     

The Synthesis of Bis（carboxyalkylmethyl） Diselenides by Selenium Transfer Reaction of Aryl Selenoamides

Aryl selenoamides react smoothly with a-haloacetic acid in various alcohol to givecorresponding bis(carboxyalkylmethyl) diselenides in good yields.     

Ion Recognition and Analytical Application of a Fibroin Modified Electrode

A novel fibroin modified electrode with ion recognition was reported. The membrane with isoelectric point of pH 4.5, was modified on graphite and carbon fiber electrodes. The pH-responsive ion recognition of the modified electrode was investigated by use of some neurocompounds. The fibroin carbon fiber electrode has been used for in-vivo determination.     

表面电沉积Ni—La2O3复合镀层的Fe26Cr1Mo不锈钢的氧化行为研究

Ｆｅ２６Ｃｒ１Ｍｏ不锈钢在９００℃氧化时，生成的氧化层在冷却过程中大量剥落，经表面共电沉积ＮｉＬａ２Ｏ３复合镀层后，抗热循环能力明显提高。     

Selection of Anodic Material Used in Electrolytic Process for Producing Hypophosphorous Acid

Black lead, Ti-Ru and Ti-PbO2 were used as anode and stainless steel was used as cathode The electrolytic process of producing hypophosphorous acid with four-compartment electrodialytic cell was studied. The comparison of some factors, such as anodic voltage, product concentration and current efficiency, of black lead, Ti-Ru, and Ti-PbO2 electrodes was conducted. As a result, theTi-PbO2 electrode is the optimal anode material used, it can be in electrolytic process for producing hypophosphorous acid.     

O-二异丙氧磷酰基丝氨酸(或苏氨酸或酪氨酸)的合成

介绍一种简单方便地合成O-二异丙氧磷酰基丝氨酸(或苏氨酸或酪氨酸)的方法.其中O-二异丙氧磷酰基-L-丝氨酸(或苏氨酸)可从对应的N-磷酰化-L-丝氨酸(或苏氨酸)利用磷酰基N→0迁移的性质并在超声辅助下合成,而N-二异丙氧磷酰基-L-丝氨酸(或苏氨酸)的合成由L-丝氨酸(或苏氨酸)在次氯酸钠的水溶液中高收率地获得.O-二异丙氧磷酰基酪氨酸的合成可通过铜盐同时保护氨基和羧基,使用二异丙基磷酰氯为磷酰化试剂磷酰化,用硫化氢脱铜保护制备.     

Quantitative analysis of 23-hydroxybetulinic acid in mouse plasma using electrospray liquid chromatography/mass spectrometry

23-Hydroxybetulinic acid is a newly isolated derivative of betulinic acid. The agent exhibits potential anti-tumor activity and functions in this regard via apoptosis. In support of pharmacokinetic and toxicological evaluations, a new assay based on liquid chromatography/mass spectrometry (LC/MS) was developed for the quantitative analysis of 23-hydroxybetulinic acid. Sample preparation consisted of extraction of the plasma by the addition of methylene chloride followed by centrifugation. Aliquots of the supernatant were analyzed using an isocratic reversed-phase high-performance liquid chromatography (HPLC) system coupled to a negative ion electrospray mass spectrometer. Molecules of 23-hydroxybetulinic acid and the internal standard limonin were detected using selected ion monitoring at m/z 471 and 469, respectively. The limit of detection of 23-hydroxybetulinic acid was 0.05 pg (0.11 fmol) injected on-column (10 pg/mL, 5 microL injection volume), and the limit of quantitation was 10 pg (21.19 fmol, 2 ng/mL, 5 muL injection volume). 23-Hydroxybetulinic acid was stable in plasma samples at -20 degrees C for at least 3 weeks. The intra-day and inter-day coefficients of variation of the assay were 3.0 and 4.8%, respectively. The utility of the assay was demonstrated by measuring 23-hydroxybetulinicacid in mouse plasma following intragastric administration (IG) in vivo. Pharmacokinetic parameters were calculated using the 3P97 pharmacokinetic software package. A two-compartment, first-order model was selected for pharmacokinetic modeling. The result showed that after IG of 200 mg/kg 23-hydroxybetulinic acid, the plasma concentrations reached peaks at 2 h with C(max) of 3.1 microg/mL. The 200 mg/kg 23-hydroxybetulinic acid suspension IG doses were found to have long elimination half-lives of 25.6 h and low bioavailability of 2.3%. No interference was noted due to endogenous substances. These analytical methods should be of value in future studies related to the development and characterization of 23-hydroxybetulinic acid.     

Positioning isolation and biochemical analysis of single DNA molecules based on nanomanipulation and single-molecule PCR

Recently, the isolation and biochemical analysis of DNA at the single-molecule level has been recognized as very important for genetic research and clinical analysis. A unique technique for the positioning, dissection, and isolation of single DNA molecules using atomic force microscopy (AFM) has been demonstrated. Full-length genome DNA molecules were first deposited and stretched by a modified "molecular combing" technique onto a 3-aminopropyl triethoxysilane-coated mica substrate. A single DNA fragment was dissected from one of those genome DNA strands with the AFM tip at the desired position, and then isolated (or picked up) after a special operation called "kneading". All the operations including imaging, dissection, and isolation could be carried out with one tip. The isolated DNA fragment on the AFM tip could be successfully amplified by single-molecule PCR.     

二氧化碳/环氧丙烷/γ-丁内酯三元共聚物微球降解性的研究

动物体内的体液和肠胃等器官的环境各不相同，这就要求各种不同用途的载药体的降解性能必须满足特定环境的要求。同时，可降解材料在不同的降解介质中通常有着不同的降解表现，这也决定着可降解材料的运用环境。因此，有必要对降解性材料在不同降解介质中的降解性进行专门的研究，由CO2和环氧化物合成的脂肪族聚碳酸酯具有良好的生物降解性能。