Preparation and properties of vesicles from condensable amphiphilic amino acids

Three double‐chain amphiphiles with amino acid groups as hydrophilic moiety were synthesized. These amphiphiles can be easily dispersed in buffer solution to form transparent dispersion. Examination of the dispersion by transmission electron microscopy (TEM) showed the formation of stable vesicular aggregates, which was also confirmed by the ability to encapsulate water‐soluble dyes. Since amino acid groups are located on the surface of the vesicles, water‐soluble carbodiimide can induce the condensation of these groups to form peptide. The phase transition temperatures of these vesicles were estimated by differential scanning calorimetry (DSC), and a decrease of phase transition temperature was observed after polycondensation due to the disturbance of the ordered arrangement of the hydrophobic chains. The leakage rate of the vesicles before and after condensation was studied by monitoring the increase of fluorescence intensity of water‐soluble dye. These vesicles belong to the least permeable ones and the leakage rate can be controlled by varying the degree of condensation or the temperature.     

硝酸铬与组氨酸配合行为的相化学与热化学研究

用相平衡方法研究了硝酸铬-组氨酸-水体系在298.15K时的溶度,绘制了体系的相图,发现并制备了文献未报道的一致溶解配合物:Cr(His)(NO3)3·3H2O(A),Cr(His)2(NO3)3·3H2O(B)和Cr(His)3(NO3)3·3H2O(C),经分析确定了其组成。用微热量计热测定了硝酸铬和组氨酸在水中的反应焓,计算了这些反应的热动力学参数(活化焓、活化熵及活化自由能)、速率常数和动力学能数(活化能、指前因子及反应级数)。     

气溶胶前向散射大气能见度测量系统传递系数的标定及校准方法

分析了气溶胶的前向角散射特性,利用标准的大气透射仪标定前向散射大气能见度测量系统的传递系数。当系统结构发生变化时,传递系数也随之改变,为保证系统测量的准确性和简化系统传递系数的标定过程,提出了一种利用标准漫透射板校准系统传递系数的方法。该方法使用了两块具有相同透射系数的漫透射板,使气溶胶粒子团在前向半球上产生漫散射,此时探测器的测量值即为包含了仪器常数的定值。当系统结构改变时,这个测量值相对于原测量值的变化率作为比例系数代入系统传递系数的计算,实现校准。     

Two New Compounds from Lindera chunii Merr.

The root of Lindera chunii Merr. is a noble traditional Chinese medicine and frequently used as a substitute for L. aggregata to cure the chronic disease of rheumatoid arthritis1. In our previous paper, we have reported some components from the roots of L…     

Separation and insertion of optical bit-serial label in optical packet switching

The bipolar phase-shift-keying (BPSK) optical orthogonal codes (OOCs) are inserted into the optical packet format of bit-serial label. The ultra-fast separation of the label and payload is performed through the auto-correlation pulses indicating the time position at which the optical switch changes the state.The insertion of the new label can also be realized by detecting the auto-correlation pulse at the line rate. Especially, the scheme can be adapted to the asynchronous separation and insertion and realize the variable-length packet switching. The results of simulation verify the feasibility of the scheme.     

模拟台风异常路径（Ⅰ）—Rankine涡模型

本文提出一个用Ｒａｎｋｉｎｅ涡模型模拟对称和非对称台风的方法·考虑到台风和Ｒａｎｋｉｎｅ涡之间物理性质的相似性，从定性上分析了这一方法的可行性·参照Ｙａｎｃｙ台风的观测数据，给出模拟某一时刻台风内部结构的Ｒａｎｋｉｎｅ涡模型的涡参数·这一结果是进一步用等值线动力学方法研究台风运动的基础     

Investigation on the viscoelasticity of synchronous hepatocellular carcinoma cells

Having made use of the micropipette aspiration technique, we here investigated the viscoelastic properties of hepatocellular carcinoma (HTC) cells from the view of cell cycle. The synchronous G₁ and S phase cells were achieved through thymine-2-desoryriboside and colchicine sequential blockage method and double thymine-2-desoryriboside blockage method, respectively. The synchronization results detected with flow cytometer showed that it could meet the requirements of the experiments nicely. Experimental results were analyzed with a standard linear solid viscoelastic model, in which an elastic element, K₁, is in parallel with a Maxwell element composed of another elastic element, K₂, in series with a viscous element, μ. The results indicated that high K₁, K₂ values and low μ value was the general characteristics of the cells; G₁ phase cells had higher K₁ values and low μ value than S phase cells, which endowed G₁ phase cells with higher elasticity and faster passive deformability than S phase cells. The results maybe also reflected the difference of cytoskeleton between G₁ and S phase cells, and suggested that G₁ phase cells were more suitable for surviving and metastasis in blood circulation than S phase cells.     

MECHANICAL PROPERTIES OF OZONIZED HDPE FILLED WITH SERICITE-TRIDYMITE-CRISTOBALITE

The mechanical properties of ozonized high density polyethylene (HDPE) blended with sericite-tridymite-cristobalite (STC) were studied in this paper. The experimental results show that some oxygen containing polar groups are introduced on the molecular chain of HDPE through ozonization, the compatibility between HDPE and STC is thus improved, the mechanical properties of the blend are markedly enhanced. Compared with untreated HDPE/STC (60/40) blend, the yield strength and notched impact strength of ozonized HDPE/STC (60/40) blend are increased from 27.0MPa to 29.5MPa and from 2.8kJ/m^2 to 13.3kJ/m^2, respectively, the notched impact strength is close to that of HDPE (13.6kJ/m^2),the yield strength is in excess of 3.9MPa of that of HDPE. The yield strength and notched impact strength will be further increased to 30.7MPa and 32.4kJ/m^2 in case the ozonized HDPE is blended with STC pretreated with silane coupling agent.     

A Unique Indolo‐[1,7]naphthyridine Alkaloid from Incarvillea mairei var. grandiflora (Wehrh.) Grierson

A novel alkaloid with a unique indolo‐[1,7]naphthyridine nucleus, incargranine B, was isolated from the whole plant of Incarvillea mairei var. grandiflora (Wehrh.) Grierson . Its structure was determined by means of spectroscopic methods.