Metallo-phosphorylation of alkenes: a highly regioselective reaction of zirconocene-alkene complexes with chlorophosphate

Zirconocene-alkene complexes Cp₂Zr(CH₂CHR) reacted with chlorophosphate to form zircono-ethylphosphonate with high regioselectivity, which is versatile and could be converted into various functionalized organophosphonates.     

Design and concise synthesis of fully protected analogues of l-gamma-carboxyglutamic acid

The design and synthesis of four nonnaturally occurring amino acid analogues of l-gamma-carboxyglutamic acid (Gla), appropriately protected for Fmoc-based solid-phase peptide synthesis (SPPS), is described. These amino acids are Bu-Mal 2, BCAH 3, Pen-Mal 4, and Cm-Gla 5. These Gla analogues have been designed to replace the glutamic acid of position 1 in the cyclic decapeptide G1TE, which is a potent inhibitor of tyrosine kinase, to further enhance binding to the Grb2-SH2 domain of signal transduction receptors. In the new amino acids, the propionic acid side chain of Glu has been replaced by a malonyl or a carboxymethylmalonyl moiety located at different distances from the alpha-carbon to optimize interactions in the phosphotyrosine-binding cavity of the Grb2-SH2 domain. Additionally, a direct and efficient synthetic route for the preparation of Fmoc-protected l-gamma-carboxyglutamic acid, which is amenable to large-scale production, has been developed to provide this important and unique amino acid(1) in 55% overall yield.     

Microchannels in conventional single-mode fibers

Microchannels are fabricated into conventional single-mode fibers by femtosecond laser processing and chemical etching. Fabrication limitations imposed by the fiber geometry are highlighted and resolved through a simple technique without compromising fabrication flexibility. A microfluidic fiber device consisting of a 4 microm wide microchannel that intersects the fiber core for refractive index sensing is further demonstrated.     

Dynamical noise filter and conditional entropy analysis in chaos synchronization

It is shown that, in a chaotic synchronization system whose driving signal is exposed to channel noise, the estimation of the drive system states can be greatly improved by applying the dynamical noise filtering to the response system states. If the noise is bounded in a certain range, the estimation errors, i.e., the difference between the filtered responding states and the driving states, can be made arbitrarily small. This property can be used in designing an alternative digital communication scheme. An analysis based on the conditional entropy justifies the application of dynamical noise filtering in generating quality synchronization.     

大学土木工程实验室开放管理对本科教学的促进作用分析

在各级各类高校实验室建设中,对实验室开放管理都有明确的要求。以山东省土木工程防灾减灾重点实验室开放管理为例,结合土木工程学科特点,从学生和教师两个实验主体详细分析了实验室开放对本科教学的促进作用。通过分析得出,通过多种形式渠道的实行实验室开放,可以全方位促进学生各种能力的培养,也可以促进教师责任心提高,提高教师实验水平,增强实验教师队伍的建设。     

纯Fe在压应力下高温氧化行为研究

研究了纯Fe在500、650、800℃压应力下的高温氧化行为.通过热重分析(TGA)的方法分析了压应力对纯Fe氧化动力学的影响,应用光学显微镜(OM)及扫描电镜(SEM)观察了纯Fe高温氧化后的表面及截面形貌.氧化动力学曲线表明压应力增大了纯Fe的氧化速率,这与压应力对氧化膜结构的影响有关.在压应力下,氧化膜显示了多孔及裂纹等特征,大大增大了氧与氧化膜接触的面积.     

腈纶接枝2-氨基乙磺酸制备新型离子交换纤维

以腈纶(PAN)直接接枝2-氨基乙磺酸(NH2CH2CH2SO3H)制备了新型的含磺酸基离子交换纤维RPFS-I,研究了2-氨基乙磺酸浓度、反应温度、反应时间对反应的影响,采用交换容量、红外光谱和拉断力等对RPFS-I进行了表征.实验结果表明:该方法可将磺酸基成功地引入到PAN纤维上,RPFS-Ⅰ纤维的交换容量达到2.7mmol/g,且机械强度无明显下降.     

豆皮与豆渣多糖的分级纯化、物化和功能性质研究

本文研究了豆皮和豆渣多糖在物化及功能性质上的差别. 对提取的多糖进行分级纯化 ,均分别得到三个多糖纯化组分. 气相和凝胶渗透色谱分析了各组分的物化性质 ,并通过乳化和胆酸结合试验比较了各组分功能性质的差别. 结果表明 ,豆皮多糖是不含蛋白质的酸性多糖 ,平均分子量为45~150kDa ,乳化性质较差 ;豆渣多糖是一种糖蛋白 ,具有优异的乳化性能 ,且其体外胆酸结合能力较高. 说明豆渣多糖是具有良好功能性质的优质水溶性多糖 ,可广泛应用于食品工业中.     

回转状态下导管螺旋桨水动力特性的数值模拟

采用滑移网格技术和计算流体力学方法,在导管螺旋桨所在的流域内求解其N-S方程,以此模拟在作回转运动的水下机器人流场作用下导管螺旋桨的推力特性,观察螺旋桨在这一环境下的水动力现象.计算结果表明:当来流从尾部流向机器人时,对于尾导管螺旋桨,有机器人影响时其推力系数比无机器人时要小,对处于机器人舷侧的螺旋桨,有机器人时其推力系数比无机器人时要大;当来流从首部流向机器人时其情形刚好相反;而当机器人轴线与流向大致垂直时,有无机器人对螺旋桨推力系数的影响不大.     

Spin–orbit coupling effects on the in-plane optical anisotropy of semiconductor quantum wells

We theoretically study the influence of the spin–orbit coupling(SOC) on the in-plane optical anisotropy(IPOA) induced by in-plane uniaxial strain and interface asymmetry in(001) GaAs/AlGaAs quantum wells(QWs) with different well width. It is found that the SOC has more significant impact on the IPOA for the transition of the first valence subband of heavy hole to the first conduction band(1H1E) than that of 1L1E. The reason has been discussed. The IPOA of(001) InGaAs/InP QWs has been measured by reflectance difference spectroscopy, whose amplitude is about one order larger than that of GaAs/AlGaAs QWs. The anisotropic interface potential parameters of InGaAs/InP QWs are also determined. The influence of the SOC effect on the IPOA of InGaAs/InP QWs when the QWs are under tensile, compressive or zero biaxial strain are also investigated in theory. Our results demonstrate that the SOC has significant effect on the IPOA especially for semiconductor QWs with small well width, and therefore cannot be ignored.