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41.
Four mono-fatty acid esters(Ia~d) were synthesized via the esterification of(3R,4R)-4,7,7-trimethyl-6-oxabicyclo[3.2.1]octane-3,4-diol(I) with fatty acid chlorides(CH_3(CH_2)_nCOCl, n = 0, 2, 4, 6) and structurally characterized by means of H RMS, IR, ~1 H-NMR, ~(13)C-NMR and X-ray diffraction. Compounds Ia~d all belong to monoclinic system, P2_1/c space group. Intermolecular O(2)–H(2)···O(1) hydrogen bonds, intramolecular O(2)–H(2)···O(3) hydrogen bonds and van der Waals' interaction between fatty acid ester groups link each of the mono-fatty acid ester molecules into a bilayer structure similar to liposome with the exposed hydrophobic moiety and the sandwiched lipophilic moiety. Especially, compounds Ia~d could be dissoluble or scattered in aqueous solution and showed hydrophilic/lipophilic property-dependent herbicidal activity against the dicotyledon plant rape(Brassica campestris) and the monocotyledon plant barnyard grass(Echinochloa crus galli). At the concentration of 10 mmol·L~(-1), the inhibition rates of compounds Ia~d against the root growth of rape are 31.9, 90.8, 99.5 and 100%, respectively and the inhibition rates against the shoot elongation of barnyard grass are 19.3, 50.0, 80.2 and 100%, respectively. 相似文献
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采用3种不同的生物信息分析法对HBV S基因序列进行分析以鉴定HBV基因型,并比较分析各方法的优缺点。采集10例HBV慢性感染者血清,抽提HBV DNA,PCR扩增HBV S基因并测序。分别采用Clustal X软件和Bioedit软件计算S基因核苷酸和氨基酸同源性;DNAstart软件、Clustal X软件和Mega 4软件绘制S基因遗传进化树;以及在线Genotyping软件,将10例S基因序列与不同型及亚型HBV S序列比较以鉴定基因型及亚型。S基因核苷酸和氨基酸同源性计算结果显示1,3,4,5,7,8,9,10号标本与B2AF121243同源性最高,核苷酸同源性分别是98.0%,99.0%,98.8%,99.1%,99.2%,99.5%,99.5%,99.6%,而2号标本与C2 M38636同源性最高,核苷酸同源性为97.7%,6号标本与C4GQ377630同源性最高,核苷酸同源性为97.3%;构建系统树法鉴定结果为1,3,4,5,7,8,9,10号标本与B2AF121243进化距离最近,而2号标本与C2M38636进化距离最近,6号标本与C4GQ377630进化距离最近;Genotyping比对发现1,3,4,5,7,8,9,10号标本属于B基因型,2,6号标本属于C基因型。结论S基因核苷酸及氨基酸同源性的计算法可有效用于乙型肝炎病毒基因分型,是对现有分型方法系统树构建法以及在线Genotyping法的补充。 相似文献
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磁斯格明子是一种具有准粒子特性的拓扑纳米磁畴壁结构.由于磁斯格明子具有较好的稳定性和新奇的动力学特性,并可被磁场、电场、电流等方式调控,有望成为高密度、低耗能、非易失性信息存储及逻辑运算的新兴信息载体.自2009年磁斯格明子首次被实验观测到至今,已有多种基于磁斯格明子的器件概念和原型器件被提出.本文对基于磁斯格明子应用的研究进展进行综述,对现阶段几种具有代表性的磁斯格明子器件应用进行简要介绍、分析和总结,包括基于磁斯格明子的赛道存储器件、逻辑计算器件、类晶体管功能器件和纳米级微波振荡器;同时阐述了几种可能的通过磁斯格明子表达二进制信息元的方法;并展望了磁斯格明子的其他潜在应用以及未来基于磁斯格明子器件应用的发展方向. 相似文献
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脱脂棉在碱存在下与环硫氯丙烷发生醚化反应,合成了一种环境功能材料--聚硫醚纤维素(PTCC)。 考察了溶液酸度对吸附容量的影响并研究了PTCC对3种阳离子染料的吸附动力学与热力学。 研究结果表明,中性介质较有利于吸附的进行;298 K、pH=7.0时,静态吸附2 h后,吸附趋于平衡,PTCC对碱性艳蓝B、碱性艳蓝R和夜蓝的饱和吸附量分别为726、652和320 mg/g;PTCC对阳离子染料的吸附过程符合Lagergren二级吸附动力学方程,吸附速率常数k2随着温度的降低而升高,低温有利于吸附反应的进行;吸附过程ΔG、ΔH和ΔS均为负值,表明该吸附是自发的放热过程,主要是通过范德华力实现的。 吸附过程的吸附等温模型符合Langmuir等温式,可以用单分子层吸附理论加以解释。 相似文献
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Skyrmions in synthetic antiferromagnetic (SAF) systems have attracted much attention in recent years due to their superior stability, high-speed mobility, and completely compensated skyrmion Hall effect. They are promising building blocks for the next generation of magnetic storage and computing devices with ultra-low energy and ultra-high density. Here, we theoretically investigate the motion of a skyrmion in an SAF bilayer racetrack and find the velocity of a skyrmion can be controlled jointly by the edge effect and the driving force induced by the spin current. Furthermore, we propose a logic gate that can realize different logic functions of logic AND, OR, NOT, NAND, NOR, and XOR gates. Several effects including the spin-orbit torque, the skyrmion Hall effect, skyrmion-skyrmion repulsion, and skyrmion-edge interaction are considered in this design. Our work may provide a way to utilize the SAF skyrmion as a versatile information carrier for future energy-efficient logic gates. 相似文献
47.
A new method of asymmetric Abel inversion for magnetic equilibrium configuration state in tokamaks
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It is difficult to obtain the asymmetrical factor along the
observation direction parallel to the plasma mid-plane when the
detected radiation is also in the mid-plane. This paper
considers the magnetic surfaces and Grad--Shafranov shift, and
develops a new method for inverse asymmetric electron density
information, during magnetic equilibrium configuration in a
tokamak. 相似文献
48.
利用HCN激光多道干涉仪,首次在HL-1M装置上在低混杂电流驱动期间观测到密度锯齿现象。分析表明,密度锯齿不是通常的q=1锯齿,而是低混杂波与杂质共同作用下的产生的q〉1的锯齿。 相似文献
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基于HCN波形数据的等离子体密度计算方法 总被引:2,自引:2,他引:0
介绍了从HCN波形信号中获取基准电平、零相位点时间信号的方法,在此基础上计算出等离子体密度。通过将信号调理与采集设备共地、根据HCN信号相位最大可能变化率来排除干扰,通过动态地计算基准电平来改进处理结果。 相似文献