Synthesis,Crystal Structure,and Herbicidal Activity of(3R,4R)-4,7,7-Trimethyl-6-oxabicyclo[3.2.1]octane-3,4-diol Mono-fatty Acid Esters

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.     

Structure and Wettability Engineering of Polycrystalline Diamond Films Treated by Thermally Oxidation,Second Growth and Surface Termination

High-quality polycrystalline diamond films with dominated(100)-oriented grains are realized by combining the thermally oxidation and the homogeneous second growth processes. Moreover, we investigate the wettability property of the polycrystalline diamonds in various stages. Different surface structures(with various grain sizes,voids, and orientations, etc.) and terminations(hydrogen or oxygen) have significant effects on the wettability of polycrystalline diamond films. The wettability is furthe...     

Novel Synthesis,Crystal Structure,and Plant-growth Regulation Activity of(1S,4R)-4,7,7-Trimethyl-6-oxabicyclo[3.2.1]octane-1,4-diol

The title compound,(1S,4R)-4,7,7-trimethyl-6-oxabicyclo [3.2.1] octane-1,4-diol(C_(10)H_(18)O_3), has been synthesized from terpinolene via one-step catalytic synthetic method and structurally characterized by means of HRMS, IR, ~1H-NMR, ~(13)C-NMR and single-crystal X-ray diffraction. The compound crystallizes in trigonal, space group R-3, with a = 27.892(9), b = 27.892(9), c = 6.720(2) ?, γ = 120°, Z = 18, V = 4527(3) ?~3, D_c = 1.230 g/cm~3, Mr = 186.24, λ(Mo Kα) = 0.71073?, μ = 0.09 mm~(-1), F(000) = 1836, the final R = 0.051 and wR = 0.161. The title compound molecule contained a 6-oxabicyclo[3.2.1]octane skeleton and two hydroxyl groups, which were connected through intermolecular O–H???O hydrogen bonds to generate a two-dimensional network. Especially, the preliminary bioassay showed that the title compound can promote the root growth and shoot elongation of rape(Brassica campestris) at low concentration(0.625~70 mmol·L~(-1)) and inhibit them at high concentration( 70 mmol·L~(-1)).     

实时直接分析-静电场轨道阱高分辨质谱法应用于化妆品中15种抗过敏药物的定性和定量分析

提出了应用实时直接分析(DART)-静电场轨道阱高分辨质谱法对化妆品中15种抗过敏药物的定性和定量检测方法。称取样品0.50g,加入50%(体积分数)乙醇溶液1.0mL,于超声波水浴中超声处理5min,涡旋振荡10min后离心5min,取上清液0.50mL,加水0.5mL混匀后再次离心5min,取上清液,按仪器工作条件进行分析。采用Dip-it Samplers模式进样,进样量为1μL。在正离子模式下,以一级全扫描-数据依赖性二级扫描(Full MS-ddMS2)进行定性分析,与自建二级(MS2)谱库进行比对,得到定性筛查结果;随即以平行反应监测(PRM)模式进行定量分析。所测的15种抗过敏药物的线性范围均在10mg·L~(-1)以内。由于所测得的15种药物的测定下限的信噪比远大于10倍,故本方法将测定下限定为0.5mg·kg~(-1)。用空白样品为基体,加入混合标准溶液进行回收试验,测得回收率在82%以上;测定值的相对标准偏差(n=6)均小于16%。应用本方法分析了20个市售化妆品样品,在其中的7个样品中检出苯海拉明,在1个样品中检出氯苯那敏,且所得结果与液相色谱-串联质谱法(LC-MS/MS)所测结果一致。     

基于多准则决策的塔状粒子群优化算法

针对经典粒子群优化算法存在早熟、收敛精度低和收敛速度慢的问题, 提出了一种新的改进算法. 该算法采用了塔状优化互联机制, 底层粒子群负责寻找局部最优解, 顶层粒子负责收集、反馈全局最优解, 为底层种群提供全局最优信息, 建立共享学习机制. 顶层粒子一旦发现停滞现象, 将通知底层粒子群采用细菌觅食优化、随机初始化等停滞优化策略, 以改善粒子群的收敛速度. 实验结果表明, 与同类算法相比, 改进算法具有更好的寻优能力, 改善了粒子群的收敛精度和收敛速度.     

用于卤素捕获的材料研究进展

卤素单质氟(F₂)、氯(Cl₂)、溴(Br₂)和碘(I₂),在化学工业中发挥重要作用.但是由于F₂、Cl₂和Br₂的毒性、腐蚀性和挥发性使得它们的安全储存和运输形成了严峻的挑战,而将这些卤素单质进行吸附预固化可以有效提高它们使用的安全性.理想的卤素单质预固化材料须满足多种性能要求,如对卤素单质的稳定性、选择性、吸脱附可逆性和可加工性等,这给预固化材料的设计和合成带来了很大的挑战.目前为止,Cl₂和Br₂的预固化材料已经有不少报道(F₂暂时还未有),对这类材料进行总结和回顾,有助于为后续的材料优化和设计提供参考.然而,截至本文撰写之前,还未有人对Cl₂和Br₂预固化材料的研究做过综述报道.因此,通过本文综述了多孔有机聚合物(POPs)、金属有机框架(MOFs)、多孔有机笼(POCs)以及金属卤化物等在Cl₂...     

透射型体相位光栅对连续激光束的空间低通滤波

利用Kogelnik一维耦合波理论,以及离散傅里叶变换,分析光栅矢量相互正交,且串联级联放置的两透射型体相位光栅对空域任意分布的连续激光光束的衍射特性;讨论其对入射光束的空间低通滤波性能,并具体模拟其对畸变高斯光束空间低通滤波的效果.结果表明,利用体光栅优良的角度选择特性,无须对畸变光束进行聚焦,即可实现入射光束角谱域中的高频成分与低频成分的空间分离,滤除畸变高斯光束中高频角谱成分,使得衍射光束与未畸变光束在空域中的光强分布非常接近,达到滤除畸变光束中杂散成分且保留有用成分的主要目的.这种方法有效地避免了聚焦型空间低通滤波,如针孔滤波在针孔附近光强过高,易致针孔周边材料损坏等不利因素,有助于应用至高功率激光光束质量的优化.     

双掺杂近化学计量比铌酸锂晶体的全息光学特性研究

在LiNbO3中掺入0.2 mol％ MnO和0.1 mol％ Fe2O3,采用顶部籽晶法生长了双掺杂近化学计量比铌酸锂晶体.紫外吸收测试结果表明,晶体成分趋近于化学计量比.采用二波耦合光路测试了晶体的光折变性能.晶体的指数增益系数达到28 cm－1,衍射效率为68.3％,响应时间为亚秒级.利用晶体进行了体全息存储实验,实验结果显示,双掺杂近化学计量比晶体的图像存储质量明显好于相同掺杂的同成分晶体,记录速度较同成分晶体提高了二个数量级.     

液体透镜的诞生和发展

本文介绍当今世界最先进的透镜成像系统——液体变焦透镜的诞生和发展.首先是哥伦比亚大学的反射式旋转液体透镜,可用作天文望远镜;透射式液体透镜从加州大学圣地亚哥分校的压力透镜,到Lucent公司的纯电力控制的液体—空气界面的透镜,再到Philips公司的方便操作的封闭式液—液界面透镜,最后到法国VariOptic公司的能自动调节光轴的改进型透镜,其中着重介绍了VariOptic的液体透镜.