A New Variational Formulation for a Kind of Reaction-diffusion Problem in Broken Sob olev Space

In this paper, a new variational formulation for a reaction-diffusion problem in broken Sobolev space is proposed. And the new formulation in the broken Sobolev space will be proved that it is well-posed and equivalent to the standard Galerkin variational formulation. The method will be helpful to easily solve the original partial differential equation numerically. And the method is novel and interesting, which can be used to deal with some complicated problem, such as the low regularity problem, the differential-integral problem and so on.     

Water-Stable Metal Azolate Frameworks Showing Interesting Flexibilities for Highly Effective Bioethanol Dehydration

The ethanol/water separation challenge highlights the adsorption capacity/selectivity trade-off problem. We show that the target guest can serve as a gating component of the host to block the undesired guest, giving molecular sieving effect for the adsorbent possessing large pores. Two hydrophilic/water-stable metal azolate frameworks were designed to compare the effects of gating and pore-opening flexibility. Large amounts (up to 28.7 mmol g⁻¹) of ethanol with fuel-grade (99.5 %+) and even higher purities (99.9999 %+) can be produced in a single adsorption process from not only 95 : 5 but also 10 : 90 ethanol/water mixtures. More interestingly, the pore-opening adsorbent possessing large pore apertures showed not only high water adsorption capacity but also exceptionally high water/ethanol selectivity characteristic of molecular sieving. Computational simulations demonstrated the critical role of guest-anchoring aperture for the guest-dominated gating process.     

Silver/graphene–polypyrrole composite for levosimendan detection

This study used a facile method to develop a novel silver/Graphene–polypyrrole (Ag/G–PPy)-modified electrode that can be used as an electrochemical sensor for levosimendan detection. The properties of the synthesized Ag/G–PPy-modified electrode were examined through field-emission scanning electron microscopy, x-ray diffraction, and transmission electron microscopy. The Ag/G–PPy-modified electrode exhibited satisfactory current signals toward levosimendan concentrations ranging from 0.21 to 6.88 μM and exhibited a low detection limit (0.12 μM). Accordingly, the proposed electrode can serve as a simple and inexpensive electrochemical sensor for levosimendan detection.     

Design,synthesis, and insecticidal activities of novel diamide derivatives with alpha-amino acid subunits

A series of diamide derivatives containing α-amino acids were designed and synthesized. These compounds were evaluated for their insecticidal activities against Plutella xylostella, Mythimna separate, Myzus persicae, and Tetranychus cinnabarinus. Most of the title compounds containing an l -phenylglycine skeleton were endowed with good activities at the concentration of 500 mg·L⁻¹. Compounds ( R)-A6 showed a potential value for further optimization as an insecticidal lead with the LC₅₀ value of 86.8 mg·L⁻¹.     

温敏性纤维素/聚Ν-异丙基丙烯酰胺复合水凝胶的固体核磁共振表征及动力学研究

利用半互穿网络方法将具有温度响应的高分子聚N-异丙基丙烯酰胺( PNIPAM)与天然纤维素复合得到温敏性水凝胶。通过固体核磁共振的1 H,13 C CP/MAS(交叉极化/魔角旋转)和QCP(定量交叉极化)等实验手段对复合凝胶的结构进行了定性及定量研究,并利用固体静态变温核磁共振实验和偶极滤波-自旋扩散实验研究了复合凝胶中PNIPAM分子链段的动力学行为。     

Synthesis,Crystal Structure and Catalytic Properties of a 2D Cobalt(Ⅱ) Coordination Polymer Based on Mixed Ligands

A new Co(II) metal-organic coordination polymer based on flexible bis(imidazole) and aromatic dicarboxylate co-ligands, namely [Co(bix)(nph)]n(H2nph = 3-nitrophthalic acid, bix = 1,4-bis(imidazole-1-ylmethyl)benzene), has been hydrothermally synthesized and characterized by elemental analyses, TG, IR spectroscopy and single-crystal X-ray diffraction. It crystallizes in the triclinic space group P1 with a = 9.3767(14), b = 10.1451(15), c = 12.1488(17), α = 102.6450(10), β = 108.856(2), γ = 98.807(2)°, V = 1035.3(3)3, Z = 2, C22H17 Co N5O6, Mr = 506.34, Dc = 1.624 g/cm3, μ = 0.882 mm-1 and F(000) = 518. In the complex, the nph2- ligands connect neighbouring cobalt atoms to form binuclear [Co(nph)]2 subunits, which are linked by pairs of bix ligands to form a 2D honeycomb-like(6,3) network. In addition, the compound is further extended into a 3D supramolecular architecture by π···π stacking interactions. Moreover, the luminescence and catalytic properties of the complex are investigated.     

基于蒙特卡洛方法的X射线探测器能谱响应研究

为解决X射线荧光测量过程中的仪器刻度和校正难题,通过理论研究并运用蒙特卡洛方法对X射线荧光仪进行建模,得到了X射线探测器能谱响曲线。结果表明:模拟的X射线探测器能谱响应全谱与实测情况基本一致,而主成份谱线则高度一致,特征峰半高宽相对误差均在5%以内。方法为X射线荧光测量的仪器刻度和校正提供重要的研究信息,不仅为元素分析工作节省大量人力物力,也为无标样X射线荧光分析提供了有力的理论支撑。方法也可用于X射线荧光分析过程中的其他研究领域。     

非晶态镍硼酸盐结构的EXAFS研究

由摩尔比分别为1:2和1:8的NiCl₂·6H₂O和Na₂B₄O₇·10H₂O作为反应物, 合成两种非晶态镍硼酸盐, 同时通过水热法合成β-Ni(OH)₂. 化学分析和热重-微商热重法(TG-DTG)分析结果确定两种非晶态镍硼酸盐的分子组成分别为NiO·0.8B₂O₃·4.5H₂O和NiO·B₂O₃·3H₂O. 激光拉曼(Raman)实验结果表明镍硼酸盐样品中主要存在的硼氧阴离子为B₃O₃(OH)₅^2-和B₂O(OH)₆^2-. 同步辐射扩展X射线吸收精细结构(EXAFS)方法对样品进行结构解析, 通过数据拟合给出样品中Ni 原子周围近邻配位原子种类、配位数以及原子间距离. 用不同晶体结构作为标准对两种非晶态镍硼酸盐进行拟合的结果表明, 样品中Ni 原子周围局域结构与Ni₃B₂O₆晶体(ICSD No.31387)中的吻合较好. Ni 原子周围配位原子为O、B和Ni, 对于NiO·0.8B₂O₃·4.5H₂O, 配位数分别为5.7、3.8和3.8, 配位距离分别为0.208、0.263 和0.311 nm; 对于NiO·B₂O₃·3H₂O, 配位数分别为6.0、4.0 和4.0, 配位距离分别为0.207、0.262和0.310 nm.     

盘绕式空间可展折叠无铰伸展臂的屈曲分析理论研究

首先介绍了无铰可展空间伸展臂(Hingeless Mast)构造特点、展开折叠机理和受力特点,然后根据弹性稳定理论和能量原理,分别推导出局部卷压屈曲和整体螺旋屈曲的临界压力表达式,并据此进行参数特性分析。本文分析理论对无铰空间伸展臂的设计具有重要指导意义。