Volumetric Properties for the Electrolyte (NaCl,NaBr and NaI) Monosaccharide (D‐Mannose and D‐Ribose)‐Water Systems at 298.15 K

Densities have been measured for the electrolyte (NaCl, NaBr and NaI)‐monosaccharide (D ‐mannose and D‐ribose)‐water solutions at 298.15 K. These data have been used to calculate the apparent molar volumes of the saccharides (V_Φ,S) and electrolytes (V_Φ,E) in the studied solutions. Infinite dilution apparent molar volumes, V_Φ,S⁰ and V_Φ,E⁰, have been evaluated, together with the standard transfer volumes of the saccharides (Δ_tV_S⁰) from water to aqueous electrolyte solutions and those of the electrolytes (Δ_tV_E⁰) from water to aqueous saccharide solutions. It was shown that both the Δ_tV_S⁰ and Δ_tV_E⁰ values are positive and increase with increasing molalities of sodium halides and saccharides, respectively. Overall, the Δ_tV_S⁰ and Δ_tV_E⁰ values have the order of NaCl > NaBr > NaI except for NaI‐ribose and NaI‐ribose. Volumetric interaction parameters for the electrolyte‐monosaccharide pairs in water were obtained and interpreted by the stereochemistry of the monosaccharide molecules and the structural interaction model.     

Zn(Ⅱ)与氯苯基苯并咪唑配合物的合成、表征和晶体结构

带咪唑、苯并咪唑等配位基团的过渡金属配合物是一类很重要的物质[1～ 9] 。本文探讨它与Ｚｎ(Ⅱ )的配位性质及配合物的晶体结构。1　实验部分1 .1　标题配合物的合成及表征将 92ｍｇ 2 (0 氯苯基 )苯并咪唑和 40ｍｇＺｎＣｌ2(ＡＲ)分别溶于无水乙醇(ＡＲ)后混合均匀 ,于室温下静置 3 0天 ,析出长方体形无色晶状物 ,产率为 47%。采用Ｐｅｒｋｉｎ Ｅｌｍｅｒ 2 4 0Ｃ元素分析仪测定配合物中Ｃ、Ｈ、Ｎ含量。用ＤＤＳ 1 1Ｃ数显电导率仪 ,以ＤＭＦ为溶剂测定配合物的摩尔电导。采用Ｎｉｃｏｌｅｔ5ＤＸ Ｂ傅立叶变换红外光谱仪 ,ＫＢｒ压…     

Studies on the Synthesis and Properties of Temperature Responsive and Biodegradable Hydrogels

Novel linear poly(NIPA‐co‐CL) copolymers have been synthesized by radical copolymerization of N‐isopropylacrylamide (NIPA) and 2‐methylene‐1,3‐dioxepane (MDO). The structure of copolymers was confirmed by ¹H NMR and IR spectroscopy. Cross‐linked poly(NIPA‐co‐CL) hydrogels have also been prepared in toluene using N,N′‐methylenebisacrylamide as cross‐linking agent. The hydrogels thus obtained exhibit good temperature response and are biodegradable in the presence of proteinase K.

Temperature influence on the enzymatic degradation by proteinase K of poly(NIPA‐co‐CL) hydrogel (G‐60).     

新型水溶性膦铑络合物催化烯烃的氢甲酰化反应研究

新型水溶性膦铑络合物催化烯烃的氢甲酰化反应研究燕远勇，左焕培，金子林（大连理工大学化工学院，大连１１６０１２）关键词烯烃，水溶性膦铑络合催化剂，氢甲酰化，醛．１．前言为克服催化剂的流失和与反应产物的分离困难，近年来均相催化的一个重要进展是开发了以磺化...     

Viscometric study of poly(vinyl chloride)/poly(vinyl acetate) blends in various solvents

The intermolecular interactions between poly(vinyl chloride) (PVC) and poly(vinyl acetate) (PVAc) in tetrahydrofuran (THF), methyl ethyl ketone (MEK) and N,N^′-dimethylformamide (DMF) were thoroughly investigated by the viscosity measurement. It has been found that the solvent selected has a great influence upon the polymer-polymer interactions in solution. If using PVAc and THF, or PVAc and DMF to form polymer solvent, the intrinsic viscosity of PVC in polymer solvent of (PVAc+THF) or (PVAc+DMF) is less than in corresponding pure solvent of THF or DMF. On the contrary, if using PVAc and MEK to form polymer solvent, the intrinsic viscosity of PVC in polymer solvent of (PVAc+MEK) is larger than in pure solvent of MEK. The influence of solvent upon the polymer-polymer interactions also comes from the interaction parameter term Δb, developed from modified Krigbaum and Wall theory. If PVC/PVAc blends with the weight ratio of 1/1 was dissolved in THF or DMF, Δb<0. On the contrary, if PVC/PVAc blends with the same weight ratio was dissolved in MEK, Δb>0. These experimental results show that the compatibility of PVC/PVAc blends is greatly associated with the solvent from which polymer mixtures were cast. The agreement of these results with differential scanning calorimetry measurements of PVC/PVAc blends casting from different solvents is good.     

Application of L-Cysteine-Capped ZnS Nanoparticles in the Determination of Nucleic Acids Using the Resonance Light Scattering Method

Nanometer-sized L-cysteine-capped ZnS particles were synthesized by a colloidal aqueous method. The functionalized nanoparticles are water-soluble and suitable for biological applications. In Tris-HCl buffer solution, nucleic acids combine with cysteine-capped nano-ZnS particles by intermolecular forces to form larger nanoparticles. There are two resonance light scattering peaks at 304.5nm and 373.8nm, respectively. The enhanced RLS is related to the concentration of nucleic acids in the range of 0.04 to 1.2µgmL^–1 for calf thymus DNA and 0.2 to 1.0µgmL^–1 for fish sperm DNA. The detection limits (3) are 19ngmL^–1 for calf thymus DNA and 23ngmL^–1 for fish sperm DNA, respectively. Four synthetic samples were analyzed satisfactorily.     

高分子免疫佐剂

随着新一代疫苗的发展,安全、高效的免疫佐剂的研究日益紧迫.本文介绍了这一领域的研究,扼要综述了高分子免疫佐剂的研究进展,并展望了高分子免疫佐剂的发展前景.     

Hydrothermal synthesis and intercalation behavior of a layered titanium phosphate Ti2(H2PO4)(HPO4)(PO4)2 · 0.5C6N2H16, with an extended γ-phase intercalated into organic amine

With a hydrothermal technique, a layered titanium phosphate with the formula Ti₂(H₂PO₄)(HPO₄)(PO₄)₂ · 0.5C₆N₂H₁₆ (denoted TP-J2) has been prepared by treating the Ti/H₃PO₄/H₂O/1-methylpiperazine system directly. The as-synthesized products were characterized by powder X-ray diffraction, CP-MAS solid-state ³¹P NMR spectroscopy, thermogravimetric and differential thermal analyses (TG-DTA). The structure was solved by single-crystal X-ray diffraction analysis and it presents an extended γ-phase intercalated with organic amine. Crystal data: triclinic, , a = 8.106 (2) Å, b = 8.197 (2) Å, c = 11.658 (2) Å.  = 78.32 (3)°, β = 80.85 (3)°, γ = 77.90 (3)°, Z = 2. Additionally, the intercalation behavior of TP-J2 with n-alkyl monoamine (n = 2, 3, 4, 6, 8, 10 and 12) was investigated. Owing to the strong brønsted base, N,N′-dimethylpiperazine, resides in the interlayer, it presented unusual features of TP-J2 in contrast with that of γ-Tip.     

Synthesis and thermal modulation of the fluorescence of a pyrene-arylmaleimide dyad and its Diels-Alder adduct

The fluorescence of a pyrene-arylmaleimide dyad and its Diels-Alder adduct can be thermally modulated through reversible Diels-Alder reaction of arylmaleimide unit with furan. Moreover, the fluorescence intensities of the Diels-Alder adduct of dyad 1 with furan vary linearly with the temperatures of the corresponding solutions, demonstrating that these molecules are interesting compounds for studies of fluorescent molecular thermometers.