静电纺丝法制备SiW11V／PMMA复合纤维

用静电纺丝法制备了SiWuV/PMMA复合纤维.讨论了电纺电压、浓度和接收距离对PMMA成纤性和纤维形态的影响.利用扫描电子显微镜、X射线粉末衍射仪、红外光谱仪等对制备的Siw11V/PMMA复合纤维进行了表征.结果表明:电压为21kV,Siw11V/PMMA溶液的质量分数为15%～50%,喷口到接收板距离为20cm时制备的复合纤维最佳;Siw11V/PMMA复合纤维中Siw11V通过氢键与PMMA分子结合形成了复合物.     

自主、探究与合作式教学模式在非化学类基础化学实验中应用

“自主、探究与合作”式教学模式是把探究性学习与合作式学习两种先进的教学模式融合到实验教学过程中,创建一种全新的实验教学模式.此教学模式充分利用信息技术和信息资源,使实验教学在培养学生创新精神、现代社会必须的团队协作精神,提高学生的实践能力、独立获取知识的能力、创新能力和决策能力上发挥更大的作用.     

Optimal configuration of bistatic sonar system using Cramér-Rao lower bound of position estimation

In order to study the optimization configuration problem of bistatic sonar system,the optimal configuration model of bistatic sonar system was established. The positioning accuracy of the dual-base sonar at different dual-base angles was obtained by calculating the Cramér-Rao lower bound(CRLB) accuracy based on the optimal configuration model. The effect of system time measurement error and angle measurement error on positioning accuracy was analyzed by simulation. The transmitting and receiving...     

Trace water triggers high-efficiency photocatalytic hydrogen peroxide production

Photocatalytic production of hydrogen peroxide(H₂O₂)has attracted much attentions as a promising method for sustainable solar fuel.Here,we demonstrate that trace water can drastically boost highefficiency photocatalytic production of H₂O₂ with a record-high concentration of 113 mmol L^-1 using alkali-assisted C₃N₄ as photocatalyst in water/alcohol mixture solvents.By electron paramagnetic resonance(EPR)measurement,the radical species generated during the photocatalytic process of H₂O₂ are identified.We propose alcohol is used to provide and stabilize-OOH radicals through hydrogen bond,while trace water could trigger photocatalytic production of H₂O₂ via providing and transferring indispensable free protons to completely consume OOH radicals,which breaks the reaction balance of-OOH radical generation from alcohol.Thus-OOH radicals could be supplied by alcohol continuously to serve as a reservoir for high-efficiency production of H₂O₂.These results pave the way towards photocatalytic method on semiconductor catalysts as an outstanding approach for production of hydrogen peroxide.     

Nonorthogonal Tight-binding Study of the Geometries and Electronic Properties of Ge_n(n=2—20)Clusters

ＩｎｔｒｏｄｕｃｔｉｏｎＳｔｕｄｉｅｓｏｎｃｌｕｓｔｅｒｓｏｆｇｒｏｕｐⅣｅｌｅｍｅｎｔｓ（Ｃ,Ｓｉ,Ｇｅ,ＳｎａｎｄＰｂ）ｈａｖｅｒｅｃｅｉｖｅｄｍｕｃｈａｔｅｎｔｉｏｎｉｎｔｈｅｌａｓｔｄｅｃａｄｅｆｏｒｔｈｅｉｒｐｏｔｅｎｔｉａｌａｐｐｌｉｃａ...     

NMR Study of Hydroxyl-Substituted Macrocyclic Hexaamine in Solution

Ｉｎｏｕｒｐｒｅｖｉｏｕｓｐａｐｅｒ[1] ,ｔｈｅｓｙｎｔｈｅｓｉｓｏｆ3,13 ｄｉｈｙｄｒｏｘｙｌ 1,5 ,8,11,15 ,18 ｈｅｘａａｚａｃｙｃｌｉｃａｍｉｎｅｈｅｘａｈｙｄｒｏｂｒｏｍｉｄｅｈａｓｂｅｅｎｒｅｐｏｒｔｅｄ .Ｔｈｅｃｒｙｓｔａｌｓｔｒｕｃｔｕｒｅｏｆｔｈｉｓｃｏｍｐｏｕｎｄ (Ｆｉｇ .1)ｈａｓｂｅｅｎｄｅｔｅｒｍｉｎｅｄｂｙｓｉｎｇｌｅ ｃｒｙｓｔａｌＸ ｒａｙｄｉｆｆｒａｃｔｉｏｎ[2 ] .ＲｅｃｅｎｔｌｙｔｈｅＮＭＲｍｅｔｈｏｄｓｗｅｒｅａｌｓｏｕｓｅｄｔｏｉｎｖｅｓｔｉｇａｔｅｔｈｅｓｔｅｒｉ…     

Purification and Characterization of an Antibacterial Peptide from Rana Temporaria Chensinensis Skin

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎａｄｄｉｔｉｏｎｔｏｔｈｅｈｉｇｈｌｙｓｐｅｃｉｆｉｃｃｅｌｌ－ｍｅｄｉａｔｅｄｉｍｍｕｎｅｓｙｓｔｅｍ，ｖｅｒｔｅｂｒａｔｅｓａｎｄｏｔｈｅｒｏｒｇａｎｉｓｍｓｈａｖｅａｄｅｆｅｎｓｅｓｙｓｔｅｍｍａｄｅｕｐｏｆｄｉｓｔｉｎｃｔｇｒｏｕｐｓｏｆｂｒｏａｄ－ｓｐｅｃｔｒｕｍａｎｔｉｂａｃｔｅｒｉａｌｐｅｐｔｉｄｅｓ［１—３］．Ａｎｔｉｂａｃｔｅｒｉａｌｐｅｐｔｉｄｅｓｃａｎｂｅｃｌａｓｓｉｆｉｅｄｉｎｔｏｔｗｏｇｒｏｕｐｓｂａｓｅｄｏｎｈａｖｉｎｇｄｉｓｕｌ－ｆｉｄｅ…     

Keggin结构钒取代硅钨酸/聚丙烯酰胺复合膜的制备及光致变色性能研究

制备了一、三钒取代的Keggin结构硅钨酸(SiW12-nVn,n=1,3)/聚丙烯酰胺(PAM)复合膜,采用红外光谱对其进行了表征.并研究了杂多酸的种类、含量以及照射光波长对SiW12-nVn/PAM复合膜光致变色性能的影响,通过ESR光谱推断了其可能的变色机理.结果表明:高含量、强氧化能力的多酸以及短波长的照射光波有利于SiW12-nVn/PAM复合膜的光致变色发生.     

双层表面活性剂改性Fe304磁流体的制备

用化学共沉淀法合成了Fe304纳柬微粒,油酸和十二烷基苯磺酸钠双层表面活性剂对其表面进行改性,得到了以水和乙醇为分散介质的纳米Fe304可聚合磁流体,讨论了纳米磁性Fe304双层活性剂表面改性过程,并采用透射电镜,虹外光谱及x射线衍射对其形态、结构、组成等进行了表征。