掺杂钨丝中钾泡形成的动力学研究

本文利用透射和扫描电镜研究了掺杂钨丝退火时钾泡形成的机理和动力学,探讨了用微扰动理论处理钾泡形成过程的可能性。结果表明,冷拨掺杂钨丝中钾管分裂的必要条件是钾管长宽比≥9,在考虑钾泡形成热力学条件后,可导出几个有意义的钾泡分布参数,并发现对于同一丝径的掺杂钨丝,在同一温度退火,形成粗细不同的钾管,比较细的钾管分裂受表面扩散所控制,反之则主要受外部体扩散所控制,与实验结果相符。     

Zn—20%Al合金的半固态压缩形变特性研究

研究了温度和应变速率对常规铸造和部分凝固铸造Ｚｎ－２０％Ａｌ金合的半固态压缩形变的影响规律。试验温度和应变速率范围分别为３８０～４３０℃和２．１×１０＾－１×１０＾－４Ｓ＾－１。试验结果表明，金属在半固态时的形变抗力比固态时大幅度降低；部分凝固铸造合金的形变能力优于常规铸造合金；在高温（４３０℃）、低应变速率（８，．４×１０＾－４Ｓ＾－１）条件下，常规铸造合金也能获得较好的极限塑性和低的变形抗力…     

无毒防锈颜料亚磷酸－磷酸钾锌的聚合及防锈性能研究

无毒防锈颜料亚磷酸－磷酸钾锌经高温处理生成聚合亚磷酸－磷酸钾锌，ＩＲ、Ｘ－ｒａｙ、ＤＴＡ、ＴＧＡ等测试证实了聚合物的形成．测定了它们的技术指标及漆膜性能、聚合物的防锈性能明显优于亚磷酸－磷酸钾锌．     

Extraordinary levels of cadmium and zinc in a marine sponge,Tedania charcoti Topsent: inorganic chemical defense agents

The Antarctic marine spongeTedania charcoti has been shown to contain extraordinarily high natural concentrations of cadmium and zinc, which have in turn been correlated to the ability of the crude ethanol extract to modulate protein phosphorylation in chicken forebrain and to inhibit the growth of several test bacteria.     

等效粒子模型在氢气氛下ZnO脱硫研究中的应用

本文用热重法研究了球形及圆柱体T305脱硫剂在氢气氛下脱除COS反应的宏观动力学。实验表明,该反应对COS为一级反应。在240～390℃的温度范围内,就粒子上的反应而言,反应初期受反应本身控制,中后期转移到颗粒扩散控制。反应活化能及产物层扩散活化能分别为19.097 kJ/mol和46.438 kJ/mol.用等效粒子模型描述动力学行为,给出了该模型的各参数估值,讨论了有氢及无氢气氛下模型参数的差异及其原因。     

Alopecia induced in young mice by exposure to excess dietary zinc

Summary Second generation mice were exposed to normal (50 ppm, Group I) or excess (2000 ppm, Group II) zinc in the maternal diet during gestation and lactation, then weaned and continued on the mother's diet until sacrifice at 8 weeks. Tibia zinc reflected dietary intake. Group II had reduced plasma copper, body weight, and hematocrit; the second coat of hair appeared late and was lighter in color than Group I, possibly as an effect of copper and pigmentation development and hair growth.     

极谱催化法连续测定镁,锌,铁

提出了在铬黑Ｔ、乙二胺、三乙酸胺体系中连续测定镁、锌、铁的极话催化波．三元素在—０．９４Ｖ、—１．４４Ｖ、—１．６７Ｖ（对ＳＣＥ、下同）产生灵敏的极谱波．各元素在０～０．８μｇ／ｍＬ范围内浓度和导数峰高里线性关系．提出的方法用于同时测定头发和水中的痕量镁、锌、铁，结果满意．     

Synthesis and crystal structure of tetranuclear zinc benzoate

A tetranuclear zinc benzoate Zr4O(C6H5CO2)6 was synthesized and characterized by X-ray single crystal determination. It crystallizes in cubic, space group Ia-3d. Its crystal cell is very large, α=4.10063(18)nm, V=68.953(5)nm^3 and Z=48. The structure is composed of discrete Zr4O(C6H5CO2)6 molecules. In each molecule, four zinc atoms are held together by a central oxygen atom, which results in the formation of a regular tetrahedron. All benzoate ligands coordinate to zinc atoms in a bidentate bridging mode. Each zinc atom is in a slightly distorted tetrahedral geometry, coordinated by three benzoate oxygen atoms and the central oxygen atom. The intermolecular interactions result in the formation of a three-dimensional supramolecular framework, with non-intersecting parallel channels.     

[Zn(bim)2]·(H2O)1.67: A metal-organic open-framework with sodalite topology

Considerable efforts have been focused on the crystal engineering of the supramolecular architectures with desired properties such as zeolitic, magnetic and electric conducting materials[1—3]. But crystal engineering is still a great challenge to the chemists since lack of control over the coordination modes of metal centers and ligands during assembly of extended structures[4]. Some successful synthetic strategies based on topologic control of building blocks have been developed especially i…