When does gradient Ricci soliton have one end?

Annals of Global Analysis and Geometry - In this paper, we study a problem of finding compact hypersurfaces of prescribed mean curvature with free boundary in a ball. We transform the problem to an...     

钼钨铌磷杂多化合物的研究（Ⅰ）：杂多酸的合成和表征

提出了分步酸化一分步加料合成[PNb_2Mo_xW_(10-x)O_(40)]~(5-)(x=0,2,4,6)系列杂多酸的方法,给出了最佳配料比和生成反应的pH值,并进行了红外、紫外、极谱、电位滴定及热稳定性研究。     

铟(Ⅲ)-向红菲啰啉络合物极谱吸附波的研究

在pH=3.8的磷酸柠檬酸盐缓冲体系中,铟(Ⅲ)-向红菲(口罗)啉络合物在单扫描示波极谱仪上于-0.67 V(vs.SCE)处产生一灵敏的吸附还原波,其二阶导数波灵敏度高,波形好.峰电位Ⅰ~O_P与钢(Ⅲ)浓度在 2.0X10~(-8)~2.0X10~(-6)mol/L范围内呈良好的线性关系,其检测限为8X10~(-9)mol/L铟(Ⅲ).该法用于试剂氧化锌和镀膜玻璃中铟(Ⅲ)的恻定,结果较好.     

REDUCING NONSELECTIVE PROTEIN ADSORPTION AND CELL ADHESION ON POLYACRYLONITRILE FILMS BY COPOLYMERIZATION OF ACRYLONITRILE WITH α-ALLYL GLUCOSIDE

In this work, the surface properties of novel sugar-containing polymers, α-allyl glucoside (AG)/acrylonitrile (AN)copolymers, were studied by contact angle, protein adsorption and cell adhesion measurements. It was found that the contactangle of the copolymer films decreased from 68° to 30° with the increase of AG content in the copolymer. The adsorptionamount of bovine serum albumin (BSA) and the adhesive macrophage onto the film surface also decreased significantly withincreasing α-allyl glucoside content from 0 to 42 wt% in the copolymer. These preliminary results reveal that both thehydrophilicity and the biocompatibility of polyacrylonitrile-based membranes could be improved by copolymerizing acrylonitrile with vinyl carbohydrates.     

混合型杂多化合物Mx[GaW9M3O40]·nH2O的合成和性质

本文报道了M_x[GaW₉M₃^′O₄₀]nH₂O(M′=Mo,V,Ti,Fe(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Mn(Ⅱ);M=k,Na,Gua,Me₄N,Et₄N,Bu₄N)的合成。通过元素分析,阴离子电荷的确定,极谱、IR及UV光谱、可见光谱、ESR、磁化率测定对其进行了表征。并研究了它们在水溶液中对酸碱的稳定性     

An unusual mixed-valence Cu(I)-Cu(II) 3-D framework

The reaction of Cu(CH(3)CN)(4)ClO(4) with 2-pyridylacrylic acid (2-HPYA) affords an unusual mixed-valence Cu(I)-Cu(II) 3-D framework ([Cu(II)(2-PYA)(2)](3).[Cu(I)(2-PYA)](2).(H2O)(2))n (1) with a novel topology which features Cu(II) dimeric units (or paddle-wheel unit). The almost perpendicular coordinating direction between the N atom of pyridyl and the O atom of carboxylate groups may be responsible for the formation of such a novel network.     

The Action of the Selenomorpholine Compounds on Escherichia coli Growth by Microcalorimetry

The action of three kinds of the selenomorpholine compounds on a strain ofEscherichia coli was studied by microcalorimetry. Differences in their capacities to affect the metabolism of this bacterium were observed. The extent and duration of the effect on the metabolism as judged from the rate constant (k) of Escherichia coli (in log phase) varied with the different drugs. The kinetics show that selenomorpholine compounds had an effect on the metabolism process of Escherichia coli. The k of Escherichia coli in the presence of the drugs increased with the increasing concentrations of the drugs (C) at low concentration; but at high concentration, the rate constant decreased with the increasing concentrations of the drugs. The experimental results reveal that the sequence of antibiotic activity of selenomorpholines is: N-selenomorpholinemethyl succinimide and its hydrochloride>N-(α-selenomorpholinebenzyl) succinimide. This revised version was published online in August 2006 with corrections to the Cover Date.     

The triplet channel in the photodissociation of ozone in the Hartley band: classical trajectory surface hopping analysis

The triplet channel in the photodissociation of ozone in the Hartley band, O3 + hv-->O(3P) + O2(3sigma), is investigated by means of a classical trajectory surface hopping method using ab initio diabatic potential energy surfaces for the B and the R states. Because of the strong recoil in the R state along the breaking O-O bond, O2(3sigma) is produced with a high rotational energy. The nonadiabatic transition probability depends markedly on the coordinate along the crossing seam. As a consequence a unique correlation is found between the internuclear geometry at the crossing and the final vibrational state of O2(3sigma). The calculated distribution of the translational energy is in good accord with the measured distribution.     

Study on the effects of fluorine and oxygen deficiency on YBa2Cu307 byab initio method

The calculations of clusters modeling the fluorine-doping and oxygen deficiency of YBa₂Cu₃0₇ have been performed by the method of all-electronab initio Hartree-Fock with self-consistent crystal field. Results show that in CuO planes electric charge significantly increases, the chemical valence of Cu decreases and the covalent bonding of Cu-O greatly weakens owing to oxygen deficiency, while the effect of F restores the local electronic structure of YBa₂Cu₃O₇. The reported opinion that F occupied the oxygen vacancy in Cu-O chains seems disputable according to the calculated bonding characteristics Project supported by the National Natural Science Foundation of China.