关于实Hilbert环

通过引进“强实Hilbert环”这一概念,本文证明了,一个环A是强实Hilbert环,当且仅当多项式环A[X]是实Hilbert环,当且仅当A[X]的每个实极大理想在A上的局限是实极大的,从而文献[1]中两个主要结果被否定.此外,本文还研究了所谓的“严格的实Hilbert环”,这类环对于半代数零点定理等方面的探讨更具应用意义.     

CORBA~( ):一个具有自卫智能体的扩展CORBA

将自卫机制加入OOP成为AOP以提高CORBA中软件的强健性和防卫能力,在CORBA这个异构环境中,一个对象申请服务之后就需等待,如果应答迟迟不到则有可能永远等待下去,为避免这种现象的产生和蔓延,在客户和服务方的行为中加入超时机制(timeout mecha-nism)并采用利己或利他策略,使得对象可独立地根据当前环境和时间决定下一步骤,将这种在协作者失败的情况下仍能生存的对象称为自卫智能体,加入白卫智能体的CORBA称为CORBA~( ),由于智能体可在任何条件下生存,CORBA~( )可为用户提供可靠的服务,也就能实现CORBA~( )中软件构成的强健性。     

The magnetic entropy changes in Gd1−xBx alloys

A series of Gd_(1−x)B_x alloys have been prepared by arc melting method. After introducing small quantity of B atom in Gd, the Curie temperature of these alloys increase while the magnetic entropy changes are almost same as that of Gd. The refrigerant capacities of these alloys are also greater than that of Gd. These results suggest that Gd_(1−x)B_x alloys may be utilized as refrigerant in household magnetic refrigeration.     

The optical properties of planar waveguides in LiB3O5 crystals formed by Cu implantation

A planar optical waveguide has been formed in a LiB₃O₅ crystal using 6.0 MeV Cu⁺-ions with a dose of 1 × 10¹⁵ ions/cm² at room temperature. Possible propagating modes were measured at a wavelength of 633 nm using the prism-coupling method. The refractive index profiles of the waveguide were reconstructed by an effective refractive index method and the beam propagation method was used to investigate the properties of the propagation modes in the formed waveguide. The results suggest that the fundamental TE₀ and TM₀ modes may be well-confined and propagate a longer distance inside the waveguide. The implantation process was also simulated using the transport of ions in matter code (TRIM), which indicates that the nuclear energy deposition may be the main factor for the refractive index change.     

Characterization of a pectic polysaccharide from the fruit of <Emphasis Type="Italic">Ziziphus jujuba</Emphasis>

A pectic polysaccharide was isolated from the fruits of Ziziphus jujuba Mill. cv. jinsixiaozao Hort. and its structure was characterized by acid hydrolysis, methylation, and NMR spectroscopies. The purified fraction Ju-B-7 had a molecular mass of over 2000 kDa. Chemical and spectroscopic analyses indicated that Ju-B-7 is composed mainly of α-1,4-linked D-galactopyranosyluronic acid and 1,2-linked L-rhamnose with a molar ratio of 8.1:1. It can significantly stimulate spleen cell proliferation in vitro (P<0.01, 10 μmg/mL). Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 311–312, July–August, 2007.     

Large time behavior of the solutions to the Boltzmann equation with specular reflective boundary condition

In this paper a half space problem for the one-dimensional Boltzmann equation with specular reflective boundary condition is investigated. It is shown that the solution of the Boltzmann equation time-asymptotically converges to a global Maxwellian under some initial conditions. Furthermore, a time-decay rate is also obtained.     

Si衬底上ZnSe外延膜的低压MOCVD生长

以硒化氢（H2Se）和二甲基锌为源材料，生长温度是300℃时，用低压金属有机化学气相沉积（LP－MOCVD）系统在Si(111)衬底上外延生长了ZnSe薄膜。通过X射线衍射（XRD）、扫描电子显微镜的能量色散（EDS）以及光致发光（PL）实验验证ZnSe外延膜的质量，在X射线衍射谱中只有一个强的ZnSe(111)面衍射峰，这说明外延膜是（111）取向的单晶薄膜，在能量色散谱中除了Si,Zn和Se原子外，没有观测到其他原子，说明ZnSe外延膜中杂质含量较少。ZnSe外延膜中Zn/Se原子比接近1，有较好的化学配比。在ZnSe外延膜的77K光致发光谱中没有观测到与深中心发射相关的发光峰，表明ZnSe外延膜的晶格缺陷密度较小。77K时的近带边发射峰447nm在室温时移至465nm附近。