特征X射线能谱法测定Fe^＋注入小麦种子的深度

用１１０ｋｅＶ Ｆｅ＾＋离子束垂直注入小麦种胚后，在扫描电子显微镜上沿种子纵沟剖面，在不同深度上测量Ｆｅ元素被激发出的特征Ｘ射线强度分布，结果表明分布呈指数衰减，与晶体中的热扩散分布相类似，并对此进行了讨论。     

HHD型核子秤电离室物理性能检测

HHD型核子秤电离室已成功地使用于HCS型核子秤.对它的各种物理性能指标进行了检测,各项性能指标都达到了设计要求。     

辐射制备缓释抗癌药阿糖胞苷的研究

报告了甲基丙烯酸酯类在室温下进行辐射聚合制备缓释抗癌药阿糖胞苷（Ａｒａ－Ｃ）的研究结果。结果表明，不仅亲水性单体，而且疏水性单体（包括ＭＭＡ、ＥＭＡ和ＢＭＡ等）都可用于辐射固化。加入到亲水性基质中的疏水性单体可以延缓药物的离体释放，其顺序是ＭＭＡ＜ＥＭＡ＜ＢＭＡ，央ＭＭＡ－ＨＥＭＡ共聚物中，Ａｒａ－Ｃ释放率随着基质中的ＭＭＡ含量增加而降低。药物的离体释放还受许多困素的控制，结果显示：药物释放量随着     

A truncated poisson regression model with applications to occurrence of adenomatous polyps

Adenomatous polyps are considered as the dominant precursor lesion of colorectal cancer. A phase III colorectal cancer prevention trial, conducted by the Arizona Cancer Center, concerns the ability of wheat bran fibre supplement to reduce the recurrence of adenomatous polyps. All participants in the study are to have had colorectal polyps detected and removed during a baseline (qualifying) colonoscopy within three months prior to enrolment. In this paper, our interest focuses on occurrence of adenomatous polyps at the baseline colonoscopy. We use a truncated Poisson model to fit these types of data. We develop a regression model to assess the effects of explanatory factors on the positive counting variable. We fit truncated Poisson parameters by a log-linear regression model and estimate regression parameters by the maximum likelihood procedure. Finally, we apply it to the baseline colonoscopy data from the Wheat Bran Fiber study.     

STRUCTURE REPRESENTATION OF THE SPECIFIC FRACTIONS FROM PINGSHUO COAL

Basic data of four fractions, PM₁, PM₆, PM₇and PM₈, derived from Pingshuo bituminous coal were obtained by ultimate analyses, mean molecular weight measure, GC/MS, ¹³C-NM R, ¹H-NM R and FTIR technigues. A method of calculating the average molecular parameters of the fractions is introduced. Based on the calculated parameters, the molecular structure models of the fractions of PM₆, PM;and PM₈are constructed. Significant structural information about the saturated hydrocarbon and aromatic hydrocarbon with heteroatom groups is given also.     

An observer-based robust adaptive controller for permanent magnet synchronous motor drive with initial rotor angle uncertainty

An observer-based robust adaptive nonlinear position and speed tracking controller is developed for a permanent magnet synchronous motor with initial rotor angle uncertainty. The unknown initial rotor position is treated as a constant motor parameter in the development of the controller. An incremental encoder, which provides relative position variation of the rotor, is used along with stator current signals to achieve stable control. However, the controller does not require the knowledge of motor parameters and it only assumes friction, external disturbances, and model uncertainties are bounded. By using state observers, the measurement of acceleration and load torque, which is required usually in the nonlinear controller design with high tracking performance, is avoided. The stability of the control system and tracking convergence are guaranteed using Lyapunov theory. Finally, the stability and efficacy of the proposed drive system are verified by experimental results.     

Growth and morphology of nanometer LiMn2O4 powder

The growth of Li_1+xMn₂O₄ via detonation reaction was investigated with respect to the presence of an energetic precursor, such as the metallic nitrate and the degree of confinement of the explosive charge. The detonation products were characterized by scanning electron microscopy. Powder X-ray diffraction and transmission electron microscopy were used to characterize the products. Li_1+xMn₂O₄ with 1-2 μm spherical morphology and more uniform secondary particles, but with smaller primary particles of diameters from 20 to 60 nm and a variety of morphologies were found. The oxides produced by this cheap method affirmed the validity of detonation synthesis of nano-size powders.     

Experimental Study on Energy Consumption of Combined Conventional and Dehumidification Drying

Conventional drying, dehumidification drying, and combined conventional-dehumidification drying of wood were experimentally studied in this article. The results showed that the energy consumption in the dehumidification drying is the least but its drying time is the longest. The energy consumption in the combined drying is more than that in the dehumidification drying but less than that in the conventional drying, and the drying time is half of that in the dehumidification drying. The advantages of the combined conventional and dehumidification drying are discussed from the experiments results.     

穿黄工程异型接头板研制与应用

本文介绍了新研制的异形接头板结构特点和工作原理,该异型接头板成功应用于南水北调中线一期穿黄工程北岸地下连续墙工程中。