Evaluation of the thermal/optical reflectance method for quantification of elemental carbon in sediments

IEECAS SKLLQG

轫致辐射能谱测定SSC高频腔体电压

介绍了利用轫致辐射能谱测定回旋加速器高频腔体电压的原理、方法及测量结果。该测量方法的优点在于采用非接触方式测量高频腔体电压 ,因而不改变高频腔体的谐振特性 ,并且不受高频频率的影响 ,测量的高频腔体电压准确可靠。

Preparation and characterization of CdS nanotubes and nanowires by electrochemical synthesis in ion-track templates

CdS nanotubes and nanowires have been synthesized with controlled dimensions by means of template-electrodeposition method in etched ion-track membranes. The diameters of nanotubes and nanowires are between 20 and I 10 nm, and the lengths are up to tens of micrometers. X-ray diffraction (XRD) and selected area electron diffraction (SAED) pattern investigations demonstrate that CdS nanotubes and nanowires are polycrystalline in nature. The UV-vis absorption spectra of CdS nanotubes and nanowires embedded in polycarbonate (PC) membranes show that the absorption edges of PC films shift towards the shorter wavelength, with decreasing diameters of the deposited nanostructures. The results indicate that nanowires are formed from nanotubes by nanotube-stuffing-growth mechanism.

beta-delayed proton decays of Tb-140 and Dy-140 as well as the spin and parity of Dy-143

Tb-140 and Dy-141 were produced via fusion evaporation in the reaction Ca-40+Cd-106. Their beta-delayed proton decays were studied by means of "p-gamma" coincidence in combination with a He-jet tape transport system, including half-lives, proton energy spectra, gamma-transitions following the proton emissions, and the branching ratios to the low-lying states in the grand-daughter nuclei. The ground-state spins and parities of Tb-140 and Dy-141 were extracted as 7(+/-) and 9/2(+/-), respectively, by fitting the experimental data with a statistical model calculation. The configuration-constrained nuclear potential energy surfaces (NPES) of Tb-140 and Dy-141 were calculated by using the Woods-Saxon Strutinsky method, which indicate the ground-state spins and parities of Tb-140 and Dy-147 to be 7(+) and 9/2(-), respectively. In addition, the configuration-constrained NPES of Dy-143 was also calculated by using the same method. From the NPES a 1/2(+) ground state and a 11/2(-) isomer with the excitation energy of 198keV were found. The calculated results are consistent with our experimental data on the decay of Dy-143 reported in Eur. Phys. J., 2003, A16: 347-351.

《中国沙地森林生态系统》评介

沙地森林是分布我国草原地区沙地上的大（中）高位芽植物为建群种形成的森林群落．由于其独特的生态条件、丰富的生物多样性和重要的生态系统功能，对我国北方防风固沙、控制土地沙漠化，改善当地农牧区人民生活环境以及三北防护林体系建设发挥巨大的生态效益、经济效益和...

从清王朝的历史看清代中国园林的发展

清代是中国古典园林发展的极盛时期,不管是造园艺术水平还是造园数量上都达到了历史上的高潮,显示中国古典园林的辉煌成就,代表了中国古典园林艺术的精华。清王朝把中国古典园林推向高潮的同时,也为现代园林的发展奠定了基础。通过回顾和分析清代的历史,探讨了清代中国园林发展的主要特点和对中国园林的贡献。

东北松辽平原农业资源的开发措施

东北松辽平原农业资源的开发措施王春裕（中国科学院沈阳应用生态研究所，沈阳１１００１５）王曦（辽宁省科学技术信息中心，沈阳１１００１５）松辽平原是我国东北地区松花江与辽河的冲积平原，南北长１０００多ｋｍ，东西宽４００多ｋｍ，地势平坦，土质肥沃，河）１１...

二恶英类物质的生物检测方法

我国的食品卫生、环境安全和公共健康正受到二恶英污染的威胁。国内虽已建成或在建少数HRGC-HRMS二恶英检测实验室,但其检测能力十分有限。笔者介绍二恶英类化合物生物检测方法,对各分析方法的原理和应用进行了对比分析;重点探讨CALUX法,与HRGC-HRMS及其他生物法相比,认为CALUX法更适于对大批量样品二恶英含量的快速定量筛选,对于二恶英污染调查有广阔的应用前景;同时对我国开展二恶英类分析检测提出了建议和展望,为完善二恶英类物质检测分析体系提供了依据。

石灰性土壤微生物量碳、氮与土壤颗粒组成和氮矿化势的关系

以黄土高原土壤类型和土壤肥力差异较大的25个农田石灰性耕层土壤为供试土样,研究了土壤微生物量碳(BC)、微生物量氮(BN)与土壤氮素矿化势(N0)、全氮(TN)、有机碳(OC)及土壤颗粒组成的关系.结果表明:BC、BN与TN、OC呈极显著正相关(P<0.01),表明BC、BN与土壤肥力关系密切,可作为评价土壤质量的生物学指标.BC、BN与N0均呈高度正相关,相关系数分别为0.665和0.741(P<0.01).BC、BN、TN、OC、N0与土壤物理性粘粒(<0.01 mm)呈显著或极显著正相关,而与物理性砂粒(>0.01 mm)呈显著或极显著负相关,与物理性粘粒和砂粒比值呈显著或极显著正相关,表明土壤有机质主要通过与土壤物理性粘粒复合而形成有机无机复合体.