X光滤片制备方法研究

研究了采用轧制、电阻加热、电子枪和C弧等制备X光滤片的方法,采用天平称重、α测厚仪和光学法等测量X光滤片厚度。分析了各种方法的适用范围及其优缺点,成功地制备了多种X光滤片。

Systematic study on alpha decay half-lives of superheavy nuclei

The a-decay half-lives of a set of superheavy nuclear isotope chain from Z = 105 to 120 have been analyzed systematically within the WKB method, and some nuclear structure features are found. The decay barriers have been determined in the quasi-molecular shape path within the Generalized Liquid Drop Model (GLDM) including the proximity effects between nucleons in a neck and the mass and charge asymmetry. The results are in reasonable agreement with the published experimental data for the alpha decay half-lives of isotopes of charge 112, 114, and 116, of the element 294118 and of some decay products. A comparison of present calculations with the results by the DDM3Y effective interaction and by the Viola-Seaborg Sobiczewski (VSS) formulae is also made. The experimental a decay half lives all stand in between the GLDM calculations and VSS formula results. This demonstrates the possibility of these models to provide reasonable estimates for the half-lives of nuclear decays by a emissions for the domain of SHN. The half-lives of these new nuclei are thus well tested from the reasonable consistence of the macroscopic, the microscopic, the empirical formulae and the experimental data. This also shows that the present data of SHN themselves are consistent. It could suggest that the present experimental claims on the existence of new elements Z = 110 similar to 118 are reliable. It is expected that greater deviations of a few SHN between the data and the model may be eliminated by further improvements on the precision of the measurements.

城市广场人性化设计与公众参与

城市广场是城市空间的重要组成部分,是市民社会生活的中心场所。要在城市广场的设计中实现"以人为本,"创造出公众真正需要的人性空间,就需要公众参与。我国城市广场规划设计中存在的主要问题是缺少公众参与。提出设计应由领导者、设计者、公众共同来完成,从而使设计更加完美。根据我国国情,公众参与城市广场规划设计应采取大众传媒发布信息,召开公众座谈会、专家咨询和审查会,邀请公众代表参与规划设计,公示设计图纸和模型等方法。

二道坊河沉积物中重金属等元素富集特征的研究

以二道坊河沉积物为研究对象 ,采用相关与回归分析综合地研究了 1 4种元素在沉积物中的富集特征 .结果表明 :地球化学性质相近的元素 ,它们在沉积物中的相关系数大多达到了显著或极显著的水平 ;通过因子分析 ,求出了 4个主因子 ,它们代表沉积物中1 4种元素测定信息的 85% ,以第一、二主因子对应的特征向量为X、Y轴将 1 4个元素分成了 3类 ;建立了大部分元素与沉积物性质之间的多元回归方程 .

SbOx/SiO2 catalysts for the selective oxidation of methane to formaldehyde using molecular oxygen as oxidant

SbOx and SbOx/SiO2 catalysts were prepared and investigated for methane selective oxidation to HCHO. HCHO selectivity up to 41% can be obtained on Sb2O5/SiO2 catalyst at 873 K and just drop gently to 18% with temperature up to 923 K. HCHO selectivity for SbOx/SiO2 catalysts decreases gently with reaction temperature, so considerable value of HCHO selectivity can still be obtained at high temperatures.

吉林省白城地区干草原栗斑腹的繁殖生态

栗斑腹在吉林省为留鸟 ,一年可繁殖两次 ,其雏鸟为典型的晚成鸟。 4月末开始有求偶追逐和争雌行为 ,5月中旬产卵。雌雄鸟筑巢时间分别是 43 min/d和 3 6min/d(筑巢第 4天 )。平均窝卵数为 5 .0 9± 0 .5 8枚 /巢 (n=3 1 ) ,孵卵前、中、后期雌鸟孵卵占白天活动时间的 3 5 %、74.5 %和 67.6% ,孵化期为 1 2 d,孵化率为 3 6.3 % ,2、8日龄喂雏分别为 4.5次 /h和 9.0次 /h。雏鸟的体重及外部器官的发育除嘴峰外 ,生长曲线均符合 Logistic方程 ,而嘴峰长的生长近似直线 ,栗斑腹雏鸟生长发育体重的生长模型为 :W =1 4.95 /1 +(e- 0 .552 ( t- 3.6 3) ) ,雏鸟 1 1日龄后出飞 ,繁殖成活率为 2 7.7%。

膜荚黄芪氮磷钾优化施肥模式研究

采用氮、磷、钾三因素二次D-饱和最优设计,通过田间试验建立了氮、磷、钾的施肥量编码值与膜荚黄芪根产量、多糖含量的效应函数。结果表明,氮、磷、钾肥对膜荚黄芪根产量的增产作用大小依次为氮肥>钾肥>磷肥;氮、磷、钾肥对黄芪多糖含量的作用大小依次为钾肥>磷肥>氮肥,其中钾肥为负效应,氮肥、磷肥为正效应。寻优结果表明,膜荚黄芪目标产量在6000～7000 kg/hm~2之间,95%置信区间的优化施肥量为N 66.85～102.92 kg/hm~2、P_2O_5 64.64～94.95 kg/hm~2、K_2O 119.78～166.48kg/hm~2;膜荚黄芪多糖含量在13%～14%之间,95%置信区间的优化施肥量为N 66.85～102.92kg/hm~2、P_2O_5 64.64～94.95kg/hm~2、K_2O 119.78～166.48 kg/hm~2;膜荚黄芪高产优质高效栽培优化施肥量为N 99.52～102.92kg/hm~2、P_2O_5 94.20～94.95kg/hm~2、K_2O 119.78～166.48kg/hm~2,N、P_2O_5、K_2O的最佳比例为1:0.92～0.95:1.16～1....

土壤中山毛榉根系呼吸的碳素损失

根系对植物生长发育过程有着重要的调控作用，其生理生化代谢过程是农学、生态学等学科研究的薄弱领域。植物生长发育过程受不同器官呼吸碳素损失的影响，根系是一个重要的碳素库［１］，其呼吸作用是生态系统碳素循环中重要的反馈途径之一［２，３］。由于很多研究侧重地上部分的研究，就环境因素对地下碳素库调控的了解还很有限，根系碳素量几乎占到植物总碳素量的５０％［４，５］，但是，目前就植物根系呼吸碳素损失的研究方法，以及影响同化产物累积和分配的机制还有待研究［１］。以往多用溶液培养、气培和分离根系［‘］来测定根系的呼吸速率或根系活力，这些测定结果与自然状态下根系的实际生理状况差异较大，难以确切掌握植物碳素平衡与分配。为此，我们设计了一种可动态测定土壤中植物根系呼吸碳素损失的方法，并在高ＣＯ２条件下植物１３Ｃ吸收与分配模式研究中取得了较好的结果。１测定原理和实验装置 呼吸作用是植物组织利用吸收的氧气和光合作用合成的碳水化合物反应，释放ＣＯ２ 和能量（ＡＴＰ，ＮＡＤＰＨ等）的生理代谢过程，通 过测定一定体积或重量的植物组织的Ｏ２含量或 ＣＯ２含量的改变可以推算植物组织的呼吸作用 强度。 实验装置高３０ｃｍ、直径１４ｃｍ，并与周围大 ...

木蹄层孔菌培养条件的研究

木蹄层孔菌是一种具重要价值的真菌。研究了不同配方的固体培养基,在不同的温度、pH值培养条件下对木蹄层孔菌菌丝生长的影响。结果显示,木蹄层孔菌的营养菌丝生长最适培养温度为28℃,最适培养pH值为7,最适培养C源为蔗糖,最适培养N源为蛋白胨。这些结果为将来木蹄层孔菌的人工培植和工业应用提供了指导作用。

Synthesis, structure and luminescence properties of zinc (II) complexes with terpyridine derivatives as ligands

Five zinc (II) complexes (1-5) with 4 '-phenyl-2,2 ':6 ',2 ''-terpyridine (ptpy) derivatives as ligands have been synthesized and fully characterized. The para-position of phenyl in ptpy is substituted by the group (R), i.e. tert-butyl (t-Bu), hexyloxy (OHex), carbazole-9-yl (Cz), naphthalen-1-yl-phenyl-amine-N-yl (NPA) and diphenyl amine-N-yl (DPA), with different electron-donating ability. With increasing donor ability of the R, the emission color of the complexes in film was modulated from violet (392 nm) to reddish orange (604 nm). The photoexcited luminescence exhibits significant solvatochromism because the emission of the complexes involves the intra-ligand charge transfer (ILCT) excited state. The electrochemical investigations show that the complexes with stronger electro-donating substituent have lower oxidation potential and then higher HOMO level. The electroluminescence (EL) properties of these zinc (II) complexes were studied with the device structure of ITO/PEDOT/Zn (II) complex: PBD:PMMA/BCP/AlQ/ LiF/Al. Complexes 3, 4 and 5 exhibit EL wavelength at 552, 600 and 609 nm with maximum current efficiency of 5.28, 2.83 and 2.00 cd/A, respectively.