Gravitational corrections to energy-levels of a hydrogen atom

The first-order perturbations of the energy levels of a hydrogen atom in central internal gravitational field are investigated. The internal gravitational field is produced by the mass of the atomic nucleus. The energy shifts are calculated for the relativistic 1S, 2S, 2P, 3S, 3P, 3D, 4S, and 4P levels with Schwarzschild metric. The calculated results show that the gravitational corrections are sensitive to the total angular momentum quantum number.

Systematic study of properties of Hs nuclei

The ground-state properties of Hs nuclei are studied in the framework of the relativistic meanfield theory. We find that the more relatively stable isotopes are located on the proton abundant side of the isotopic chain. The last stable nucleus near the proton drip line is probably the (255)Hs nucleus. The alpha-decay half-lives of Hs nuclei are predicted, and together with the evaluation of the spontaneous-fission half-lives it is shown that the nuclei, which are possibly stable against spontaneous fission are (263-274)Hs. This is in coincidence with the larger binding energies per nucleon. If (271-274)Hs can be synthesized and identified, only those nuclei from the upper Z = 118 isotopic chain, which are lighter than the nucleus (294)118, and those nuclei in the corresponding alpha-decay chain lead to Hs nuclei. The most stable unknown Hs nucleus is (268)Hs. The density-dependent delta interaction pairing is used to improve the BCS pairing correction, which results in more reasonable single-particle energy level distributions and nucleon occupation probabilities. It is shown that the properties of nuclei in the superheavy region can be described with this interaction.

Ar16+ 离子与Au和Mo靶相互作用产生的X射线截面随入射角度的变化

本实验工作是在兰州重离子加速器国家实验室ECR离子源完成。实验采用能量为336keV的低能高电荷态Ar16+离子轰击Au、Mo金属靶，入射离子与靶表面之间的夹角分别是20°，25°，……，80°，入射角与出射角之和为90°。测量了不同角度下Mo的Lα、Lβ，Au的Mα和Ar的Kα特征X射线谱，对实验谱进行了高斯拟合，计算了不同入射角下的各条X射线的产额和产生截面，并将靶原子发射出的X射线截面与ECPSSR和带结合能修正的BEA理论计算的结果进行了比较。发现当入射角较小时，Ar16+与金属靶相互作用时所产生出的各条特征X射线截面随入射角的增加而增加，当入射角达到40°左右后X射线截面基本上保持不变。与ECPSSR计算值相比，本实验中Au的X射线截面比较接近，实验值比ECPSSR计算值小不到一个量级；而Mo的X射线截面实验值比ECPSSR计算值大3-4个量级，但产额与带结合能修正的BEA计算值很接近

Template-assisted syntheses of two novel porous zirconium methylphosphonates

Two porous zirconium methylphosphonates (designated as ZMPmi and ZMPme respectively) were synthesized by using dibutyl methylphosphonate (DBMP) as a template. Two efficient post-synthetic treatments were developed to remove the incorporated template without destroying the hybrid structures. The materials were characterized by SEM, EPMA, TG, DTA, FTIR, and NMR. Specific surface area and porosity were evaluated by BET, alpha(s)-plots and DFT methods based on N-2 adsorption-desorption isotherms. The specific surface areas of ZMPmi and ZMPme are determined to be 279 and 403 m(2) g(-1) and the maxima of pore size distributions are at 0.7 and 1.3 nm respectively. (c) 2005 Elsevier Inc. All rights reserved.

Polymeric fullerene oxide films produced by decomposition of hexanitro[60]fullerene

A new poly(fullerene oxide) thin film material has been fabricated by thermal activation and electron bombardment on hexanitro[60]fullerene (HNF) film deposited on a An substrate, all under vacuum conditions. The reaction products in the polymerization process are analyzed by XPS, UPS, IR, TGA-MS and LDI-MS techniques. It is found that the main effect of thermal and radiation treatments is to induce cleavage of -NO bonds from HNF molecules resulted in the release of nitric oxide gas and the formation of fullerene-bound oxyradicals, C-60-C-6. Spectroscopic evidence strongly suggests that rearrangement of fullerenic nitro moieties into nitrito groups is involved in the HNF decomposition process prior to the generation of reactive oxyradical intermediates. Consequently, the intermolecular coupling reaction of these oxyradicals leads to carbon polymer networks containing oxygen-bridged fullerenes. The thermally generated polymeric thin film is stable up to 900 K. Electron bombardment is also effective in both the decomposition of -NO2 groups and the removal of -OH groups present in HNF films. UV irradiation at 365 nm alone is shown to be not as efficient for the polymer formation. (C) 2003 Elsevier Ltd. All rights reserved.

Characterization of metal-containing molecular sieves and their catalytic properties in the selective oxidation of cyclohexane

Three types of metal-containing molecular sieves with AFI, AEL and CHA structures (Me = Co, Mn, Cr and V) were synthesized hydrothermally and characterized by XRD, XRF, TG, TPR, NH3-TPD and FT-IR. It was revealed that metals were incorporated into the framework of molecular sieves and induced the presence of charge centers. Both cobalt and manganese in the framework of AIPO-5, AlPO-11 and SAPO-34 were not reducible before the structure collapse. The redox behaviours of these catalysts in cyclohexane oxidation at 403 K using O-2 as oxidant were examined. CoAPO-11 exhibited best activity and good selectivities for the monofunctional oxidation products (88.5%). Cyclohexanol was the major product over most catalysts, whereas for Cr-containing molecular sieves, high selectivity of cyclohexanone was observed. Investigation of reaction mechanism based on CoAPO-11 and CrAPO-5 catalysts indicated that the decomposition of cyclohexyl hydroperoxide (CHHP), the intermediate in cyclohexane oxidation, followed the pathway: cyclohexanone <-- CHHP --> cyclohexanol -->cyclohexanone. (C) 2004 Elsevier B.V. All rights reserved.

耕地土壤交换性钙镁比值的研究

对沈阳市郊区1994个耕地表土(0～20cm)样点和4个典型剖面中交换性Ca/Mg的比值进行了对比研究。结果表明:不同土属耕层土壤中Ca、Mg交换量有较大差别,交换性Ca/Mg的比值主要受母质等成土因素的影响;棕壤的各个土属的Ca/Mg在4左右,石灰性草甸土和草甸沼泽土的Ca/Mg则在8以上。棕壤和草甸土典型剖面不同层次中的Ca/Mg比值有着随深度加深而降低的趋势;由于Ca的植物返还率较Mg高,同一土壤类型中Ca/Mg比值的最大值出现在表土层,母质层中的Ca/Mg则相对稳定。对土壤Ca/Mg进行研究可以丰富土壤离子交换性能研究和土壤发生学特性研究的内容。

黄孢原毛平革菌合成木素过氧化物酶的营养调控

本文研究了营养条件对黄孢原毛平革茵(Phanerochale chrysosporium)ME-116合成木素过氧化物酶及其同工酶组分的影响.在最适培养条件下获得1500U/L的酶活.高效液相色谱分离的5个同工酶组分中以P_2组分含量最高.低碳高氮培养基最适于酶的合成.降低氮和KH_2PO_4含量致使各组分含量下降,而改变MgSO_4和CaCl_2浓度对P_2组分无影响.表面活性剂吐温80主要通过提高细胞膜透性而增加酶的合成.黎芦醇对5种同工酶组分的合成均有诱导作用.培养基中各营养因子对木素过氧化物酶的合成存在着复杂的交互作用.

江西省丘陵区湿地松多效益经营模式适宜经营密度的研究

通过拟合林分枝叶生物量及林下植被生物量与林分郁闭度的关系求算出湿地松水保林的适宜郁闭度范围 ,利用林分郁闭度与林分平均直径和林分株数密度的关系式 ,导算出湿地松水保林的适宜密度 ,用公式N1=15 761.64 /D表示 .以价值生长量最大作最优指标函数 ,采用动态规划方法求算出材脂两用林的最适经营密度线N2 =2 3 62 5 .12D-1.152 3 .综合得出江西省丘陵区湿地松多效益经营模式适宜经营密度就是以上两条密度线所夹范围 .

植被恢复过程中土壤养分的变化

在纸坊沟流域不同退耕年限的区域采集表层0~20 cm土样274个,分析了不同植被及其退耕年限下的土壤养分变化规律。结果表明,退耕后林草覆盖下的土壤有机质和全氮含量有所增加,特别是刺槐林地增加幅度较大,全磷含量变化不显著,草地覆盖下土壤的速效氮含量低于农田速效氮含量;土壤有机质、全氮、全磷、硝态氮和铵态氮随退耕年限增加呈现出先减少后增加的趋势;退耕年限与土壤有机质和全氮存在显著的正相关性。

辽西地区水分亏缺与树木生长关系

利用修正的Thornthwaite最大蒸发力公式,计算了辽西地区不同市的水分亏缺量。各市最大潜在蒸发散计算结果是:朝阳1180.6 mm,锦州1146.0 mm,葫芦岛1140.1 mm,阜新1030.3 mm;水分亏缺量计算结果为:朝阳-658.3 mm,锦州-538.4 mill,葫芦岛-544.8 mm,阜新-626.9 mm。利用美国spss数理统计软件计算了油松与蒙古栎的胸径连年生长量和对应的各年1—12月份的月均温、月降雨量、平均相对湿度的回归关系,表明油松生长与温度紧密,蒙古栎生长与水分关系紧密。

沈阳地区水灾后“被淤”农田土壤肥力状况及改良途径

<正> 1 引言沈阳地区位于辽宁省中北部,属中温带受季风影响的半湿润大陆性气候。该地区地貌类型多样,东北和西南紧靠长白山余脉千山山脉,属低山丘陵,中西部是辽阔平原地貌由东北向西南倾斜。全地区有大小河流15余条,大部向西南的辽中、新民等地汇集再出境入海,上游是旱坡地,而且林地的森林覆盖率较低。1995年7～8月,沈阳地区连降大雨,达658.3mm,相当于27a的全年平均降雨量的总和,造成百年不遇的特大洪水,致使平原地区大片农田被淹达20d左右,面积达6.67×10~5hm~2。这次洪水源于天然降雨并汇集上游地区地表径流而形成的,水体混浊,悬浮物