碱金属离子在汞金属界面吸附作用的量子化学研究

应用量子化学方法对碱金属离子在汞金属界面的吸附作用进行了研究.选取汞金属界面的3个典型的位置(空穴、桥位和顶点),采用MP2方法计算得到Li+、Na+、K+3种离子在汞表面不同位置的吸附能.结果 表明:3种金属离子都是在空穴位置有较大的吸附能,然后是桥位和顶点位置;对于平衡结构,从Li+到Na+和K+,随着离子半径的增...     

AI~(3 ),Ph~(2 )掺杂提高SIO_2驻极体正电荷贮存性能

运用熔凝工艺在非晶态ＳｉＯ２薄膜驻极体中掺入质量分数为０．２的Ａｌ２Ｏ３和质量分数为０．４的ＰｂＯ．高温恒栅压正电晕充电及等温电荷衰减等实验表明,经Ａｌ(３＋)和Ｐｂ(２＋)离子掺杂改性的ＳｉＯ２薄膜（ＳｉＯ２－Ａｌ２Ｏ３－ＰｂＯ）具备较好的正极性驻极体性能,其正电荷储存稳定性在２１０ｄ后高于９５％;热激放电（ＴＳＤ）正电荷电流谱成为简明的负向放电曲线,峰值稳定于ｔ＝２９０℃附近;薄膜成形温度降低为８００℃左右,工艺得到简化．这表明有针对性的离子掺杂可以有效改善ＳｉＯ２薄膜体内的微观网络结构,从而提高其电荷注人与存储能力．     

六元瓜环与系列镧系金属离子的相互作用

本文通过单晶X-射线衍射方法考察了六元瓜环(Q[6])与系列镧系金属离子在硝酸镉(Cd(NO3)2)存在条件下的相互作用。实验结果表明:(Q[6])只与镧系金属中的镧(La)、铈(Ce)、镨(Pr)、钕(Nd)四种离子配位,形成1∶1的配合物,而与其余的稀土金属离子不发生直接配位作用,这一特性有可能用于轻稀土离子与重稀土离子分离的应用。     

酸沉降影响下土壤金属元素的变化

分析了重庆地区酸沉降对土壤金属元素的影响。结果表明：重庆重酸沉降区土壤耕作层交换性盐基含量Ｋ＋、Ｎａ＋、Ｃａ（２＋）、Ｍｇ（２＋）明显低于底层（１０～６０ｃｍ）土壤，显示出表层土壤矿质营养元素流失严重，而土壤中活化的有毒金属元素（Ｃｄ、Ｃｒ、Ｐｂ、Ｚｎ、Ｃｕ、Ａｌ）含量也明显高于对照区，且土壤表层活性Ａｌ增幅显著。因此．重庆酸沉降对土壤表层金属元素的影响是主要的。     

Alkylammonium cations treating and K-Ar dating of illite from mudstones

Two kinds of mudstones from the Tarim Basin and the Tuha Basin were treated with C8 and C18 alkylammonium cations. Both of them were dated by the K-Ar method. One kind of rock contains mainly diagenetic illite, and the other contains mixed layer illite/smectite (I/S). Sample separation and alkylammonium cations treatment were performed first, and K-Ar dating followed. The result shows that fine-grained minerals have younger K-Ar ages and coarse-grained components have older ages. Plots of K-Ar age versus K2O (%) are linear, the range of diagenetic age can be estimated by extrapolation. The reaction results of the above samples are different after alkylammonium cations treatments. The samples containing mainly illite show a decrease in K2O and an increase in age by 1-25 Ma, suggesting that preferential exchange of young diagenetic clay rather than detrital clay by alkylammonium cations, therefore the age of diagenetic illite can be calculated directly by the % K2O and radiogenic 40Ar removed. For the I/S dominant samples, detrital illite was opened preferentially by C8 alkylammonium cations treatment. Detrital age can be calculated, but it is hard to obtain the diagentic age directly.     

第一主族阳离子-苯复合物相互作用的理论研究

运用从头算MP2和密度泛函B3LYP方法,在6-311＋＋G^＊＊基组水平上对第一主族阳离子-苯复合体系的构型进行了自由优化,并定义阳离子位于苯环正上方。频率计算表明为合理构型,复合物的键长、原子电荷、分子轨道成份、前沿轨道能等表明,碱金属阳离子与苯的作用包含p-π和s-π作用方式,阳离子与苯结合时电子从苯向阳离子转移,形成电荷转移复合物,与氢键的结合方式相似。M^＋…benzene and benzene…M^＋…benzene复合物的红外光谱特征频率分别位于120～740cm^-1和140-890cm^-1,为阳离子垂直于环平面上作来回振动,其红外光谱振动频率随Li、Na、K向长波方向红移,并红外强度随Li、Na、K降低。     

Antioxidant responses and salt stress tolerance of Aloe vera irrigated by seawater with different salinity

The variations of antioxidant enzyme activities including superoxide dismutase （SOD： EC 1.15.1.1）, peroxidase （POD： EC 1.11.1.7） and catalase （CAT： EC 1.11.1.6）, lipid peroxidation and major electrolytes in Aloe vera irrigated for three years with seawater having different salinity were studied. The results indicate that POD activity increased significantly at 10% seawater level, whereas decreased at higher seawater levels. The SOD activity decreased with increasing seawater concentration except for treatment with 100% seawater （denoted as T100%） under long-term salt stress. Salinity decreased CAT activity,and increased lipid peroxidation and cell membrane injury. In addition, Ca^2＋ content was high in Aloe irrigated by seawater of low salinity level, but low in Aloe irrigated by seawater of high salinity level. An opposite trend was observed for the effect of seawater on Na^＋ content of plants. K^＋ and Mg^2＋ contents remain relatively stable under various seawater levels, which benefit plant growth.     

中国工业源大气盐基阳离子排放量估算

盐基阳离子排放清单的建立 ,对于中国酸沉降控制有重要的意义。针对电力、建材和钢铁工业 ,基于颗粒物的排放量和化学组成 ,分别计算工业点源和工业面源的大气盐基阳离子排放量 ,并绘制中国盐基阳离子排放强度分布图。结果表明 ,中国 2 0 0 0年工业源排放盐基阳离子总量为 4 17.0万 t,其中工业面源占 81.0 %。中国工业源盐基阳离子排放强度分布呈现东部高西部低的格局 ,最大值出现在河南省 ,达到了 2 12 .8kmol.km- 2 .a- 1。