景观可视化及其应用

介绍了景观可视化的概念,回顾了景观可视化的发展历程,然后介绍了景观要素,包括地形、植被、水、人工构件(建筑物、基础设施等)、动物(包括人)、大气和光的可视化表达方法,阐述了景观可视化在景观规划、景观变化、气候变化、城市景观、景观视觉影响评价和森林管理等方面的应用,最后提出了景观可视化的未来发展趋势。

神农架地区珍稀植物沿河岸带的分布格局及其保护意义

在神农架香溪河流域从源头到河口的不同海拔高度沿河岸带共设置 4 0个与河流方向平行的10 0m× 10m的样带 ,进行了植物群落学调查研究 .结果表明 ,沿河岸带分布有珍稀植物 14种 ,占神农架地区珍稀植物总数的 4 2 .4 % .这些珍稀物种主要分布在海拔 12 0 0～ 180 0m山地常绿阔叶落叶阔叶混交林带 ,珍稀植物种类的物种丰富度在中等海拔高度上最大 .珍稀植物的种类可划分为低海拔、中等海拔和高海拔 3组 .针对珍稀植物的分布特点 ,明确指出应重视河岸带在生物多样性、尤其是珍稀物种保护方面的重要作用 .

小柏根和白石清热冲剂废渣栽培平菇试验

小柏根和白石清热冲剂废渣栽培平菇试验姚志红（中国科学院沈阳应用生态所，１１００１５）随着食用菌栽培业的迅速发展，棉子皮等一些传统生产原料供不应求或价格过高的问题日趋突出，在非产棉地区更成了生产发展的限制因素。因此，不断挖掘当地可利用的潜在资源，开辟新...

樟子松林存在的奥秘与开发前景

樟子松林存在的奥秘与开发前景中国科学院沈阳应用生态研究所博士研究生卜军呼伦贝尔草原南部、大兴安岭西麓有一大片具有神秘色彩的森林，这就是举世闻名的红花尔基沙地樟子松林。红花尔基四面远离海洋，大气和土壤干旱，又没有任何屏障来阻挡蒙古高原吹来的北季风，所以...

Improved efficiency by doping blue iridium (III) complex in europium complex-based light-emitting diodes

We demonstrated high-efficiency red organic light-emitting diodes (OLEDs) employing a europium complex, Eu (III) tris( thenoyltrifluoroacetone) 3,4,7,8-tetramethyl-1,10-phenanthroline (Eu(TTA)(3)(Tmphen)), as an emitter and a blue electrophosphorescent complex, Iridium ( III) bis[4,6-di-fluorophenyl-pyridinato-N,C-2] picolinate (FIrpic), as an assistant dopant codoped into 4,4-N, N-dicarbazole-biphenyl (CBP) host as an emissive layer. A pure red electroluminescence (EL) only from Eu3+ ions at 612 nm with a full width at half maximum of 3 nm was observed and the EL efficiency was significantly enhanced. The maximum EL efficiency reached 7.9 cd A(-1) at 0.01 mA cm(-2) current density, which is enhanced by 2.8 times compared with electrophosphorescence-undoped devices. The large improvements are attributed to energy transfer assistance effects of FIrpic, indicating a promising method for obtaining efficient red OLEDs based on rare-earth complexes.

球形Gd_2O_3:Eu纳米发光材料的制备

引言自1966年提出用Gd2O3∶Eu红粉代替以往红粉以来,Gd2O3∶Eu被用于高清晰度电视、投影电视、平板显示、绿色照明工程等所需的高效优质发光材料,由于其光视效能较以往的红粉大大提高,因此得到了广泛的关注[1~3]。商用荧光粉一般采用高温固相法合成,颗粒一般为微米级且形状不规则。近年来,由于纳米科技的发展,以及纳米材料所具有的特异的光学性质[4,5],纳米发光材料引起了越来越多的科研工作者的关注。纳米级的Gd2O3∶Eu发光材料的主要合成方法有:燃烧法[6]、配合物前驱体热分解法[7,8]、超声化学法[9]等,采用以上方法制备的纳米Gd2O3∶Eu颗粒形状较不规则。发光材料的发光性能与其形态有很大关系,球形颗粒可以提高其密堆性,从而提高其发光亮度。并且荧光粉涂屏工艺的要求也迫切需要合成球形的荧光粉。均相沉淀法可以通过改变条件很好的控制所合成颗粒的形貌[10]。本文采用均相沉淀法制备了规则球形的纳米级的Gd2O3∶Eu发光材料,对其形成机理进行了讨论,并通过光谱研究对纳米Gd2O3∶Eu颗粒和体相材料的光谱进行了比较。1实验部分1.1仪器和药品氧化钆(99.99%,上海跃龙),氧化铕(99.99%,上海...

Electrocatalytic performance of Pt-TiO2/C complex catalysts for oxidation of methanol

It is reported for the first time that the Pt-TiO2/C catalyst prepared with chemical reduction and sol-gel method showed the excellent electrocatalytic activity and stability for the electrooxidation of methanol. When the atom ratio of Ti to Pt in the catalysts is 1/2, the catalysts showed the best electrocatalytic properties. After the catalyst is treated at 500 degreesC, the performance is further improved. It is hopeful to use the catalyst in the pratical DMFC.

碳载Pt-TiO_2复合催化剂对甲醇氧化的电催化性能

报道了通过化学还原和溶胶 -凝胶法制备不同组成的 Pt-Ti O2 /C催化剂及其对甲醇的氧化反应 .结果表明 ,该催化剂具有很好的电催化活性和稳定性 .催化剂中的 Ti和 Pt的原子比为 1 /2时 ,催化剂的性能最好 .在 5 0 0℃下热处理后 ,催化剂的性能得到进一步的改善 .这种催化剂有望能在 DMFC中获得实际使用.

Characterizing CO2 fluxes for growing and non-growing seasons in a shrub ecosystem on the Qinghai-Tibet Plateau

To assess carbon budget for shrub ecosystems on the Qinghai-Tibet Plateau, CO2 flux was measured with an open-path eddy covariance system for an alpine shrub ecosystem during growing and non-growing seasons. CO2 flux dynamics was distinct between the two seasons. During the growing season from May to September, the ecosystem exhibited net CO2 uptake from 08:00 to 19:00 (Beijing Standard Time), but net CO2 emission from 19:00 to 08:00. Maximum CO2 uptake appeared around 12:00 with values of 0.71, 1,19, 1.46 and 0.67 g CO2 m(-2) h(-1) for June, July, August and September, respectively. Diurnal fluctuation Of CO2 flux showed higher correlation with photosynthetic photon flux density than temperature. The maximum net CO2 influx occurred in August with a value of 247 g CO2 m(-2). The total CO2 uptake by the ecosystem was up to 583 g CO2 m(-2) for the growing season. During the non-growing season from January to April and from October to December, CO2 flux showed small fluctuation with the largest net CO2 efflux of 0.30 g CO2 m(-2) h(-1) in April. The diurnal CO2 flux was close to zero during most time of the day, but showed a small net CO2 eff lux from 11:00 to 18:00. Diurnal CO2 flux, is significantly correlated to diurnal temperature in the non-growing season. The maximum monthly net CO2 eff lux appeared in April, with a value of 105 g CO2 m(-2). The total net CO2 eff lux for the whole non-growing season was 356 g CO2 m(-2).

利用部分基因保留和“移民”技术提高基因算法的性能

在介绍了由文献［１，８］提出来的带有对称编码的基因算法后，本文进一步讨论了这种基因算法中采用的部分基因保留技术和“移民”技术对算法性能的影响，确定了“移民”技术的３个必须步骤、最佳基因保留量（２５％）及其选择范围（２０～５０％）．对算法的计算机实验所得到的结果表明，如果不采用这两项技术，带有对称编码的基因算法的性能就会降低，所得到的解的质量就会下降，有时甚至会使新的基因算法表现的象传统的基因算法一样，对象机器人的动力学优化控制这样的问题无能为力。