一种按基因重要度收敛的进化算法

提出基因重要度的概念,通过实验证明基因重要度对于单变量边缘分布算法(Unvaried Marginal Distribution Algo-rithm,UMOA)收敛的重要性.由此提出一种基于基因重要度的进化算法.该算法首先对组成染色体的各基因进行重要度排序,随后对重要度大的基因先进行收敛操作,每次收敛当前重要度最大的基因,直到所有基因全部收敛.实验数据表明,本算法的收敛速度更快,而且更容易求出满意解.

Broadly Tunable Grating-Coupled External Cavity Laser With Quantum-Dot Active Region

A broadly tunable and high-power grating-coupled external cavity laser with a tuning range of more than 200 nm and a similar to 200-mW maximum output power was realized, by utilizing a gain device with the chirped multiple quantum-dot (QD) active layers and bent waveguide structure. The chirped QD active medium, which consists of QD layers with InGaAs strain-reducing layers different in thickness, is beneficial to the broadening of the material gain spectrum. The bent waveguide structure and facet antireflection coating are both effective for the suppression of inner-cavity lasing under large injection current.

Formation of a novel type of reverse microemulsion system and its application in synthesis of the nanostructured La0.95Ba0.05MnAl11O19 catalyst

In the study, a novel microemulsion system, consisting of water, iso-propanol and n-butanol, was developed to synthesize the nanostructured La0.95Ba0.05MnAl11O19 catalyst with high surface area and catalytic activity for methane combustion.

复边藓在中国的重新发现

Cinclidotus fontinaloides (Hedw ) P Beauv,which was previously collected and reported only once from Tibet in 1859 by Mitten,was rediscovered from Xinjiang (Mt Tianshan),China The description and illustrations of the species based on Chinese collection is presented in details for the first time in China

科尔沁草甸草地放牧和割草条件下土壤种子库研究

研究了科尔沁沙地草甸草地在放牧、割草两种利用方式下的土壤种子库的大小、组成及其与地上植被的关系 .结果表明 ,在自由放牧下 ,土壤种子库密度为 6 15 8± 16 4 7粒·m-2 ,在割草利用下 ,土壤种子库密度为 8312± 2 5 4 0粒·m-2 .放牧干扰下 ,种子库组成以矮小、短命的一年生植物为主 ,其中一二年生植物占 81 6 6 % ,占比例最大的前 4种植物分别为虎尾草 (38 5 5 % )、灰绿藜 (15 4 2 % )、毛马唐 (14 95 % )和狗尾草 (9 83% ) ,多年生植物种子密度仅为 112 9± 30 2粒·m-2 ;割草干扰下 ,一二年生植物占6 8 0 8% ,其中狗尾草占 5 2 7% ;而割草地多年生植物种子密度为 2 6 5 3± 811粒·m-2 放牧地土壤种子库密度与地上植物相关不显著 ;割草地土壤种子库密度与地上植物多度显著相关 (r=0 76 ,P <0 0 1) .放牧地种子库的Shannon Wiener指数、丰富度指数分别为 2 96和 2 98,明显小于割草地的 3 10和 5 0 9,表明自由放牧更易使物种多样性下降 .

外源添加物对秸秆还田土壤中无机氮转化影响

采用室内培养方法,研究秸秆不同还田方式土壤中加入无机氮肥和玉米秸秆对无机氮转化的影响。在田间秸秆不同还田处理的土壤中加入氮肥(硫酸铵)培养,初期土壤NH_4~+-N的含量较高,随着培养时间延长,NH_4~+-N的含量下降,培养15天后NH_4~+-N的含量趋于平衡;而土壤中NO_3~--N含量在培养期间逐渐增加,培养30天后NO_3~--N含量趋于平衡;秸秆不同还田处理土壤中添加秸秆培养,粉碎还田处理的土壤中NH_4~+-N的含量在整个培养过程中处于最低,培养后期覆盖还田和高茬还田的土壤NH_4~+-N的含量略有下降。

Multifunctional metallophosphors with anti-triplet–triplet annihilation properties for solution-processable electroluminescent devices

With the goal to provide organometallic triplet emitters with good hole-injection/hole-transporting properties, highly amorphous character for simple solution-processed organic light-emitting diodes, and negligible triplet-triplet (T-T) annihilation, a series of new phosphorescent cyclometalated Ir-III and Pt-II complexes with triphenylamine-anchored fluorenylpyridine dendritic ligands were synthesized and characterized. The photophysical, thermal, electrochemical and electroluminescent properties of these molecules are reported.

Solvent Vapor-Induced Self Assembly and its Influence on Optoelectronic Conversion of Poly(3-hexylthiophene): Methanofullerene Bulk Heterojunction Photovoltaic Cells

Nanoscale-phase separation of electron donor/acceptor blends is crucial for efficient charge generation and collection in Polymer bulk heterojunction photovoltaic cells. We investigated solvent vapor annealing effect of poly(3-hexylthiophene) (P3HT)/methanofullerene (PCBM) blend oil its morphology and optoelectronic properties. The organic solvents of choice for the treatment have a major effect oil the morphology of P3HT/PCBM blend and the device performance. Ultraviolet-visible absorption spectro,;copy shows that specific solvent vapor annealing can induce P3HT self-assembling to form well-ordered structure; and hence, file absorption in the red region and the hole transport are enhanced. The solvent that has a poor Solubility to PCBM Would cause large PCBM Clusters and result in a rough blend film. By combining an appropriate solvent vapor treatment and post-thermal annealing of the devices, the power conversion efficiency is enhanced.

White electroluminescence from a single polymer system: Improved performance by means of enhanced efficiency and red-shifted luminescence of the blue-light-emitting species

High-efficiency white electrolurninescence from a single polymer is achieved by enhancing the electroluminescence efficiency and effecting a red-shift in the emission spectrum of the blue emissive species. A single-layer device of the resultant polymer exhibits a higher luminous efficiency than the nonmodified species (12.8 cd A(-1), see figure) and an external quantum efficiency of 5.4 % with CIE coordinates of (0.31,0.36), exemplifying the success of the reported methodology.