旱地胡麻覆膜穴播种植与节水补灌试验研究

干旱是威胁宁南山区胡麻生产持续发展的首要限制因子。采用地膜覆盖穴播种植技术 ,探索了旱地胡麻覆膜穴播种植的增产机理及其增产效应。结果表明 ,覆膜穴播可以提高土壤地温 ,保持土壤水分 ,促进土壤速效养分的充分释放和有效利用。又因穴播种植 ,胡麻籽粒顶土合力增强 ,出苗率高达 79.4%～ 96.2 % ,籽粒产量提高 37.9%～ 46.2 %。与此同时 ,作者于胡麻覆膜穴播种植后 ,在胡麻的关键生育期枞形后期—现蕾初期 ,进行了膜上节水补灌试验。结果表明 ,节水补灌 30 0～ 450 m3 /hm2可提高籽粒产量 30 %～ 44% ,水分生产效率达0 .30～ 0 .32 kg/(hm2 · mm) ,水分生产效率提高 8%～ 1 4 .9%。这一新的种植方式 ,效益显著 ,应在干旱半干旱地区的胡麻产地大面积推广应用

农业生态系统养分循环再利用的作物产量增益

在辽西褐土上进行8年的田间试验结果表明，在不同化肥基础上，每年以60％的收获产品堆腐后循环回田，平均分别可获得29．6％（不施化肥）、15．2％（N肥）、11．1％（NP肥）和9．2％（NPK肥）的增产率，或分别每年增产粮食1.33、0．99、0．79、0．64t·hm－2．养分循环再利用的作物增产效益在试验的8年中有着逐年增长趋势，表明以堆肥形式循环回田养分对作物的增产作用存在着明显的残效叠加效应，因此，只有通过长期田间试验方能准确评估农业系统中养分循环再利用的作物产量增益．

黄土丘陵区小流域系统生态经济要素分析——以宁夏隆德县李太平小流域为例

以隆德县李太平小流域为例,对比分析了退化小流域系统恢复重建过程中系统的生态经济要素变化,揭示系统演变趋势。应用能值方法分析了投入产出的动态变化,评价治理的生态经济效果。结果显示:农、林、牧业用地比例由1990年的6·2∶2·0∶1·0变为2003年的1·9∶1·4∶1·0,土地利用及种植结构趋于合理,农业产值所占比重由79·6%下降为54·8%,林业、牧业、副业产值比例分别由9·6%、9·6%、1·1%上升为22·7%、15·1%、7·4%,收入多样性指数也呈增加趋势,显示了流域收入构成的多元化,有利于生态经济系统的稳定。同时,恩格尔系数减小,表明人民生活水平日益提高。基于能值的流域生态经济系统投入产出效率动态研究结果表明在调整后的土地利用格局及种植结构下,净能值产出率由1990年的2·5增长到2003年的3·41,资源利用效率逐年提高,环境负荷率在1990、1995和2003年分别为2·55、2·44和2·11,呈减小趋势,能值持续性指数从1990年的0·98增加到2003年的1·62,经济与生态环境的协调性不断提高。研究结果表明该治理模式是成功的。

蛭弧菌BDG-9质粒不稳定性研究

本文建立了研究难于单独连续培养的专性蛭弧菌质粒稳定性的方法体系。应用此方法体系发现并证明了在专性蛭弧菌BDG9中所含的质粒pSTⅠ存在着独特的质粒缺失现象,当蛭弧菌BDG9单独培养时,在通常决定质粒稳定性的复制功能和分配功能都正常的情况之下,随着细胞的传代,质粒pSTⅠ逐渐丢失,蛭弧菌的生长繁殖也逐渐停止,表明质粒pSTⅠ的存在对BDG9细胞单独生长有重要作用。

1990～2000年中国土壤碳氮蓄积量与土地利用变化

基于2473个土壤剖面资料和1980年代末~1990年代末陆地卫星TM影像分析中国1990~2000年林地、草地、耕地之间的土地利用变化对土壤碳氮蓄积量的影响。IPCC建议的国家温室气体清单方法计算表明从1990~2000年中国林地、草地、耕地土壤(30cm)有机碳氮库分别损失了77.6±35.2TgC(1Tg=106t)和5.6±2.6TgN,年均损失约7.76TgC/yr和0.56TgN/yr,其中耕地土壤碳库分别增加了79.0±7.7TgC和9.0±0.7TgN,草地土壤碳氮蓄积量分别损失了100.7±25.9TgC和9.8±2.2TgN,林地土壤碳氮蓄积量分别损失了55.9±17.0TgC和4.9±1.1TgN。同时根据中国6大行政区林地、耕地和草地之间的相互转换面积、土壤有机碳氮密度的变化率进行估算,表明土壤(30cm和100cm)有机碳氮蓄积量分别损失了53.7TgC、5.1TgN和99.5TgC、9.4TgN。由于中国不同地区土地利用变化的空间格局差异显著,从而导致东北地区土壤碳氮蓄积量变化较大,而华东地区变化较小。

除虫菊酯和拟除虫菊酯的毒理作用和药效

除虫菊酯是新型植物源农药，由于其具有杀虫谱广，杀虫活性高，对哺乳动物毒性低等优点而被广泛地应用于室内卫生昆虫防治。拟除虫菊酯是人工合成的除虫菊酯的结构类似物。由于人们在使用过程中不可避免地会接触除虫菊酯类药物，对其进行毒理学研究显得尤为重要。本论文以雄性Sprague-Dawley大鼠为材料，研究了除虫菊酯、氯氰菊酯、增效醚（PBO）和迷迭香对大鼠大脑突触体ATP酶活性的影响。采用Percoll梯度离心法分离出大脑突触体，通过测定ATP酶催化ATP产生的无机磷量测定ATP酶的活性。结果：总ATP酶和Mg2+-ATP酶在10 μM除虫菊酯作用下的活性分别为80.3％和45.9％，当除虫菊酯浓度上升到100 μM时，活性分别下降到5.4％和6.2％；总ATP酶在100 μM氯氰菊酯作用下活性为80.7％，氯氰菊酯浓度上升到1000 μM时，活性下降到2.3％；在3000 μM PBO作用下，总ATP酶活性为79.9％，相同浓度的迷迭香能使总ATP酶活性下降到66.8％；当有3倍浓度PBO存在时，10 μM除虫菊酯降低总ATP酶活性至37.8％，100 μM氯氰菊酯降低总ATP酶活性到28.5％；有3倍浓度迷迭香存在时，10 μM除虫菊酯降低总ATP酶活性到72.9％，100 μM氯氰菊酯降低总ATP酶活性至43.0％。结论：除虫菊酯和氯氰菊酯在适当浓度下都能显著抑制总ATP酶和Mg2+-ATP酶的活性。除虫菊酯的抑制作用比氯氰菊酯显著，除虫菊酯类药物对Mg2+-ATP酶活性抑制比对总ATP酶活性的抑制显著。增效剂PBO能有效增强除虫菊酯和氯氰菊酯对突触体ATP酶活性的抑制作用。在极高浓度下，PBO单独也能部分抑制ATP酶的活性。迷迭香本身只在极高浓度下才对ATP酶起部分抑制作用，但是能轻微增强除虫菊酯和氯氰菊酯的抑制活性，这可能与其延迟除虫菊酯和氯氰菊酯被氧化有关。本研究结果表明，除虫菊酯只在浓度 > 1 μM时才会对ATP酶起显著的抑制作用(p < 0.05)，但是前人研究表明除虫菊酯在0.01 μM下即能有效改变昆虫钠离子通道动力学，可见，除虫菊酯类药物在0.01－1 μM浓度下既能有效杀灭害虫，又对人畜安全，这一结论可用于指导除虫菊酯类药物的使用。此外，本研究还测定了云菊5％除虫菊酯乳油对东亚飞蝗四龄和五龄若虫的室内药效实验，结果表明除虫菊酯能有效杀灭东亚飞蝗，适用于东亚飞蝗防治。

Red-light-emitting iridium complexes with hole-transporting 9-arylcarbazole moieties for electrophosphorescence efficiency/color purity trade-off optimizationE

The synthesis, structures, photophysics, electrochemistry and electrophosphorescent properties of new red phosphorescent cyclometalated iridium(III) isoquinoline complexes, bearing 9-arylcarbazolyl chromophores, are reported. The functional properties of these red phosphors correlate well with the results of density functional theory calculations

Red-Light-Emitting Iridium Complexes with Hole-Transporting 9-Arylcarbazole Moieties for Electrophosphorescence Efficiency/ Color Purity Trade-off Optimization

The synthesis, structures, photophysics, electrochemistry and electrophosphorescent properties of new red phosphorescent cyclometalated iridium(III) isoquinoline complexes, bearing 9-arylcarbazolyl chromophores, are reported. The functional properties of these red phosphors correlate well with the results of density functional theory calculations. The highest occupied molecular orbital levels of these complexes are raised by the integration of a carbazole unit to the iridium isoquinoline core so that the hole-transporting ability is improved in the resulting complexes relative to those with I-phenylisoquinoline ligands. All of the complexes are highly thermally stable and emit an intense red light at room temperature with relatively short lifetimes that are beneficial for highly efficient organic light-emitting diodes (OLEDs).

Hole-transporting polymers containing carbazol-3,9-diyl and 1,4-phenylene fragments in the main chain

New carbazole-based polymers, which contain various content of electro-active fragments in the main chain connected via alkylene spacers, have been synthesized by Ni(0)-catalyzed Yamamoto-type aryl-aryl coupling reactions. These compounds represent amorphous materials of high thermal stability with glass-transition temperatures of 139-151 degrees C and thermal decomposition starting at temperatures above 400 degrees C. UV-vis absorption and photoluminescence emission spectra of the materials confirmed that the conjugated segments in the macromolecules are rather short.

Mo的掺杂对Ce_(0.8)Gd_(0.2)O_(1.9)烧结温度及电性能的影响

掺杂的CeO2基固体电解质因其在中低温条件下(500￣700℃)具有高氧离子电导率而成为有希望的IT-SOFCs(intermediate temperature-solid oxide fuel

Facile synthesis of 9,10-diarylphenanthrenes and poly(9,10-diarylphenanthrene)s

One-pot reduction of 9,10-diaryl-9,10-dihydrophenanthrene-9,10-diols to 9,10-diarylphenanthrenes was achieved with Zn/H+ in acetic acid. Accordingly, various novel phenanthrenes and polyphenanthrenes with efficient blue emission were easily synthesized.

Phase transition behavior and molecular orientation of oligo(9,9 '-dioctylfluorene-alt-bithiophene)

A novel conjugated oligomer, oligo(9,9'-dioctylfluorene-alt-bithiophene) (OF8T2), was found to exhibit a unique phase transition between crystalline and liquid-crystalline states, and a liquid-crystalline glass was easily generated, offering better TFT device performance. In thin films, upon annealing the OF8T2 molecules oriented preferentially with their planes of conjugation being normal to the substrate, and both film thickness and annealing temperature were critical to the film morphology and the molecular orientation. When the OF8T2 film was deposited on a rubbed polyimide surface and annealed, the molecules aligned their long axes along the rubbing direction.

SiO2 nanoparticles as scatterers for random organic laser action in red fluorescent dye 4-(dicyanomethylene)-2-tert-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran doped polystyrene films

Random multimode lasers are achieved in 4-(dicyanomethylene)-2-tert-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped polystyrene thin films by introducing silicon dioxide (SiO2) nanoparticles as scatterers. The devices emit a resonance multimode peak at a center wavelength of 640 nm with a mode linewidth less than 0.87 nm. The threshold excitation intensity is as low as 0.25 mJ pulse(-1) cm(-2). It can be seen that the microscopic random resonance cavities can be formed by multiple scattering of SiO2 nanoparticles.

Ti0.8Zr0.2V1.1Mn0.9-xNi0.4Crx固溶体贮氢合金结构和电化学性能

研究了Ti_(0.8)Zr_(0.2)V_(1.1)Mn_(0.9-x)Ni_(0.4)Cr_x(x为0～0.4)固溶体电极合金的结构和电化学性能。结果表明,Ti_(0.8)Zr_(0.2)V_(1.1)Mn_(0.9-x)Ni_(0.4)Cr_x系列合金是由具有体心立方(BCC)结构的V基固溶体相和C14Laves第二相组成的双相合金。

Strings of interconnected hollow carbon nanoparticles with porous shells prepared using simple solid-phase synthesis

Strings of interconnected hollow carbon nanoparticles with porous shells were prepared by simple heat-treatments of a mixture of resorcinol-formaldehyde gel and transition-metal salts. The sample was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and nitrogen adsorption. Results show that the sample consisted of relatively uniform hollow particles with sizes ranging from 70 to 80 nm forming a strings-of-pearls-like nanostructure. The material with porous shells possessed well-developed graphitic structure with an interlayer (d(002)) spacing of 0.3369 nm and the stack height of the graphite crystallites of 9 nm.