高产抗旱优质谷子新品种辐谷7号的选育与推广利

利用400Gy 60Co γ射线处理87070谷子品系干种子,选育出辐谷7号新品种。该品种具有株型紧凑、茎秆矮、高产抗旱优质并且适应种植地区广等特点。2002年2月通过陕西省农作物品种审定委员会审定,截止2008年在黄土高原地区累计推广10.8万hm2。

水文条件对紫色土坡面土壤侵蚀及养分流失的影响

采用人工模拟降雨试验,研究水文条件对紫色土坡面土壤侵蚀及氮和磷养分流失的影响。试验处理包括2个施肥水平(低肥和高肥水平),4个水文条件(自由下渗、土壤水分饱和、壤中流、壤中流+降雨)和一个降雨强度(60 mm/h,历时60 min)。结果表明:壤中流+降雨和土壤水分饱和条件下的土壤侵蚀量分别是自由下渗条件下的3.1和1.7倍,同自由下渗相比,壤中流、壤中流+降雨和土壤水分饱和条件下,地表径流中NO3-N、HPO4-P的浓度和流失量有显著增加;低肥水平条件下,自由下渗、土壤水分饱和、壤中流和壤中流+降雨地表径流中,NO3-N的浓度分别是0.88、58.90、698.41和87.80 mg/L,对应水文条件下地表径流中,HPO4-P的浓度分别是0.252、0.322、0.811和0.383 mg/L,高肥水平条件下,径流中的NO3-N和HPO4-P的浓度也有相同的趋势;土壤水分饱和条件下,地表径流中NO3-N和HPO4-P的流失量分别是自由下渗条件下的27~39和1.3倍,壤中流+降雨条件下,地表径流中NO3-N和HPO4-P的流失量分别是自由下渗条件下的100~114和1.5~1.7倍,同时,壤中流+降雨和土壤...

垂直腔面发射激光器的热学特性

通过求泊松方程、电流密度方程、载流子扩散方程以及有源层结压降方程自洽解的方法,计算了垂直腔面发射激光器(VCSEL)的电势分布,进而求解热传导方程,得到VCSEL的温度分布.详细分析了注入电流密度小于或等于阈值电流密度时,晶片键合结构垂直腔面发射激光器的键合界面阻抗、氧化层限制孔径、外加电压以及分布布拉格反射镜的热导率的大小对VCSEL内部温度分布的影响.

ECR plasma CVD法淀积980 nm大功率半导体激光器端面光学膜技术

介绍了电子回旋共振等离子体化学气相沉积(简称ECR plasma CVD)法淀积980nm大功率半导体激光器两端面光学膜的工艺条件，探索了膜系监控的方法和优越性，讨论了这种淀积方法的优点和淀积的光学膜的优良特性。

Epitaxial growth of SiC on complex substrates

Epitaxial growth of SiC on complex substrates was carried out at substrate temperature from 1200 degreesC to 1400 degreesC. Three kinds of new complex substrates, c-plane sapphire, AlN/sapphire, and GaN/AlN/sapphire, were used in this study. We obtained a growth rate in the range of 1-6 mum/h. Thick (6 mum) SIC epitaxial layers with no cracks were successfully obtained on AlN/sapphire and GaN/AlN/sapphire substrates. X-ray diffraction patterns have confirmed that single-crystal SiC was obtained on these complex substrates. Analysis of optical transmission spectra of the SIC grown on sapphire substrates shows the lowest-energy gap near 2.2 eV, which is the value for cubic SiC. The undoped SIC showed n-type electrical conductivity. (C) 2001 Elsevier Science B.V. All rights reserved.

对流扩散方程的绝对稳定高阶中心差分格式

将作者提出的数值摄动算法改进为区分离散单元内上游和下游并分别对通量进行高精度重构的双重数值摄动算法,与原(单重)摄动算法相比,双重摄动算法既提高了格式精度又明显扩大了格式的稳定域范围,利用双重摄动算法,即分别利用上游和下游基点变量的摄动重构将高阶流体力学关系及迎风机制耦合进二阶中心格式之中,由此构建了对流扩散方程的对网格Reynolds数的任意值均稳定(绝对稳定)高精度(四阶和八阶精度)三基点中心TVD差分格式,通过解析分析以及3个算例计算证实了构建格式的优良性能;3个算例包括一维线性、非线性(Burgers方程)和二维变系数对流扩散方程,数值计算表明:构建的格式在粗网格下不振荡,构建格式在粗网格时的最大误差L∞和均方误差L2与二阶中心格式在细网格时的相应误差一致,对线性方程,构建格式在细网格下可达到L2精度阶

何首乌炮制前后生物活性和化学成分的变化研究

何首乌为常用中药，由何首乌及含何首乌的中成药制剂所引起的不良反应也时见报道，科学阐明不良反应的物质基础并提出解决方案对何首乌的使用十分重要。本论文研究了何首乌炮制前后KM小鼠肝脏毒性基因表达谱、生物活性及化学成分的变化。所获结果支持何首乌炮制的目的是减毒、改性（改变药效），何首乌生、熟异治的观点。制首乌对抑郁症的效果显著优于生首乌，这与本草所记载的何首乌炮制后补肝肾、益精血，归肝、肾经一致。 主要结果如下： 1、 生、制首乌的毒理基因芯片研究结果 何首乌的不良反应主要表现在肝损害方面。本研究建立了生何首乌和制何首乌不同剂量的肝毒性作用模型，体重指标统计发现生何首乌各剂量组平均体重显著下降，中剂量组（10 g/kg.d）体重下降20 %，高剂量组（20 g/kg.d）体重下降42%，50%动物死亡，提示动物机体能量代谢障碍；基因芯片研究结果表明何首乌是CYP450的抑制剂，生何首乌相对于制何首乌CYP3A4、CYP4A5显著下调，导致毒性成分在体内的吸收增加，服用大剂量的生何首乌后产生明显的肝毒性；主要对以下六条Pathway产生影响：①PPAR signaling pathway，主要毒性靶基因有RXRB CYP7a1、Acadl、Apoa2、Cyp4a、 FABP2 、MAPKKK5等基因。②Calcium signaling pathway，主要毒性靶基因有CAMK2B、CACNA1F、S100A1、 F2R、Ryr1、Slc8a2、Camk4 ③Neuroactive ligand-receptor interaction，主要毒性靶基因有Chrm4、 Ntsr2 、 GABRR1、 GRIK3、F2R等基因。④Wnt signaling pathway，主要毒性靶基因有Daam2、Rac1 等基因。⑤Complement and coagulation cascades，主要毒性靶基因有F2R、Serpina1b、Cfi 、FGA等基因。⑥Oxidative hosphorylation，主要毒性靶基因有Atp5e、NDUFA1等基因。生何首乌毒性明显强于制首乌，且生何首乌水煎液的毒性大于生何乌首丙酮提取物的毒性，这一结果表明，何首乌主要的毒性成分很可能并不仅仅是传统所认为的以大黄素为代表的蒽醌类化合物，而是何首乌中大量存在的有效组分二苯乙烯苷与大黄素相互作用的结果，这一研究结果与前述的何首乌对肝药酶的影响是一致的。后续生、制首乌的化学成分差异研究表明，炮制后二苯乙烯苷含量明显降低：生首乌为5.512 %、清蒸制首乌为3.811 %、豆制首乌为3.538 %,大黄素的含量炮制后显著升高,生首乌为0.094 %、清蒸制首乌为0.119 %、豆制首乌为0.126 %。 2 生、制首乌药效差异研究结果 本文采用慢性中等强度不可预知应激刺激模型(chronic unpredictable mild stress, CUMS)和动物行为绝望实验法，研究生、制首乌抗抑郁活性的差异，制首乌（5 g/kg.d）与模型组相比有显著差异（P< 0.01），生首乌制首乌（5g/kg.d）与模型组相比无显著差异，这一结果表明制首乌抗抑郁活性显著优于生首乌。 本文比较了生、制首乌对四氧嘧啶糖尿病模型小鼠血糖的影响的差异，生首乌（5 g/kg.d）与模型组相比有显著差异（P< 0.01），制首乌（5 g/kg.d）与模型组相比无显著差异，这一结果表明生首乌降糖活性优于制首乌。这一结果与历代中医古书中生首乌治疗消渴症（糖尿病）的记载一致。 3生、制首乌化学成分差异的研究结果 本文选用HPLC-DAD指纹图谱技术结合药效成分含量测定来研究生、制首乌化学成分的差异。炮制后，何首乌中的主要化学成分并未消失，只是其含量发生了改变。炮制后二苯乙烯苷含量明显降低：生首乌为5.512 %、清蒸制首乌为3.811 %、豆制首乌为3.538 %,大黄素的含量炮制后显著升高,生首乌为0.094 %、清蒸制首乌为0.119 %、豆制首乌为0.126 %。 综上所述，炮制前后何首乌中二苯乙烯苷和大黄素含量比的变化可能是何首乌炮制减毒、改性的物质基础。 根据上述结果我们建立了生、制首乌的质量控制新模式。 In recent years, some adverse drug reactions (ADR) about some traditional Chinese medicine were reported at times. As a Chinese medicine most in use, the ADRs of Radix Polygoni multiflori (RPM) and the medicines containing the RPM were also mentioned. The resolution of the problems caused by the ADRs is very important for the use of the RPM as a medicine. The process (or preparation) is a significant feature for the clinical use of the Chinese medicine and an important technology for the safe use and good effect of the Chinese medicine. By processing, the toxicity of the Chinese medicine can be reduced, its properties can be changed and curative effect can be enhanced at the same time. The changes of the gene expression profiles for KM mice hepatotoxic effects, and the change of the biological activity and the chemical composition after being processed of the RPm were studied in the present dissertation. The RPm heatotoxicity mechanism and the toxicity target genes were explained on the gene level for the first time. With the antidepressant activity, and the hypoglycemic effect as the target, the differences on the pharmacodynamics between the processed RPm and unprocessed RPm, for the first time, were investigated. The results obtained show that the antidepressant activity of the processed RPM is far higher than the ones of unprocessed RPm. As we know, the results were reported for the first time. The quality control systems (QCS) for the processed and the unprocessed RPm were founded. The HPLC-DAD was used in the systems founded on the basis of the toxicology and the pharmacodynamics experiments. As we know, the OCSs were reported for the first time. The above-mentioned experimental results confirm that the unique process theory of the traditional Chinese medicine (TCM) used for the process of the Radix Polygoni multiflori (RPm) is correct, i.e after being processed the toxicity of the RPm decreases and its Pharmacodynamic effects change. It is known to author that there have been no similar reports in the literatures up to now. The main experimental results are summarized as follows: 1 The results on the mice toxicology gene chip for the unprocessed and processed RPm The KM mice hepatotoxic model caused by the RPm at the different dosages was established in the present study. The results obtained show that the mouse average body weight obviously decreased in the groups at the different dosages of the unprocessed RPm: the 10 g/kg.d .group decreased 20%; 20 g/kg.d. group decreased 42%, and 50% mice died at 20 g/kg.d. group. The main experimental results on the mice toxicology gene chip The RPm is the CYP450 inhibitor. As compared with the processd RPm, the CYP3A4, CYP4A5 of the unprocessed RPm demonstrate the marked downregulation, which leads to the increase of the poison absorbtion into the body with the result that the unprocessed RPm yields the marked hepatotoxication. The hepatotoxication was produced because the following 6 pathways were affected: ①PPAR signaling pathway, the chief toxicity target genes are RXRB, CYP7a1, Acadl, Apoa2, Cyp4a, FABP2 and MAPKKK5 etc. ②Calcium signaling pathway, the chief toxicity target genes are CAMK2B, CACNA1F, S100A1, F2R, Ryr1,Slc8a2 and Camk4 etc. ③Neuroactive ligand-receptor interaction, the chief toxicity target genes are Chrm4, Ntsr2, GABRR1, GRIK3 and F2R etc. ④Wnt signaling pathway, the chief toxicity target genes are Daam2, Rac1 etc. ⑤Complement and coagulation cascades, the chief toxicity target genes are F2R, Serpina1b, Cfi and FGA etc. ⑥Oxidative phosphorylation, the chief toxicity target genes are Atp5e, NDUFA1 etc. The above experimental results, for the first time , demonstrate on the gene level that the unprocessed Rpm toxicity is far stronger than the processed RPm one, and the toxicity of the water decoction of the unprocessed RPm is greater than the one of its acetone extracts, which shows that the chief toxicity components of the RPm are probably not only the anthraquinones, for example, the emodin, but the complex compounds produced by the interaction between the emondin and the stilbene glucoside which is the largest component of the unprocessed RPm. The result is accordance with the above effect of the RPm on the hepatic drugenzyme. Aftter being processed, in fact, the content of the stibene glucoside in the RPm markedly decreases. 2. The results on the pharmacodynamic differences between the unprocessed and processed RPm The results obtained show that the effects of processing on RPm pharmacodynamic behaviour received in the Chinese Material Medica are correct. It is known to author that this is the first experimental result in the research materials now available. The chief results are as follows: For the treatment of the antidepressant, the curative effect of the processed RPm is far better than the one of the unprocessed RPm. By contrast with the above results, the hypoblycemic effect of the unprocessed RPm is better than the one of the processed RPm. 3. The results on the Chemical Composition The results obtained by using HPLC-DAD fingerprint and by the determination of effective component content show that the main chemical components in the RPm after being processed do not disappear, but their contents change. The contents of the stilbene glucoside (SG) and emodin in the different samples were determined as follows: SG contents 5.512 % for the unprocessed RPm 3.811 % for the processed RPm (Steamed) 3.588 % for the processed RPm (black soybean) Emodin contents 0.094 % for the unprocessed RPm 0.119 % for the processed RPm (Steamed) 0.126 % for the processed RPm (black soybean) The combination of above experimental results on the toxicity, the pharmacodynamics and the chemical composition indicates that the changes of the content ratio of SG/emodin may be the substance base of the toxicity decrease and pharmacodynamic changes of the RPM by the processing.

Influence of in-medium nucleon-nucleon cross section on the isoscaling parameter alpha

The influence of in-medium nucleon-nucleon cross section on the isoscaling parameter a is investigated for two couples of central nuclear reactions Ca-40 + Ca-40 and Ca-60 + Ca-40; Sn-112 + Sn-112 and Sn-124 + Sn-124 within the isospin dependent quantum molecular dynamics. The calculated result shows that the influence of the in-medium nucleon-nucleon cross section on the isoscaling parameter a is mainly determined by the corresponding number of collisions, both for isospin dependent and isospin independent parameterizations. The mechanisms behind the effects of the in-medium nucleon-nucleon cross sections on the alpha are investigated in more details.

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 .

黄土丘陵区土壤团聚体分形特征及其对植被恢复的响应

采用计算分形维数的方法,对黄土丘陵区典型草原带土壤团聚体的分形特征及其对植被恢复的响应进行研究。结果表明:1)在植被恢复初期,土壤>10 mm粒级的团聚体含量在0~20和20~40 cm层次均较高,含量为331.4~525.6 g/kg。随植被恢复年限增加,10~7、7~5、5~3、3~2、2~1 mm粒级的团聚体绝对含量下降差异不明显。1~0.5、0.5~0.25和<0.25 mm小粒级土壤团聚体含量,在植被恢复初期(7 a)较高。2)随着植被恢复年限增加,土壤>5 mm粒级的水稳性团聚体含量相对下降很快,恢复7 a之后,大粒级土壤团聚体表现为上层含量比下层含量低的趋势。相对于干筛结果而言,土壤水稳性团聚体的粒径分布更为均匀、稳定,恢复7 a之后的土壤>0.25mm团聚体含量占到40%~50%,而>5 mm的土壤团聚体则占10%~23%。植被恢复过程中,土壤团聚体由大的团块向小颗粒的土壤团聚体转换,粒径分布更为均匀,土壤结构逐渐改善。3)不同恢复年限土壤团聚体分形维数变化范围为表层2.75~2.86,表下层2.77~2.89,变化范围小,20~40 cm土层的分形维数大于0~20 cm,恢复植被可使土壤分形...