羊草生殖生物学研究

羊草 (Leymus chinensis (Trin.) Tzvel. ) ，隶属禾本科赖草属，是欧亚大陆草原区东部的重要草原建群种之一。羊草是牧草之王，属于我国有比较优势的战略性生物资源，对我国北方畜牧业发展以及保护生态环境均具有重要作用。 羊草较弱的有性生殖特性限制了其应用，本文从实验生物学角度，研究了羊草有性生殖的基本特点，并试图通过现代分子生物学手段探讨自交不亲和性的有关机理。本论文的主要结果如下： 1. 实验发现羊草具有自交不亲和性。以6 个羊草居群为材料，测定得知开放授粉时的结实率在6.5% - 56.7%之间，自交时结实率为0.6% - 4.3%，差异极其显著; FDA 染色法检测结果显示羊草成熟花药中有活性的花粉达到92.2% 以上;在发育时间顺序和空间结构上，羊草雌蕊、雄蕊适于异花和自花授粉;花粉柱头亲和性实验表明，自交花粉只有5.5%-11.7% 是亲和的，杂交花粉亲和率达到了60.0%-84.8%，说明自交花粉在柱头上萌发受到抑制，其次，荧光显微镜还观察到“不亲和花粉”在进入柱头后生长缓慢，或停止延伸。 2. 初步确定羊草自交不亲和性具有配子体型遗传特点。以不同居群羊草杂交后的姊妹系作为实验材料，观察到自交组合的亲和率变幅为0 % - 6.9 %，杂交组合的亲和率具有连续性变异和变幅较宽的特点（47.5％ - 96.0 %），且正反交结果具有一定的一致性（88.2％），表现出配子体遗传特性。 3. 羊草居群内结实率存在一定变异。以羊草单株为单位分别进行自交、随机互交和开放授粉，结果显示三者的平均结实率分别为4.6%，18.1% 和35.7%，株间的变异系数分别为33.4%，21.2%和17.1%，这些株间的变异均达到统计上的显著差异;同时羊草自交、杂交和开放授粉之间具有一定的相关性，显示羊草的这种株间差异与株系本身的生理特性相关。 4. 分离了羊草硫氧化还原蛋白 H 基因(ThioLc)并对其功能进行了分析。克隆了ThioLc全长和cDNA序列。序列分析结果显示，DNA全长2257 bp，包括3 个内含子和4 个外显子，与水稻Thio h 的cDNA 序列相比，具有 32.0% 的同源性;Southern 杂交显示 ThioLc 在羊草基因组中是单拷贝;Northern 杂交显示 ThioLc 在羊草根、茎、叶和幼小的雌蕊中没有表达, 在成熟雌蕊和幼小的花粉中微量表达, 在成熟花粉中大量表达，说明分离的羊草硫氧化还原蛋白H 基因具有花粉特异表达特点。 5. 原核表达的ThioLc 蛋白具有较高的催化活性。构建了ThioLc 基因的原核表达载体，检测证明ThioLc基因在大肠杆菌中正常表达;提取表达蛋白，纯化，用胰岛素和二硫苏糖醇反应体系进行硫氧化还原蛋白的催化作用反应，结果表明表达的蛋白具有催化活性。这一结果为进一步搜寻靶向蛋白和研究该蛋白的结构、功能和作用方式奠定了基础。

宁夏新建二代防护林网蛀干害虫发生特点和危害特性

本文以宁夏银川二代林网中林分和害虫调查资料为基础 ,研究了二代林网主要蛀干害虫——光肩星天牛 (Anoplophora glabripennis Mostch)和木蠹蛾 [Cossus cossus ori-entalis Gaede &H olcocerus vicarius(Walker) ]分别在新疆杨林和刺槐林中因不同的树龄、径粗、林向、郁闭度、林地类型 (林缘和林内 )而呈现出的相应发生特点和为害特性。结果显示 ,新疆杨大于 6年生、胸径超过 1 2 cm径阶受光肩星天牛危害频率高 ;实验用片林林缘到林内 2 m范围内新疆杨受光肩星天牛危害显著高于林内 ,而东、西、南、北 4个方向 ,以东边受害最轻 ;与其它树种组成的混交林林缘同样重于林内。刺槐易受木蠹蛾危害的树龄和径节分别是 6 a～ 1 2 a和 1 2 cm～ 2 0 cm;刺槐片林无论是纯林还是混交林均为林缘重于林内。以上蛀干害虫对树龄和径粗均有较强的一致性选择

聚合物整体柱微萃取与高效液相色谱联用检测水性化妆品中的性激素

建立了水性化妆品中睾酮、甲基睾酮和孕酮的聚合物整体柱微萃取和高效液相色谱联用检测方法。聚(甲基丙烯酸-乙二醇二甲基丙烯酸酯)毛细管整体柱作为萃取介质,表现出较大的萃取容量。实验优化了影响萃取效率的参数,包括萃取流速、样品溶液pH值、盐浓度以及有机相含量。样品经过磷酸盐溶液稀释和过滤后便可直接进行萃取分析。睾酮、甲基睾酮和孕酮在10～1000μg/L的浓度范围内具有良好的线性关系,相关系数均大于0.996;它们的检出限分别为2.3,2.8和4.6μg/L;日内及日间相对标准偏差分别小于7.7%和7.5%。本

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in surface sediment and bivalve from the Changjiang Estuary, China

Surface sediments and bivalves were collected from the Changjiang Estuary in December 2003 and November 2004, respectively. Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in these samples were measured with high-resolution chromatography (HRGC)/High Resolution Mass Spectrometer (HRMS). The concentrations of total PCDD/Fs and toxic equivalent (TEQ) were 169.83 +/- 119.63 and 0.81 +/- 0.36 pg/g dry weight (dw) in sediments, and 580.33 +/- 240.17 and 7.24 +/- 3.65 pg/g dw in bivalves. The homolog compositions of PCDD/Fs were similar among samples, the most abundant congener was octa-chlorinated dibenzo-p-dioxin (OCDD) and then octa-chlorinated dibenzofuran (OCDF) and 1,2,3,4,6,7,8-hepta-chlorinated dibenzo-p-dioxin (HOCDD). The herbicide pentachlorophenol (PCP) and sodium pentachlorophenol (Na-PCP) were proved the main source of PCDD/Fs in this area.

低轮FOX分组密码的碰撞-积分攻击

FOX是最近推出的系列分组密码，它的设计思想基于可证安全的研究结果，且在各种平台上的性能优良．本文利用碰撞攻击和积分攻击相结合的技术分析FOX的安全性，结果显示碰撞-积分攻击比积分攻击有效，攻击对4轮FOX64的计算复杂度是2^45.4，对5轮FOX64的计算复杂度是2^109.4，对6轮FOX64的计算复杂度是2^173.4，对7轮FOX64的计算复杂度是2^237.4，且攻击所需数据量均为2^9；也就是说4轮FOX64／64、5轮FOX64／128、6轮FOX64／192和7轮FOX64／256对本文攻击是不免疫的．

共价氢化物在光度分析中的应用

本论文由两部分工作组成。第一部分（铋化氢-二乙氨基二硫化甲酸银分光光度法测定铋）提出一个测定铋的新的分光光度方法，对影响方法准确度和精密度的各种因素进行实验，确定了适宜分析条件。用硼氢化钾-氯化钠-铝粉（重量比2:1:5）还原片，0.5N盐酸介质、15-25 ℃时，将铋离子转化为铋化氢，用5.0毫升0.2%的二乙氨基二硫化甲酸银氯彷溶液吸收显色。有色溶液最大吸收波长为425毫微米，摩尔吸光系数为4.6 * 10~4升。厘米~(-1)·摩尔~(-1)。铋量0-20微克符合比尔定律。经过对发光材料、铝合金和矿石中铋的测定，证明此方法有较好的实用价值。第二部分（砷、锑、铋的氢化物与二乙氨基二硫代甲酸银形成的有色物质性质的探讨）针对文献中砷化氢与AgDDC形成有色物质性质的两种不同看法，结合我们在AgDDC分光光度法测定砷、锑、铋中观察到的现象，用分光光度法对三种有色溶液的吸收光谱进行分析和讨论。实验证明，砷、锑、铋的氢化物与AgDDC形成的有色物质不可能是下列络合物：1、砷、锑、铋与二乙氨基二硫代甲酸（简称HDDC）或其它配位体形成的络合物；2、砷、锑、铋或银与HDDC形成的同核或异核的多核络合物；3、砷、锑、铋与HDCC及有机碱形成的三元络合物。同时指出，砷、锑、铋的氢化物与AgDDC之间可能发生的氧化还原反应，反应形成的有色物质属於银溶胶。由於上述三种氢化物还原AgDDC的能力不同，故所产生的银溶胶分散程度不同，而具有各自特征的颜色及吸收光谱。我们结合实验现象对砷的吸收曲线有两个吸收峰的问题进行了讨论，指出410毫微米波长处的吸收峰是砷的有色物质本身固有的，是由另一种分散程度的银溶胶产生的。

重掺B对应变SiGe材料能带结构的影响

硅锗异质结双极晶体管(SiGe HBT)一般以重掺硼(B)的应变SiGe层作为基区.精确表征SiGe材料能带结构对SiGe HBT的设计具有重要的意义.在应变SiGe材料中,B的重掺杂一方面会因为重掺杂效应使带隙收缩,另一方面,B的引入还会部分补偿Ge引起的应变,从而改变应变引起的带隙变化.在重掺B的应变SiGe能带结构研究中,采用半经验方法,考虑了B的应变补偿作用对能带的影响,对Jain-Roulston模型进行修正,并分析了重掺杂引起的带隙收缩在导带和价带的分布.

环糊精衍生物的设计、合成及其对环辛烯光异构化研究

环糊精(Cyclodextrins, CDs)经化学修饰后可以得到各种类型的衍生物，不仅可以扩展其原有的键合能力，而且还可以改变其选择性，是当代超分子化学的一个研究热点。环糊精第二面的仲羟基比第一面的伯羟基有着更好的催化性能，第二面的选择性修饰将产生更多有价值的衍生物，可用于催化、酶模拟、手性识别等方面。 取代苯甲酰基修饰环糊精对顺式环辛烯(cis-cyclooctene)光异构化反应有非常重要的影响作用，苯环上取代基的性质和取代位置与产物的%ee值和对映体构型之间存在某种内在联系。有目的地选择适宜取代基，设计、合成新型环糊精光增感剂, 有可能按预定目的得到更高%ee值的反式环辛烯；同时，取代苯甲酰基修饰环糊精对cis-cyclooctene光异构化的增感机理有待于进一步阐明。 本论文工作对环糊精的化学修饰以及超分子体系对cis-cyclooctene不对称光异构化反应方面的进展进行了调研。合成了一系列单-6-位取代苯甲酰基修饰环糊精，用于cis-cyclooctene光异构化增感反应，并用圆二色光谱滴定法研究这些环糊精衍生物与cis-cyclooctene的相互作用，以探索光增感反应机理。在此基础上，探讨了环糊精第二面的选择性修饰方法。内容主要包括： 1. 简要介绍了超分子化学的概况，并对环糊精的选择性修饰方法和超分子体系对cis-cyclooctene不对称光异构化反应的主要成果和最新进展进行了评述。 2. 合成了12种单-6-O-(取代苯甲酰基)-β-环糊精，其中10种为新化合物。采用紫外光谱、红外光谱、核磁共振波谱以及质谱等手段对化合物的结构进行了表征。 3. 探索了直接选择性修饰环糊精第二面的便捷新方法。用取代苯甲酰咪唑酯为酰化试剂，0.2M碳酸盐缓冲溶液(pH=9.9)作催化剂，能够有效地活化2-位仲羟基，对环糊精第二面进行选择性修饰，此方法既简便又经济；同时，发现取代苯甲酰基能够在β-CD第二面的2-位、3-位羟基间相互迁移。 4. 用单-6-O-(取代苯甲酰基)-β-环糊精作光增感剂，对cis-cyclooctene光异构化反应进行研究。实验结果证明：取代苯甲酰基上的取代基性质、位置、长度对反应的对映选择性有很大影响；此外，反应体系溶剂极性对产物的%ee值和对映体构型也有重大影响。用单-6-O-(3-甲氧苯甲酰基)-β-CD作增感剂，cis-cyclooctene光异构化反应产物(R)-trans-cyclooctene的对映选择性为45.8%ee，是到目前为止取得的最好对映选择性。 5. 采用圆二色光谱滴定法研究环糊精衍生物与cis-cyclooctene的相互作用，计算包结物的平衡常数，研究包结物的相对稳定性，为探索光增感反应机理提供基础。我们猜测：电子效应对cis-cyclooctene光异构化反应的影响，可能比取代基位置对反应的影响更大，借助电子效应有希望获得更高的%ee值。 Cyclodextrins can be subjected to diverse modifications to give a wide variety of cyclodextrin derivatives, which could not only extend their original molecular binding ability, but also alter their molecular selectivity. Therefore, cyclodextrin chemistry is currently a significant topic in supramolecular chemistry. The more open secondary hydroxyl side of CDs is stated to be catalytically very important, modifications of this face are believed to produce valuable derivatives for catalysis, enzyme mimic, chiral discrimination, etc. Mono-6-O-(substituted benzoyl)-β-CDs as novel supramolecular photosensitizing hosts have recently excited considerable attention in photochirogenesis. The supramolecular photosenstization of cis-cyclooctene mediated by them gave chiral trans-cyclooctene, enantiomeric excess of which was critically affected by the substituent introduced to the sensitizer moiety. In order to enhance the photoenantiodifferentiating ability, and elucidate the origin mechanisms of substituent-dependent enantioselectivity, in this work a series of mono-6-O-(substituted benzoyl)-β-CDs have been synthesized, and applied for enantiodifferentiating photoisomerization of cis-cyclooctene. The major contents are as follows: 1. The general aspects of supramolecular chemistry were descibed briefly. The new progress and important achievements on methods of selective modification of cyclodextrin and supramolecular enantiodifferentiating photoisomerization of cis-cyclooctene were reviewed. 2. Twelve mono-6-O-(substituted benzoyl)-β-CDs including ten novel compounds have been synthesized. Their structures have been characterized by using UV-vis, IR, NMR and MS methods. 3. A new convenient strategy for direct acylation of β-cyclodextrin on the secondary hydroxyl face was achieved by using the combination of N-benzoylimidazole and carbonate buffer in DMF, and the acyl migration between the C-2 and C-3 hydroxyl groups of β-cyclodextrin was found. 4. Experiments using mono-6-O-(substituted benzoyl)-β-CDs as chiral sensitizing hosts for mediating the enantiodifferentiating photoisomerization of cis-cyclooctene, were carried out. The results indicate that enantiomeric excess was critically affected, or even switched in sign, by the substituent introduced to the sensitizer moiety, and polarity of solvent. Using mono-6-O-(3-methoxybenzoyl)-β-CD as chiral sensitizing host, (R)-trans-cyclooctene was obtained in up to 45.8% enantiomeric excess, which is the highest value ever reported for supramolecular photochirogenesis with analogous hosts. 5. The conformational variation of these modified CDs and their complexation behaviors with cis-cyclooctene were examined by circular dichroism spectroscopy in water-methanol mixed solvents, which reveal that the orientation of chromophore was highly sensitive to the type, position and length of the introduced substituents. In the end, the complex stability constants(Ks) were calculated, and the mechanisms of reaction were discussed. Maybe, electronic effects are more important than positions of substituents for mediating the enantiodifferentiating photoisomerization of cis-cyclooctene.

生姜化感作用机理及其栽培模式研究

近年来，随着对作物重茬（连年种植）障碍原因的深入研究，植物的化感作用越来越受到国内外众多学者的重视。而作为重要调料和药用植物的生姜，其连作障碍也备受关注，系统地研究生姜化感作用将有助于理解和最终解决生姜连作障碍问题。本文通过研究生姜不同部位、不同浓度的水浸液对与其间作的两个物种（大豆和四季葱）种子的萌发及幼苗生长的影响，从而证明生姜化感作用的存在；并通过温室盆栽实验研究了生姜的自毒作用（即研究生姜不同部位、不同浓度的水浸液对其幼苗的形态、生理生化、光合作用、土壤酶、土壤微生物多样性及土壤养分的影响），从而揭示生姜退化和衰老的机制，并为生姜筛选出合适的间作物种提供科学依据，对生姜连作障碍提出科学的解决方法。主要研究结果如下： 1. 与对照相比，生姜所有部位（根茎、茎、叶）、所有浓度（10、20、40、 80 g l-1）的水浸液均抑制了大豆种子和葱籽的萌发率、幼苗生长、水分吸收和脂肪酶活性，并且其抑制程度随着水浸液浓度的增加而增强，其生姜各部位水浸液抑制效应的强弱顺序为茎＞叶＞根茎。这一结果表明生姜根茎、茎、叶含有能够抑制大豆种子和葱籽种子萌发和幼苗生长的水溶性化感物质。根茎是生姜的主要收获部位，而生姜的残株（主要是茎和叶）应该从大田中处理掉以减轻其抑制效应。生姜水浸液中主要化感成分包括：根茎水浸液中主要是丁香酸和伞花内脂；茎水浸液中主要是阿魏酸，且其含量最高为73.4 ug/g；叶水浸液中除了阿魏酸，其他六种物质均检测出来，但含量较高的主要有丁香酸、伞花内脂和香豆酸。 2. 生姜茎和叶不同浓度的水浸液均显著抑制了生姜幼苗的株高、每株叶片数和叶面积，其抑制程度随着水浸液浓度的增加而有所增强，而生姜幼苗每株分枝数差异不显著；同时生姜水浸液也极大程度地影响了生姜幼苗的生物量（包括地下生物量、地上生物量和总生物量，均为鲜重）。在同一浓度下，茎水浸液对生姜幼苗形态指标及生物量指标均显示出最强的抑制作用，叶水浸液次之，根茎水浸液最弱。与对照相比，低浓度的生姜根茎水浸液提高了生姜幼苗叶片内四种抗氧化酶（SOD、POD、CAT、APX）活性，高浓度的根茎水浸液抑制了四种抗氧化酶活性，而茎和叶水浸液均随着浓度的增加而抑制了四种抗氧化酶活性，三种水浸液均随着浓度的增加降低了生姜幼苗叶片内叶绿素的含量，而增加了生姜幼苗叶片的相对电导率和丙二醛含量。同时，三种水浸液均随着浓度的增加降低了生姜幼苗的光合参数（包括胞间CO2浓度、气孔导度、蒸腾速率及净光合速率）。 3. 三种生姜水浸液对所测六种土壤酶活性均产生了不同程度的影响，其中影响最大的是酸性磷酸酶和蔗糖酶，在10 g l-1 时就达到了显著水平，并且所有酶均有随着水浸液浓度增加而增大的趋势；相同部位的水浸液随着浓度的增加，细菌和真菌的数量呈增加趋势，而放线菌的数量呈减少趋势；三种生姜水浸液均随着浓度的增加降低了土壤中有机质的含量，加剧了土壤中硝态氮含量的积累，根茎水浸液对土壤有效磷、速效钾和铵态氮均显示出低浓度提高其含量而高浓度降低其含量的趋势，而茎和叶水浸液则随着浓度的增加均降低了其含量。 4. 与生姜单作相比，所有间作系统均在旺盛生长期和收获期不同程度地提高了土壤酶活性，同时也增加了土壤细菌数量及土壤微生物总数但不显著；所有间作系统在旺盛生长期和收获期均不同程度地影响了土壤真菌及放线菌数量（增加或减少），所有间作系统间的多样性指数差异不显著，除了旺盛生长期四种作物（生姜-大豆-四季葱-大蒜）的间作模式显著降低了多样性指数，其值仅为生姜单作的33.18%；生姜与大豆间作不仅提高了19.6%的生姜产量而且获得了较好的经济效益，并且，所有间作系统均显著抑制了生姜姜瘟病的发生。 5. 不同栽培模式不同程度地影响了收获期生姜的株高、分枝数、根茎产量及内在品质。其中处理2显著地促进了生姜的分枝（10.5%），同时处理2、3和4也促进了生姜的生长（株高分别增加了15.0%、11.4%和14.0%），并且这三个处理提高了生姜的产量；处理2和3能有效提高生姜块茎中维生素C（分别较单作生姜显著提高了3.29%和4.05%）、处理3显著提高了可溶性糖（8.2%）、姜辣素（4.6%）和蛋白质等有益物质的含量，降低硝酸盐有害物质的含量（处理2显著降低了14.0%），改善了姜块的外观和内在品质。并且，生姜与大豆间作具有最高的纯收入和产投比，分别较生姜单作提高了24.80%和8.8%。Recently, allelopathy has been more and more paid attentions by national and foreign scholars with profound research on reasons of crop replanted (continuous planted) obstacle. Ginger rhizome is valuable all over the world either as a spice or herbal medicine and ginger replanted obstacle is also paid attentions. Systematic research on ginger allelopathy will contribute to understanding and ultimate solving problem of ginger replanted obstacle. The effects of ginger aqueous extracts with different parts and concentrations on seed germination and early seedling growth of soybean and chive were studied in this article to testify that ginger existed allelopathy. Furthermore, ginger autotoxicity was also studied by pot experiment in greenhouse (namely research on effects of ginger aqueous extracts with different parts and concentrations on morphological indexes, physiological and biochemical indexes, photosynthesis, soil enzymes, soil microbial diversity and soil nutrients) to reveal mechanism of ginger degeneration and senescence, provide scientific basis for selecting appropriate intercropping species and put forward scientific resolvent for ginger replanted obstacle. The main results were as follows: 1. All aqueous extracts at all concentrations inhibited seed germination, seedling growth, water uptake and lipase activity of soybean and chive compared with the control, and the degree of inhibition increased with the incremental extracts concentration. The degree of toxicity of different ginger plant parts can be classified in order of decreasing inhibition as stem＞leaf＞rhizome. The results of this study suggested that rhizome, stem and leaf of ginger contained water soluble allelochemicals which could inhibit seed germination and seedling growth of soybean and chive. The rhizome is the main harvested part of ginger. The residue (mainly stems and leaves) of the ginger plant should be removed from the field so as to diminish its inhibitory effect. The main allelopathic components of three kind of aqueous extracts were as follows: Rhizome extract chiefly contained syringic acid and vmbelliferone and stem extract mainly contained frulic acid whose content was the highest (73.4 ug/g). The other six substances were detected except of frulic acid, but only contents of syringic acid, vmbelliferone and p-coumaric acid were higher. 2. Stem and leaf aqueous extracts of ginger with different concentrations significantly inhibited plant height, leaf numbers per plant and leaf area, and the degree of inhibition increased with the incremental extracts concentration. However, tiller number per plant of ginger seedling showed no significant difference. At the same time, ginger aqueous extracts also influenced biomass including under-ground biomass, above-ground biomass and total biomass (fresh weight) to a large extent. Under the same concentration, stem aqueous extract showed the mostly inhibitory effect on morphological indexes and biomass indexes of ginger seedling. Rhizome aqueous extract showed the leastly inhibitory effect and leaf aqueous extract was intervenient. Enhanced concentration of ginger aqueous extracts significantly reduced total chlorophyll content, accompanying with increases in memberane permeability (REL) and lipid peroxidation (MDA). Compared with the control, rhizome ginger aqueous extract of lower concentration (10 g l-1) increased the activities of major antioxidant enzymes (superoxide dismutase, SOD; peroxidase, POD; catalase, CAT; ascorbate peroxidase, APX) of ginger leaf tissue and higher concentration inhibited the activities of four antioxidant enzymes. However, stem and leaf aqueous extract inhibited the activities of four antioxidant enzymes with increase in concentration. Meanwhile, enhanced concentration of ginger aqueous extracts significantly reduced photo-parameters of ginger seedling (including CO2 concentration, stoma conductivity, net photosynthesis rate and transpiration rate). 3. Rhizome, stem and leaf ginger aqueous extract showed different effect on six soil enzyme activities, and acid phosphatase and invertase showed significant effect when aqueous extract concentration got 10 g l-1. Furthermore, six soil enzyme activities increased with increase in aqueous extract concentration. Bcterial and fungi number tended to increase while antinomyces tented to decrease with the increase in aqueous extract concentration of identical part. Ginger aqueous extracts reduced soil organic matter content with increased concentration, accompanying with NO3-—N accumulation in soil. Rhizome aqueous extract showed the same tendency for available P, available K and NH4+—N, namely lower concentration increased their contents in soil and higher concentration reduced their contents. While stem and leaf aqueous extracts reduced their contents with the increamental concentration. 4. All intercropping systems increased soil enzyme activities to different extent both at VGS and at HS compared to solo ginger. All intercropping systems increased the colony numbers of soil bacteria and total of soil microbe but not significantly either at VGS or at HS. All intercropping systems increased the colony numbers of soil fungi and actinomytes to a different extent (increase or decrease) both at VGS and at HS. For DI, difference between all cultivation patterns and S-G was not significant either at VGS or at HS except that G-S-C-G whose value was only 33.18% of S-G at VGS significantly decreased. G-S not only increased ginger yield by 19.6% but also obtained better economic benefit. Furthermore, all intercropping systems significantly inhibited occurrence of bacterial wilt of ginger. 5. Different cultivated pattern influenced plant height, tiller numbers, rhizome yields and intrinsic quality of ginger. Treatment 2 significantly facilitated tiller occurring (10.5%). Treatment 2, 3 and 4 promoted ginger growth (plant height respectively increased 15.0%、11.4% and 14.0%) and enhanced rhizome yields. Treatment 2 and 3 effectively increased vitamin C content (significantly increased 3.29% and 4.05% compared to solo ginger). Treatment 3 significantly increased contents of beneficial substances such as soluble sugar (8.2%), gingerols (4.6%) and protein. Treatment 2 significantly decreased contents of deleterious substance namely nitrate (14.0%) and improved appearance and intrinsic quality of ginger rhizome. Furthermore, treatment 2 (ginger/soybean intercropping) could obtain better economic benefit and showed the highest net income and ratio of benefit and cost whose values respectively increased by 24.80% and 8.8% compared to solo ginger.

三种瘤细胞对重离子和γ射线的辐射敏感性

目的　比较体外培养的瘤细胞对重离子和γ射线的辐射敏感性。方法　以人肝癌SMMC 772 1、宫颈癌HeLa和小鼠黑色素瘤B16细胞为材料 ,用集落形成法研究了细胞经γ射线和重离子处理后的存活情况。结果　细胞经γ射线处理后均表现为有肩区的存活曲线 ,属多靶击中模型。细胞经重离子处理后表现为无肩区的存活曲线 ,属单靶击中模型 ,在细胞存活分数为 5 0 %和 10 %时得到SMMC 772 1、HeLa、B16细胞的RBE值分别为 3 40、2 76、4 6 7和 1 88、1 5 3、2 2 2。结论　在相同剂量下 ,重离子能更有效地杀灭瘤细胞

~(237)Th的半衰期测量

利用 6 0MeV/u的18O离子束轰击天然铀靶 ,通过多核子转移反应生成重丰中子核素2 37Th ,由多步快速放射化学分离方法从被照射过的靶物质中分离出钍元素。观测到了2 37Th的子体2 37Paγ活性的生长及衰变行为 ,确定了2 37Th的存在 ,测得其半衰期为 (4.6 9± 0 .6 0 )min。

不同起源沙地樟子松林结构与生长比较研究(英文)

樟子松已成为三北沙区防护林主要乔木造林树种,但是,最早于20世纪50年代在科尔沁沙地引种的沙地樟子松却出现了生长衰退、枯梢直至死亡的现象,而天然状态的樟子松在该阶段却正处于旺盛生长期。为了比较沙地人工樟子松林与天然林的林分结构、生长特点及所处立地的生态因子的异同,对辽宁省彰武县章古台(最早引种沙地樟子松区)和内蒙古自治区红花尔基(天然樟子松分布区)的樟子松林进行了综合调查。结果表明,Weibull分布函数可较好地模拟人工林树木直径分布,正态分布函数可用于模拟天然林树木直径分布。基于树干解析的树木生长模型(Chapman-Richards)分析,人工林胸径、树高与材积的相对生长率与平均生长率的最大值比天然林分别提早11、22年,6、18年和35、59年。人工林材积的生长加速度高峰值出现在14年,而天然林则出现在33年;人工林的数量成熟龄为43年,天然林为102年;因此,可以推断天然林的寿命比人工林要长近60年。这一结果可以归纳为以下综合作用:1)两种起源地生态因子的巨大的差异,主要包括:人工林区的纬度、平均气温、降水量、蒸发量、海拨高度等较天然林区高;2)人工林的林分密度较天然林大;3)人工林区的干扰强度较天然林强。图4表6参23。

多环芳烃污染土壤的生物泥浆法修复

通过小型泥浆反应器的运行 ,确定了生物泥浆法修复多环芳烃污染土壤的温度、水土比和通气量参数 .采用 2 :1的水土比 ,控制温度、通气量分别为 2 0℃～ 2 5℃ ,60L/h可以达到较好的修复效果 .用从污染土壤中分离出的真菌在纯培养条件下对多环芳烃进行降解 ,经 34d的培养 ,镰刀菌对芘和苯并蒽的降解率为 90 %和33 3% ,毛霉可以分别降解 81 .5%和 4 9.2 % ,青霉可以分别降解 52 %和 4 6%

解集GCM输出模拟黄土塬区土壤水分平衡的潜在变化

壤水分平衡对气候变化存在着响应,在全球变化的大背景下,研究土壤水分的可能变化是气候变化影响评估中非常重要的一项内容。目标是利用经验统计方法解集GCM网格逐月的降水和温度数据,并使用建立的气候变化情景作为WEPP的输入文件评估黄土高原王东沟流域2010～2039年土壤水分平衡(土壤水分、蒸发、渗漏和蒸腾)的可能变化。结果表明,3种情景预测2010～2039年王东沟流域年均降水可能增长1.8%～17.5%,年最高温度和最低温度分别可能增长0.5～0.9℃和2.0～2.3℃。作物蒸腾变化主要在4～6月份,土壤蒸发变化主要发生在7～9月份;作物蒸腾年均变化-5%～19%,土壤水分年均变化-4%～4%,土壤蒸发年均变化-7%～7%,均为A2a减少,B2a和GGal增大;A2a的土壤水分渗漏增长最大,GGal次之,B2a基本不变。这些结果表明气候变化及其导致的作物生长变化对土壤水分平衡存在重要的影响。