地下水埋深对春玉米田土壤水分及产量的影响

通过6种地下水位控制处理和对照春玉米试验,探讨了地下水埋深对春玉米农田土壤水分、产量以及水分利用效率的影响。结果表明,地下水埋深对春玉米0～100cm层次土壤水分的影响较大。地下水位越浅这种影响显得越明显;无论地下水埋深深浅,田间累计地下水补给量变化规律可分为4个阶段,即稳定增长期、缓慢增长期、快速增长期和趋于稳定期。地下水位越高,累计地下水补给量越大,土壤排水量越大。较大降雨后土壤开始排水日期随着地下水埋深加深而滞后;地下水埋深1.0m时春玉米产量和水分利用率最高。地下水位在1.0m以下时,水分利用效率随地下水位加深而减少。     

Beta-thujaplicin: new quantitative CZE method and adsorption to goethite

Beta-thujaplicin (beta-TH) is a toxic tropolone derivative present in the heartwood of western red cedar (Thuja plicata) and is used as a preservative and antimicrobial additive in a number of commercial goods. beta-TH released from western red cedar timber used outdoor and from other products containing beta-TH may transfer to soil and leach to groundwater and surface waters. The objective of this study was to quantify the adsorption of beta-TH to goethite as a typical model for geosorbents. Adsorption was studied using pH-adjusted goethite suspensions with solid:solution ratios of 1:500, 0.01 M NaNO(3) electrolyte, and 20 degrees C. beta-TH was determined using a new capillary zone electrophoresis (CZE) method providing a detection limit of 0.21 microM. Near-sorption equilibrium was attained within 48 h. beta-TH showed maximum adsorption at low pH (3.8) and a 70% drop in adsorption from pH 6.2 to 8.8. The Langmuir type adsorption isotherm at pH 5.5 approached a maximum adsorption of 220 micromol/g (= 6.2 micromol/m(2)), which is more than twice the amount of phosphate adsorbed under similar conditions. The affinity of beta-TH for goethite is low as compared with organic ligands such as citrate, oxalate, and 2,4-dihydroxybenzoate. The adsorption data and FTIR analyses indicate that beta-TH is most likely adsorbed as monodentate mononuclear surface complexes at the surface of goethite. Hydrophobic adsorption is thought to contribute to the adsorption, in particular at low pH. The strong adsorption of beta-TH to goethite suggests low mobility in most soil environments, the risk of contamination increasing in soils with high pH (calcareous material), low contents of iron and aluminum oxides, phyllosilicates, and organic matter.     

重齿小蠹聚集信息素诱捕器的应用技术研究

重齿小蠹对人工合成聚集信息素的昼夜反应节律发生在白天7：00～21：00,反应高峰在14：00-19：00,反应模式为＂单峰式—白天型＂;利用人工合成的聚集信息素对重齿小蠹成虫发生期监测表明,成虫扬飞的开始时间为5月20日左右,扬飞高峰期为6月下旬和7月上旬,扬飞末期为8月26日,成虫扬飞的持续期为98 d。2007-2009年大量诱杀防治的试验前、后重齿小蠹致死木平均分别为3.39株/hm2和0.76株/hm2,致死木减少了77.58%,而对照区试验前、后致死木平均分别为15.89株/hm2和18.11株/hm2,致死木增加了13.97%,3 a大量诱杀试验的防治效果显著。     

电控发动机尾气检测与故障诊断的研究

为寻求根据汽车尾气参数来诊断汽车故障的方法，利用径向基函数（RBF）神经网络，对丰田雷克萨斯（LEXUS）400电控发动机进行故障诊断研究。研究结果表明，径向基函数神经网络对发动机故障的诊断是迅速、准确的。     

Probing the Local Effects of Magnetic Impurities on Superconductivity

The local effects of isolated magnetic adatoms on the electronic properties of the surface of a superconductor were studied with a low-temperature scanning tunneling microscope. Tunneling spectra obtained near magnetic adsorbates reveal the presence of excitations within the superconductor's energy gap that can be detected over a few atomic diameters around the impurity at the surface. These excitations are locally asymmetric with respect to tunneling of electrons and holes. A model calculation based on the Bogoliubov-de Gennes equations can be used to understand the details of the local tunneling spectra.     

向海沼泽湿地土壤特征及可持续利用

基于对向海沼津湿地土壤形成条件和主要成土过程的研究，将其沼泽土壤划分为4个亚类型，并分别描述了各自的分布规律和剖面特征。在向海沼泽湿地土壤盐渍化、沙化、退化问题日益严重的大前提下提出了可持续开发利用对策。     

Paleo-Eskimo mtDNA genome reveals matrilineal discontinuity in Greenland

The Paleo-Eskimo Saqqaq and Independence I cultures, documented from archaeological remains in Northern Canada and Greenland, represent the earliest human expansion into the New World's northern extremes. However, their origin and genetic relationship to later cultures are unknown. We sequenced a mitochondrial genome from a Paleo-Eskimo human by using 3400-to 4500-year-old frozen hair excavated from an early Greenlandic Saqqaq settlement. The sample is distinct from modern Native Americans and Neo-Eskimos, falling within haplogroup D2a1, a group previously observed among modern Aleuts and Siberian Sireniki Yuit. This result suggests that the earliest migrants into the New World's northern extremes derived from populations in the Bering Sea area and were not directly related to Native Americans or the later Neo-Eskimos that replaced them.     

基于SSR和SRAP标记的苹果品种亲缘关系分析

【目的】用SSR和SRAP分子标记技术,分析苹果(Malus domestica Borkh.)重要栽培品种的亲缘关系,为苹果杂交育种亲本及组合的选配提供参考。【方法】用亲缘关系较近的金冠和秦冠筛选SSR和SRAP多态性引物,利用SSR和SRAP分子标记技术对37个苹果栽培品种进行遗传多样性和亲缘关系分析。【结果】筛选出了用于37个苹果主栽品种亲缘关系分析的10对SSR和10对SRAP引物,其分别产生56和64条扩增带,平均多态性比率分别为61.09%和70.8%。根据SSR+SRAP分析结果,37个苹果品种被聚为6大类。【结论】所选取的引物能够有效地揭示供试苹果品种的遗传多样性,并且苹果品种分类与传统系谱基本一致。