鄂尔多斯地区历史城市的城市平面组合和子城特征

结合文物资料和前人的研究成果,在2003～2007年多次野外实地考察的基础上,对我国农牧过渡带-鄂尔多斯高原及毗邻地区内209座历史城市的城市平面组合和子城进行了研究。鄂尔多斯高原及毗邻地区历史时期的城市平面组合形式大致可分为两种:独立组合式和相连并列式。汉代城市的子城周长大致符合晁错的设计规模;子城以偏于地势较高和利于防卫的城内一隅为最常见的形态;子城作为城市中枢系统衙署所在,在位置选择中要得到最好的防御保障。     

改性膨胀珍珠岩去除废水中磷酸盐的研究

采用膨胀珍珠岩经过镧系稀土金属元素改性后处理了含磷废水。结果表明:改性后的膨胀珍珠岩对废水中的磷酸盐有明显的去除效果,当废水pH值为6~9,磷浓度为25mg/L,按改性膨胀珍珠岩与磷质量比为50:1来处理含磷废水,反应时间在4h之内,剩余磷酸盐的浓度小于0.5mg/L,磷酸盐的去除率达97%以上。     

模拟消化体系中乳及发酵乳对铁化学状态及透析率的影晌

本文通过体外消化来模拟消化系统以研究乳及发酵乳对FeCl3中铁的化学状态及透析率的影响，结果表明，在消化过程中乳及发醇乳可促进铁的溶解、以及Fe3 的还原和铁的透析，这一作用与样品的pH元失，认为是消化过程中产生的氨基酸和肽起了作用。研究还发现，原乳先加铁盐再送行发酵所产生的作用要较发醇后再加铁盐的作用大，认为发醇乳对铁化学状态及透析率的影响具有时间效应。此外，有乳存在的各试验组其Fe3 透析率较可溶性铁的透析率与对照组差异更大。     

长期轮作连作对不同作物土壤磷组分的影响

对长期轮作连作条件下的大豆、玉米、小麦土壤磷组分进行研究,试验结果表明,供试土壤在不施肥情况下,土壤全磷以轮作区降幅最大,而土壤有效磷以小麦连作区降幅最大,土壤磷组分以大豆连作区土壤中的Ca2-P降幅最大;在施有机肥的情况下,土壤全磷以大豆连作区增幅最大,而土壤有效磷以轮作区增幅最小,土壤磷组分以轮作土壤中的Ca2-P增幅最大。     

渗透胁迫对玉米幼苗叶片不同形态多胺含量的影响

用高压液相色谱法，研究了玉米品种农大108（抗旱性较强）和掖单13（抗旱性较弱）幼苗叶片中游离态(free, f)、酸可溶性共价结合态(AS-conjugated)和酸不溶性共价结合态(AIS-bound) 多胺（polyamine, PA）与渗透胁迫的关系。结果发现，渗透胁迫7 d，农大108的fSpd和fSpm的含量显著(P＜0.05)上升，而掖单13的fPut的升幅显著(P＜0.05)。用S-腺苷蛋氨酸脱羧酶（SAMDC）抑制剂甲基乙二醛-双（鸟嘌呤腙）（MGBG）处理农大108，显著抑制了渗透胁迫诱导的fSpd和fSpm的增加，并且加重了渗透胁迫伤害，用外源Spd处理掖单13，则显著促进了渗透胁迫诱导的fSpd和fSpm的增加，并且减缓了渗透胁迫的伤害。渗透胁迫下，农大108幼苗叶片中AS-conjugated-PA和AIS-bound-PA的上升幅度都显著大于掖单13。用转谷氨酰胺酶（TGase）抑制剂菲咯啉(o-Phen)处理，则抑制了渗透胁迫诱导的AIS-bound-PA含量的上升，并加重了渗透胁迫的伤害。上述结果说明，玉米幼苗叶片中的fSpd、fSpm、AS-conjugated-PA和AIS-bound-PA的升高有利于增强幼苗的抗渗透性。     

An Effect of Various Nitrogen Forms Used as Fertilizer on Lupinus albus L. Yield and Protein, Alkaloid and α-Galactosides Content

The influence of various forms of nitrogen supplied to the ground as N₂, NH, NO, [NH + NO], –NH₂, and Nd (N‐deficiency) on Lupinus albus L. cvs. Butan (sweet) and Bac (bitter) yield and protein, alkaloid and α‐galactoside biosynthesis in their seeds were studied. The experiments were performed in a greenhouse on perlite using, in all cases, the same dose of P, K, Mg and micronutrients (B, Zn, Mn, Cu, Mo, Fe). The Nd treatment contained only macro‐ and micronutrients without any nitrogen support. We found that different nitrogen forms used as a fertilizer had a significant influence on the development and yield structure of both lupin cultivars. It was found that the plants developed most favourably when nitrogen was supplied as N₂ and [NH + NO]. For the other forms, the anomalies like necrosis, chlorosis, leaves with small surface of assimilation were noticed. However, these observations were not always reflected by all parameters of yield structure. The forms of nitrogen had a pivotal influence on yield of generative and vegetative parts of lupin. Moreover, significant differences in protein, alkaloid and α‐galactoside content in seeds were observed.     

Agronomical and morphological differentiation among winter and spring triticales

A collection of 299 secondary hexaploid triticale cultivars and advanced breeding lines from 18 countries, which were considered a representative sample of the existing diversity, was evaluated for morphological and agronomical characters with autumn planting at Lleida, Spain, from 1988 to 1991. The entries were classified as having winter (84) or spring (215) growth habit and among this latter group were complete (73) or substituted (147) types according to CIMMYT's terminology. Winter and spring triticales were grouped by cluster and principal component analyses. Winter triticales were taller with longer growth cycles, longer spikes, and more spikelets per spike than spring types. At early stages they also had prostrate growth. Spring-substituted types were separated from complete material. As a group, spring-substituted triticales differed more from winter types than the spring complete genotypes, which showed intermediate characteristics. Complete types of spring habit had tendency to be taller, with longer spikes, more spikelets per spike and bigger and heavier grains than substituted triticales. Greater variation in morphological and agronomical parameters was detected among winter triticales followed by the complete-spring group.     

磷在棕壤中淋溶迁移特征研究

采用室内土柱淋溶模拟试验，研究相当于一年降雨条件下磷肥在棕壤土垂直方向上的淋溶迁移特征及鸡粪、秸秆对磷素迁移转化的影响。结果表明：土壤施肥量与速效磷、迟效态磷增加量呈极显著正相关。相关系数分别是0．99141。，0．99774；水溶性磷、Al—P与土壤速效磷相关性最好，相关系数分别达0．972和0．926，2500mg／kg鸡粪与25mg／kg磷肥配施能降低磷淋溶率，并能极显著提高土壤中速效磷的增加量，相当于单施50mg／kg的磷肥；秸秆与磷肥配合施用在短期内对土壤磷素的有效性影响不大，但可以减少磷素向下层迁移。     

氮、磷的农业非点源污染防治方法

非点源污染最主要的影响就是使水体富营养化、水质变差,从而影响到生产、生活、社会与经济的发展,其中氮、磷的农业非点源污染又是最主要的。经过30多年的研究,非点源污染研究逐渐从初期的定性化研究转向定量化,由统计、调查与机理研究转向实用治理研究。就众多的防治方法来看,大体可以分为两大类,即“源”(Source)防治和“汇”(Sink)防治。     

灌溉方法对保护地土壤有机氮组分及剖面分布的影响

用Bremner有机氮分组法测定了连续7年采用不同灌溉方法灌溉的保护地土壤各剖面层次有机氮组分含量。结果表明,土壤全氮及有机氮各组分含量均随土层深度的增加而降低,但有机氮各组分占全氮的比例随土层深度增加的变化却无明显规律。用3种灌溉方法灌溉,不同土层间土壤有机氮各组分含量的差异主要存在于0～50 cm土层,50 cm以下差异很小;相同土层,土壤有机态氮含量均以酸解氮为主,且酸解氮中各组分绝对含量和相对含量的大小排列顺序均为,未知态氮〉氨态氮〉氨基酸态氮〉氨基糖态氮。在0～80 cm土层,土壤酸解氮占全氮的比例大多在58%～60%之间,只有渗灌处理0～10 cm,10～20 cm及沟灌处理0～10 cm土层酸解氮占全氮的比例较低,分别为34.21%,50.75%和48.02%;而非酸解氮占全氮的比例大多在32%～36%之间。3种灌溉方法相比较,除个别层次外,酸解氮中氨基酸态氮、氨基糖态氮及氨态氮占全氮的比例在各土层中滴灌和渗灌处理均高于沟灌处理,而酸解未知态氮和非酸解氮占全氮的比例则为沟灌处理高于滴灌和渗灌处理。