水肥耦合对苦荞产量的影响

水分和肥料是农业生产中影响作物生长的2个重要环境因子,合理地灌溉和施肥是增加作物产量的重要途径.试验采用4因素5水平二次通用旋转组合设计,通过盆栽水肥耦合试验,研究水肥耦合对苦荞产量的影响.结果表明:氮、磷、钾及水分单因素效应对苦荞产量的影响均呈抛物线趋势,影响顺序为,灌水量氮肥钾肥磷肥;水肥对苦荞产量的影响存在耦合效应,影响最大且达到显著水平的是水氮耦合,其他耦合如氮磷耦合、氮钾耦合、磷钾耦合、水磷耦合和水钾耦合对产量影响效果均不显著;当各因素为,x1=0.205、x2=0.0821、x3=0.0846、x4=0.267,即实际水肥耦合配比为氮肥476 kg/hm2、磷肥333 kg/hm2、钾肥279 kg/hm2、灌水量4 608 L/hm2,可获得最优水肥耦合模型的苦荞产量.     

不同水氮耦合对小麦旗叶主要光合特性的影响

在防雨水泥池栽条件下,以周麦18和济麦20为研究材料,研究水氮耦合对小麦旗叶主要光合特性的影响.试验结果表明:当土壤相对含水量低于40%时,施氮处理小麦旗叶气孔导度降低,胞间CO2浓度升高,光合速率受非气孔因素制约而降低;当土壤相对含水量为45%~75%时,随着氮肥施用量的增加,小麦旗叶的光合速率、气孔导度不断增加,胞间CO2浓度逐渐减小,气孔因素制约了光合速率的提高;当土壤相对含水量高于75%时,氮素营养对小麦旗叶光合特性的促进作用减弱.     

棉花膜下滴灌水氮耦合的初步研究

采用田间单因素和复因素试验研究了棉花膜下滴灌耗水和氮素养分吸收的规律,并建立棉花膜下滴灌水氮耦合方程。研究结果表明,现蕾前吸收的氮素养分不到总量的5％,盛花到吐絮期吸收养分的比例最大,超过60％,棉花膜下滴灌将大部分氮肥以追肥分配给棉花是符合棉花养分需求的生理规律的。膜下滴灌棉花全生育期耗水量在北疆石河子地区,苗期平均耗水量为44mm,蕾期平均耗水量为113mm,开花．盛铃期平均耗水量为182mm,盛铃期一吐絮期平均耗水量为98mm,总耗水量为437mm,随着灌溉量的增加,棉花耗水量也逐渐增加。建立了棉花水氮耦合回归方程,据此计算最高产量灌溉量为4189．5m3／hm2,最高产量施N量为223．5kg／hm2。采用“空间寻址法”计算最佳水肥耦合组合,发现棉花产量在4560～5040kg／hm2的频率最大,相应的最佳灌溉量、施氮量分别为4125m3／hm2、205．5kg／hm2以及4170m3／hm2、223．5kg／hm2。因此建议施氮量214．5kg／hm2,灌溉量4125m3／hm2为最佳水肥耦合组合。     

甘草配方施肥及各元素对光合作用的贡献率

采用三元二次正交回归设计进行4 a生甘草施肥试验,探讨不同施肥配比与施肥量对甘草光合作用的影响.结果表明:氮、磷、钾的单因子效应和互作效应对甘草的净光合速率均有很大影响,在相同栽培管理条件下,合理施用氮肥、磷肥、钾肥均可提高甘草净光合速率;施用氮肥对提高甘草光合作用的影响大.氮×磷、氮×钾均表现为正效应,其交叉项分别为0.810 0和0.275 7;磷×钾表现为负效应,其交叉项为-0.550 8.由此说明,氮和磷、氮和钾的有效配比均可促进甘草的光合作用.通过高光合施肥措施中的xi取值频率分布分析频率标准差,得出甘草最佳的施肥配方:N 96.85~104.35 kg/hm2、P2O579.91~88.62 kg/hm2、K2O 73.77~81.56 kg/hm2.     

节水灌溉条件下水氮耦合对烤烟生长发育及生理性状的影响

以土壤水分下限和施氮量作为控制指标,研究水氮耦合对烤烟生长发育及光合蒸腾的影响.试验结果表明:相同土壤含水率情况下增大氮肥的使用量可以显著增大烤烟的叶面积指数,提高烟株叶面的光合活性,促进烤烟的生长;氮肥的用量还影响到烤烟对水分的吸收,当施氮量为67.5 kg/hm2并且伸根期、旺长期、成熟期的土壤水分控制下限(占田间持水量的百分数)分别为60%,80%和70%时,烤烟能够获得较好的品质和较高的产量.     

水氮调控对水稻叶片荧光参数影响的正交分析

为揭示水氮调控对水稻叶片荧光参数的影响,实现节水灌溉条件下水肥的高效利用,以盆栽水稻为研究对象,采用正交试验方法研究水氮调控对水稻叶片荧光参数的影响。结果表明:(a)施氮量N对水稻叶片荧光参数的影响最大;土壤水分W和控水阶段S的重要性相当,并列第2位。(b)以水稻叶片荧光参数最优为目标,确定各因素最佳水平,得出最佳试验组合为N3W2S2和N3S2W2,即高施氮量(300 kg/hm2),控制灌溉标准,拔节孕穗前期进行土壤水分控制。     

不同水氮处理对滴灌春小麦氮素积累转运及产量的影响

为了明确施氮量和灌溉量对小麦花后干物质、氮素积累与转运的影响及其与产量关系,本研究在大田滴灌条件下,研究了常规灌溉Wc和适度亏缺灌溉W1、W2、W3,Wc灌水量5250 m3/hm2,W1、W2、W3总灌水量均为4575m3/hm2和施氮量,常规施氮N20(300 kg/hm2)、氮肥后移N16a (240 kg/hm2)、氮肥前移N16b(240 kg/hm2)、不施氮N0(0 kg/hm2),对春小麦开花前后的干物质积累和氮素积累、转运及产量的影响。结果表明:小麦干物质的积累量理论值以适度水分亏缺下氮肥前移N16b积累的干物质量理论值高于氮肥后移N16a。氮素积累量在4个灌溉水平下以适度亏缺灌溉的W1水平最大,施氮量为0-300 kg/hm2范围内氮素累积量随施氮量的增加而增加;氮素转运量和贡献率以茎鞘为最大,叶片次之,颖轴最小,水分和施氮量的增加有助于氮素的转运。适度亏缺W1水平下N16b施氮处理的小麦籽粒产量与N20差异不显著;相同施氮量下,W1水平N16b处理的氮肥生产效率达到33.38%,显著高于N16a、N20,N16b的氮肥农学利用率为17.66%,显著高于N16a、N20。综上结果表明:W1N16b处理既保证了小麦的产量与品质,又减少了水氮资源的投入,提高了经济效益且保护了生态环境,因此W1N16b为本实验下的最优水氮耦合模式。     

光氮耦合对番茄生长及光合特性的影响

基于两种光照强度和四种氮素水平的双因子条件,研究了光氮耦合对番茄幼苗生长及光合特性的影响.结果表明:光、氮及其耦合对番茄幼苗的生长及光合特性有不同影响;与全光照W1处理相比,遮光W2处理抑制了番茄幼苗的株高生长,但幼苗的叶面积、干物质的量积累及叶片数的生长呈上升趋势;在遮光条件下,番茄幼苗叶片的净光合速率、气孔导度呈上升趋势,胞间CO_2浓度和蒸腾速率有所降低;在一定范围内,光强越大,番茄幼苗光合作用越旺盛,但遮光条件下施氮能改善作物的光合作用;与无氮N0处理相比,随着供氮水平的增加,番茄幼苗生长指标和光合特性呈现先升后降的变化趋势;全光照W1处理下,峰值出现在中氮N2水平;遮光W2条件下,峰值出现在低氮N1水平.番茄幼苗最优的光照和施氮耦合模式为遮光低氮(W2N1),该组合有利于获得较高的生物量和光合效率.     

两种水稻土磷素渗漏流失及其与Olsen磷的关系

采用田间试验的方法,研究了太湖地区两种水稻土(爽水型水稻土和囊水型水稻土)稻季磷素向下渗漏流失情况及其与土壤Olsen-P浓度的关系.结果表明:在每季度30 kg/hm2常规施磷处理水平下,两种水稻土土壤渗漏水的溶解态磷(Dissolved P,简称DP)平均浓度均远超过了水体富营养化的阈值(0.02 mg/L).施磷处理能显著增加30 cm深度渗漏水磷浓度.土壤磷素渗漏迁移流失的主要形态是颗粒态磷(Particulate P,简称PP).爽水型水稻土和囊水型水稻土各处理土壤渗漏水PP/TP的平均值分别为70.9%和67.0%.囊水型水稻土稻季的磷素渗漏流失量约为每季度469.7 g/hm2大干安镇爽水型水稻土378.5 g/hm2.爽水型水稻土和囊水型水稻土土壤渗漏水中磷浓度各存在一个突变点(Change-point),两者分别为33.0 mg/kg和26.3 mg/kg.即当爽水型水稻土和囊水型水稻土土壤(0～10 cm)中的Olsen-P浓度分别大干33.0 mg/kg和26.3 mg/kg时,土壤30 cm深度的渗漏水磷浓度将随着Olsen-P浓度的增加迅速增大.两种水稻土突变点的差异可能与它们的有机质和黏粒含量不同有关.     

氮密互作对荞麦花期光合特性和产量的影响

以苦荞通荞一号(T1)和甜荞通荞二号(T2)为实验材料,在大田条件下设置3个播种密度(60、90、120 kg/hm~2)和4个施氮水平(0、90、270、360 kg/hm~2),研究了氮密互作对荞麦花期光合特性和产量的影响,旨在探究一个提高荞麦产量的最优氮肥水平和种植密度的平衡点,为制定合理的栽培措施,实现高产提供数据支持.结果表明,氮肥和密度显著影响荞麦的籽粒产量,两者之间存在互作效应.荞麦在花期的光合速率与产量之间存在显著的相关关系,提高荞麦的光合速率能增加籽粒产量.该实验条件下,通荞一号和通荞二号适宜的播种密度均为90 kg/hm~2,适宜的施氮量为270 kg/hm~2.因此,在荞麦的高产培育中,可通过调节施氮量和种植密度,提高植株的光合从而获得籽粒产量的高产.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that