云南软香型籼稻品种滇屯502的复壮研究

软香型品种滇屯502是云南特色优质米生产的当家品种,30余年生产应用种性退化严重,在无病虫害防治条件下,其稻瘟病发病率为100%,产量减少41.9%。为了对该品种进行复壮,采用单穗选择、株系比较、品系鉴定的方法,紧扣稻瘟病抗性、香味和软米几个重要而典型的性状,开展滇屯502复壮相关研究。结果表明,在2.67万株滇屯502群体中筛选出3个复壮品系,入选率为0.01%。这3个品系表型和食味品质与滇屯502相似,但产量和稻瘟病抗性较滇屯502分别至少提高41.1%和58.3%。利用复壮品系混系繁殖形成的复壮滇屯502,较原种滇屯502的生产力得到明显提高。本研究结果可为云南软香常规稻品种复壮提供技术和经验指导。     

超声空化对软性磨粒流切削效率和质量的影响

为提高软性磨粒流切削的效能,研究了利用超声空化作用加快材料去除的方法。在分析磨粒抛光试验和计算流体动力学仿真结果的基础上,提出并验证磨粒碰撞壁面的动能是影响切削效率主要因素的假设;根据对超声空化气泡溃灭,及其在外围水域中冲击波形成与传播的研究结果,分析气泡溃灭在推动磨粒改变其动能时所起的增强湍流效果的作用。在此基础上搭建了超声辅助磨粒流试验装置,以表面覆有氧化层的硅片为试验对象,根据其表面氧化层的去除情况,分析超声空化对硅片表面材料去除能力的影响,并在磨粒流加工无氧化层硅片表面的试验中,观察到超声空化对磨粒流切削的显著影响。验证了超声空化能使磨粒流中的磨粒的动能发生改变,从而起到提高切削效率和提高表面质量的作用,以期为超声波作用下磨粒流加工工艺的改进提供参考。     

砒砂岩对毛乌素沙地风沙土储水能力影响的研究

为探析砒砂岩对于风沙土储水能力的影响,在毛乌素沙地设置不同比例砒砂岩与沙复配成土试验小区(砒砂岩与沙的体积比分别为1∶1,1∶2,1∶5),进行单季玉米种植,并分别于2013—2015年连续3年对0—120cm深度内土壤水分进行动态监测。结果表明:从2013—2015年,适量砒砂岩的加入将风沙土储水量从100mm左右提升至200mm以上,并可逐步调节土壤水分至不亏缺状态,显著提升土壤的保水蓄水能力,有利于作物生长需求;土壤储水以40cm以下中深层土壤储水能力改善作用最为明显,且经多年种植,0—40cm和80—120cm土层逐步成为土壤水分较为稳定的土层,利于作物根系对水分的吸收利用;砒砂岩与沙1∶1~1∶5范围内,随砒砂岩所占比例提高,复配土储水特征的改善作用有增强趋势,但趋势不显著。     

Studies on the humus forms of forest soils

Samples described in the previous paper were analyzed for humus composition by the method of Kumada el al,, elementary composition of humic acids, nitrogen distribution among humic acid, fulvic acid, and humin, and organic matter composition by the modified Waksman method. The samples obtained by physical fractionation from each horizon of Higashiyama soil were as follows: f₁ and f₂ from the L layer, f₁, f₂ and f₃ from the F layer, f₁ f₂, sand, silt, and clay fractions from the H-A and A horizons.

With the progress of decomposition, the following tendencies were rather clearly observed.

The extraction ratio of soluble humus, amounts of humic acid and fulvic acid, and PQ, value tended to increase with some exceptions. The degree of humification of humic acid proceeded. Most humic acids belonged to the Rp type, but those of the clay fractions belonged to the B type.

As for the elementary composition of humic acid, transitional changes from the Lf₁ to the clay fraction of the A horizon were observed. But differences in elementary composition among humic acids were far less, compared with those among whole fractions.

Nitrogen contents in humic, fulvic, and humin fractions increased with the progress of decomposition and humiliation, and the largest relative increase was found in fulvic acid nitrogen.

According to the modified Waksman's method, the amounts of residues and protein increased, while the total amounts of each extract, except for the HCl extract, and the amounts of sugars and starch, phenolic substances, hemicelluloses and pectin, and cellulose decreased. Sugars and starch comprised only a small portion of the hot water extract, and polyphenols substances comparable to sugars and starch were also found in the extract. Hemicelluloses and pectin accounted for only about one-half of the HCl extract. Several characteristic differences in the elementary composition of extracts and residues were found.

Pheopigments existed in benzene-ethanol extracts and their amounts seemed to decrease from Lf₁ to Ff₂.     

Adsorption of xanthan polymer on allophane and effect on the changes in colloidal stability of allophane by heavy metal ions

The influence of divalent cations at concentrations of 10^-6.0 to 10^-4.0 M on the colloidal stability of partially deflocculated allophane by gum xanthan (GX) polysaccharide at pH 6.5 was investigated at two GX concentrations. Experiment in the presence of 10^-2.0 g L^-1 GX showed that the stability decreased by the addition of divalent cations and the effect of the decrease due to the cationic species was evident in a higher concentration range, i.e., 10^-5.0 to 10^-4.0 M. The order of the effect was Pb >Zn > Cd > Mg. Experiment in a 10^-4.5 g L^-1 GX solution revealed that (i) the stability increased by the addition of heavy metal cations at 10^-5.0 M (the order of the effect was Pb > Zn > Cd) and decreased at a concentration above 10^-4.5 M, (ii) whereas the stability decreased by the addition of Mg ion. The striking difference in the stability behavior due to the difference between the two GX-concentrations was attributed to the (i) degree of GX-adsorption (and hence negative charge from the carboxyl group in GX) onto allophane based on the electrophoretic mobility, (ii) complexation of heavy metal cations by organic ligand (carboxyl group) in GX which was adsorbed onto allophane, and (iii) surface complexation by heavy metal cations and hydroxyl groups on allophane. The results were discussed in relation to the characteristics of the particles of allophane, viz., (i) polymer-coated soft particles, and (ii) semi-soft particles on which the rigid (hard) surface of allophane substantially remained.     

优质弱筋小麦扬辐麦2号的选育

采用扬麦 1 5 8与突变品系 1 90 1 2杂交 ,再经辐射诱变选育而成的优质弱筋小麦新品种扬辐麦 2号 ,其品质符合国家弱筋小麦标准 ,表现高产稳产 ,抗逆性强 ,千粒重高 ,后期熟相好 ,适应长江中下游淮南麦区种植     

同步辐射(软X、紫外)辐照麦类作物种子的诱变效应

同步辐射（软Ｘ,超软Ｘ射线）辐照麦类作物种子的生物学效应显。Ｍ１代出现条状叶绿素缺失,其出现率高达４０％－１００％〈其中大麦的缺失有４种类型,这在γ辐照中没有出现。Ｍ２工出现了宽的突变谱,最高达９种类型的突变,其最高总突变率为γ射线的２．７倍,有益突变率为γ射线的５．７倍。     

草本植物根系网的固土机制模式与力学试验研究

针对生物软措施的力学固土护坡作用进行了力学机制方面的探讨,提出植物根系网固土力学机制模式的四个层次,以及对不同草本植物根系的固土性能进行了力学试验比较。结果表明不同植物根系具有不同的抗拉强度。香根草根系平均抗拉强度最大达85 m Pa,其次为假俭草,平均抗拉强度27.3 m Pa,白三叶根系平均抗拉强度为24.6 m Pa,莎草根系平均抗拉强度为24.5 m Pa,宜安草根系平均抗拉强度为19.7 m Pa,百喜草根系平均抗拉强度为19.23 m Pa,马尼拉草根系平均抗拉强度为17.5 m Pa,狗牙根根系平均抗拉强度为13.45 m Pa。不同的植物根系具有不同的抗拉强度、不同的固土性能与其遗传结构及其组织材料不同有关。充分了解和认识植物根系固土性能,科学合理运用生物软措施代替或部分代替工程措施在我国繁重的生态环境保护和恢复的基本建设工程项目中具有重要的应用价值和意义。     

境外网络游戏的软权力作用分析

境外网络游戏是软权力在文化领域的重要载体之一,正日益凸显其重要地位,大多是通过网络游戏的内容和背景展现出来,意在增加本国经济效益的同时,以达到能够吸引不同国家和地区的更多玩家,灌输和宣传本国的思想和文化,使之成为配合其各国软权力战略实施的双重作用。面对这种新的文化渗透模式,研究如何应对境外网络游戏的隐性影响,是目前研究的主要课题。     

软构件技术在作物管理智能决策系统设计中的应用

基于知识模型和生长模型的作物管理智能决策系统是一个综合了多领域的作物信息和专家知识，集成了多方面相关支持技术的决策系统。因此，如何设计好系统中的各功能模块，使其便于非系统开发者对其精华部分的学习和理解，同时又能即插即用，利于系统的维护，是系统成功与否的关键。以小麦作物为例，论述基于软构件技术的作物管理智能决策系统设计中软件平台的选用、系统的构件化结构设计与实现过程以及数组在接口上的传递等关键技术，从而为农业管理决策系统的开发提供一种构件化的基础框架。