Increasing productivity and protein content using early-maturing rices and efficient nitrogen management

Germplasm with shorter duration than that of the currently grown varieties is being generated to maximize productivity of irrigated rice. However, short-duration varieties often produce yields lower than the medium- and long-duration varieties. Experiments were conducted during the 1980–82 dry and wet seasons to increase productivity through the use of very early-maturing rices and the improved management of nitrogen (N) fertilizers.Results over three years showed that IR58 and IR9729-67-3 (growth duration 100 ± 5 days) yield as well as or higher than IR36 although earlier maturing. They generally had a higher productivity (kg ha^–1 day^–1) than IR36 (110 ± 5 days).Three years' data suggest that the improved timing of broadcast applications of urea in split doses increased grain yield comparable with the basal incorporation of slow-release sulfur-coated urea (SCU) or deep point-placement of urea supergranules (USG).Results on elite breeding lines showed that the early-maturing IR9729-67-3 produced higher protein yield ha^–1 than longer duration varieties such as IR8 and IR42 in the dry season. Furthermore, contrary to earlier results, single basal incorporation of slow-release SCU increased the protein yield of rice by 53 kg ha^–1 and deep point-placement of USG by 43 kg ha^–1 over split application of prilled urea.     

Influence of modified forms of urea and nitrogen levels on weed growth and grain yield of lowland rice

The growth of weeds and their subsequent reduction of rice yield as affected by N source neem cake coated urea (NCU), dicyandiamide coated urea (DCU), rock phosphate coated urea (RPCU), urea supergranules (USG) and prilled urea (PU) was studied on a clay loam soil at Coimbatore, India. Experiments were conducted in northeast monsoon (NEM) 1981, summer 1982, and southwest monsoon (SWM) 1982 seasons.The crop was associated with eleven weed species, and the dominant weeds wereEchinochloa crus-galli, Cyperus difformis andMarsilea quadrifolia. The weed flora varied between seasons. Deep placement of USG reduced the dry weight of weeds in NEM and summer seasons at 60, 90 and 120 Kg N ha^–1 whereas it increased the dry weight at 60 and 90 but not 120 Kg N ha^–1 in SWM season. The dry weight of weeds decreased with increased N rates for all N sources during NEM and summer seasons. In SWM season, dry weight of weeds increased with increased N rates for all N sources except USG. The grain yield of rice was drastically reduced with the deep placement of USG at 60 but not 120 Kg N ha^–1 in SWM season. The differential effect of the N sources between seasons was due to the change of the weed flora. Dominance ofE. crus-galli during SWM season had greater influence on weed dry weight and grain yield of rice.Nitrogen uptake by weeds was frequently greater in unfertilized plots, particularly in NEM and summer seasons. In SWM season, the apparent fertilizer N recovery by weeds was high for USG. It decreased from 53% for 60 Kg USG-N ha^–1 to 4% for 120 Kg USG-N ha^–1.Contribution from the part of Ph.D. work of the first author at Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore-641 003, Tamil Nadu, India.     

Cycling hardening and serration yielding of Fe-Ni-Cr alloy at high temperature under out-phase TMF

Behaviour of hardening and serration yield of a Fe-Ni-Cr alloy under isothermal cycling (ISC) and out-phase TMF was studied on the basis of varied hysteresis loops. Cycling hardening and serrated yielding for ISC depend on the temperature and the total strain range, stronger hardening with serrated yielding at higher strain range under ISC at 600 °C, but no hardening and serrated yielding occurred under ISC at 800 °C. Stronger hardening with stress serration occurred at the thermal path going to the lowest temperature, no stress serration occurred at the highest temperature under the out-phase. The hardening also depends on the total strain range, higher total strain range with lower cycling temperature resulted in a stronger hardening and remarkable serration yielding behavior. Weaker hardening without serrated yielding occurred at near 800 °C may due to an obvious cycling stress drop under out-phase TMF. Change in the shape of the hysteresis loops also expresses the degree of the damage of the tested alloy under out-phase and ISC.     

1-乙基-3-甲基咪唑四氟硼酸盐离子液体结构性质的模拟计算

离子液体以其独特的性质广受关注,被称为"绿色设计者溶剂",人们对其潜在的应用价值做了大量的研究.实验采用HyperChem软件构建了1-乙基-3-甲基咪唑四氟硼酸盐([EMIM][BF4])离子液体分子结构的3D模型,并用PM3法进行预优化,然后应用Gaussian 03w程序分别在RHF/6.31G(d)和BLYP/6-31G(d)计算水平上进行量子化学计算,并经振动频率和强度分析得到理论红外谱图.结果表明,[EMIM][BF4]离子液体的阴阳离子存在着氢键等弱相互作用.     

量子Klein-Gordon模型色散关系的含时变分法研究

通过采用含时变分原理,在结合Hartree型多粒子试探波函数和Jackiw-Kerman型单粒子波函数的基础上,研究了带对称单阱非谐格点势的量子Klein-Gordon模型的声子色散关系.在满足最小测不准关系的条件下,导出了粒子的期望值所满足的运动方程,并以此得到了声子色散关系.结果表明:与经典模型相比,由于量子涨落的影响,量子模型中的有效格点势的二次方项系数增大,声子元激发的带隙变宽;二次方项系数和带隙随着量子涨落和格点势的四次方项系数的增大而增大.     

含氮、磷有机配体对(CdSe)_2量子点结构和电子性质的影响

使用密度泛函理论方法研究了量子点(CdSe)2与配体L(L=PH3、PH2Me、PHMe2、PMe3、NH3、NH2Me、NHMe2、NMe3)之间的相互作用及其产物的结构和性质。配体中的P或N原子与Cd原子上分别形成较强的Cd—P和Cd—N配位键,从而影响(CdSe)2的结构和电子性质。配体作用下,(CdSe)2的几何结构、电荷分布、轨道能级、吸收光谱等均发生变化,但2类配体的影响,尤其是甲基数目的影响,存在较大差异。     

磁场中双量子位Heisenberg模型的纠缠与量子相变

以双量子位Heisenberg模型为例,讨论了磁场方向对纠缠的影响。结果表明：一定温度下,保持磁场的大小不变,仅改变其方向,不仅能获得最大纠缠,还产生了量子相变。     

金属材料屈服强度的应变率效应和热激活理论

对４种金属材料进行了应变率为１０＾－４－１０＾３ｓ＾－１的拉伸试验，结果表明，屈服中度随应变率的升高分两阶段线性升高，提出了位错线热振动对加载频率的响应的热激活作用机理，依据该机理计算所得Ⅰ，Ⅱ区临界应变εｃ与实测值相符，并在此基础上将应变率对掘强度影响的机制图重新划分为：Ｉ区，富热激活区；Ⅱ区，贫热激活区。     

A NEW BATO COMPLEX^99mTcCl（4—MCDO）3MeB FOR MYOCARDIAL IMAGING

A new nertral complex,^99mTcCl(4-MCDO)3MEB,((Bis[4-methyl-1,2-cyclohex-anedionedioximato(1-)-O]-[4-methyl-1,2-cyclohexanedione-dioximato(2-)-O] methyl-borato(2-)-N,N‘,N″,N‘‘‘,N‘‘‘‘0-chlorotechnetium,generally called BATO(Boronic acid adducts of technitium dioximes),has been synthesized and evaluated for potential use in myocardial perfusion imaging,It has intrinsic affinity for the blood clearance.The uptake of heart.lung and blood in mice at 2min separately are 1.12,2.48 and 6.66%ID.The complex formation is rapid,simple and highly yielded(≥93%).This process is easy to kit formation.     

响应面法微波降解EGCG制备EGC研究

目的 为探究微波降解EGCG方法制备EGC的效果,以EGC得率最大化为目标,探究微波降解的最佳工艺参数,并建立反映各参数间关系的二次多元方程模型。方法 本研究采用EGCG溶液为原料,运用微波加热降解EGCG制备EGC,通过梯度设置EGCG浓度、微波时长、微波强度三个工艺参数,进行单因素实验、响应面分析及最佳工艺组合验证实验,优化确定EGCG微波降解制备EGC的最佳工艺参数。结果 综合单因素实验及响应面分析,得到的最佳微波降解参数为：EGCG浓度5mg/ml、微波时长3.5min、微波强度为400W,且利用响应面法建立了EGC得率(Y)与EGCG浓度(A)、微波时长(B)、微波强度(C)的二次多元方程模型：Y=59.52+8.38*A+5.38*B+3.53*C-4.04*AB+6.92*AC-9.19*BC-9.99A2⁺0.0786*B2^-15.36*C2^,模型中,EGC得率最高可达62.08%。对最佳微波降解工艺参数进行验证实验,EGC得率为63.40%,与模型预测值接近。结论 运用微波降解EGCG制备EGC具有操作简单,可行性高的优势,且EGC得率稳定性高。