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921.
春研2号苦瓜是以强雌系A94为母本、自交系B8为父本育成的早熟苦瓜一代杂种,表现早熟、丰产、连续结果能力强、抗逆性强、品质优等优良特性。果实青白色,棒形,单果约重400g,粒瘤,富有光泽,苦味适中,口感脆嫩,外观商品性及风味品质佳。可露地早熟栽培或春季保护地栽培,一般产量60000~90000kg/hm2,前期产量、总产量、品质性状优于蓝山苦瓜。  相似文献   
922.
923.
Digestates vary in composition and studies regarding their impact on C and N dynamics in soils are scarce. The objective was to analyse the C and N dynamics of digestates originating from various substrates applied to a sandy Cambisol and a silty Anthrosol. In three laboratory experiments (4–6 weeks), the effects of digestate properties, N rate and water content were tested. Averaged over both soils, 21% of the C supplied was emitted as CO2. Potential NH3 emissions during the first week ranged between 6% and 12% of NH4+ present in the digestates. The emission factors in the sandy Cambisol were on average 1.2 and 2 times higher for CO2 and potential NH3, respectively, compared to the silty Anthrosol. Similarly, net nitrogen mineralization in the sandy Cambisol was approximately twice the N mineralized in the silty Anthrosol. Net nitrification was not influenced by soil texture or different digestates, but increased with increasing application rates and had highest values at 75% of water holding capacity. Our results indicate that the type of substrate input for anaerobic digestion influences the properties of the digestate and therefore the dynamics of C and N. However, soil texture can affect these dynamics markedly.  相似文献   
924.
Abstract

In a lysimeter study it was found that moderate rates of ammonium nitrate increased utilization percentages in spring wheat, and the leaching was 10% or less of added N. Over-optimal rates reduced utilization percentages and increased leaching to almost 50% of the highest doses. Late split application of calcium nitrate increased the percentage of N in grain. Furthermore, leaching of N was not reduced, but occurred somewhat later in the fall and winter seasons. Leaching of Cl? was more rapid and that of SO4 2- was delayed relative to the leaching of NO3 ?. Rather large negative N balances were obtained, also after over-optimal application rates, and total N content of the soil was reduced. Compared with the N0 treatment, differences in soil N residues amounted to 15–25% of added N in seven years. Gaseous losses had apparently taken place both from the added N and from soil N according to the total-N analysis.  相似文献   
925.
926.
针对联合收割机割刀机构的工作特点,采用2K-H型行星齿轮机构,分析了割刀机构工作原理。通过建立2K-H型行星轮系的优化设计模型,应用NSGA-2算法对2K-H型行星齿轮机构进行多目标优化设计。以最小体积和最大承载力为优化设计目标,通过编制MATLAB程序得到Pareto前沿,进而得到最优解,与以往多目标优化设计比较,设计得到了很好的改善。  相似文献   
927.
Increasing attentions have been paid to mineral concentration decrease in milled rice grains caused by CO2 enrichment, but the mechanisms still remain unclear. Therefore, mineral(Ca, Mg, Fe, Zn and Mn) translocation in plant-soil system with a FACE(Free-air CO2 enrichment) experiment were investigated in Eastern China after 4-yr operation. Results mainly showed that:(1) elevated CO2 significantly increased the biomass of stem and panicle by 21.9 and 24.0%, respectively, but did not affect the leaf biomass.(2) Elevated CO2 significantly increased the contents of Ca, Mg, Fe, Zn, and Mn in panicle by 61.2, 28.9, 87.0, 36.7, and 66.0%, respectively, and in stem by 13.2, 21.3, 47.2, 91.8, and 25.2%, respectively, but did not affect them in leaf.(3) Elevated CO2 had positive effects on the weight ratio of mineral/biomass in stem and panicle. Our results suggest that elevated CO2 can favor the translocation of Ca, Mg, Fe, Zn, and Mn from soil to stem and panicle. The CO2-led mineral decline in milled rice grains may mainly attribute to the CO2-led unbalanced stimulations on the translocations of minerals and carbohydrates from vegetative parts(e.g., leaf, stem, branch and husk) to the grains.  相似文献   
928.
质粒分子是转基因产品核酸定量检测的一类新型标准物质,具有易制备、周期短、成本低等特点。采用实时荧光定量PCR技术,并协同7家实验室对转基因油菜TOPAS 19/2质粒分子进行了基因组的可替代性研究、协同实验研究及不确定度评定。T检验表明,质粒和基因组所产生的内源和外源基因标准曲线的斜率和线性相关系数没有显著性差异。对多家定值的数据进行了统计分析得出,TOPAS19/2质粒分子的量值结果0.910,扩展标准不确定度(K=2)为0.013。  相似文献   
929.
早熟晚粳机插秧700kg/667m~2精确定量栽培技术规程   总被引:2,自引:1,他引:1  
通过对早熟晚粳稻品种武运粳19号及武2645新品种的引种试验和示范,将"机插育壮秧、控行缩株适苗、麦草全量还田、精确定量施肥"等技术进行集成,制订了早熟晚粳机插精确定量栽培技术规程,以期为大面积机插秧实现高产提供技术支撑。  相似文献   
930.
以水溶液体系作为对照,利用分光光度法研究了W/O型微乳液体系中水杨酸(SA)和水杨酸甲酯(MS)清除超氧阴离子自由基(·O2-)的性能.结果发现,在水浴时间为20min、pH值为8.20和邻苯三酚加入量适宜的情况下,W/O微乳液体系中SA、MS对·O2-的清除率分别可达72.92%、81.47%.微小的pH值变化会引起邻苯三酚自氧化速率的显著变化,电解质溶液对其也有明显的影响,但对SA、MS清除·O2-的能力影响不大.  相似文献   
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