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1.
In this paper, we consider the inverse problems for a kinds of normal matrices. Some necessary and sufficient conditions for existence of solution of these problems are given. The expression of the general solution is given. 相似文献
2.
徐海祥 《湖南农业大学学报(自然科学版)》1993,20(2)
In this paper, the author proved the partial regularity of the generalized solutions of the super critical growth elliptic system. Furthermore, the everywhere regularity of generalized solutions of three special systems are obtained. 相似文献
3.
The effect of 50% shading and NO3:NH4 ratio (0:100, 75:25, 50:50, and 25:75) in the nutrient solution on growth, yield, quality and N metabolism in hydroponically grown strawberry (Fragaria × ananassa var Camarosa) was evaluated. Both fresh and dry weights of leaves were significantly lower when a high concentration of either NO3 (100%) or NH4 (75%) was the sole N source in the nutrient solution. In unshaded plants, increasing of both NH4 and NO3 ratio in the nutrient solution reduced photosynthetic (Pn) rate, however in shaded plants the reduction of Pn became more pronounced at a higher ratio of NH4 in the nutrient solution. The yield in terms of fresh and dry weight of fruit per plant was significantly increased at the 75:25 and 50:50 (NO3:NH4) treatments. Fruit size was significantly affected by the treatments, so that the biggest fruits in both shaded and unshaded plants were obtained under the 75:25 and 50:50 (NO3:NH4) treatments. Total soluble solid (TSS) in unshaded plants was increased with increasing NH4 ratio in the nutrient solution, however in shaded plants it was reduced at high NH4 ratio in the nutrient solution. In both shaded and unshaded plants, higher concentration of NH4 significantly reduced the post-harvest life of the fruits. The increase of tissue N concentration was nearly proportional to the NH4 concentration in the nutrient solution. The activity of nitrate reductase (NR) was increased by increasing NH4 from 0 to 50% and then reduced at a higher ratio of NH4 in the solution. Shading increased NH4 concentration so that the shaded plant had nearly twice as high NH4 concentration in the leaves. The increase of NH4 concentration induced by shading could be partially the reduction of NH4 assimilate because of the shortage of carbohydrate. 相似文献
4.
顾明 《信阳农业高等专科学校学报》2013,23(2):23-25
金融消费者是为生活消费需要而购买、使用金融商品或接受金融服务的人,具有追求盈利最大化、抗风险能力差以及弱势地位突出等特点。现阶段我国有关金融消费者权益保护方面的工作同发达国家相比还很不完善,存在缺乏专项立法、相关法律滞后、缺乏专业纠纷解决机制以及对金融消费者合法权益保护不到位等问题,急需国家相关部门出台相关政策文件改善和解决。 相似文献
5.
企业的发展通常要遵循企业的生命周期理论,从企业最初创立进入生存期,到企业规模进一步增大进入成长期,再到企业成熟期和衰退期,每个生命周期阶段的生产经营和管理策略都有所不同。当企业进入成长期,其发展潜力进一步释放,生产销售数据呈现快速增长的趋势,企业的管理形式也逐渐趋向成熟。对于成长型的企业而言,人力资源管理水平和现状关乎着企业的发展速度和水平,是企业未来的战略资源。而成长型的饲料企业相比于大型、集团化企业,存在人才吸引力低、人才流失严重、人力资源管理水平低等问题,这会影响饲料企业的转型升级。因此,本文以饲料企业为研究对象,基于当前我国成长型饲料企业的发展历程和企业特点,深入分析饲料企业人力资源面临的问题,并针对性地提出解决策略,破除饲料企业人力资源对企业发展的限制,帮助企业进一步健康发展。
[关键词] 成长型饲料企业|人力资源|问题|解决策略 相似文献
6.
He Chuanjiang 《保鲜与加工》1993,(3):116-120
A three critical point theorem is proved. As its applications, Dirichlet problem for a class of quasilinear elliptic equations cf second order is considered. 相似文献
7.
8.
本文从什么是新型职业农民,重点阐述睢县新型职业农民培育的现实状况,分析新型职业农
民培育中存在的问题,提出了培育新型职业农民要构建多元化培训模式的方案,理论培训与实际操作
相结合,跟踪考察落实情况并不断改进,将新型农民培养定为农村发展的战略性举措。 相似文献
9.
10.
Magda Marin Luis A. Valdez-Aguilar Ana Maria Castillo-Gonzalez Joel Pineda-Pineda Juan J. Galván Luna 《Journal of plant nutrition》2013,36(1):12-26
Nutrient solution composition plays an important role in root uptake rate due to interactions among nutrients and internal regulation. Studies to determine the optimum nutrient solution concentration are focused on individual ions, ignoring the adaptation mechanisms triggered by plants when growing in a varying external nutrient concentration. The objective of the present study was to determine the response in growth and tissue ion concentration of lilium cv. ‘Navona’ to nutrient mixtures of varying proportions of nitrogen (N), potassium (K+), and calcium (Ca2+) in solution using mixture experiments methodology in order to determine the optimum concentration. Bulbs of lilium were transplanted in plastic crates and drip-irrigated with the treatment solutions, which consisted of a mixture of N, K+, and Ca2+ whose total concentration was 340 mg L?1 and minimum concentrations of each ion was 34 mg L?1. Chlorophyll concentration (SPAD), shoot fresh weight (FW), leaf FW, and leaf area were measured 60 days after transplanting and ion analysis was performed on shoot tissues from selected treatments. Lilium exhibited a moderate demand for N and K+ (136–170 mg L?1 N and 116–136 mg L?1 K+) and a very low demand for Ca2+ (34–88 mg · L?1). This low demand may be due to the remobilization of the nutrients stored in the bulbs. Integrating the predictions of the models estimated to produce >90% of maximum growth, the optimum nutrient solution should contain Ca2+ at a concentration between 34 and 126 mg · L?1, K+ between 119 and 211 mg · L?1, and N between 92 mg · L?1 and 211 mg · L?1. Increasing external N concentration affected internal N concentration but not internal K+ or Ca2+ concentrations, despite that the increase in external N was associated with a decrease in external K+ and Ca2+. Similar trends were observed for external K+ and Ca2+ concentration. In conclusion, lilium was able to maintain a relatively constant K+ and Ca2+ concentration regardless of the lower concentration in the nutrient solution when N was increased (similar response was observed for K+ and Ca2+) and it has a low Ca2+ demand and moderate N and K+ supply. 相似文献