浅谈工商管理的学科性质及其对研究方法的要求

工商管理的学科性质及其对研究方法的要求，是我国市场经济条件下面临的一个新课题。本文从综合性、实践性、不精确性、软性四方面论述了工商管理学科的性质，认为工商管理学的研究方法分为实证研究与理论研究两大类；实证研究又分为实验研究与非实验研究；其中非实验研究分为统计调查研究、实地研究、无干扰研究三大类；统计调查研究分为问卷法和访谈法。无干扰研究分为文本分析、现有统计数据分析、历程比较分析等研究方法。     

空肠弯杆菌研究现状

空肠弯杆菌是一种人兽共同感染的病原菌,也是导致腹泻最常见的病菌,主要症状是发热和急性肠炎。主要从病原的生物学特征、肠毒素的研究、人畜带菌率及流行病学的研究现状进行综合讨论。     

两种优良野生草坪植物生态生物学特性分析

通过 1 998～ 2 0 0 0年对野生宿根画眉草和鼠尾粟观察 ,对其形态特征和生物学特性进行了鉴定分析 ,从草坪和水土保持植物利用的角度对其进行建坪试验和水土保持试验 ,发现其具有优良坪用性状和水土保持效果。并对其特性作了综合性描述。     

物理化学教学中体现的科学研究规律和方法

科学研究的一般规律和方法是具有创新能力人才所必须掌握的.文章介绍了物理化学教学过程中所体现出来的科学研究的一般规律和方法.     

育秧方式对杂交早稻生育特性的影响

对水稻软盘秧、旱秧和湿润秧秧苗素质及其生育特性进行了系统比较，分析了软盘秧和旱秧高产的原因及不利高产的因素。     

盐碱地区园林树种的选择和应用研究--以山东德州市为例

阐述目前德州地区园林树种选择存在的问题,以及德州市自然环境和植被状况,总结德州地区耐盐碱园林树种的选择和应用情况,并为今后耐盐碱园林树种的应用提出可行性建议。     

Using Static and Dynamic Indicators to Evaluate Soil Physical Quality in a Sicilian Area

Both capacitive indicators derived from the water retention curve and dynamic measurements of the flow‐weighted mean pore radius, R₀, were used to assess the soil physical quality of two agricultural areas (cropland and olive orchard) and two natural areas (grassland and managed woodlot plantation) potentially subject to soil degradation. The overall idea of the study was to investigate whether a dynamic indicator quantitatively derived from hydraulic conductivity measurements could be used to supplement the traditionally applied capacitive indicators retrieved from water retention measurements. According to the available criteria, only the surface layer of the cropland site showed optimal soil physical quality. In the grassland and woodlot sites, the physical quality was deteriorated also as a consequence of compaction because of grazing. Overall, the physical quality was better in tilled than nontilled soils. The optimal soil in terms of capacitive indicators had hydraulic conductivity close to saturation that was intermediate among the different land uses, and it remained 1·3–1·9 times higher than that observed in the natural sites even when the largest pores emptied. A depth effect on R₀ was observed only when larger macropores were activated. It was suggested that water transmission parameters are more affected by changes in large pore domain. The plant available water content and Dexter's S‐index showed inverse statistically significant regressions with R₀. The empirical relationships were physically convincing given that, at increasing R₀, the contribution of macropores increases, water is transmitted faster below the root zone and the soil's ability to store water is reduced. Copyright © 2013 John Wiley & Sons, Ltd.     

Recultivation of Agricultural Land Impaired by Construction of a Hydropower Plant on the Sava River,Slovenia

Hydropower plants on the lower river Sava, Slovenia, were developed without sealing the underground upstream. As a consequence, without the countermeasures of elevating and recultivating, the agricultural land on the river banks would be inundated because of the water‐table increase of the river. To remedy this, the fields were elevated and recultivated. The goal of this study was to assess soil quality and production potential after land raising and recultivation and to answer the question whether it is possible to recover soil quality and crop yield after large‐scale mass manipulation, such as land raising. After recultivation and after the second year of land reuse for the two cultures grass–clover mixture and corn on two sites, Middle Pijavsko and Lower Pijavsko, soil physical and chemical characteristics and crop yields were evaluated. Mixing of topsoil with the second horizon during removal and during backfill with filling material resulted in uneven soil fertility, plant growth and decreased yield. Driving on the refilled second layer with heavy machinery caused soil compaction in the Middle Pijavsko in spite of favourable soil texture (loam, 38·7% sand). On the areas with very high sand content (over 55%) and low clay content (10%), soil compaction was not as severe or persistent. Recultivation measures restored the agricultural land almost to the production potential prior to powerplant construction. Immediate intensive land use (corn) showed less favourable effect on soil characteristics. Copyright © 2015 John Wiley & Sons, Ltd.     

Turbiscan Lab分散稳定性分析仪研究异丙甲草胺水乳剂物理稳定性

为获得不同因素对异丙甲草胺水乳剂物理稳定性的影响规律,同时验证Turbiscan Lab分散稳定性分析仪预测和评价水乳剂物理稳定性的可行性,利用Turbiscan Lab分散稳定性分析仪,结合加速试验[(54±2)℃,14d]结果,研究了乳化剂用量、体系pH和电解质离子等对磷酸酯盐稳定的异丙甲草胺水乳剂物理稳定性的影响。结果表明:乳化剂三苯乙烯基苯酚聚氧乙烯醚磷酸酯三乙醇胺盐(SCP)用量为6.0%(质量分数)时,水乳剂稳定性最好;过酸或过碱均会破坏水乳剂的稳定性,pH=9时水乳剂可获得较好的稳定性;Mg2+压缩油水界面双电层,导致水乳剂稳定性下降,且Mg2+添加浓度越大,水乳剂越不稳定。Turbiscan Lab分散稳定性分析仪以多重光散射为技术核心,在不破坏样品的前提下,能够准确测定乳状液中浮油、沉淀和液滴粒径大小的变化情况,与加速试验结果吻合度高,不仅能够缩短试验周期,而且可以分析不稳定现象发生的机理。     

北沙柳研究进展

北沙柳属杨柳科柳属植物,具有萌蘖力强,耐旱、耐盐碱和抗风沙的特点,是中国西北地区固沙造林的主要树种之一,兼具生态效益、经济效益和社会效益。我们综述了国内外近年来北沙柳的相关研究成果包括生长繁殖、生理生态特征、与真菌共生作用、防风固沙、分子生物学及产业化开发与利用,并对未来发展前景做出展望,提出优良种质资源收集、分子定向育种和资源合理开发等建议,旨在为北沙柳的种质资源库管理、资源保护和合理开发应用提供科学依据。