浅谈湖南林业分类经营

本文通过对湖南林业经营现状进行了广泛调查研究,并结合湖南的省情特点,对实施林业分类经营的建设设想和面临的问题进行了探讨。     

Classification of pedogenic cementation in Podzols by pocket penetrometry

According to the German Soil Taxonomy, the formation of cemented horizons in Podzols is restricted to the precipitation of iron oxides. However, in iron‐poor sandy substrates, also illuviation of only organic compounds can form cemented horizons with penetration resistances of up to 14 kg cm⁻². We present a reproducible field test for classifying pedogenic cementation in Podzols and suggest considering cemented horizons (Bmh and Bhm) in the upcoming edition of the Guidelines for Soil Mapping.     

风景区自然景观资源评价及合理开发

文章以庐山风景区为例,对自然景观资源进行了分类与分级评价,并依据评价的结果及当前风景区自然景观资源的开发利用现状,提出了庐山风景区自然景观资源进一步科学开发与管理的合理化建议,以期为今后庐山风景区自然景观资源的可持续发展提供一定的理论参考。     

Evaluation of some systems for classifying soil sensitivity to acid deposition in the South African highveld

Abstract. The Skokloster and Stockholm Environmental Institute (SEI) approaches were applied to the assessment of 145 soils of the South African highveld region in terms of sensitivity to acid deposition. The critical load class calculated by variants of these methods was compared with the acid neutralizing capacity (ANC) determined by pH measurement of soil suspended in a dilute acetate buffer solution. This rapid index of ANC correlates well both with ANC determined by an established but more laborious method which involves titration and equilibration of soil with HCl, and with a number of soil properties related to base status. The correlation between Skokloster or SEI critical load classes and ANC was weak. It was concluded that ANC determination would be a preferable basis for classifying these soils in terms of their sensitivity to acid deposition, since the method is direct and integrates the contribution of various soil properties to acid sensitivity instead of requiring the relative contribution to be calculated according to somewhat arbitrary weightings given to broadly defined classes of soil properties.     

新疆的大戟属植物及地理分布

本文记载新疆的大戟属植物３８种，其中讨论和订正９种，并新记录３种。     

基于DTA山体部位分类决策方案的改进与微观地形自动分类研究

在数字地形分析DTA的理论体系框架下,研究了微观地形分类的体系、方法,认为Dragut等在2004年提出的山体部位分类决策方案割裂了微观地形表达上的同一性,仅以曲率或坡度划分不同的山体部位容易形成重叠。以土壤侵蚀研究中的临界坡度值为参考改进了Dragut等提出的山体部位分类决策方案。提出了基于栅格DEM和DTA技术实现微观地貌形态分类的关键技术在于提取地形地貌因子和制定合理的分类决策方案。并以黄土高原的局部DEM为数据源,以改进的山体部位分类决策方案为应用参考,在DTA技术支撑下进行了微观地形自动分类的试验研究。结果表明,以栅格DEM为数据,基于DTA技术提取相关微观地形地貌因子,形成合理的分类决策方案就可以实现微观地形地貌的自动划分。     

浅谈坡面覆盖材料

介绍了国内外坡面覆盖材料的发展情况,对常见材料进行分类和介绍,定义了一些专业名词,并展望我国边坡覆盖材料的发展前景。     

猫下泌尿道综合征

猫下泌尿道综合征（FLUTD）是猫最常见的疾病之一,因其发病率高、病因复杂、确诊困难、治疗后易复发等特点,逐渐成为猫科疾病的研究热点。FLUTD包括多种疾病类型,精准治疗、合理预防已成为科学防控该疾病的关键。本文从FLUTD的分类、流行病学及风险因子、发病机制、临床症状、诊断和防治对该综合征进行综述,以推动猫下泌尿道综合征的深入研究及临床诊疗的发展。     

Physiological effects of different Cd concentrations on maize root architecture and classification北大核心CSCD

In this research, a hydroponics experiment was conducted to apply different concentrations of cadmium (Cd) (0, 5, 10, 25, 50, 100, 200 μmol·L-1) to maize seedlings with two leaves and one new leaf, in order to explore the effects of the different Cd concentrations on the maize seedling growth, Cd absorption kinetics and root morphology and classification. After 5 days of Cd stress, the maize seedings were sampled, the plant height, main root length, aboveground and underground biomass, root architecture, Cd content and photosynthesis and related parameters were measured. It was found that with increasing Cd stress, the plant height, main root length, biomass and tolerance index of shoots and roots, total root length, root surface area, root volume, root forks and root tips all decreased significantly; Root average diameter and root:shoot increased significantly (P<0.05). Meanwhile root parameters (root length, root surface area and root volume) of root diameter classes designated Ⅰ-Ⅲ (0-1.5 mm) showed a decreasing trend, which had a significant (P<0.05) negative correlation with root Cd concentration. The proportion of root length, root surface area and root volume with diameter between 0-0.5 mm showed a downward trend under Cd stress. Under Cd stress, Cd concentration and accumulation in underground and aboveground parts of maize seedlings increased significantly, chlorophyll content decreased, and photosynthesis was inhibited. This study has shown that Cd affected root development mainly by inhibiting the growth and morphology of fine roots, and inhibited photosynthesis, elongation and biomass accumulation of the aboveground and underground parts of the maize seedings. © 2022, Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

牛奶中不同酪蛋白遗传变异体及其分型鉴定研究

牛奶中存在不同种类的蛋白质,且不同基因型遗传变异体牛奶蛋白质的构型和功效存在差异。酪蛋白分型鉴定方法有基因鉴定、毛细管电泳分离鉴定、高效液相色谱分离鉴定等。本文对比介绍了不同构型κ-酪蛋白和β-酪蛋白的分型鉴定方法,重点验证了高效液相色分离谱鉴定方法的精密度、回收率,同时将该方法应用于生乳和乳制品酪蛋白分型检测鉴定,区分不同牧场牛群的遗传变异体类型和比例。通过该方法可指导牧场快速分群饲养奶牛,生产不同酪蛋白类型的生乳,并加工不同类型的高品质乳制品。