农村土地价值的影响因素分析

分析了农村土地价值的影响因素,并从提高土地收入保障角度寻求提高土地价值的途径和方法。结果表明：农村土地的价值不仅体现在土地产生的直接收益,还表现在土地为农民带来的间接收益,包括土地的交换价值和潜在的发展价值。通过产权制度改革、土地经营形式多元化、种植结构调整、农民组织的重构来改变土地利用方式可以增加土地价值,使土地从生存保障发展为投资保障,从而提高农村土地的价值。     

黑蜣(Bess beetle)纤维素酶的组分及其特性分析

以30日龄的黑蜣幼虫为材料,对其整体匀浆后组织液中的纤维素酶组成及活性进行了分析。结果表明:黑蜣体内存在内切β-1,4-葡聚糖酶(Cx酶)、β-葡萄糖苷酶;β-葡萄糖苷酶和Cx酶的最适宜温度为分别为40℃和50℃;Cx酶和β-葡萄糖苷酶分别在pH值为6.4和5.2时具有最大的活力;β-葡萄糖苷酶和Cx酶的最适宜反应时间为80 min。Cx酶具有比β-葡萄糖苷酶更强的温度适应性,在30～50℃温度范围内可维持最大酶活力的66.20%。     

Aggregate-related changes in network patterns of nematodes and ammonia oxidizers in an acidic soil

Nitrification plays a central role in global nitrogen cycle, which is affected by biological interaction between soil microfauna and microorganisms. However, the complexity of soil biotic communities made it difficult to reveal organizational principles of the community and the interactions among species. Here, we used the network analysis to decipher the interactions between nematodes and ammonia oxidizers within aggregate fractions under 10-year manure application, and examine their associations with soil variables and potential nitrification activity (PNA). Three aggregate fractions included large macroaggregates (>2000 μm, LA), small macroaggregates (250–2000 μm, SA), and inter-aggregate soil and space (<250 μm, IA). Aggregate factions showed a remarkable effect on association networks of nematodes and ammonia oxidizers. The average connectivity (avgK) and the number of edges in overall networks increased with increasing aggregate sizes, while the average geodesic distance (GD) followed the opposite trend. The LA network could be viewed as a better organized or a better operational soil food web with more functional interrelated members than the SA and IA networks. The modules related to PNA were significantly correlated and clustered together as meta-modules in networks of aggregate fractions. The role-shifts prevailed among the network members such as significant module memberships (MMs) and generalist/specialist operational taxonomic units (OTUs). A half of shared nodes were further identified as shared MMs, dominated by ammonia-oxidizing bacteria (AOB) especially for Nitrosospira cluster 3a and 10. Soil pH could explain partly the shift of module hubs in different networks, while grazing by bacterivores might account for three exclusively connecters related to Nitrososphaera clusters 1.1. The strongly coupled modules correlated positively to pH and total carbon (TC), regardless of aggregate fractions. The network analysis approach provided new insights into potential importance of network interactions between nematodes and ammonia oxidizers in soil nitrogen cycling.     

《荀子》音乐教化思想实质及价值

荀子为儒学大师，主张性恶论，力推人文教化，尤其重音乐教化，试图借助音乐等艺术作品来打造充满人文气息的文化氛围，尊礼崇礼，使人的尊贵得以凸显，人禽有别。同时，他认为人人经过自身的修为都可以成为善人，君子与小人的区别在于自己的把控。这些观点对于推行人文教化大有启示：即要重视音乐等艺术作品及良好文化氛围对人的熏陶与“化”的作用，特别是他的重养人之情、养人之欲观点在当下对于制定规范措施有借鉴的价值。     

四种柱花草种子萌发中参与氮代谢的酶活性变化

研究了4种柱花草种子萌发过程中参与氮代谢的蛋白酶、肽酶和硝酸还原酶活性的动态变化。结果表明,蛋白酶的活性随着柱花草种子萌发的深入而不断上升,在种子即将露白胚根突破种皮的时候蛋白酶活性达到最大值。此后,随着胚芽的生长蛋白酶活性逐渐降低,其中热研2号柱花草的蛋白酶活性高于其他3种;肽酶活性的变化总体呈上升趋势;硝酸还原酶呈S型变化。了解柱花草种子萌发期各种酶活性的变化规律,为深入研究柱花草种子萌发时贮藏物质的动员和代谢机理提供数据。     

Soil aggregation: Influence on microbial biomass and implications for biological processes

Our 1988 paper, describing the effects of cultivation on microbial biomass and activity in different aggregate size classes, brought together the ‘aggregate hierarchy theory’ and the ‘microbial biomass concept’. This enabled us to identify the relationships between microbial and microhabitat (aggregate) properties and organic matter distribution and explain some of their responses to disturbance. By combining biochemical and direct microscopy based quantification of microbial abundance with enzyme activities and process measurements, this study provided evidence for the role of microbial biomass (especially fungi) in macroaggregate dynamics and carbon and nutrient flush following cultivation. In the last ten years environmental genomic techniques have provided much new knowledge on bacterial composition in aggregate size fractions yet detailed information about other microbial groups (e.g. fungi, archaea and protozoa) is lacking.We now know that soil aggregates are dynamic entities – constantly changing with regard to their biological, chemical and physical properties and, in particular, their influences on plant nutrition and health. As a consequence, elucidation of the many mechanisms regulating soil C and nutrient dynamics demands a better understanding of the role of specific members of microbial communities and their metabolic capabilities as well as their location within the soil matrix (e.g. aggregates, pore spaces) and their reciprocal relationship with plant roots. In addition, the impacts of environment and soil type needs to be quantified at the microscale using, wherever possible, non-destructive ‘in situ’ techniques to predict and quantify the impacts of anthropogenic activities on soil microbial diversity and ecosystem level functions.     

小叶九里香枝干抑菌活性成分的研究

为了获得小叶九里香枝干中抑制炭疽病菌的活性成分,在活性追踪指导下,利用硅胶柱色谱、Sephadex LH-20凝胶柱色谱及半制备液相色谱等方法对小叶九里香枝干进行了研究。经追踪分离鉴定到1个活性化合物XY-01,利用质谱、核磁共振谱鉴定化合物为九里香甲碱(Koenidine),该化合物可有效抑制香蕉炭疽病菌和芒果炭疽病菌的生长,EC50值分别为34.28和45.88μg/mL,表明九里香甲碱抑菌活性较好、结构简单,具有开发为新型植物源杀菌剂的潜在价值,九里香甲碱系首次从小叶九里香中分离得到。     

云南温带多年生优良牧草——扁穗雀麦

分析总结了扁穗雀麦的分布、来源、植物学特征、生物学特性、饲用价值和栽培利用措施,以促进该优良牧草的推广利用。由于扁穗雀麦在云南冬春潮湿阴凉环境条件下仍保持绿色,故可作为解决冬春青绿饲料的优良牧草利用。     

抑霉乳酸菌的筛分及其抑菌特性研究

试验旨在获取生物抑霉的优良菌株以及为质量安全青贮饲料生产提供高效菌剂。从青贮饲料、酸奶以及奶豆腐中分离纯化出乳酸菌和霉菌,并且通过双层平板法对具有抑制霉菌活性的乳酸菌菌株进行筛选,测定其上清液抑霉效果;采用蛋白酶处理和高温处理法分析乳酸菌抑霉的有效成分。结果表明:分离筛选的乳酸菌和霉菌经鉴定为植物乳杆菌和黄曲霉菌,且植物乳杆菌对黄曲霉菌的生长有明显抑制作用。蛋白酶处理对乳酸菌无细胞上清液的抑菌活性有不同影响,而加热处理并不改变其抑菌效果。研究表明,植物乳杆菌对黄曲霉菌生长有明显的抑制作用,推测其抑菌活性物质为蛋白质、肽类等,并且这些抑菌活性物质的热稳定性较高。     

连作及轮作土壤微生物菌群对黄瓜幼苗生长及土壤酶活性的影响

通过植物-土壤反馈试验,研究连作及轮作土壤微生物菌群对黄瓜幼苗生长和土壤酶活性的影响。结果表明,轮作土壤微生物处理黄瓜植株鲜质量、叶绿素含量、土壤中性磷酸酶、蔗糖酶活性显著高于连作土壤微生物处理;连作及轮作土壤微生物处理增加了黄瓜幼苗干质量、鲜质量、叶绿素含量及总叶面积,显著提高了土壤中性磷酸酶、蔗糖酶、脲酶活性。综上,连作及轮作土壤微生物菌群对黄瓜幼苗生长均产生正反馈作用,并且轮作土壤微生物的正反馈作用大于连作土壤微生物。