秸秆深还机具特点和作业效率分析

秸秆深埋还田(秸秆深还)作为一种新兴的秸秆还田模式,其机具有别于地表覆盖还田和铧式犁翻压还田。为了科学管理、合理运用秸秆深还机械,提高机组的作业效率,在调查测试秸秆深还作业的基础上,对机具的特点进行了分析,同时对测试机组分别进行了时间利用率和作业效率分析。结果表明:对于各个机具的作业时间利用率和总作业效率影响因素有所不同。作业速度、幅宽、故障维修和地头转向是影响机械作业效率的主要因素。根据调查和分析的结果,针对秸秆深还作业中存在的问题提出了机组的合理运行模式。     

Why viewing nature is more fascinating and restorative than viewing buildings: A closer look at perceived complexity

The present paper addresses the question which visual features trigger people’s often more positive affective responses to natural compared to built scenes. Building on notions about visual complexity and fractal geometry, we propose that perceived complexity of magnified scene parts can predict the greater fascinating and restorative qualities of natural versus built scenes. This prediction was tested in an experiment in which 40 participants viewed and rated 40 images of unspectacular natural and built scenes in their original size, and at 400% and 1600% magnification levels. Results showed that the original, unmagnified natural scenes were viewed longer and rated more restorative than built scenes, and that these differences were statistically mediated by the greater perceived complexity of magnified parts of natural scenes. These findings fit with the idea that fractal-like, recursive complexity is an important visual cue underlying the restorative potential of natural and built environments.     

深松整地作业技术要点

根据康平县在实施深松整地作业中遇到的实际问题,介绍深松机具的选择原则、作业质量标准、作业时间确定方法,以及作业技术要点和注意事项,为提高全县深松整地作业质量提供参考。     

高校大型图书馆存在与流通阅览服务状况网络调查

通过对我国高校大型图书馆馆舍的数量、分布、层高、主要库室开放时间、电子资源利用条件、读者准入制度等基本存在以及服务状况进行网络调查，探讨高校图书馆馆舍条件与流通阅览部门服务效果之间的关系。     

Changes in Physical Properties of Soils with Land Use Time in the Brazilian Savanna Environment

Soils from central Brazil have been intensively used over the last decades because of the rapid conversion of savannas ( Cerrado ) into corn/soybean fields. The objective of this work is to study modifications in the physical properties of soils in the Rio Verde watershed, as a function of the land use time for agriculture, determined from classification of Landsat satellite images between 1980 and 2010. Soil samples were collected at surface (0–20 cm) and subsurface (20–40 cm) horizons for the different classes of land use time (<10, 10–20, 20–30, and >30 years). The following physical properties were measured: bulk density (BD), air permeability (K_a), penetration resistance (PR), microporosity (MI), macroporosity (MA), and total porosity (TP). Results showed a strong expansion with time of agriculture that occupied 35·3% (1980), 37·4% (1990), 51·3% (2000), and 60·9% (2010) of the watershed area. When properties were compared with those from the reference areas (preserved soils under native vegetation), significant differences were observed for all the physical attributes of soils for a land use time higher than 20 years. Overall, BD and PR increased with land use time, and the opposite was verified for K_a, MA, and TP. Some physical properties presented values (e.g., 1·54 g cm⁻³ for BD and 0.06 cm³ cm⁻³ for MA) close to the critical ones reported to affect crop development, but they were not still impacting on local soybean yield. Copyright © 2013 John Wiley & Sons, Ltd.     

The Method of Diagnosing Brain-dysfunction Based on Membership Function and BP Neural Network

Membership functions.formed with the characteristic values obtained by applying the continuous reaction time (CRT) theory from controls and heptic encephalopthy and proposedin this paper.whith these membership functions,the CRT data to be diagnosed are calculated in advance,and then discriminated by BP meural network to differentiate patients with or without braindysfunction.The troubles of low accuracy and efficiency,encountered in training BP network withfuzzy samples.scattered data and extended samples,are solved.     

Construction and characterization of a BAC library of soybean

We have constructed a soybean (Glycine max (L.) Merrill) bacterial artificial chromosome (BAC) library from green leaf protoplasts of the cultivar, Misuzudaizu. The library contains 53,760 clones with an average insert size of 116 kb. About 2.9% chloroplast DNA origin was revealed by PCR and colony hybridization. Apart from 2.8% clones having no insert, this library represents 5.2 genome equivalents. With this genome coverage, the probability of having any DNA sequence represented in the library is higher than 99.5%. Three-dimensional pools of the BAC library in combination with the use of a high efficiency genome scanning (HEGS) electrophoresis facilitate rapid and efficient PCR-based screening. An average of five positive clones were identified after screening the BAC library with SSR and STS markers. BAC-end walking was performed for three SSR associated BACs. This library will provide a good resource for positional cloning of agronomically and biologically important QTL genes that Misuzudaizu possesses.     

Structure and variation of subterranean clover populations from Sicily,Italy

Summary A collection of subterranean clover lines singled out from populations of the species Trifolium brachycalycinum and T. subterraneum collected in Sicily, Italy, was examined at two localities for flowering time and at one locality for oestrogen content and seed yield. The structure and variation of the populations of the two species were compared. The relationship between flowering time of the populations and some environmental features of their collection sites was examined to assess whether the maturity requirements of the two species were similar and to frame selection models focused on developing varieties of appropriate maturity. Populations of T. subterraneum were, on average, more complex than those of T. brachycalycinum, being characterized by higher number of lines per population and greater intra-population variation for flowering time, oestrogen content and seed yield. Furthermore, populations of T. subterraneum were, on average, about 15 days earlier than sympatric populations of T. brachycalycinum. Both the greater variation and the relative earliness of T. subterraneum occurred irrespective of the environments of origin of the populations. Inferences are drawn on the adaptive advantages that such features confer to T. subterraneum. Mean flowering time of the populations increased on increasing annual rainfall and altitude of the collection sites. However, the changes in maturity appeared almost exclusively related to variations in rainfall in T. subterraneum, while in T. brachycalycinum the effect of altitude was greater and that of rainfall less marked than in the former species.     

盐水鹅辐照保质试验研究

鹅是食草家禽,鹅肉属现代健康食品。盐水鹅在20℃的贮存条件下仅36h就会出现异味变质。介绍了通过用不同包装材料、不同辐照剂量保质处理以及对盐水鹅氨基酸影响的研究,探讨了盐水鹅辐照保质的方法,为延长盐水鹅货架期提供新途径。