丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)在土壤生态系统中发挥着巨大作用,但目前AMF还不能纯培养,只能通过与宿主植物共生的方式扩繁.为研究不同宿主植物对AMF的扩繁效应,本研究选择玉米(Zea mays)、高粱(Sorghum bicolor)、黑麦草(Lolium perenne)、三叶草(Trifolium pratense)作为宿主,分别对聚丛根孢囊霉(Rhizophagus aggregatus)和幼套近明球囊霉(Claroideoglomus etunicatum)进行扩繁.在种植后的第30、60、90和120天分别对接种AMF后宿主植物根系的AMF侵染率、基质中的AMF孢子密度以及AMF的接种势进行测定分析.结果 显示,不同宿主对AMF的扩繁效应不同,扩繁结束后聚丛根孢囊霉及幼套近明球囊霉对宿主植物的侵染率由高到低依次为玉米＞高粱＞三叶草＞黑麦草,聚丛根孢囊霉的孢子密度由高到低依次为玉米＞高粱＞黑麦草＞三叶草,幼套近明球囊霉的孢子密度影响由高到低依次为高粱＞玉米＞三叶草＞黑麦草.同一宿主对不同AMF的扩繁效应也不同,玉米和黑麦草对聚丛根孢囊霉的扩繁效应高于幼套近明球囊霉,三叶草和高粱对幼套近明球囊霉的扩繁效应高于聚丛根孢囊霉.试验还发现,AMF的孢子密度与其对植物的侵染率有关,并且存在极显著正相关的关系.本研究表明,玉米是聚丛根孢囊霉扩繁的最佳宿主植物,高粱是幼套近明球囊霉扩繁的最佳宿主植物.

贸易效率是影响中国与RCEP伙伴国贸易增长的重要路径.借鉴新经济地理学的"3D"(density,distance,division)框架理论,在分析贸易效率影响机理的基础上,以RCEP成员国2000-2019年面板数据构建随机前沿引力模型,测算了中国与RCEP伙伴国的出口效率和进口效率,基于"一步法"非效率模型实证分析了密度、距离、分割对出口效率和进口效率的影响.研究结果表明:中国与RCEP伙伴国出口效率和进口效率存在异质性,进出口潜力巨大,其中进口潜力大于出口潜力.RCEP伙伴国经济密度提升有利于提高中国出口效率,但不利于提高进口效率,城镇化对中国进出口效率影响显著为负;交通基础设施对中国进出口效率具有显著正向影响,且在2008年金融危机后影响强度更大,通信基础设施有助于改善中国进出口效率;签订自由贸易协议对中国进出口效率具有正向影响,伙伴国政府效能可以显著提升中国出口效率,对进口效率的提升具有时滞效应.最后,针对研究结论,从提高密度、缩短距离和减少分割三个方面提出了相关政策建议.

阐述以弱酸-弱碱两步法制取改性脲醛树脂胶的原理及其技术难点,介绍以弱酸-弱碱两步法制取改性脲醛树脂胶的制胶配方及其生产刨花板、中纤板实践以及取得的成效,可供相关企业借鉴.

从时空压缩效应、通用目的技术、信息通信平台和网络效应四个功能维度,分析信息通信基础设施对全要素生产率增长的影响机理.利用2000-2016年东盟国家面板数据,对信息通信基础设施的全要素生产率增长效应进行实证研究,发现信息通信基础设施对东盟国家的技术进步具有显著的正向影响,对东盟国家的技术效率具有显著的负向影响,对属于技术进步主导型的东盟国家全要素生产率具有显著的正向影响.信息通信基础设施具有显著的网络效应,对东盟国家全要素生产率的促进作用呈现倒U型的非线性特征.最后,针对研究结论提出了相关政策建议.

Currently, cassava pull up the bulk of the work is still using the manual method, although there is a large cassava harvesting device, but these large equipment is not suitable for the foothills of the Guangdong , Guangxi , Guizhou and other regions, and large equipment investment cost is high, the product promotion in rural areas there are a lot of resistance.In order to solve the farmers harvest cassava manual harvesting in the process of slow speed, easy to hurting hands, etc., this paper puts forward a horizontal lever cassava pull up device of machinery, and before applying for the national invention patent, this paper will use UG to the mechanical design and simulation movement, realizes the mechanization of cassava pull up clamping and pull up and reduce the labor intensity of cassava pull up, at the same time also can improve the efficiency of cassava harvest, improve the economic benefits of cassava crop production and the production level, meet the growth needs of cassava.

At present,the majority of cassava extraction work is still carried out by hand,although there are large-scale cassava harvesting device, but these large equipment is not suitable for Guangdong,Guangxi,Guizhou and other regions of the hilly area,and large equipment,high input costs,There is a great resistance to product promotion in rural areas. In order to solve the problem of slow harvesting and easy hand injury in the process of peasants harvesting cassava, this paper presents a mechanical mechanism for horizontal leveraged cassava lifting device, and before it has applied for na-tional invention patent,this paper will use UG to the machine to verify the feasibility of the device,to achieve the mecha-nized clamping and pulling up from cassava and to reduce the labor intensity of cassava uptake,but also to improve the efficiency of cassava harvesting,improve the economic benefits of cassava planting and Product level to meet the growth needs of cassava.

运用网络分析方法和改进的Mundell-Fleming模型,分析了中国和主要东盟国家经济增长的空间网络关联关系,并测度了中国与主要东盟国家经济增长的溢出效应.结果表明:中国与主要东盟国家经济空间网络存在10对关联关系;各个国家在网络中的地位和作用差别较大,不利于整体网络的稳定;国家间经济增长的交叉溢出效应非常明显,打破了两两国家间的溢出关系;中国与主要东盟国家经济增长的关联性不强,与部分国家甚至存在竞争关系;东盟国家内部也存在增长竞争现象,但是总体上合作大于竞争.

改革开放是我国的一项基本国策。自实施改革开放政策以来,我国就与东盟国家之间建立了广泛的经济合作关系。本文在系统全面的梳理我国与东盟国家经济开放发展战略脉络的前提下,按照CAFTA深化合作与打造升级版的需要,在"一带一路"战略背景下,提出了一些研究领域作为今后加强中国面向东盟开放经济战略研究的方向参考,主要包括:我国与东南亚地缘经济战略的定位与调整,中国—东盟跨境产业网络分工与我国产业开放战略,面向东盟的互联互通战略升级,面向东盟的金融市场一体化战略,面向东盟互信机制建设战略等。

Electronic and magnetic properties of the RE2Ti3Si4 (RE = Gd, Tb, Er) compounds have been investigated by means of LSDA + U method which is based on the density functional theory (DFT). Excellent agreement is obtained between the calculated and experimental values for the structural parameters, which indicates that the method we used at the present is reasonable. Mulliken analysis shows that RE (RE = Gd, Er) and Ti atoms lose charges while Si obtain charges. From the analysis of the density of states for the RE2Ti3Si4 (RE = Gd, Tb, Er) compounds, we can make the conclusion that Si mainly contributes to the bonding states, while Ti and RE contribute to the anti-bonding states. RE atoms exhibit strong magnetism, Ti atoms exhibit different magnetic strength in different compounds, while Si is non-magnetic because all the subshells are completely occupied by the majority and minority spin. In order to obtain believable magnetic moments, we revised our calculated results and realized expected values. (C) 2015 Elsevier B.V. All rights reserved.

In order to select suitable substrate for seedling growth of Artemisia annua, experiments were conducted to study the effects of six different substrates and inoculation with arbuscular mycorrhizal fungi on the seedling growth of A annua. The results showed that the seeds of A annua in the mixture substrate with the volume ratio of peat and sand at 1 ∶2 germinated earliest and the first true leaf appeared. Moreover, the germination rate,seedling height, root length, fresh weight, dry weight and mycorrhizal colonization rate in this mixture substrate were the highest among the six substrates. The promoting effects on seedling growth of A. annua were more significant after inoculation with arbuscular mycorrhizal fungi. Therefore, the mixture substrate with the volume ratio of peat and sand at 1∶2 can be used as an ideal substrate for mycorrhizal seedling of A. annua in the seedling production.

T his paper analyzes the characteristics of population distribution and migration evolu‐tion in Guangxi by using six census data after 1949 .The result shows that population distribution in the Southeast is always larger than the Northwest in Guangxi ,and the evolution will be stable by de‐grees ,the population migration has a strong spatial correlation on the path of the adjacency and coast . The population emigration destination is periodic fluctuation ,and at the present is city and town .

工业、海港等区位理论以及边境区位研究能够有效指导并推进中国-东盟沿边跨国区域合作开发。为此，应基于区位理论加强跨国区域相关国家及地区之间的沟通协调，以形成一致的思想认识与努力方向，并以区位理论系统指导中国-东盟边境区位合作开发的务实推进，具体措施包括加强通道和口岸建设，加强服务于中国-东盟边境区位合作开发的国际协调机制建设等。

The structural, elastic, and electronic properties of eight intermetallics in Ti–Cu–Me (Me=Al, Ga and In) systems were investigated with the first-principles method. The calculations were performed within the generalized gradient approximation (GGA) with the density functional theory (DFT) using the supercell (SC) method. Calculation results show that the SC approximation is accurate at zero pressure. These intermetallics are classified as stable and metastable in our investigation. The stable phases are those presented in the equilibrium phase diagram at room temperature. The metastable phases are those that usually appear in the equilibrium phase diagram at higher temperatures. The values of calculations show that the TiCuAl, Ti2CuAl5, and TiCu2In compounds are brittle, and the Ti0.5CuAl0.5, TiCu2Al, TiCuGa, Ti2CuGa5, and Ti0.5CuIn0.5 compounds are ductile at zero pressure.

The structural, energy stability, and magnetic properties of the diluted magnetic semiconductors Sn1-xGdxTe (x = 3.125 at. %, 6.25 at. %, and 12.5 at. %) were investigated based on density functional theory. The calculated lattice parameters of the Sn1-xGdxTe compounds at zero pressure and zero temperature are in very good agreement with the existing experimental data. The energy stability of different configurations was also investigated, and the results show that Gd atoms prefer to occupy the nearest neighbor positions to the next nearest. It is hopeful to obtain ferromagnetic actual samples with Gd concentration around 6.25 at. %. It also confirms that there is presence of a small ferromagnetic interaction, competitive with the main antiferromagnetic interaction. However, this ferromagnetic interaction is too weak to show global magnetic moment. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4761964]

Using the LabVIEW platform and optimization function module programmed to optimized design mechanical axle pin,introduces the general steps of this method and the usage of nonlinear optimization function.At last,checking the result whether right with traditional optimization tools and demonstrate the practicality of LabVIEW in mechanical optimum design field.

介绍了一种用于水果、蔬菜及中草药的汁液冷冻浓缩方法及气流式提取器,这种方法是将预冷温度1～2℃的汁液在强压下送至-5～-10℃的冰板成形器内,形成连续排出的松软薄冰板,经封闭管道进入压强为2～3kg/cm2的气流式提取器中,由气流的贯穿作用将浓缩液提出,气流式提取器是由上、下孔板分别连接到封闭罩体两侧的冰板入口和出口,罩体的上、下部分分别设有进气管和抽气管,各管之间的罩体内侧设有挡板。这种装置和工艺方法所需设备台数少,能耗低,具有广阔的推广应用前景。

Under the conditions of knowledge-based economy and global markets economy,the focus of fierce competition will gather in the competition of innovation talents.This paper discusses the means of innovative mechanical talents.It designed a mode of independent experimental clas-ses which fit the personnel training of mechanical innovation,to build a mechanical manufacturing Integrated experimental platform for simulated enterprise production.

Results obtained in pot culture experiment indicated that the content of alkaline hydrolytic nitrogen,effective phosphorus and available potassium in maize changed with the time under different fertilization treatments,nutrient content of treatment five(mixed fertilizer) and treatment four(organic-inorganic compound fertilizer) were significantly higher than treatment two and three(organic fertil-izer) within 30 days after fertilization,the nutrient content of treatment five decreased rapidly after 30 days,but treatment four increased,the nutrient content of treatment four were much higher than other treatments at sixty days,no obvious difference was found in treatment five and other treatments.The experimental results showed that the nutrient content of treatment four was steady and higher,and was benificial to nutrient absorption of crops.

利用品种抗性是防治稻瘟病等主要水稻病虫害最经济有效的措施,同时杂交水稻优良种子的推广应用也为水稻增产作出了巨大的贡献,但近年来由于生物学混杂、机械混杂和人为利用相似的种子等严重影响了杂交稻的种子质量.目前杂交稻的种子纯度和真伪鉴定通常是在播种前到海南进行田间种植鉴定,随着分子生物学和生物技术的发展,人们开始研究和应用DNA分子标记技术进行杂交稻种子纯度和真伪鉴定,以克服海南田间种植鉴定周期长、异地鉴定费用高等缺点.

Field experiments were conducted to investigate dry matter accumulation and translocation and grain filling after flowering with three indica rice Baguixiang(superior quality rice),Guihuazhan(good quality rice) and Zhenguiai(inferior quality rice,CK) as materials in the spring and summer seasons in 2007.Results showed that high quality rice(including superior and good quality rice varieties Baguixiang and Guihuazhan) had greater dry weight of leaves and culm and sheath per culm,as well as higher dry matter translocation ratio and rate of leaf after heading.However,little difference was found in dry matter translocation in culm after heading between high quality rice and the control.According to the simulation of dry matter accumulation of grain in the three rice varieties with the Richards′ equation,high quality rice showed earlier initial filling,longer active filling period and lower maximum filling rate.About 1/5 to 1/3 of dry matter in grains were from leaf and culm dry matter redistribution after heading and the post-anthesis dry matter contribution to grain in high quality rice was 1.5 to 2.0 times of the control.Correlation analyses indicated that grain growth was correlated with dry matter redistribution of leaf.It can be concluded that great leaf dry matter accumulation and redistribution were one of the most important reasons of high quality in rice.