合理利用粗饲料 大力发展草食家畜

本文对粗饲料的概念、种类、饲用特点加以概述,对其利用优点等加以论述,目的是使粗饲料能够得到科学、合理的开发、利用,解决好人畜争粮的问题,从而推动草食家畜发展,满足社会发展的需要。     

重金属污染土壤木本-草本联合修复研究进展

植物修复是一种新型的重金属污染土壤修复技术,由于原位修复、费用低、太阳能驱动等优点而成为研究者关注的热点。但是,植物修复技术目前仍存在重金属生物有效态含量低和修复植物生物量小的2个制约因子,寻找新的环境友好活化剂和具有高萃取率的植物修复模式是研究者必须解决的技术瓶颈。笔者在国内外研究文献的基础上,总结了木本、草本植物在重金属土壤污染修复方面的已有研究,并结合生态位理论,分析了木本-草本联合修复在土壤重金属污染治理中的可行性,提出了木本-草本联合修复尚需解决的科学问题。     

冬季自然条件下12种屋顶绿化木本植物抗寒性分析

为探索屋顶绿化木本植物的抗寒能力,筛选出耐寒强的屋顶绿化木本植物,在2010年12月、2011年1月和2月冬季自然降温条件下,结合实地观测屋顶和地面温度、风力、相对湿度等气象因子,采用电导法,分别对12种木本植物1年生休眠枝条细胞膜透性进行测定。结果显示,石家庄冬季屋顶比地面温度高、风速大、相对湿度低。构树、柳树、金银木抗寒能力强,‘金叶’榆、桑树、杠柳、白榆、小叶杨、‘金叶’女贞抗寒能力较强,珍珠梅、棣棠、红瑞木抗寒能力较弱。运用电导法评定屋顶绿化木本植物抗寒性是可靠的,为快速筛选抗寒性强的屋顶绿化木本植物提供了参考依据。     

Decomposition of woody debris in managed Pinus radiata plantations in New Zealand

Decay rates of stems, branches and roots were assessed in Pinus radiata (D. Don) plantation forests located throughout New Zealand. Stem and branch decay rates were obtained using (1) post-harvest material from two central North Island locations (Kaingaroa and Tarawera Forests) based on a 10-year chronosequence (in ground contact or suspended) and (2) post-thinning stems and attached branch material from five sites covering a range of climatic conditions across New Zealand (Woodhill, Puruki, Hokonui, Nemona and Selwyn) with up to 5 years of decay. Stem, stump and root decay rates were determined from two central North Island locations (Kinleith and Puruki) from thinnings with 0, 5, and 10 years of decay (Kinleith) and mature trees at 0 and 11 years of decay (Puruki). Stem and branch post-harvest material decayed faster when in contact with the ground than when elevated above the ground. The proportion of material elevated or in ground contact was not estimated in this study. P. radiata discs from young trees and post-harvest residue showed no significant diameter effect on decay rate and could be used confidently to predict whole stem decay rate. Discs from older trees covering a larger diameter range at Puruki showed a significant effect of diameter on decay rate. Decay rates of coarse roots at the two central North Island sites were faster than above-ground whole stem decay rates. Exponential models incorporating mean annual temperature for P. radiata stems in ground contact arising from thinning and harvest currently provide the best estimate of residue decay in New Zealand. There was no increase in carbon concentration with decay, suggesting that live stem values may be applied to all dead wood for determining the mass of carbon change with decomposition. Nitrogen concentrations increased with decay.     

河南省毛梾种质资源的自然分布与变异类型

毛梾(Cornus walteri wanger)为良好的油料、用材和绿化兼用树种。根据调查观察结果,总结分析了河南省毛梾种质资源的自然分布特点,从形态(果实大小、果穗大小、嫩枝颜色)和开花结果习性两方面介绍了其变异情况与主要变异类型,并就进一步推进毛梾的保护发展和科学研究工作提出了对策建议。     

木本植物化感研究进展

总结了近年来有关木本植物在化感作用方面的研究进展。国外研究主要集中在化感现象研究、化感物质分离、纯化和鉴定以及化感物质在生物入侵方面的重要作用, 探讨化感物质对植物抑制或促进作用的生化机制研究等; 国内研究较明显地分2个阶段, 主要集中于2个方面, 即化感现象的研究(阶段)和化感物质分离、纯化、鉴定的研究(阶段); 同时, 对今后化感物质在群落或种群调节作用方面的研究做作出了预测。     

冰雪灾害后粤北杉木林冠残体和凋落物的持水特性

对冰雪灾害后杉木林的林冠残体和凋落物的储量、持水量、持水率和吸水速率进行研究.结果表明:杉木林冠残体的干、枝、叶和皮的干质量分别为11.42,7.03,5.76和1.78 t·hm-2,凋落物干质量为5.93 t·hm-2;各组分的最大持水量表现为干(11.83 t·hm-2)>叶(11.24 t-hm-2)>凋落物(10.88 t-hm-2)>枝(6.73 t·hm-2)>皮(2.38 t·hm-2);各组分中叶的最大持水率居首位,达295%,凋落物为272%,皮为234%,枝和干分别为196%和193%;浸泡时间在0.5～6 h之间,各组分的吸水速率随浸泡时间的增长急剧下降,此后缓慢下降;各组分的持水量和持水率随着浸泡时间的增加按照自然对数方程增加,各组分的吸水速率随浸泡时间的增长按负指数方程下降.     

木本植物组织培养褐化控制策略

木本植物组织培养过程中褐化现象严重,采取有效措施进行褐化控制是木本植物组织培养成功的关键。在进行木本植物组织培养过程中先进行培养材料的基因型、生理状态和长部位的影响研究,然后通过培养基的调控、抗褐化剂的使用以及培养条件改变来控制培养材料的褐化是一条有效的途径,对今后顺利开展木本植物组织培养研究有重要的借鉴意义。     

Dynamic Properties of Yangla Copper Tailings Material

Tailing sands, coarse tailing sands and fine tailing sands all were prepared by artificial partitioning experimentation in accordance with the requirements of central line damming. DDS 70 electromagnet kinetic equipment was used to study the dynamic strength, stress strain relationship, dynamic modulus and damping ratio of three tailing sand types. The dynamic strength and parameters were determined, and some influential factors, such as particle composition, confining pressure, consolidated stress ratio and dynamic stress, were discussed. The test results provide basic data for the stability evaluation of the Yangla copper tailing dam under a magnitude 8 earthquake.     

Index of Factors Influencing the Shear Strength of Asphalt Mixtures

Asphalt mixtures with high shear strength have great capability to resist perpetual deformation under high temperatures. We used a single penetration test to analyze the material design indexes for high performance asphalt mixtures. The test results show that the performance of the asphalt binder and the performance of the coarse aggregate, especially the fine aggregate, greatly affect the shear strength of asphalt mixtures. We also suggest that the coarse aggregate with a high aggregate particle index, fine aggregate with high angularity, and asphalt with high viscosity can increase sharply the shear strength of an asphalt mixture. Furthermore, the degree of compaction of an asphalt mixture should be controlled to guarantee excellent long term performance of asphalt pavement.