路面水泥砼配合比设计的分析

在道路建设中，水泥混凝土路面被广泛采用。本文对路面水泥混凝上配合比设计进行了分析，有一定参考价值。     

北美兰云杉菌根化育苗技术研究

本研究针对北美兰云杉植物在pH8~9的碱性土壤上育苗其出苗率和保苗率低,且生长缓慢,原有森林培育技术难以有效地解决这一生产上的实际难题,试图采用菌根化生物技术进行育苗,对其进行了14个菌根菌的育苗应用研究。在同一种源不同菌种层次上进行优良外生菌根的筛选,综合生长指标进行评价。     

黄菠萝剪根摘芽混交造林试验

采用剪根摘芽苗木处理方法,对黄菠萝与落叶松、云杉、红松等树种进行带状混交试验,观察黄菠萝保存率.结果表明,对黄菠萝幼苗采用剪根摘芽的苗木处理方法进行混交试验可以有效的提高黄菠萝保存率,可在生产上推广应用.     

慈竹、西风竹、硬头黄竹整秆带蔸埋秆育苗试验

对慈竹、西风竹、硬头黄竹三个竹种分别采用不同年龄的竹秆进行整秆带蔸埋秆育苗试验。结果表明：三个竹种都可萌发、生根、成苗。但硬头黄竹、西风竹成苗率低、育苗成本高，不可在生产上推广应用。慈竹成苗率高，育苗成本低，经济上可行，可在生产上推广应用，但以采用2、3年生竹秆为宜。     

三倍体毛白杨不同砧木嫁接试验

为探索不同砧木亲合力对三倍体毛白杨一条鞭芽接成活率的影响 ,试验分别采用赤峰杨、少先队杨、群众杨作砧木进行了一条鞭芽接试验。结果表明 ,在上述砧木上进行芽接 ,其亲合力对成活率影响差异不显著     

花叶络石的耐荫性试验和应用

通过对花叶络石采用不同方式进行耐荫性试验得出:花叶络石可以在遮荫的情况下,获得较好的枝条生长量和叶色表现,以及这种特性在育苗和园林绿化上的应用。     

两种苔藓植物在建筑材料基质上的生长情况研究

采用对比实验的方法，对武汉市常见的青藓和尖叶走灯藓两种苔藓在多种建筑材料上进行了生长情况研究，运用SPSS回归分析，预测了未来可能的生长情况。结果表明：两种苔藓在生态砼和红土砖块上生长状况都比较好。通过苔藓在斜坡和树体上的生长情况，初步得出结论苔藓在垂直空间上可以生存生长，对苔藓的垂直绿化应用提出了合理的建议。     

我国古树研究文献分析

采用文献计量学方法,对我国近28年来在学术期刊上发表的古树研究文献的年份分布、期刊分布、文献作者单位、引用频次、下载频次和主题类型等几个方面进行了研究。最后对古树研究状况进行了总结并提出了建议。     

山地侧柏林树高的测定

侧柏(Platycladus orientalis(L.)Franco)多生长于山地坡地,立地条件差,难以测定水平距离,因此不适合采用传统方法对其树高进行测定。本研究通过测定树体上3个部位与观测者之间的水平夹角,采用三角函数计算方法,运用Excel软件公式功能,对山地侧柏人工林的树高进行了测定,并与激光全站仪的测定结果进行了对比分析。测定结果表明,三角函数法在山地侧柏林树高测定上的应用效果较好,平均精度达到97%以上,在测高时完全可以替代激光全站仪。     

柿子高接换种技术研究

采用不同嫁接时间、不同嫁接部位及嫁接时不同的护理方法等对成年柿子树进行高接换种试验，结果表明，不同嫁接时间对柿子大树高接的成活率和新梢粗生长具有极显著的影响；在不同部位嫁接和嫁接时采用不同护理方法对柿子大树高接的成活率有极显著的影响，但对新梢生长影响不显著。应选择在2月下旬至3月中旬，在柿子主枝或副主枝上进行1树多桩的大树高接换种方法，同时嫁接包扎后宜采用套袋 袋下方留出水孔方法对嫁接处进行护理。     

太阳能炕热过程动态模拟

指出了中国北方农村广泛使用火炕进行采暖，但传统火炕存在空气污染和热效率比低下的问题。提出了一种新型的太阳能炕并建立了动态数值模型。基于该数学模型，以特定气象参数为条件，研究了太阳能炕的蓄热特性和炕表面温度特性。结果表明：在炕表面温度一定的条件下（25℃），房间空气温度波动非常小，炕内水管表面温度不超过40℃。因此太阳能热水很适合作为炕的加热热源。另外，炕的蓄热质量对房间温度影响较大，合适的蓄热质量能保证晚上炕没有加热的情况下，房间空气温度仍然处在舒适的范围。     

雷竹林覆盖不同发热物质发热规律及对土壤温度的影响

【目的】探索不同发热物质的发热规律,分析雷竹笋用林覆盖中发热物质对土壤温度的影响,为凝练高效低碳雷竹林覆盖模式提供适宜的发热材料和施用方法。【方法】选用生产中广泛使用的3种材料(新鲜鸡粪、枯饼和麦灰)作为发热物质覆盖雷竹林,调查覆盖期内不同时期和不同土层深度的土壤温度,并通过方差分析比较其差异性。【结果】新鲜鸡粪、枯饼和麦灰作为发热物质覆盖雷竹笋用林,土壤温度均在10℃以上,高于未覆盖林地。11月26日覆盖后,前2~5周土壤温度较高,第6周开始温度逐渐下降,第13周(翌年2月底)温度达到最低,之后随着气温的上升,土壤温度又开始上升。不同发热物质的发热规律有所不同,麦灰发热速度快并且集中,前期土壤温度高,增温效果明显,但持续发热时间短,第3周开始土壤温度下降;枯饼发热速度平稳,持续发热时间较长,高温期内土壤温度变化幅度较小;鸡粪发热量相对较低,覆盖初期土壤升温慢,温度较低,但后期土壤温度较高。发热物质和土层厚度均对不同土层的温度差异产生显著影响(P <0.05),覆盖初期发热物质起主导作用,覆盖中期土层厚度起主导作用,覆盖后期共同影响,但二者的交互作用不显著(P> 0.05)。【结论】笋用林覆盖中,不同发热物质的发热规律和发热量不同,鸡粪发热量较小,麦灰持续发热时间短,枯饼发酵分解速度比较平稳,持续发热时间较长,是比较理想的发热物质。生产中可使用枯饼为发热物质,配合适宜的谷壳保温层厚度或采用二次覆盖等措施,实现控制土壤温度和竹笋出土时间,提高笋用林产量和效益的目标。     

提高落叶松材渗透性的工艺研究

落叶松材改性处理的关键研究是它的渗透性 [2 ]。在常温条件下对落叶松板材进行加压处理 ,因温度不能调整 ,试验的动态环境系数变少 ,很难取得预期的处理效果。加热加压法与常温加压法相比 ,把温度作为一个可变参量 ,使用正交分析法进一步研究落叶松材的渗透性。     

大别山野生“扒皮菇”菌种分离与栽培条件研究

选择不同培养基对大别山野生＂扒皮菇＂菌种进行分离与栽培试验研究。结果表明,PDA培养基可以作为野生扒皮菇母种培养基,母种菌丝长势较好,长速较快。以小麦培养基作为栽培种培养基菌丝生长最好,棉籽壳培养基次之,玉米芯培养基最差。3种培养基在温度20~30℃,昼夜平均温差14℃,pH值4~4.5,空气相对湿度85%~95%条件下,均未有子实体的出现。     

Predicting the humidity control capacity of material based on a linear excitation-response relationship

The Cb value is a useful parameter for estimating the humidity control capacity of materials. It is defined as the ratio of the range of variation of relative humidity in a steel box lined with the material of interest to that in an empty steel box, when sinusoidal temperature variation is applied. However, because it takes a long time to obtain the Cb values for materials at each temperature variation period, we developed an easier method based on a linear excitation-response theory to obtain the Cb values without measuring at each period. Japanese cedar was the material used in this study. The temperature excitation, a jump from a constant temperature to another constant temperature, was used to obtain the absolute humidity response. Under the assumption that the temperature excitation-humidity response relationship is linear, we were able to predict humidity variation to sinusoidal temperature variation at any period, and we obtained the Cb value for each temperature variation period. Predicted values agreed well with the experimental values. From this, it was found that the Cb value could be predicted without measuring the Cb value at each period over a long time. In addition, the peak time difference, which is closely related to the Cb value, could also be predicted in a similar manner.     

Characterisation of the curing of liquefied wood by rheometry, DEA and DSC

Liquefied wood is a naturally based product which has the potential to be used as an adhesive. The bonding of wood with liquefied wood requires a high enough temperature to cure the liquid polymers and achieve bond strength. Dielectric analysis, rheometry and differential scanning calorimetry were used to analyse the curing process of low solvent liquefied wood. For the liquefaction, ethylene glycol was used as a solvent and sulphuric acid was used as a catalyst. The dielectric analysis was used for in situ measurements of the curing of liquefied wood during the bonding of wood. It was found that curing started after a temperature of 100 °C had been reached in the bond. This is correlated with the water evaporation and the diffusion of water and ethylene glycol from the liquefied wood into the wood substrate. Rheological measurements proved the influence of the substrate on the curing of the liquefied wood during bonding. Differential scanning calorimetry showed that the curing of liquefied wood occurs in two parts: first, the initial elimination of water and ethylene glycol from the liquefied wood, and then the chemical reaction of the liquefied wood at higher temperatures.     

Tunnel Cloches-Development of a Nursery Technique for Growing Conifers

Clear polythene used as a cloche with buried edges to coverseedbeds is an effective method of improving growth of somespecies of conifer seedlings. The polythene protects seed andseedlings from birds and provides a warm, moist, sheltered environmentin which nutrient leaching is reduced. Cloches can reduce thetime for producing planting stock by one year. Costs are reasonable,capital investment low, and little advance planning is required,unlike other intensive raising systems such as polythene greenhouses.Species response varies, with pines giving consistently goodresults. Sitka spruce is difficult to grow under cloches becauseof high temperature damage, even if white polythene and seephoseirrigation are used to moderate extremes of temperature. LargeDouglas fir and larch seedlings can be raised under clochesthough good results may not be achieved.     

Development of a monitoring system for guided circular saws: an experimental investigation

ABSTRACT

Lack of a monitoring system for guided circular saws marks one of the most critical machines in sawmills as a production bottleneck. Monitoring systems are being researched and developed for machine tools, especially for the metal cutting industry; but there are limited studies on the development of monitoring systems for circular saws in wood manufacturing process. In this study, sensors with the possibility to indicate sawing deviation were chosen that could be mounted in or on the saw guides. The sensors were: a microphone, an accelerometer, temperature sensor, an acoustic emission (AE) sensor, and a newly developed displacement sensor. A load cell was used to measure the lateral force on the guides. The outputs from these sensors were compared to the standard deviation of the board surface measured at the top of the cut. The signals from the displacement sensor, microphone, accelerometer, guide force sensor, and AE senor had no correlation to changes in the sawing deviation as measured by the standard deviation at the top of the board. Under laboratory conditions, the sound level and the AE signal did indicate the beginning and end of the cut. It was found that blade temperature is a good indicator of saw cutting performance. A newly developed temperature sensor can provide accurate temperature of the saw during cutting. The sensor can be used for measuring the rate of heating to cooling over time which can be used as a monitoring system to detect if there is any issue in the system.     

植被遥感研究的新思路——走出传统光谱理论应用的误区

对遥感中沿用几十年的植被光谱理论提出质疑,阐述了传统植被遥感中存在的误区,提出新的观点及研究思路。第一次提出干旱植被指数(LDVI)和综合植被指数(IVI)的概念,探讨了干旱地区草原植被的信息提取及定量分析方法。     

GC法测定天然冰片中的d-龙脑和樟脑

采用GC法测定天然冰片中的d-龙脑和樟脑的含量。分析柱为CP-WAX毛细管柱〈30 m×0.32 mm×0.5μm〉;升温程序为50℃,以5℃/min升温到100℃,保持1 min,再以10℃/min快速升温到180℃,保持5 min,进样流速比5∶1;FID检测器温度为250℃;进样口温度为200℃,载气为高纯氮气,体积流量为2 mL/min;空气体积流量为300 mL/min;氢气体积流量为30 m L/min;进样量为1μL。本方法操作简便、准确,精密度、分离度良好、分析时间短,为天然冰片的测定及其质量控制提供参考。