桉树人工林胸径变化特征与环境因子的关系研究

2014年6月13—14日,利用DD型茎干生长测量仪对海南西部儋州桉树人工林胸径进行定点定株连续监测,分析了桉树人工林胸径变化特征对其环境因子的响应。结果显示:1桉树胸径变化呈明显的昼夜变化规律,表现为白天收缩,傍晚和夜间复原和膨胀的过程;2桉树胸径变化与土壤水分含量与大气相对湿度之间呈现极显著正相关关系,与大气温度和太阳辐射之间呈现极显著负相关关系。     

稻田小麦免耕栽培技术

一、适时开沟排水开沟要防止破坏耕层土壤,同时要掌握好稻田排水时间。排水过迟,土壤水分含量过高,收稻时易踩紧弄僵耕层土壤;排水过早,土壤水分过少,不但影响水稻灌浆,也不利于小麦播种和出苗。一般田块在水稻散籽时排水较为适宜,做到收割时泥不陷脚,人走不留深脚印,但又不开大裂为度。水稻收割后,对低凹湿田要进一步开厢理沟,排除田间     

秃杉育林期营林要点

一、林地管理1.林地植被管理。在秃杉人工林的幼林期,林地易长杂草、灌木等,应在其萌发初期及时铲除。铲除的杂草、灌木,就地埋入林地土壤,可起到施绿肥的作用。林地每年进行除草、铲灌两次:第一次在春夏之交,第二次在杂草种子尚未成熟传播之时。2.林地土壤管理。由于秃杉人工初植林刚经过整地,地表缺乏覆盖,林地土壤水分蒸发量较大,故要进行松土,以减少土壤水分蒸发。同时,土壤疏松有利于微生物活动与有机质的分     

黑龙江省黑土耕地利用中存在的问题及原因

黑土耕地是世界上极为稀缺的土地资源。然而,黑龙江省黑土耕地资源正在急剧退化,表现为水土流失严重,土层变薄,土壤肥力减退,耕地质量下降,黑土理化性状日趋恶化,黑土耕地数量难以稳定。其原因不仅在于气候、地形、土壤、冻融、植被等自然因素的影响,而且更重要的原因则在于过度开垦和掠夺式经营、工农业生产造成的土壤污染、耕作制度不合理、土壤实用功能转移等人为因素的影响。保障＂东北粮仓＂农业可持续发展和国家粮食安全的战略任务,使保护黑土耕地更加凸显其重要性。     

瞬态模拟软件在《热质交换设备》教学中的应用分析

以《热质交换原理与设备》课程教学中的复合式热质交换设备为研究对象,为加深学生对该内容的理解,应用瞬态系统模拟计算软件建立系统模型,对苏州地区的一级直接蒸发冷却空调系统、二级蒸发冷却空调系统和三级蒸发冷却空调系统进行供冷工况下的模拟计算。得出了相应的空气处理后的温度、相对湿度,并对结果进行分析,研究对实际的空调工程、通风工程的系统选型设计、方案比较均具有参考意义,对学生学习掌握《热质交换原理与设备》课程教学中的相关内容起到一定的促进作用。     

水稻幼苗立枯病的防治方法

水稻幼苗立枯病是寒地水稻塑膜旱育苗和大棚盘育苗常见的病害,危害十分严重,特别是遇到持续低温或气温不稳定时发病尤重.另外,土壤水分和土壤酸碱度与本病的发生也有密切关系.     

船用机械密封若干问题的研究

首先论述了机械密封研究的关键问题，即处理好机械密封的开启力和闭合力之间的关系；随后从“密封环的几何模型与力学分析模型、结构力变形和热变形的影响系数法的计算模型”等方面，论述船用机械密封的动态耦合问题。     

双层土壤中垂直接地极对地网接地电阻的影响

地网接地电阻与土壤结构和特性密切相关。该文利用双层土壤模型接地电阻计算方法详细分析了垂直棒的长度和数量对大中型地网和小型地网接地电阻的影响。结果表明下层土壤电阻率较低时垂直棒的长度对小型地网接地电阻影响较大,垂直棒的长度对大型地网作用不明显。当下层土壤电阻率较高时可以适当增加垂直棒的数量来降低地网接地电阻。     

中国非家族企业的“家”文化治理格局浅析

民营企业具有包括"家族企业"与"非家族企业"在内的两种基本形态。受我国历史、社会、政治、经济等诸多因素影响,我国部分"非家族企业"也呈现出明显的具有中国特色的"家文化"治理特征,表现出重视创业者的绝对影响、强调过分亲密的员工关系、依赖内部提拔等诸多特点,本文将从该现象形成原因、竞争优势、潜在问题及解决方案等方面进行探讨,分析该现象的植根土壤和多方影响。     

谈谈测土配方施肥技术(下)

(接上期)四、测定土壤养分时的注意事项1.土壤样品采集的原则。采集的土壤样品必须具有代表性。因为在进行土壤养分测试时,通常用来化验的土壤是很少的,而化验的结果却代表较大地块,采样误差一般要比化验误差大很多。所以,缩小采样误差的关键是采集的土壤要有充分的代表性。一般是先把采样区域划分为若干采样地块,同一采样地块里的地形,近期耕作     

MOISTURE MEASUREMENTS OF EVERYDAY MATERIALS*

The relative humidity of the air inside a house has an important effect on people's comfort and behaviour; in particular it affects the need for ventilation, and consequently the heating energy use. The actual level of r.h. in a house is affected primarily by the relative rate of production and loss of moisture. However, the process is a dynamic one, and the r.h. in the non-steady state is affected by moisture uptake and release by building and furnishing materials. Published data on moisture absorption is inadequate, and measurements were made at ECRC of the behaviour of some common materials.     

储粮通风减损技术在滇西地区的应用

2011年冬季对2号仓（玉米）、3号仓（籼稻）、6号仓（小麦）、15号仓（粳稻）4个试验仓进行节能减排通风减损实仓试验。当引入粮堆后的仓外空气的相对湿度大于等于粮食水分增加2％时粮堆空气的相对湿度,但小于粮食水分增加3％时粮堆空气的相对湿度同时外界温度与粮温温差大于等于6℃时利用轴流风机进行通风。冬季通风结束后2号仓平均粮温9．9℃,水分增加0．1％,3号仓平均粮温9．1℃,水分增加0．9％,6号仓平均粮温11．4℃,水分减少0．1％,15号仓平均粮温10．2℃,水分增加0．1％。     

留样盲测方法用于原粮质量控制的研究

本文检测了稻谷、玉米和小麦留样的水分及脂肪酸值,阐明了检测期间内留样水分及脂肪酸值的变化规律,探讨了采用留样盲测方法对原粮水分和脂肪酸值检测项目进行质量控制的有效性及适用性。研究结果表明：在温度20℃～25℃、相对湿度60％-80％的保管条件下,稻谷、玉米和小麦水分项目的留样盲测数值在60天的跟踪期均较稳定,适宜用该方法进行质量监控;而对于脂肪酸值检测项目,稻谷和玉米留样再测的有效期则分别缩短至50天和35天。     

MOULDS IN THE HOME

Mould growth in homes is one of Britain's biggest housing problems which is becoming even more widespread. Such growth is not only unsightly, smelly and presents a potential health hazard but leads to deterioration of the building fabric. Mould spore concentrations both indoors and outdoors are reviewed and the environmental conditions needed for germination are given. The critical factor to prevent mould is maintenance of a low relative humidity. This can be achieved by either lowering the moisture content or raising the temperature. Moisture removal at source, background heating, and heat pump dehumidifiers are recommended.     

MOISTURE STUDIES IN THE DOMESTIC ENVIRONMENT

In an attempt to ascertain the measure of agreement as to what constitutes dryness in textile goods following laundering and during domestic storage, a series of trials were carried out employing a large sample of testers. Each was asked to register a decision, whether damp or dry, for articles in wool, cotton and poly-cotton (67% polyester, 33% cotton). These articles were of known moisture contents, measured as percentage moisture regains, following exposure to controlled atmospheres ranging between 0 r.h. and 95% r.h. Considerable variations in dampness perception were recorded between individual testers and results differed with the fibre content; poly-cotton presented the most difficulties. Nevertheless it was possible to discern for each textile, a moisture content band below which goods could be declared acceptably dry. Implications for the indoor drying and storage of laundered articles were reviewed. Dryness acceptable to the majority (90% of the sample) could be achieved within a normal indoor atmosphere (50% r.h., 20°C) for poly-cotton but not for wool or cotton. For these, a reduced humidity or an elevated temperature would be required, necessitating the expenditure of energy such as is commonly available in the domestic airing cupboard. Results were applied to a psychometric chart to make recommendations for effective temperatures within such cupboards.     

改性海泡石除甲醛净化剂的研制

通过海泡石改性研制了一种除甲醛净化剂,研究了温度、空速、进口甲醛含量、相对湿度等条件对甲醛容量的影响,实验结果表明,该常温深度甲醛剂在相对湿度10％。90％,温度0～40℃范围可快速净化空气中的微量甲醛,净化深度≤0．1mg／m^3,甲醛容量≥5％。     

毫米波防撞雷达三维显示界面的设计与实现

提出了一种地形分块加速绘制算法。算法递归地将地形划分为多个大小相等的地形块 ,通过统计地形块中目标分布的稀疏度以及无目标地形块所占的比例,寻找最优的地形分块 方式。此外,提出了一种利用Diamond-Squares算法生成随机纹理,并融合顶点颜色为地形 着色的方法,渲染的地形真实感强、层次分明。最后,介绍了防撞雷达三维显示中的场景漫 游方式。该方法已成功应用于实际工程中,显示效果良好,并且具有通用性,可以应用于一 般的三维地形绘制。     

Price and profitability in fish smoking in southwestern Nigeria

Comparative market prices for four freshwater and four marine fish species in the raw and processed forms were determined in a survey within Lagos and Oyo States of Nigeria. Costs of processed fish were calculated relative to the sale prices of their raw equivalents, taking moisture differences and cost of processing into consideration. All the species would have to be sold in the processed form for much higher prices than was found during the survey if sales were to be by weight. Processed catfish, sardine, mudfish and mackerel appear to be sold at a loss while three species (tilapia, sole and bongafish) are sold at very marginal profit. Only tigerfish is sold at reasonable profit. It is suggested that anyone going into fish smoking as a modern business venture should be prepared to face unfair competition in pricing from the small operators who appear to be underpricing their products and who currently dominate almost the entire fish market in Nigeria.     

在储小麦实仓通风调质试验

利用通过雾化过滤的高湿空气,对粮面高4 m的1 447 t小麦进行通风调质。经过127 h的调质,粮食平均水分由原来的11.7%增长到12.5%,投入产出比1：7,取得了良好的经济效益,达到了较理想的通风调质目的。     

水土保持措施在开发建设项日中防治水土流失的效果研究

本文通对“昆-石”高速公路三个弃渣场的土壤肥力进行试舱调查研究，将三个渣场土壤的肥力状况，本文选用土壤结构、土壤台水量、速效N、速效P、有机质进行试验，试验数据与背景值相比较，说明水土保持措施在开发建设项目中防治水土流失的作用。研究表明，水土保持措施能够有效的改善土壤结构、提高土壤肥力，能够有效的防治水土流失。