可溶性纳米复合材料

聚酰亚胺（以下简称ＰＩ）作为一种功能材料已被广泛应用于航空航天及微电子领域。然而随着科技的发展，对材料也提出了更高的要求。有机－无机纳米复合在提高材料的耐热性能、力学性能以及尺寸稳定性等方面都表现出了较大的优势，不失为进一步提高ＰＩ耐热性和高温尺寸稳定性的有效手段。可溶性Ｐ１，具有微电子领域所需要的再加工性能，制备可溶性ＰＩ／ＳｉＯ２纳米复合材料，使进一步再加工成为可能。 试样制备 将３，３’──二甲基一４，４──二氨基二苯甲烷（以下简称ＭＭＤＡ）溶解于为分析纯的Ｎ──甲基──２──吡咯烷酮（以下简称为ＮＭＰ）中，加入等摩尔工业用的、且重结晶后的３，３’，４，４’一四酸Ｍ＄Ｍ苯酮（以下简称ＢＴＤＡ），制备后得到固体含量为１０％的聚四胺酸（以下简称ＰＡＡ）溶液．在一定量的ＰＡＡ／ＮＭＰ溶液中，加人不同量的正硅酸乙酯（以下简称ＴＥＯＳ）和去离子水、催化剂，连续搅拌６小时成均相，即进行溶胶一凝胶（ｓｏ！一ｇｅ！）反应。在玻璃板上铺膜、干燥热处理、亚胺化，即得到不同ＳＩＯ。含量的ＰＩ／ＳＩＯＺ纳米复合膜。其制备过程如下： 其性能如下 １．光学透明性 不同 ＳＩＯ。含量的ＰＩ／ ＳＩＯ。复合材料的表观为透明性，ＳＩＯＺ...     

四川箬竹属一新种

四川箬竹属一新种胡成华，姜建明（南京大学南京２１００９３）密穗箬竹新种图１ＯＮＥＮＥＷＳＰＥＣＩＥＳＯＦＩＮＤＯＣＡＬＡＭＵＳＮＡＫＡＩＦＲＯＭＳＩＣＨＵＡＮ，ＣＨＩＮＡ￥ＨｕＣｈａｎｇ－Ｈｕａ；ＪｉａｎｇＪｉａｎ－Ｍｉｎｇ（ＮａｎｊｉｎｇＵｎｉｖｅ...     

萜烯－马来酸酐不饱和聚酯树脂的合成及其性能研究

以优级松节油为原料，合成萜烯－马来酸酐加成物（简称ＴＭ）．再以ＴＭ、马来酸酐、二元醇等为基料，合成了几种不饱和聚酯树脂（ＴＭ－ＵＰ树脂）．讨论了不同配方及合成工艺与树脂产品性能的关系，并对其物化性能、树脂浇铸体力学性能及耐腐蚀性能等进行了测试，从中选出了几种综合性能较好、工艺较简单、成本较低的ＴＭＡ－ＵＰ树脂配方．通过比较得知制得的ＴＭ－ＵＰ树脂性能达到或超过通用型商品ＵＰ树脂，完全可代替通用型商品ＵＰ树脂应用．     

苯基异氰酸酯在N,N—二甲替乙酰胺中的副反应

本文研究了异氰酸基在Ｎ，Ｎ－二甲替乙酰胺中的副反应，虽然４，４－二苯基甲烷二氰酸酯在ＤＭＡＣ中很稳定，且在３℃时不发生任何反应，但在４０℃时，异氰酸基的含量逐渐减少，以致最后形成凝胶。用苯基异氰酸酯作为ＭＤＩ的模型化合物，进行ＰＩ在ＤＭＡＣ中副反应产物的鉴定研究，鉴定出以下五种副反应产物；（１）１，３－二苯基脲（ＤＰＵ）；（２）１，３－二苯基－５－苯胺甲酰基－６－二甲胺基尿嘧啶（ＰＵＲ）；（３）１     

难易生根桉树多酚氧化酶,吲哚乙酸氧化酶活性及其同工酶的比？…

尾叶桉的ＭＬＡ无性系（简称ＭＬＡ）是难生根无性系,尾叶桉的Ｕ６无性系（简称Ｕ６）,刚果１２号桉Ｗ５无性系（简称Ｗ５）为易生根无性系。ＭＡＬ各器官的多酚氧化酶（ＰＰＯ）活性比Ｕ６、Ｗ５的低,而ＭＬＡ各器官的吲哚乙酸氧化酶（ＩＡＡＯ）活性比Ｕ６、Ｗ５的高。各树种的ＰＰＯ活性、ＩＡＡＯ活性及ＰＰＯ同工酶均具有器官的特异性。讨论了ＰＰＯ和ＩＡＡＯ与不定根的发生和发展的关系。     

山杨二元材积模型的研究

山杨二元材积模型的研究陈东来，秦淑英（河北林学院林学系保定０７１０００）关键词山杨，二元材积模型，拟合中图分类号Ｓ７５８．５１ＡＳＴＵＤＹＯＦＳＴＡＮＤＡＲＤＶＯＬＵＭＥＭＯＤＥＬＳＦＯＲＰＯＰＬＡＲ（ＰＯＰＵＬＵＳＤＡＶＩＤＩＡＮＡ）ＣｈｅｎＤｏｎ...     

水分逆境下杨树光合作用的气孔与非气孔调控

对杨树无性系：Ｉ－２１４（Ｐｏｐｕｌｕｓｅｕｒａｍｅｒｉｃａｎａｃｖ．Ｉ－２１４〕，健杨（Ｐ．ｅｕｒａｍｅｒｉｃａｎａＧｕｉｎｉｒｃｖ．Ｒｏｂｕｓｔａ），中东杨（Ｐ．ｂｅｒｏｌｉｎｅｎｓｉｓ）和群众杨（Ｐ．Ｐｏｐｕｌａｒｉｓ３５－４４）一年生盆栽插条苗进行干旱处理，研究了水分胁迫对四种苗木光合作用和叶绿素ａ荧光的影响．结果发现，苗木受旱后可变荧光提高２０－５０％，而恒定荧光未受水分胁迫的影响。鉴于光抑制是以可变荧光的降低为特征，因此得出光系统ＩＩ光反应中心未受伤害的结论。对土壤干旱敏感的Ｉ－２１４和健杨受旱后净光合作用（Ｐｎ）剧烈下降，主要是由于非气孔因素的影响：即ＲＵＢＰ羧化酶（Ｒｕｂｉｓｃｏ）的活性降低．耐旱性强的群众杨和中东杨，Ｐｎ下降的幅度较小，气孔因素和非气孔因素都是影响光合作用的因子。通过干旱或ＡＢＡ处理的叶片叶温升高，抑制了Ｒｕｂｉｓｃｏ的活性，也使叶绿素ａ荧光诱导曲线上的Ｍ峰消失，从而证实了Ｍ峰与光合作用暗反应的相关性。     

异氰酸酯胶芦苇刨花板生产工艺研究

芦苇的ＳｉＯ２含量高，使用脲醛胶（ＵＦ）难以获得良好的胶合结果，本研究采用二苯基甲烷二异氰酸酯（ＭＤＩ）胶粘剂压制芦苇刨花板，试验结果表明，当ＭＤＩ施胶量为４％和５％，刨花板的密度为０．７０ｇ／ｃｍ＾３时，其物理力学性能指标分别达到我国Ａ类刨花板优等品种和二等品的标准要求，如果ＭＤＩ单价由现在２０．００元／ｋｇ下降到１７．３０元／ｋｇ，ＭＤＩ芦苇创花板和ＵＦ芦苇刨花板的生产成本相同。     

中国海南省茶秆竹属一新种

中国海南省茶秆竹属一新种符国瑗（海南省林业局标本室海口５７０２０３）ＡＮＥＷＳＰＥＣＩＥＳＯＦＰＳＥＵＤＯＳＡＳＡＦＲＯＭＨＡＩＮＡＮＰＲＯＶＩＮＣＥＣＨＩＮＡ￥ＦｕＧｕｏａｉ（ＦｏｒｅｓｔｒｙＢｕｒｅａｕｏｆＨａｉｎａｎ，Ｈａｉｋｏｕ５７０２０３）...     

树干削度方程研究概述

树干削度方程研究概述胥辉（新疆农业大学，乌鲁木齐８３００５２）秦安臣（河北农大林学院，保定０７１０００）关键词削度方程；材种；出材率中图分类号Ｓ７５８．１ＡＲＥＶＩＥＷＯＮＴＨＥＳＴＵＤＩＥＳＯＮＳＴＥＭＴＡＰＥＲＥＱＵＡＴＩＯＮＯＦＴＲＥＥＳＸｕＨ...     

马来松香合成耐热绝缘漆的研究

以马来松香为原料合成了多元醇,并用氨基树脂交联,制备了耐热经缘漆－氨基经缘烘漆,讨论了不同多元醇,不同氨基树脂和固化条件等因素对漆膜性能的影响。研究结果表明,该漆可作为Ｂ级绝缘漆使用。     

Response of LAI-2000 estimates to changes in plant surface area index in a Scots pine stand

We assessed the accuracy with which the LAI-2000 plant canopy analyzer measured changes in leaf area index (LAI) and plant area index (PAI) in a 25-year-old Scots pine (Pinus sylvestris L.) stand. Stand density was 2100 stems ha(-1) and mean tree height was 8.7 m. Needle and branch areas of the stand were reduced progressively to zero by the stepwise removal of branches on all trees growing in a circular plot with a radius of 25 m. An LAI-2000 estimate was taken after each step reduction. The needle and branch surface areas removed at each step were estimated from direct measurements and were compared with the changes in the LAI-2000 estimates. Initially (before removal of branches), directly measured PAI was 5.2 (needles = 86%, branches = 8% and stems = 6%). The LAI-2000 estimate of total surface area was 66% of direct PAI and 77% of direct LAI. There was a nonlinear relationship between the LAI-2000 estimate and directly measured PAI, such that their ratio (equivalent to the clumping factor) increased from 0.66 to 1.05 with decreasing PAI. At the last measurement, when only stems were left, the LAI-2000 estimate agreed well with the direct measurement of PAI. The LAI-2000 underestimated the direct measurement of LAI at the first three steps when LAI was > 2 and the proportion of woody area was small (< 20%). However, because the LAI-2000 estimate included stem and branch areas, it overestimated the direct measurement of LAI at the last three measurements when the proportion of woody area was large (> 20%).     

催干剂对氨基环氧树脂阴极电泳漆的影响

以氨基环氧树脂为基体树脂，Co^2 ,Pb^2 盐为催干剂合成了阴极电泳漆，并对膜性能进行考察，结果表明，所合成的阴极电泳涂料在PH值为6－7、电泳时间2min的条件下。加入不同的催干剂，在不同的烘干温度下，得到性能不同的漆膜。经过膝膜综合性能试验，结果表明，加入钴和铅复合催化剂，在160℃左右烘干20min，可得到完全固化，硬度较高、耐潮、耐盐、耐酸碱性较好的漆膜。     

Pre-commercial thinning,birch admixture and sprout management in planted Norway spruce stands in South Sweden

Early management of the regenerated seedlings shapes the future stand properties. To address these issues, pre-commercial thinning (PCT) and control treatments were applied to planted Norway spruce (Picea abies L. Karst) and naturally regenerated birch (Betula pendula Roth., Betula pubescens Ehrh.) stands in forest experiments in southern Sweden (lat. 56–57?N) containing 1.1–5.5?m tall saplings. The treatments were retention of 1000 or 2000?stems?ha^?1 of Norway spruce, with no birch or birch at 1000?stems?ha^?1. Treatments were replicated with and without annual removal of birch sprouts from stumps. The periodic annual increment (PAI) over five years was calculated for total stand volume and individual trees. The mean PAI of dominant trees was significantly higher both following all PCT treatments than controls, and following low rather than high-density PCT. Birch retention did not affect growth of the dominant trees but PAI was lower in plots with uncontrolled sprouting. The PAI of birch was significantly higher in low-density Norway spruce plots than in control plots and the high-density plots. The treatment response was significant even in stands with initial heights of only 1–2?m.     

Ecoeffective production of timber

Abstract

Development in surface mould growth on painted/unpainted wooden claddings and acting climatic factors were investigated over a period of 3 years. Eight wood substrates, including modified, preservative-treated and untreated wood, were tested in combination with three types of paint: (1) water-borne alkyd modified acrylic paint without fungicide; (2) solvent-borne alkyd paint without fungicide; and (3) ICP (internal comparison product). One set of samples was exposed unpainted. The samples were tested according to a modified version of EN 927-3. A logistic regression model was fitted to the data. The degree of mould growth varied with exposure time, coating typology, wood substrate, temperature and relative humidity. Exposure time and coating typology contributed most to the model. After 3 years of outdoor exposure unpainted panels and panels coated with solvent-borne paint without fungicide had more mould growth than panels coated with ICP and water-borne paint without fungicide. Unpainted oil/copper–organic preservative-treated claddings had higher resistance to mould growth than other unpainted wood substrates. Coated untreated pine and coated acetylated pine were more susceptible to mould growth than other coated wooden substrates.     

Stand density and growth of Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis> (L.) Karst.) and European beech (<Emphasis Type="Italic">Fagus sylvatica</Emphasis> L.): evidence from long-term experimental plots

On the basis of nine Norway spruce (Picea abies (L.) Karst.) and ten European beech (Fagus sylvatica L.) thinning experiments in Germany, for which both residual and removed stock had been registered first during 1870, I scrutinize how moderate and heavy thinning from below (B-, C-grade) affects the production of merchantable volume compared with light thinning (A-grade). In relation to A-grade, cumulative merchantable volume (CV) of B- and C-grade amounts in average to 103–107% in juvenile and to 97–102% in mature Norway spruce stands. The corresponding findings for European beech are 101–106% and 94–102%. CV of individual stands varies between 89% and 130% for Norway spruce and 73% and 155% for European beech (CV of A-grade = 100%). These findings are substantiated by the relation between stand density (SDI) and periodic annual increment (PAI). On the B- and C-grade plots of spruce and beech, respectively, SDI was reduced down to 41–91% and 31–83% of the A-grade. When SDI is reduced in young stands, PAI follows a unimodal curve. Norway spruce’s PAI culminates in 109% if SDI is reduced to 59%; European beech’s PAI culminates in 123% when density is reduced to 50%. Whereas Norway spruce’s growth reacts most positively on thinning under poor site conditions and with increment reduction on favourable sites, European beech behaves oppositely. With stand development the culmination point of the unimodal relation moves towards maximum density, so that in older stands PAI follows the increasing pattern, which is the left portion of a unimodal curve. A model is presented which apparently unifies contradictory patterns of stand density–growth reactions by integrating relative stand density, average tree size and site fertility effects, and makes the findings operable for forest management.     

3种水性漆在杨木表面的润湿性对比研究

选取丙烯酸酯、聚氨酯、丙烯酸-聚氨酯共聚物3种水性漆为滴液,用接触角测试仪对3种水性漆在杨木表面的接触角进行测试,对比分析其对杨木表面润湿性的影响。结果表明:未进行超纯水稀释的水性漆中,丙烯酸酯、共聚物水性漆在杨木径切面的润湿性优于弦切面,聚氨酯水性漆则反之;共聚物水性漆相比于其他两种漆润湿性更好,聚氨酯次之,丙烯酸酯水性漆的润湿性则相对较差。相比未进行超纯水稀释的水性漆,经稀释处理的3种水性漆在杨木表面的接触角均有不同程度的下降。接触角下降率分析表明:丙烯酸酯水性漆相比其他两种漆在杨木表面的润湿性更好,此外共聚物水性漆在杨木弦切面润湿性优于径切面,而其他两种水性漆则相反。     

竹炭粉在乳胶涂料生产中的应用

以高温炭化的竹炭粉作为颜料与填料制备乳胶涂料,研究不同颜基比及不同的涂层厚度下,乳胶涂料的碘吸附性以及涂膜性能。结果表明:粒径600目的炭粉,碘吸附值398 mg.g-1,颜基比在2.0∶1~2.5∶1之间,涂布层厚度在25~30 g.m-2,制得炭基乳胶涂料吸附性能好。     

用于重组竹地板底漆的热熔漆漆膜性能研究

对以热熔漆为底漆涂饰的重组竹地板及其对照组地板进行紫外光/冷凝耐老化试验,分析耐老化试验前后地板的漆膜性能,结果表明:耐老化试验前后热熔漆涂饰重组竹地板和对照组地板的各项性能均达到GB/T20240-2006《竹地板》中的规定,热熔漆漆膜性能表现更好。采用体式显微镜观察漆膜表面情况,采用裂纹条数、裂纹长度、裂纹面积比描述漆膜开裂情况,结果表明:耐老化试验后热熔漆涂饰重组竹地板的裂纹条数、裂纹长度、裂纹面积比相比于使用传统底漆涂饰重组竹地板分别下降了89.6%、62.5%和35.1%。热熔漆相比于传统底漆具有更好的抑制重组竹地板漆膜开裂的作用。     

保山市核桃烘烤现状调查分析

核桃鲜果现代智能化烘烤方式烘干,对提高核桃产品品质,增强市场竞争力有重要作用。2011年,对保山市几个核桃加工企业、农民专业合作社进行了核桃鲜果烘烤方式访谈,并对几种主要的烘烤方式开展试验,分析几种烘烤方式的关键技术及优劣势,认为烘烤方式正在向无烟烘烤方式转变,研发低成本、智能控制的户用型烘烤设备是产业发展的需要。