PF胶杨木大片刨花板喷蒸真空热压的工艺优化

以饱和蒸汽压力、喷蒸时间、蒸汽保持时间和抽真空时间为变量因子 ,利用BY60 2× 4喷蒸试验压机 ,采用二次数学模型D =4近似饱和最优设计及复合型法 ,研究了水溶性A阶PF胶杨木大片刨花板的喷蒸真空热压工艺 ,求得回归方程 ,进行工艺优化。所得回归方程的预测偏差小 ,可用于预测刨花板性能。     

喷蒸—真空热压刨花板

以喷蒸热压法制造刨花板的试验研究结果表明：喷蒸热压与普通热压相比，不仅热压周期可大大缩短，且制品质量有所改善。真空处理对喷蒸热压是必要的。     

南京林业大学科技成果简介：（三）厚型中密度纤维板产业化

在常规热压机上，增加对板坯喷射蒸汽和真空负压抽吸系统，采用既保留原有对板坯接触传热，又直接对板坯喷注的加热方式，使板坯中心快速达到水分汽化蒸发和胶黏剂固化所需的温度，从而完成厚型MDF的热压，在大幅度缩短热压时间、提高生产能力同时，生产出结构均匀、性能满足MDF国家标准要求的厚型MDF。该项目利用喷蒸-真空热压的专利技术生产厚型MDF，单位产品能耗低，     

硼酸锌防腐处理对杨木定向刨花板性能的影响

以速生杨木为木材原料,酚醛树脂(PF)和异氰酸酯树脂(MDI)为胶黏剂,硼酸锌(ZB)为防腐剂,制备了杨木定向刨花板(OSB),以研究ZB添加量（0.5%、1.0%和3.0%）对OSB试板的物理力学性能和防腐性能的影响。结果表明,各试板的物理力学性能均满足我国LY/T 1580—2000《定向刨花板》中OSB/3类板的要求;添加ZB显著提高了试板的防腐性能。添加0.5%的ZB对PF、MDI两种胶黏剂胶合的杨木OSB性能无不利影响。ZB添加量在0.5%~3.0%范围内,MDI胶杨木OSB的力学性能基本随ZB添加量的增加而下降。相同ZB添加量及施胶量的情况下,MDI胶杨木OSB的力学性能优于PF胶杨木OSB。     

预压缩杨木的动态润湿性

动态润湿性是木质材料的一个重要界面特性,用于描述胶黏剂在木材表面上的润湿行为。笔者采用润湿模型描述动态接触角(θ)在木质基材表面上的扩展过程,模型中利用参数K值来描述胶黏剂在木质基材表面上的动态润湿行为。应用此模型分析了不同压缩工艺条件下脲醛树脂和酚醛树脂的湿润性能;比较了不同压缩工艺参数如压缩率、热压温度和热压时间对动态润湿性的影响。结果表明,润湿模型能够准确地描述胶黏剂在预压缩杨木表面的动态湿润过程。在预压过程中,保压时间是对K值影响最为显著的因素。     

工艺参数对大豆基胶黏剂刨花板密度梯度的影响

按不同密度及热压工艺参数制备大豆基胶黏剂刨花板,在静曲强度、内结合强度、2h吸水厚度膨胀率等主要技术指标满足刨花板国家标准的前提下,检测断面密度梯度,研究影响大豆基胶黏剂刨花板密度梯度的主要因素.试验结果表明:刨花板密度梯度呈U型变化,表层密度大于芯层密度,表、芯层密度差较大;采用厚度规控制厚度的生产方式,在生产相同密度大豆基木质刨花板时,热压压力对刨花板密度梯度的影响最大.随着热压压力的增加,密度梯度呈增大趋势;其次是刨花密度;热压温度和热压时间对刨花板密度梯度的影响较小.     

国内期刊题录

(一)木材工业(二)乳制品1.高新技术在木材工业中的应用2.当前木材供需形势分析及预测3.上海市木材市场价格行情4.进口木材及制品关税率简况表5.竹材胶合板的新进展6.国外木质人造板的涂饰7.美国木材纤维的有效利用8.拌胶技术的新进展9.利用柠檬按制造刨花板10.定向刨花板的刨花形态及制造设备n·刨花板用石蜡乳液制备技术12.刨花板生产用GDN一3不脱水脉醛树脂胶的研究13用计算机图像处理法研究胶滴在刨花表面的分布14.刨花蒸汽处理最优工艺条件的探讨15.固化剂用量及其添加方法对刨花板性能的影响16.利用泡桐枝极材、小径木制造刨花板17.…     

大豆蛋白胶枫木刨花板热压工艺研究

为了解决甲醛等有害物质的释放问题,使用大豆蛋白胶作为热压枫木刨花板的无甲醛胶粘剂,研究了刨花板的热压工艺.在实验室条件下,通过单因素试验分别分析了热压温度、热压时间、施胶量和密度对枫木刨花板内结合强度及表面结合强度的影响;并通过响应面设计得出最佳试验参数.结果表明,大豆蛋白胶可以用于枫木刨花板的制造,其最佳工艺参数为:热压温度180℃,热压时间27.5min,施胶量15.7%,密度780kg/m3.在此条件下,压制的板材性能均达到GB/T4897.1-2003对在干燥状态下使用的普通用板要求.     

《厚型板材制造——侧面喷蒸热压技术》通过鉴定

2010年12月,江苏省教育厅组织有关专家对南京林业大学主持的"厚型板材制造——侧面喷蒸热压技术"项目进行了鉴定。该项目研发了侧面喷蒸热压技术,将普通胶合板压机改造成具有侧面喷蒸-真空的组合式热压机,形成了厚型板材的制造工艺和技术,并应用于制造厚型单板层积材(LVL)及秸秆墙体材料。     

异氰酸酯胶黏剂压制刨花板的力学性能

利用正交试验法研究压制工艺对异氰酸酯胶黏剂刨花板性能的影响.结果表明:异氰酸酯树脂胶黏剂的黏度、固含量适中,符合国家标准,可大规模推广使用;施胶量、热压温度和热压时间对刨花板性能有较大影响.通过极差及位级趋势分析可知:在试验范围内,制备刨花板的静曲强度、内结合强度均随着施胶量、热压温度和热压时间的增加呈增大趋势.其中,施胶量对刨花板内结合强度的影响最显著,热压时间次之,热压温度最弱;刨花板最优制备工艺为施胶量210 g/m2、热压温度180℃、热压时间450 s,此时内结合强度与静曲强度分别为0. 51MPa和22. 4 MPa.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with