四虎无码,天天碰天天干,爱爱AV无码爱爱,农村熟女88AV

造價(jià)通
更新時(shí)間：2025.06.08
南方地區(qū)楊樹(shù)膠合板材定向培育技術(shù)的研究

格式：pdf

大?。?span class="single-tag-height">180KB

頁(yè)數(shù)：

Based on the results of more than ten year's scientific research and practice, some key techniques for cultivating poplar veneer glued wood were summarized systematically. The results were as follows: (1)Selecting appropriate poplar clones for various cultivation zones according to their growth rate and wood quality. (2)Choosing good sites being suitable for poplar clone growing (at least SI≥18?m). (3)Adopting reasonable planting density which can produce more timbers to meet the need of plywood(the tree spacing should be more than 5?m×5?m). (4)Using correct planting methods for different soil conditions, however, large seedling with 2 year old root and 1 year old stem (seedling height>4?m)were advocated. (5)Taking effective measures to tend the stand, the most effective measure was interplanting with crops. (6)Pruning was neccessary to produce non node timber, but pruning method, pruning intensity and pruning season should be controlled properly. If the 6 measures mentioned above were carried out, the poplar forests with a high yield and high quality could be ensured. In order to provied some theoretical basis for cultivating poplar veneer glued wood, 4 optimum cultivation patterns were also established using the method of two dimensions system.

阻燃桉樹(shù)膠合板的初步研究

格式：pdf

大?。?span class="single-tag-height">437KB

頁(yè)數(shù)： 6頁(yè)

以磷酸二氫銨(MAP)溶液為阻燃劑,通過(guò)浸泡尾葉桉單板,研究了單板的載藥量;以Ⅱ類(lèi)膠合強(qiáng)度為指標(biāo),利用正交試驗(yàn)對(duì)常規(guī)膠合板生產(chǎn)工藝進(jìn)行了優(yōu)選。在此基礎(chǔ)上,選取浸泡時(shí)間和最優(yōu)生產(chǎn)工藝試制了阻燃桉樹(shù)膠合板,并對(duì)其Ⅱ類(lèi)膠合強(qiáng)度和燃燒性能進(jìn)行了檢測(cè)。結(jié)果表明:不同厚度尾葉桉單板的載藥量隨浸泡時(shí)間的延長(zhǎng)呈現(xiàn)相似的增長(zhǎng)規(guī)律;試驗(yàn)所得常規(guī)尾葉桉膠合板最優(yōu)生產(chǎn)工藝為施膠量210 g.m-2、熱壓溫度130℃、熱壓時(shí)間8 min,該條件下膠合板的Ⅱ類(lèi)膠合強(qiáng)度達(dá)到了2.01 MPa;單板浸泡8h后,單板平均載藥量為32.05 kg.m-3,所制得阻燃膠合板氧指數(shù)提高了13.9%,炭化長(zhǎng)度減少了8.3 mm(26.2%),阻燃性能明顯提高,而膠合強(qiáng)度也達(dá)到了Ⅱ類(lèi)膠合板的國(guó)家標(biāo)準(zhǔn)。研究初步證明利用常規(guī)桉樹(shù)膠合板生產(chǎn)工藝生產(chǎn)阻燃桉樹(shù)膠合板是可行的。

熱門(mén)知識(shí)

樹(shù)膠怎么形成的

精華知識(shí)

樹(shù)膠怎么形成的

最新知識(shí)

樹(shù)膠怎么形成的
點(diǎn)擊加載更多>>

相關(guān)問(wèn)答

樹(shù)膠怎么形成的
點(diǎn)擊加載更多>>
專(zhuān)題概述
樹(shù)膠怎么形成的相關(guān)專(zhuān)題

分類(lèi)檢索：

综合国产| 扒开末成年粉嫩的小缝图片| 麻豆人人操人人干97| AV女性爱网| 亚洲Av日韩AV永久无码一| 狠狠色狠狠色综合网| 色月激情| 你懂的在线视频一区二区三区 | 免费牲交视频| 国产91色综合久久久久| 欧美乱人伦人妻中文字幕| 你懂的亚洲| 国产偷国产偷亚洲清高| 九色少妇丨porny丨蝌蚪| 成人av一区二区在线播放| 五月综合丁香久久婷婷| 七月婷婷丁香| 91精品91久久久中77777| 久久久精品国产99久久精品麻追| 中字幕一区二区三区乱码| 91黄色网免费观看| 亚洲精品无码福利电影| 欧美亚洲系列| 欧美国产日本| 亚洲精品成a人在线观看| 男人天堂五月天| A级全黄试看30分钟小视频| 日韩一级欧美| 公的大龟慢慢挺进我的体内视频 | 极品新婚夜少妇真紧| 伊人视屏| 国产精品无码一区| 亚洲伊人伊成久久人综合网| h片在线看| AV无码免费播放,久久| 九色在线播放| 亚洲久热| 伊人精品无码一区二区三区电影| 丁香五月激情亚洲| 欧美日韩国产亚洲乱码字幕| 最新日韩av|