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991.
Hai-Xia?Yu Chong-Rong?Fang Man-Ping?Xu Fei-Yan?Guo Wen-Ji?YuEmail author 《Journal of Wood Science》2015,61(2):159-164
The silk industry in China produces a large amount of mulberry branches as by-product every year. Mulberry branches have high longitudinal toughness and good overall mechanical properties. However, these branches are incinerated because their utility in other industries is limited by their small size. This study determines the feasibility of manufacturing scrimber from mulberry branches by using cold pressing method, followed by thermo-curing with different densities and resin contents. Results show that density [ranging from (0.81–1.24) g/cm3] exerts a greater effect on the shear strength, modulus of rupture (MOR), and modulus of elasticity (MOE) than resin content (changing from 8 to 20 %). The increase rate slows down when the density exceeds 1.1 g/cm3 and the resin content reaches more than 12 %. The strength-to-weight ratio analysis shows that the MOR/density and MOE/density maximum at 1.02–1.10 g/cm3. The density and resin contents of mulberry scrimber with cold compress and heat setting can be set to 1.0–1.1 g/cm3 and at approximately 12 %, respectively. The mechanical properties of the product meet the maximum requirement indicated in the Chinese national standard for construction. Mulberry scrimber can be a very promising supplement for wood because of its good performance, abundant supply, and renewability. 相似文献
992.
Guifeng, Yiyang County, belongs to a seriously degraded red soil region. In 1991, Pinus elliottii and Lespedaza spp. were the species selected for the establishment of a mixed forest in the area. The results of an investigation of the
soil system in a 12-year-old forest indicated the following: (1) Organic matter and total nitrogen of the forest soil to a
depth of 40 cm were 88.0 and 36.0% higher, respectively, than those of a control plot; total phosphorus and available phosphorus
were 40.9 and 22.3% higher than those of the control; available potassium contents were 8.13% lower than those of the control.
(2) Soil aeration and the soil air regime improved. (3) Proteinase, catalase, and urease in the forest soil to a depth of
40 cm were usually higher than those in the control plot and decreased with soil depth.
Translated from Acta Agriculturae Universitatis Jiangxiensis, 2005, 27(1) (in Chinese) 相似文献
994.
“2003中国木制品进出口贸易洽谈会”于10月28—30日在上海召开,我参与了此次会议的策划、组织、推广工作,主要负责会议的国际招商。“2003中国木制品进出口贸易洽谈会”是在“2002年全国木材进出口贸易会”基础上策划组织的,旨在促进中国木制品出口和原材料的进口交流和贸易。 2003会议的策划与2002会议最大的不同在于:更加注重国际国内公司直接的面对面的贸易交流洽谈,而且在会议期间加入产品展示区域。这样,吸引国际 相似文献
995.
Yuan Li Li Xiaomin Yu Hongxian Guo Libin Zhang Taizhong Gao Qingjun Zeng Daihua 《林业研究》1997,8(4):235-239
There are five species of swan in the world. Three of them were recorded in China. They are whooper swan (Cygnus cygnus), whistling swan (Cygnus columbianus) and mute swan (Cygnus olor). Among them. whooper swan is the most famous in China. Whooper swan is a resident bird in China. They breed in Xinjiang
Ugyur Autonomous Region. Inner Mongol Autonomous Region. Heilongjiang Province. etc., and winter in Qinghai. Shandong. Henan
Province, etc, and the lower reaches of the Changjiang River. The total number in China is about 5.000 in breeding grounds
and 15.000 in wintering grounds. Higher number were found in 1960s. Because of the changes in environment and hunting, of
picking up eggs and of catching nestlings, their population is being reduced rapidly. They are in danger now. In order to
protect the whooper swans, some protection measures must be taken, such as strengthening public education and scientific research,
estabilshing a base of raising and breeding: developing international cooperation, strengthening the construction of natural
reserves in the breeding and wintering grounds. Up to the end of 1993. 34 natural reserves have been established in China.
(Responsible Editor: Sun Yueqi) 相似文献
996.
在海涂含盐土壤中,角竹造林后成园快,笋单产高于哺鸡竹;角竹笋期5月14日~6月10日,哺鸡竹为4月29日~5月10日,盛笋期在出笋中前期,延续约10~12d;竹笋单株重量哺鸡竹明显大于角竹,笋株粗重期在出笋初期和中前期,比盛笋期约早3d,延续时间同盛笋期。因此,宜扩大角竹造林面积,延长供笋期,多产市场淡季笋,以获得更佳的效益。 相似文献
997.
998.
本文应用数理统计方法对邢台县浆水镇9村265户样本资料进行了系统分析。指出农户家庭经营是我国农村普遍存在的基本经营形式。这一新生事物完全适应现阶段农村生产力发展水平,其收入已成为农民收入的主要来源。近年来,农民收入虽有大幅度提高,但水平仍然很低,农户间收入差距也在不断扩大,山区农村经济仍在一个低水平上运行。本文还对影响农民收入水平的相关因素和农户收支结构进行了分析,并有针对性地提出改善家庭经营管理的建议。最后,对加强农户家庭经营方面的研究与领导也提出具体意见。 相似文献
999.
1000.