共查询到20条相似文献，搜索用时 15 毫秒
1.
Cytoplasmicpolyhedrosisvirus(CPV)ofEendrolimussuperans(DsCPV)isone.oftheimportantpatholo-gensofthelarvaeOfDendFOHffiussuPerans.InoFdertoutiIizeDsCPVincontrol,themorphoIogy,toxicity,infeCtionanddestroyingprocedureinthemidgutofinsectofDsCPVwereStudied.ThecontrolofDen-dIOhffiussuPeranswiththisvirusinasmaIIareainforestwascarriedout.ResearchmethodMorphologyobservationScanningeIectronmicroscopeandtransmissioneIeCtronmicroscopewereusedtoobservethemor-phoIogy.ToxicityteStingThesameamo… 相似文献
2.
CHANG Delong SONG Zhanqian HU Weihua HUANG WenhaoLI Fuhai ZHANG Yunling. Paulownia Research Center of China Zhengzhou P.R.China. Research Institute of Chemical Processing Utilization of Forest Productsof Chinese Academy of Forestry Nanjing P.R.China 《中国林业科技(英文版)》2006,5(1):1-7
INTRODUCTIONPaulownia is one of important species with fastgrowth and high yield oriented to industry uses inChina, paulownia wood is widely used in furniture-making, decorating materials, musical instrumentsmanufacture (Jiang Jianping 1990), etc. Brown orblack stain often appears on the surface of paulowniawood during processing and using. Discolorationseriously affects paulownia utilization, and it cancause huge loss due to low grade and price causedby stain (Cheng Junqing 1983a, 1983b… 相似文献
3.
CHAI Yubo LIU Huanrong LIU Junliang Research Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China 《中国林业科技(英文版)》2007,6(1):19-24
Adding low molecular weight resins into wood can overcome wood intrinsic defects, which is a new approach for the high efficient utilization of plantation. This paper reviews the researches on low molecular weight resins modifying wood, including different impregnating resins, impregnation technologies, properties of treated wood and mechanism of modifying wood. In the end, some suggestions and prospects are put forward. 相似文献
4.
PENG Limin WANG Haiqing HE Weili Research Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China 《中国林业科技(英文版)》2006,5(1):40-44
INTRODUCTIONGlulam (namely glued laminated lumber) is a kind ofproducts that are assembled by sawn lumbers or smallsquares laminated in grain directions and glued in thedirection of thickness, width and length with adhesives.Not only does glulam possess the same property asnatural wood does, but also can avoid some defects,such as warping, distortion, split, etc. As one kind ofthree main engineered wood products as laminatedveneer lumber (LVL) and I-beam, glulam is widely usedin construc… 相似文献
5.
《中国林业科技(英文版)》2008,(4):19-22
This work was undertaken to research organic wood-flour putty as wooden surface undercoat. Four types of wood-flour (300, 500, 800 and 1 000 mesh) were prepared through the technological processes of shattering, coarse grinding and fine grinding. And latex (16% of solid content) and two kinds of agents (A and B) were added into the putty. In this experiment, effects of agent and particle size of wood-flour on properties of organic wood-flour putty, such as painting properties, water resistance, and abrasive... 相似文献
6.
YU NmglouWorld Bank Loan Project Management Center. State Forestry Administration. Beijing . China 《中国林业科技(英文版)》2002,(3)
Basedon the results of monitoring the environment of China National Afforestation Project (NAP) and the investigation on insect pests and diseases in 1.2 million ha of plantations, the author elaborates the areas, species and causes of insect pests and diseases occurring in the project's areas and provides fundamental theory for guiding environmental protection and plantation establishment in a sound way. Since the project's activities strictly follovved the guideline of environmental protection in past five years, little losses were caused by some commonly insect pests and diseases. 相似文献
7.
LI Xiazhen XIE Lisheng REN Haiqing XU Ming . Research Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China . School of Industry Central South University of Forestry Technology Changsha P.R.China 《中国林业科技(英文版)》2007,6(4):31-37
The general steam-injection pressing is mainly used for produce particleboards and medium density fiberboard. However, it is difficult to produce soft fiberboard with desired strength. However, the closing steam-injection pressing that based on the steam-injection pressing could. The wooden frame sealing up the slab could prevent the steam from emitting when the steam injected into the slab. The caloric released by steam condensation make the slab reach high temperature level for a short period. This method is very appropriate for making thick panels in theory, especially for the soft fiberboard. It makes a great leap forward on the hot pressing process that for wood-based panels. Moreover, it will be a meaningful technological breakthrough in developing new products and improving wood utilization. 相似文献
8.
DAI Yucheng LIU Chunjing XU Cunbao Institute of Applied Ecology. Chinese Academy of Science. Shenyang . China Forestry Institute of Tiding. Liaoning Province Tieling Fenline Nature Reserve. Heiloneiiang Academy of Forestry. Yichun 《中国林业科技(英文版)》2003,(2)
Poroid species of wood-inhabiting fungi growing on spruce (Picea koraiensis Nakai or Picea yezoensis (Sieb. & Zucc.) Carriere) in Northeast China were investigated during 1993-2002, and 71 species were recorded from these trees or their wood. Skeletocutis lilacina A. David & Jean Keller and Skeletocutis papyracea A. David are new to China. Fomitopsis pinicola (Sw.:Fr.) P. Karst., Onnia leporina (Fr.) H. Jahn, Perenniporia subacida (Peck) Donk, Phaeolus sckweinitzii (Fr.:Fr.) Pat., Phellinidium sulphurascens (Pilat) Y.C. Dai and Phellinus yamanoi (Imazeki) Parmasto are the pathogens on the two trees. Among the 71 species 18 species (ca. 25% of all species) are considered as rare species, 34 species (48% of all species) are the occasional species, and 19 species (27% of all species) are the common species. 相似文献
9.
GAO Ruiqing TENG Tonglian LI XiaolingResearch Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China 《中国林业科技(英文版)》2005,4(3):45-52
INTRODUCTIONBeing one of tropical species, rubberwood (Heveabrasilie) has been planted on large scale in Hainan,Yunnan, Guangdong and Guangxi since the 1950s inorder to crop the latex for rubber-making. Theeconomical life-span of rubberwood tree is 25 to 30years. In order to improve the yield of the latex, therubberwood trees must be refreshed in a period oftime. From the 1980s, rubberwood trees have beencut in fixed quantity and refreshed every year. It isestimated that the output of r… 相似文献
10.
Review on Agroforestry Systems in China 总被引：3，自引：0，他引：3
ZHANG Jianfeng SUN Qixiang Research Institute of Forestry Chinese Academy of Forestry 《中国林业科技(英文版)》2005,4(3):80-84
INTRODUCTIONChina is the most populated country in the world. Thepopulation of the mainland amounts to 1.3 billion in2004. The land area is approximately 9.6 million km2,of which the proportion of arable land is low. Thiscovers about 10% of the total land area; on the average,there is around 0.09 ha of tilled land per capita.Furthermore, the arable land is unevenly distributed inthe country. Forests cover 13.92% of the whole landarea, 134 million ha or 0.095 ha per capita (Xu Xingquanet … 相似文献
11.
WANG Chunfeng LI NuyunAfforestation Department of State Forestry Administration 《中国林业科技(英文版)》2003,(4)
The author reviews the developing process of afforestation over the past 50 years in China, based on historical records. The general situation on the key afforestation projects and organizing ways, relevant policies as well as techniques are stated in this article. The author also discusses further on the problems facing with Chinese afforestation. 相似文献
12.
XU Deying YAN HongResearch Institute of Forest Ecology. Environment Protection. CAF. Beijing . China Research Institute of Forestry. CAF. Beijing . China 《中国林业科技(英文版)》2002,(4)
A special interpolation program GREEN has been developed to determine the climatic parameters for the distribution region of Chinese pine (Pinus tabulaeformis Carr.) based on the researches on the distribution of the tree species. The central region, which is the most suitable distribution region, and potential distribution region of the species under current climatic conditions were mapped using a Geographic Information System IDRISI. According to the averaged predictions by 5 GCMs for 2030, a projection was made for the future distribution of the pine. The results show that the potential distribution area of Chinese pine will have a small northward shift, though not significantly. The east part of the northern boundary will move northwards by 1.4 degree, while the southern boundary will move northwards about 0.2 degree in latitude. The east and west edges will both move towards the distribution center. The potential distribution region will shrink by 9.4% compared with the current area. The species wi 相似文献
13.
Studies of the impact of traditional agroforestry practices on soil nutrient status in the Amazon Basin have largely been
limited to upland sites, many of which are oligotrophic. However, rural population density in Amazonia is highest on the floodplains
of the major rivers and shifting cultivation has been practiced on the floodplains for millennia. We established a slash-and-burn
cultivation plot and an untreated forest plot in tidal floodplain successional forest in the Islands of Abaetetuba, Pará,
Brazil, and sampled soils (0–10 cm) during four phases of the agroforest cycle (n = 9 in each plot for each sampling period):
(1) prior to clearing, (2) following burning, (3) harvest one (rice at four months), and (4) harvest two (sugar cane at 15
months). During the course of this pilot experiment, background temporal variability in SOC, total N and available mineral
nutrient pools (P, K, Ca, Mg) exceeded treatment effects, suggesting that soil nutrient pools in this environment are well-buffered
against the effects of shifting cultivation. These results contrast markedly with those reported for Amazonian upland sites
where nutrient pulses and declines associated with the agroforest cycle have been demonstrated and may restrict the potential
for low-input, continuous cultivation. Physical limitations imposed by flooding and fluvial erosion, rather than nutrient
constraints, restrict the potential of agricultural intensification in the tidal floodplains.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
14.
ZHAO Yong YAN Zhen LIU Yurong WANG Shu .Research Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China .Materials Science Technology College Beijng Forestry University Beijng P.R.China 《中国林业科技(英文版)》2006,5(4):23-26
INTRODUCTION Bark accounts for 10% of a log and there are about 2.5 billion m3 of logs consumed every year all over the world, which produce 250 million m3 of bark. It will bring a huge amount of money if we make good use of the bark as a raw material of industry. Since middle- and small- diameter classes wood of poor quality and remnant products account for an important part of forest resource, we should advance comprehensive utilization energetically and orient it to whole-tree utilizati… 相似文献
15.
SHU Lifu TIAN XiaoruiResearch Institute of Forest Ecology Environment Protection. Chinese Academy of Forestry. Beijing China 《中国林业科技(英文版)》2002,(3)
China is not rich in natural forest sources. Owing to natural and historical factors, forest fires have long been frequenting China. Forest fire prevention is the most important of all. Forest fire prevention and controlling have long been held as a very important factor in our ecological plans. Taking china 's special geographical location, topography, climate and the distribution of forest sources into consideration, we have every reason to believe that forest fires in China have their own special environment and occurrence. China suffers forest fire hazards heavily. Forest fires arise occasionally from thunderstruck or self-burning of peat. However, most fires are due to man's fault while inappropriately using fires in production and daily life. Since China is located in the Northern Hemisphere with a vast territory, there is a striking difference in the climate between South China and North China. 相似文献
16.
SHEN Wenxing ZHOU Dingguo XUXinping College ofEconomic Management Nanjing Forestry University Nanjing P.R.China 《中国林业科技(英文版)》2006,5(2):33-45
1 CONCLUSIONS — CHOICES OF POPLARINDUSTRY Through the analysis on the present situation and problems of the poplar industry in Jiangsu province, we find out that the development of the poplar industry is affected by thedeficiency of theresource cultivation, industrial structure,policies, institutionandtechnology, and also find out that the whole poplar industry should be under constant management innovation (including innovations of institution, policy, organization and technolog… 相似文献
17.
CHEN Xiaoming FENG YingResearch Institute of Resource Insects Chinese Academy of Forestry Kunming . P.R.China 《中国林业科技(英文版)》2002,(2)
As an importam bio-resource, insect resources have not been put into full play as healthy food. Based on study and analysis, the nutritive value of edible insects was reviewed. The results showed that insects have rich protein (20%-70%), amino acid (30%-60%),fat (10%-50%),fatty acid, carbonhydrate (2%-10%), mineral elements, vitamins and other activated elements which are good for human 's health. As protein resources, the nutritive value of edible insects is as good as animal and plant resources. Insects have feature of rich species and large population, therefore as nutritive resources, edible insects can befully used and have great development potentiality. 相似文献
18.
JIANG Zehui LV Wenhua** FEI Benhua REN Haiqing WU Yuzhang ChineseAcademyof Forestry Beijing P. R. China 《中国林业科技(英文版)》2006,5(2):1-6
Wood color is an important factor to determine wood impression. It is also the most vivid and active factor in furniture and interior decoration design. It is an important index to evaluate wood commercial value, and strongly influences wood sale competition power. Wood discoloration is the change of normal wood color. Plywood, veneer, furniture and decorative wood products have some limits on wood discoloration, and export products have also strict limit on it. Discoloring of biomass wood is… 相似文献
19.
INTRODUCTIONSome scientists and specialists think that agriculturalresidues are the second forest resource in China.Straw boards use the agricultural residues, such aswheat straw, rice straw and so on, as main rawmaterial, which are one-year-growth plants and veryrich in China. Producing straw boards can increasewood resource and decrease consumption of wood(Zhou Dingguo, et al, 2000).Wetting is a term to describe what happens when aliquid meets with a solid surface. The surface contact… 相似文献
20.
MI Feng LI Jiyue LV Nan. College of the Resources Environment Beijing Forest University Beijing P.R.China . College of Environment Peking University Beijing P.R.China 《中国林业科技(英文版)》2005,4(3):70-79
Forests possess many kinds of ecological functions,which, if expressed in monetary value, would be moreimpressive and definite to make the public as well asthe government recognize its comprehensive effectsand values, and to enhance their consciousness of forestresources protection. However, to date there is nostandard system about how to evaluate forest ecologicalbenefits. Therefore, it is exigent for us to find out howto identify its public benefits and to make scientificevaluation on variou… 相似文献