2002 Vol. 19, No. 4
Comparative molecular fields analysis (CoMFA)was applied to the studies of the correlation of the pyrethroid and their acute toxicity-DL50 (rat , P .O .).The comparison of CoMFA results with different lattice spacing and different atom probes was investigated .The relation square of prediction is 0.99 , and the standard error of prediction is 0.08 .CoMFA resulted in a quantitative description of the major steric and electrostatic field effects and gave significant new insights to factors governing toxicity .The model was used to predict the acute toxicity of new compounds with satisfactory results.
Influence of different physical and chemical factors on the growth of phosphate-solubilizing bacteria (PSB) were investigated .The results showed that ①PSB was able to thrive and grow very well when its volume in a 100 mL flask was 20 mL , which was considered as optimal .②The bacteria grew well in slightly alkaline conditions and the optimal pH was 8.5 ～ 9.0 .③The temperature for the largest number of cell after two days'incubation was 30 ℃. ④Glucose was the best source of carbon ;the most suitable Nitrogen and Carbon concentrations were 8 gL-1 and 0.21 gL-1 respectively .⑤Mg2 + , Mn2 + , and Ca2 + could improve the quantity of the initial growth of this bacteria .But Fe2 + and Al3 + especially Fe2 + inhibit the bacteria's initial growth .
The bacteria carried pine wood nematode was observed using improved stained methods through optical microscope for the first time .It was found that bacteria exist on the surface and in environment of nematode .The amount of bacteria carryed by nematode was counted with bacterial nutrient troth agar medium .About 170 ～ 280 bacterial cells were found on each nematode .This result further confirmed that pine wood nematode and its carrying bacteria cause the pine wilt .
The insect diversity was analyzed by means of data obtained in insect investigation from 1998 to 2000 . Lepidoptera , Hymenoptera , Coleoptera , Diptera were dominant orders from Mount Tianmu , China .The diversity of species and genera indicated that insect population had a stable structure .Abundance index varied from 2.42 to 32.69 , but diversity index changed in a narrow range .There were abundance rare and endemic insect species in Mount Tianmu
Based on one-year field research , main wetland vegetation types in Zhjiang Province were basically made clear .In this paper , main wetland vegetation types and their classification system in Zhejiang Province were fully reported for first time .Wetland types in Zhejiang Province were classified by such eleven vegetation types as deciduous coniferous forest , evergreen coniferous forest , mangrove and semi-mangrove , bamboo forest , deciduous broad-leave forest , evergreen broad-leave forest , deciduous broad-leave shrub , halophilous shrub , top grass , low grass and water area vegetation , and by 129 formations such as Form.Metasequoia glyptostroboides , Form. Kandelia canedel Form .Bambusa pachinensis , Form .Pterocarya stenoptera , Form .Tamarix chinensis , Form. Phragmires australis , Form.Cynodon dactylon , Form.Salvinia natans and so on .In addition , vegetation types and their distribution characteristics in such 5 wetlands as marine and coastal wetlands , rivers , fresh lakes , reservoirs , highland swamp in Zhejiang Province were discussed .
The effect of different intensity of artificial disturbance (ck , the original forest ;class A , the regeneration of selection cutting ;class B , the natural regeneration ;class C , Chinese fir ;class D , Phyllostachys heterocycla cv .pubescens) on the restoration of different layers of Castanopsis eyrei forest in Mount Longxi , Fujian , was discussed with diversity indices of species (DI), evenness degree (ED)and dominant degree (DD).The results show that with the increasing of intensity of disturbance , DI and ED of all species go up to class A then go down , excluded that ED of shrubs layer present S-like descant and DI and ED of herb layer in S patterns come down to class C then ascend .Excepting that Dd of herb layer rise to class A then descend and DD of vive layer go up to class C then go down , DD of other layers shows linear increase .
Study on the litter decomposition and phosphorus release in an oak (Quercus variabilis ) forest ecosystem was made by means of decomposition date obtained from litter bag in Jiangsu Province The mathematical models of litter weight residual rate with decomposition duraton were set up , and also the half declining and 95 % declining times were estimated .The main results showed that the order for annual decomposition rate of litter weight was fine roots medium-diameter roots fallen leaves withered branches thick roots , while the order for annual release rate of phosphorus was fine roots medium-diameter roots withered branches fallen leaves thick roots . Results also showed that temperature , moisture content and microorganism were the main factors to influence litter decomposition .
In order to study the effects of nitrogen application on leaf output and flavone concentration in leaves of ginkgo seedlings , two-year-old ginkgo seedlings were transplanted and grew in pot culture at five levels of nitrogen(N)supply :0 , 1.5 , 3.0 , 4.5 and 6.0 gseedling-1 .The results of the trial were showed as follows :① Different levels of nitrogen supply had remarkable effects on the leaf output and its component items .With increasing levels of N supply from 0 to 3.0 gseedling-1 there were greater leaf output , single-leaf area , leaf area per seedling and single-leaf weight , while with increasing levels of N from 3.0 to 6.0 gseedling-1 all of the items decreased, which indicated that seedlings were injured by excessive nitrogen supplies .②Different levels of nitrogen application marked effects both on flavone content in leaf and flavone yield in per seedling of ginkgo .Among five treatment of nitrogen application , the treatment 1.5 gseedling-1 had greatest flavone content in leaf and flavone yield in per seedling .③1.5 gseedling-1 should be recommended as the proper amount of nitrogen application for two-year-old leaf-producing plantation of ginkgo , by which greater flavone yield in per unit area could be expected .
The longitudinal vibration model for wooden heterogeneous material was built in his paper , which was wood for analyzing the effects of free water gradient on longitudinal vibration frequency in its longitudinal direction . The results form experiments showed that this extents were ordered as fundamental , 2nd , and 3rd vibration modes . In addition , the measurement value of elasticity modulus after log storing 6 to 7 months was increased as 10 % as that of fresh log , which reason was from free water gradient .
Sargentodoxa cuneata is a traditional Chinese medicine .In order to find out the primary effective components, the flavnoids in different organs were extracted and analyzed by HPLC and polycrylamide membrane chromatography .The results showed that there were 10 , 10 , 8 and 5 kinds of flavonoids in the leafblade , twig , leafstalk and stem , respectively .The HPLC analysis of the hydrolyzed flavnoids extracted from the leafblades of Sargentodoxa cuneata suggested that there were 8 kinds of flavonoids in leaflades of Sargentodoxa cuneata .The relatively more components in the leafblades and twig suggested that there was wide application of Sargentodoxa cuneata .
By adopting distillation of Pleioblastus amarus leaves and GS-MS analysis .The volatile composition of preioblastus amcrus leaves was extracted , separated and identified in which 53 chromatographic humps were gained.Forty-two kinds of composition which make up 94.69 % of the total mass volatile composition were identified .3-hexen-1-ol is the composition with the highest content of 27.08 %;2-hexenal with the second highest content of 10.02 %.There are 9 alcohol compounds in 42 kinds of composition , and 7 acid compounds and 7 aldehydes compounds , among the identified composition , whose contents respectively make up 38.87 % and 15.46 %and 14.49 % of total volatile composition respectively .For the first time , Z (4H )-benzofuranone , 5 , 6 , 7a-tetr with the content of 0.38 % is identified from the pleioblastus amarus .
The contents of endogenous polyamines (putrescine , spermidine and spermine) on flower buds of Ginkgo biloba were analyzed during the differentiation .The results showed that the concentration of putrescine and spermidine increased markedly and had a peak at the physiological differentiation stage of female and male flower buds and spermine concentration showed a slight increase .The three kinds of polyamines were very low when the morphological differentiation began .At morphological diffdfentiation stage , putrescine and spermidine concentrations on female flower buds increased again .The changes of putrescine concentration on maleflower buds was similar to that on female flower buds .Spermidine content of male flower buds showed a peak before early July and then kept at a low level at the mirosporocytes differetiation stage .Spermine concentrations on female and male flower buds was low and showed no significant change during the stage .The date indicate that there is some intermal connection beween polyamines and flower buds differentiation .
More than 10-year studies of Torreya grandis in Zhaojia Town of Zhuji City , Zhejiang Province , suggests that cell activatar containing nitrifying wound phenol has effect to prevent preharvest fruit drop .Wanguobao and Atonik , growth regulators , useful matters for preventing fruit drop , were selected .The application could be made in the mid-last ten days of April (blooming period)and the second-last ten days of May (fruit drop period) by spraying tree crowns with 2 500-fold solution of Wanguobao or 3 000-fold solution of Atonik , resulting in more than 312 % and 120 % of fruit setting respectively .
In order to study the difference of enviornmental factors in winter under evergreen and deciduous street trees , the authors determined the illumination , air temperatur and relative humidity under four species of steet trees , Platanus acerifolia , Sapindus mukorossi , Cinnamomum camphora and Magnolia grandiflora , with digital luminometer and ventilation psychrometer , and studied their relationship in the Wulin Square of Hangzhou City . The results showed that ratio changing under two different environment shapes bell , the curve of temperature math shapes `M' , and the curve of relative humidity math shapes single peak .Therefore , deciduous treesare better choice as street trees in cold winter area .
The health functions of eco-tourism resort relate to many environmental factors , and to establish a good health environment is one of important tasks in the construction of eco-health parks .After expounding the function of each health factors of eco-tourism resort , the paper uses Jinkeng Forestry Park in Zengcheng City , Guangdong Province as an example to illustrate the place selecting of eco-tourism resort and its tree spices changing.
According to investigation , Qingshan Lake wetland ecological systems , which include river , reservoir ,swamp and forest living in water with main tree Taxodium ascendens , have such characteristics as synthetical functionality , species diversity , landscape particularity and ecological vulnerability .There are unreasonabale plan of resource protection and tourism in the exploitation of Qinshan Lake wetland landscape at present .The construction of ecotourism projects such as water-living birds attracted areas , water-living forest areas , wetland plant gardens and so on may effectively protect and exploit diversity and peculiarity of wetland landscape , so as to ensure the sustainable develoopment of wetland ecological systems .
Five types of interior landscape including bonsai displaying , building-attached-planter design , interior landscape , indoor garden , and roof garden were classified in this paper according to the scope of work to perform, the scale and complexity of design , and the distribution of viewpoint .The characteristics and requirements of different types were also discussed .
Chinese classical gardens fully elaborate the expressiveness of lines of Chinese drawings in their overall arrangement , setting up rockeries , plastic water and the modelling of buildings .Their structure , space , level , rhythm and decorating style are expressed by means of the change between heaviness and lightness , hardness and softness, turning and revolving , and the permutation and combination of the drawing lines .Therefore , the meaningful lines play a very important role in the formation of artistic conception beauty .
Three models to predict price of forest land were set up .Model 1 was relatively simple , in which price of forest land was decided only by its demand and supply .On the basis of model 1 , model 2 concerned price of the related goods , in which price of forest land was decided not only by its demand and supply but also by price of the related goods .model 3 was based on model 2 , in which expected price of forest land was concerned in addition to all of the factors mentioned in model 2 .By the means of partial and general equilibrium analysis , the article intends to solve the problem of how to predict price of forest-land in the process of forest-land capitalized management .
Based on the second order moment of the accurate light intensity at the transverse plane , the Transmissior characteristics of nonparaxial Gaussian beam have been investigated .The beam width follows a simple hyperbolic propagation law .The numerical results also show that the propagation factor M2 of nonparaxial Gaussian beam is a function of the initial Gaussian half width w0 , and M2 factor can be smaller than unity as w0 being smaller than 0.123 times of the wavelength .
Through the investigation of the phenomenon of cheating in examinations , the paper analyzes its cause and holds that to solve this problem radically .The key is to strengthen the standard of examination management , adjust the examination time , change the proportion of the result of examinations , adopt varied ways of examination and reform the method to weigh up the mark of students .The paper also points out that the causes to the phenomenon are very complex , but the reform in course examination methods is an efficient way to solve the problem of cheating in colleges and universities.
From 1988 to 1992 , selective breeding of superior plants of Myrica rubra was done in seven main producing homes of Zhejiang , such as Cixi , Yuyao , Huangyan etc .31 superior plants were breeded by grafting , which were selected among eight varieties , and their collective region was set up .Then the relative concentrative resource pool of main varieties of Myrica rubra was constructed in forestry center of Quxian County .It had been not only transformed into producing material , was also provided advantageous to hybridize and to improve variety .Biji bayberry showed the finest bearing properties among all clones , which bearing time and output were in the first place , but Dongkui bayberry fruited later , its output was low , and other varieties were in the middle of them in this aspect .The first fruiting weights of Biji and Dongkui bayberry were lower than their mother trees , but the difference of Dongkui bayberry was insignificant , and its fruit was still big and the properties could be bequeathed , and nutritional shortness could be reason of small fruits temporarily .The environmental factors , such as light , hotness and humidity etc ., could result in advancing of maturation period of all clones by 5 ～ 8 d.
In order to improve of culturing in Agrocybe cylindracea , its nutritive characteristics were studied .The result showed that brown sugar was the best carbon sources , and peptone was the best nitrogen source , and the best suitable temperature of it was 25 ℃.The pH value for it was wide , but the best suitable pH value was 5.5 ～ 7.5 .
The climate condition is ascendant and the resource of cash forestis abundant , especially the development of typic commerce forest is very rapid recently in Zheijang Province .But the phenomena of water and soil losses come forth in different degree because of man-made and nature reasons , which has affected the healthy development of commercial forest .Citrus forest , Castanea mollissima forest and bamboo forest being as emphasis , the application of water and soil conservation technology in Zhejiang Province was reviewed to find a synthetical technology for commercial forest which can contain ecological benefit of economic benefit in deed and make typic commerce forest develop healthily along continuable way in Zhejiang Province .
The authors conclude and analyses the environmental value views , theories of evaluation , specific methods , achievements on forest environmental value evaluation ;The main views of forest environmental values are labor value view , unility value view , dual value view and natural value view , and the relevant theories of forest environmental value are labor value theory , unility theory , efficacy theory and energy theory .Some achievements on forest environmental value evaluation has been achieved .At last the authors point out the problems in the field of forest environmental value evaluation study .