关于“大树”进城的几点思考

"大树"进城可发挥较大的生态效益和观赏效果。但超过一定限度,容易引发生态环境不平衡等弊病。分析了"大树"进城带来的积极作用和不利影响,提出了"大树"进城的应对建议及措施。

Optimization of Preparative Separation and Purification of Total Flavonoids from Radix Puerariae by Macroporous Resin Method

Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separation and purification process was evaluated by measuring the concentration of total flavonoid in the fractions with UV spectrophotometer. Results The SP70 macroporous resin was the most effective compared with other macroporous resins. The optimum conditions were screened, which were 0.5 g· mL^- 1 corresponding to crude drug for concentration of extract, pH 5 - 6, and appended 60 times the volume of the resin bed （BV） with the adsorption speed 2 BV·h^-1, and the volume of aq. 70% （V/V） ethanol as eluant was 5 BV with desorption speed 2 BV·h^-1. By this method, the final contents of total flavonoids exceeded 80%. Conclusion The SP70 macroporous resin is the most effective one for large-scale isolation and purification of flavonoids from Radix Pueraria, which meets industrial needs.

Walnut Tree Grafting Experiments in Different Areas in Yunnan Province

Yunnan has an area of 2.88 million hm2 walnut trees. Due to freezing in- jury and rapid growth, however, there are a lot of iron walnuts or inferior-quality walnuts ready for grafting. In five years, we conducted experiments in Kunming （Yunnan Academy of Forestry）, Gongshan County, Gucheng City, Luliang County, and Ludian County by cleft grafting, veneer grafting, bark grafting and whip grafting. The grafting approaches should be selected according to grafting requirements, characteristics, and survival rate. For example, with a low survival rate, cleft grafting can be abandoned, and the rest approaches might be chosen as per practical demands.

Optimization for Purification and Characterization of Recombinant Hirudin Ⅲ from E. coli

Aim To optimize purification conditions of recombinant hirudin 3 in thefermentation broth and characterize the product. Methods Reambinant hirudin 3 was isolated andpurified from the fermentation broth by three column chromatography steps with macroporous resin,DEAE cellulose DES2 and preparative RP-HPLC, respectively, and the optimal conditions were obtained.Purity of the product was determined by SDS-PAGE and analytical RP-HPLC. The molecular weight wasdetermined by mass spec-trometry. The structure of the product was analyzed by peptide map.ResultsThe product with purity of 95.4786% was obtained after three purification steps in the optimumconditions with a total yield of 39%. The molecular weight of the product was 6 913.32 ± 6.55 Da,coincident to the theoretical molecular weight of r-hirudin 3. The structure of the product wascoincident to r-hirudin 3 either. Conclusion The optimized purification steps can be successfullyemployed for purification of r-hirudin 3 from E. coli using batch-type approaches. The productobtained with high purity was confirmed to be r-hirudin 3.

Absorption capacity of major urban afforestation species in north-eastern China to heavy metal pollutants in the atmosphere

Totally 24 arbor tree species and 6 shrub species were measured on their absorption capacities to heavy metal Pb, Cd, Cr, and Hg by collecting and analyzing the leaves of trees along different streets in Harbin city in Sept. to Oct. of 2003. The results showed that all the measured species had certain absorbency to the pollutants (Pb, Cd, Cr and Hg), but there existed significant difference in absorption capacity for different species to different pollutants. The measured tree species were classified into three categories by their absorption quantum of heavy metal pollutants. Among the species measured,Betula platyphylla, Ulmus pumila var.pendula, andPrunus persicaf.rubro-plena had high capacity in absorbing Pb;Populus xiahei, P. nigra var.Italica, P. alba x P. berolinensis andSalix matsudana had had high capacity in absorbing Cd;Phellodendron amurense, Syringa oblata, Salix matsudana, Pinus tabulaeformis var.mukdensis, Picea koraiensis, Prunus persica f.rubro-plena, P. triloba andAcer negundo, etc. had high capacity in absorption of Cr;Prunus triloba, Quercus mongolica, Salix matsudana, Sambucus williamsii, Pyrus ussuuriensis andSpiraea fritschiana were good at absorption of Hg. This study might offer scientific foundation for selection of urban afforestation species in different polluted conditions caused by heavy metals. Keywords Greening tree species - Heavy metal - Pollutants - Plumbum - Cadmium - Chromium - Mercury - Absorptivity CLC number S731.2 - X501 Document code A Foundation item: This study is financially supported by the Special Programme for Agriculture under Ministry of Chinese Science and Technology (No. 2002BA516A15-01).Biography: MU Li-qiang (1966-), female, Associate professor in Northeast Forestry University, Harbin 150040, P. R. China.Responsible editor: Zhu Hong

Research Progress in Effect of Bagging,Reflective Film and Greenhouse Film on Fruit Size of Peach

Referring to a large number of literatures, the effects of bagging, reflective film and greenhouse film on fruit size of peach were reviewed in this paper so as to provide basis for conducting relevant researches and producing larger fruits. The effects of different types of bags on fruit size of peach were analyzed. The weight variation of single fruit after bagged was investigated, and the relevant reasons were analyzed. In addition, the complexity of effect of greenhouse film on fruit size was also discussed. It is proposed that further comprehensive study on effect of bagging on fruit size should be carried out.

A Comparison of Macrofauna Communities in Different Mangrove Assemblages

The characteristics of macrofauna communities in three mangrove assemblages [Avicennia marina＋Acgiceras corniculatum （MC）community, A.corniculatum （C） community and Bruguiera gymnorrhiza＋A.corniculatum （GC） community] were studied in Zhanjiang Mangrove Nature Reserves during 2005 and 2006. Of the three mangrove assemblages, the macrofauna species number, density, biomass, Richness index and Shannon-Wiener index were the highest, and the Simpson dominance index was medial at MC community. However the Pielou Evenness index of MC community was slightly lower than that at C community. At C community, the number of macrofauna species obviously reduced, especially infaunal, caving and adhering life forms, and the biomass and density were the lowest. Because of the even distribution of individuals of different species, the Simpson dominance index was the lowest and the evenness index was the highest. Although the Richness index at C community was slightly lower than that at MC community, the Shannon-Wiener index was near to that at MC community. At GC community, the number of macrofauna species, especially infaunal and caving life forms, continued to decrease comparing C community, but the biomass and density increased slightly. As the distribution of individuals of different species was uneven, the Simpson dominance index was the highest and the Pielou Evenness index was the lowest. Furthermore, the Richness index dropped to the lowest. The Shannon-Wiener index also dropped accordingly to the lowest. The dominant life forms of MC were infaunal and caving, while those of C and GC community were both caving. The ratio of the GS/GSB of macrofauna communities in the three mangrove assemblages were 0.48, 0.63 and 0.80, respectively. The community structures at the same mangrove assemblages were all quite similar, with those at GC community being most similar. However, there were obvious differences among the community structures at the three different mangrove assemblages. These results implied that the different mangrove assemblages had different affects on the macrofauna communities and shed light on the macrofauna adaptation capability to specific habitats.

国际关系中的选择压力:计算与应用

选择—遗传—变异是社会演化的核心机制,遗传侧重于人类社会在时间中的延续,变异侧重于人类社会在空间中的展开,而选择压力是把遗传和变异统一起来的关键作用力。在国际关系中,强国施加选择压力,弱国承受选择压力,力量损失梯度越大,强国对弱国的选择压力越小;强弱双方的关系越敌对、实力对比越悬殊,强国对弱国的选择压力越大。当存在多个联系紧密的国家时,强国偏好使用“软柿子”策略来延缓选择压力的衰减,而弱国偏好使用“大树”策略来降低自己所承受的选择压力。选择压力也可以用于结盟问题的研究,以中俄是否应该通过结盟来应对美国威胁为例,使用军费评估实力时,从2019年开始,中俄达到了结盟临界点。

Effects of Climatic Factors on Tree-ring Maximum Latewood Density of Picea schrenkiana in Xinjiang, China

Based on two tree-ring maximum latewood density （MXD） chronologies of Picea schrenkiana from the Manas River Basin, Xinjiang, the response characteristics of MXD to climate variation was discussed. Correlation analysis between MXD chronologies and instrumental records from Shihezi meteorological station showed that each chronology was significantly and positively correlated with the maximum monthly average temperature in July-August, and especially, the regional chronology （RC） was the most highly correlated variable （r=0.54, P〈0.001）. Afterwards, the maximum average temperature in July-August was reconstructed using RC. Comparison among reconstructed temperature, observed values, and the drought index （Is） confirmed that precipitation would affect MXD when the absolute value of Is is greater than 1.5σ （｜Is｜ 〉 2.5 during 1953-2008） or near to 1.5a over a 2-3 year period. The response characteristics are related to the semiarid climate of the study area. In dry years, lack of precipitation would limit the thickening of latewood cell walls and, as a result, impact MXD. Therefore, compared with relatively humid regions, the response of tree-ring MXD to air temperature similarly would be influenced by extreme moisture conditions in semiarid areas, and MXD, as a temperature proxy, should be used prudently on a limited scale.

Review on Effects of Application of Exogenous Growth Regulating Substance on Fruits Weight of Peach

The effects of exogenous growth regulating substance on the fruit weight of peach were reviewed. Paclobutrazol could increase the single fruit weight in dif- ferent degree, and cytokinins could also increase the single fruit weight. GA3 and B9 had no effect on fruit size or on reducing single fruit weight. Chlorflurenol-methy, ABT and salicylic acid had no effect on fruit size. Suggestions on the future re- search were put forward.

Mineral Elements in Different Varieties of Camellia sinensis

To understand the mineral elements in different varieties of tea （ Camellia sinensis）, 17 mineral elements in eight tea varieties including Yunnan Dayezhong, No. 43 Longjing and No. 6 Zaobaijian, were measured. The results showed that nine elements, such as P, K, Ba, Mn, Cu, were significantly different among varieties, others did not. Black tea varieties usually contain high contents of Cu and K. As a conclusion, mineral elements should be extensively considered in breeding tea varieties.

Separation and Purification of Macranthoidin B and Dipsacoside B from Flos Lonicerae by HP-20 and HP-SS Macroporous Resin

[Objective] This study was conducted to develop a method for rapidly separating macranthoidin B and dipsacoside B from Flos Lonicerae. [Method] HP-20 and HP-SS macroporous resin were applied to separate and purify macranthoidin B and dipsacoside B from Flos Lonicerae. The extract of Flos Lonicerae was first loaded onto an HP-20 column to enrich saponins, which were then separated by an HP-SS macroporous resin column to get pure macranthoidin B and dipsacoside B.[Result] The optimal HP-20 purification conditions included： a concentration of sample liquid at 4.8 mg/ml, a sample volume of 2 BV, an adsorption flow rate at 1.5BV/h, an ethanol concentration for desorption at 60%, a desorption volume of 3 BV,and a desorption flow rate at 1.5 BV/h. Total saponins were then separated by an HP-SS macroporous resin column which was eluted sequentially by water, 20%ethanol, 30% ethanol, 40% ethanol and 50% ethanol. Two purified compounds were obtained in fractions eluted by 40% ethanol and 50% ethanol, respectively. The two compounds were identified as macranthoidin B and dipsacoside B by13 C and1H nuclear magnetic resonance spectroscopy. [Conclusion] The combination of HP-20 and HP-SS macroporous resin could efficiently separate macranthoidin B and dipsacoside B from Flos Lonicerae.

Response of seedlings of different tree species to elevated CO_2 in Changbai Mountain

Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998-1999). Two concentrations of CO2 were designed: elevated CO2 (700 祄olmol-1) and ambient CO2 (400 祄olmol-1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%-40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO2 varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO2 than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO2.

Application of Maximum Probability Approach to the Fault Diagnosis of a Servo System

In an actual control system, it is often difficult to find out where the faults are if only based on the outside fault phenomena, acquired frequently from a fault system. So the fault diagnosis by outside fault phenomena is considered. Based on the theory of fuzzy recognition and fault diagnosis, this method only depends on experience and statistical data to set up fuzzy query relationship between the outside phenomena (fault characters) and the fault sources (fault patterns). From this relationship the most probable fault sources can be obtained, to attain the goal of quick diagnosis. Based on the above approach, the standard fuzzy relationship matrix is stored in the computer as a system database. And experiment data are given to show the fault diagnosis results. The important parameters can be on line sampled and analyzed, and when faults occur, faults can be found, the alarm is given and the controller output is regulated.

Macroporous Resin Adsorption for Purification of Flavonoids in Houttuynia cordata Thunb

Flavonoids are one main kind of effective components in Houttuynia cordata Thunb., which display a wide range of pharmacological activity. In this study supercritical fluid extraction （SFE） with carbon dioxide was first used as preparat ion step to remove the volatile components, which are also active components, from Hout-tuynia cordata Thunb. Then ultrasound-assisted extraction was used to obtain the crude flavonoids and the macro-porous resin adsorption technology was further employed to purify the flavonoids. Nine kinds of macroporous resins with different properties were tested through static adsorption, and one macroporous resin labeled as D101 was selected. The effect of several factors, such as the ratio of column height to diameter, initial concentration and pH, on both flavonoids yield and content were explored by dynamic adsorption to obtain reasonable conditions of adsorption and desorption. The experimental results show that the content of fiavonoids can be above 60% with fia- vonoids recovery of 93.3 % under the optimum conditions of purification. HPLC analysis of the final flavonoids product shows it contains quercitrin, hypefin, rutin and quercetin.

Calcitriol analog ZK191784 ameliorates acute and chronic dextran sodium sulfate-induced colitis by modulation of intestinal dendritic cell numbers and phenotype

AIM: To investigate the effects of ZK1916784, a low calcemic analog of calcitriol on intestinal inflammation. METHODS: Acute and chronic colitis was induced by dextran sodium sulfate (DSS) according to standard procedures. Mice were treated intraperitoneally with ZK1916784 or placebo and colonic inflammation was evaluated. Cytokine production by mesenterial lymph node (MLN) cells was measured by ELISA. Immunohistochemistry was performed to detect intestinal dendritic cells (DCs) within the colonic tissue, and the effect of the calcitriol analog on DCs was investigated. RESULTS: Treatment with ZK191784 resulted in significant amelioration of disease with a reduced histological score in acute and chronic intestinal inflammation. In animals with acute DSS colitis, down- regulation of colonic inflammation was associated with a dramatic reduction in the secretion of the proinflammatory cytokine interferon (IFN)-γ and a significant increase in intereleukin (IL)-10 by MLN cells. Similarly, in chronic colitis, IL-10 expression in colonic tissue increased 1.4-fold when mice were treated with ZK191784, whereas expression of the Th1-specific transcription factor T-beta decreased by 81.6%. Lower numbers of infiltrating activated CD11c+ DCs were found in the colon in ZK191784-treated mice with acute DSScolitis, and secretion of proinflammatory cytokines by primary mucosal DCs was inhibited in the presence of the calcitriol analog. CONCLUSION: The calcitriol analog ZK191784 demonstrated significant anti-inflammatory properties in experimental colitis that were at least partially mediated by the immunosuppressive effects of the derivate on mucosal DCs.

Comparison between Decolorization Effects of Activated Carbon and Macroporous Resin on Periplaneta americana L. Skimmed Cream

[Objective] The aim of this study was to investigate the decolorization ef- fects of activated carbon and macroporous resin on Periplaneta americana L. skimmed cream and compare the advantages and disadvantages of the two decolorization technologies. [Method] Periplaneta americana L. skimmed cream was decolored with activated carbon and macroporous resin, and freeze-dried to collect solid decolorization products. By investigating the yield, decolorization rate, protein retention rate and decolorization operation process, the advantages and disadvantages of the two decolorization technologies were compared. [Result] Both activated carbon and macroporous resin can be used for decolorization. To be specific, macroporous resin-decolorization is superior in the yield and protein retention rate, while activated carbon-decolorization is superior in decolorization rate and decolorization operation process. [Conclusion] Macroporous resin-decolorization can be used if protein is the main ingredient required in the experiment, while activated carbon-decolorization can be used if protein is not the main ingredient required.

Optimization of Preparative Separation and Purification of Total Polyphenols from Sargassum tenerrimum by Column Chromatography

Polyphenols from the ethanol extracts of Sargassum tenerrimum （ST） with potent antiallergic effects were studied to optimize separation process through column chromatography. The adsorption and desorption characteristics of three widely used adsorbents： macroporous resin, silica gel, and polyvinylpolypyrrolidone （PVPP）, were critically evaluated respectively and studied for the optimization of preparative separation of polyphenols. Static operations on these adsorbents showed that macroporous resin had the best adsorption and desorption capability among the three adsorbents. Dynamic adsorption and desorption with macroporous resin packed column were also conducted to optimize the parameters such as： with the optimal values shown in brackets, the concen- tration of extract solution （4 times diluted）, pH value （6-7）, adsorption speed （3BVh-1, bed volumes/per hour）, concentration of ethanol （80%）, elution speed （3 BV ht） and elution volume （7 BV）. The chromatographic process so optimized gave a purity of 62.43% from the crude polyphenols, providing a promising basis for large scale preparation of bioactive polyphenols upon further scaling up tests.

STUDIES ON THE SORPTION OF MACROPOROUS PHOSPHONIC ACID RESIN FOR LANTHANUM

The influences of medium pH sorption temperature, sorption time, etc. on thesorption capacity of macroporous Phosphonic acid resin for La3+ were determined Thesorption rate constant was k298 = 7.64×10-5 s-1. The complex ratio of phosphonicgroups of the resin to La3+ was 3:1. The basic sorption parameters were determinedThe sorption mechanism of macroporous phosphonic acid resin for La3+ was examinedby chemical analysis and IR- spectrometry.