摘要：
Laboratory batch experiments were conducted to study arsenic （As） removal from a naturally contaminated soil using phosphoric acid （H_3PO_4） and potassium dihydrogen phosphate （KHEPO_4）. Both H_3PO_4 and KHEPO_4 proved to reduce toxicity of the soil in terms of soil As content, attaining more than 20% As removal at a concentration of 200 mmol/L. At the same time, acidification of soil and dissolution of soil components （Ca, Mg, and Si） resulted from using these two extractants, especially H_3PO_4. The effectiveness of these two extractants could be attributed to the replacement of As by phosphate ions （PO~(3-)_4）. The function of H_3PO_4 as an acid to dissolve soil components had little effects on As removal. KH_2PO_4 almost removed as much As as H_3PO_4, but it did not result in serious damage to soils, indicating that it was a more promising extractant. The results of a kinetic study showed that As removal reached equilibrium after incubation for 360 rain, but dissolution of soil components, especially Mg and Ca, was very rapid. Therefore dissolution of soil components would be inevitable if As was further removed. Elovich model best described the kinetic data of As removal among the four models used in the kinetic study.
摘要：
Maire Yew (Taxus mairei) is an important ornamental plant with anticancer properties. Since its natural resource is limited and reproduction is difficulty, both seed germination and stem cuttings were conducted under controlled environmental conditions. Different storage regime had significant effect on germination rate and seedling survival rate. Seeds stored under moisture-controlled sand had the highest germination and survival rates of 97.3 and 92%, respectively. The average seedling height was 36.6 cm and the highest plant was 48.0 cm. Seeds directly sowing in the field had germination rate of 39.7% and the survival rate of 38.8%. The average seedling height was 13.2 cm. Seeds of Maire Yew stored under the ambient conditions had detrimental effect and no germination was recorded. Media played an important role on rooting of stem cuttings. The highest rooting percentage, 78.0%, was observed from pure sand substrate and the lowest, 36.7%, was from red clay. The mixes of perlite and sand, vermiculite and sand yielded 42.7 and 59.3% of rooting. The best timing to collect stem cuttings of Maire Yew was late November, which led to the rooting percentage of 78.6%. Too early or too late will reduce the rooting percentage. Soft-wood stem cuttings around late June should be avoided. Both seed germination and stem cuttings could be applied for commercial production of Taxus mairei and further studies should focus on its germplasm resource and breeding.
作者机构：
[Zhong Qiu-ping; Xie Bi-xia; Wang Sen] Cent S Univ Forestry & Technol, Sch Resources & Environm, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Wang Sen] C;Cent S Univ Forestry & Technol, Sch Resources & Environm, Changsha 410004, Hunan, Peoples R China.
关键词：
peach gum;supernatant;rheological property
摘要：
The rheological properties in the supernatant of peach gum from Prunnus dulcis were discussed in order to provide more scientific technical parameters and references for developing peach gum as a kind of medicinal gum.The rheological properties in the supernatant of peach gum were comparatively studied in different material ratios,temperatures,shaking times,pH values and salinities.The results show that,1) the mathematical model of shear rate with material ratio and shear stress is Y=0.069X12+0.035X2 -1.174,R2=0.942;2) the mathematical model of shear rate with temperature and shear stress is Y=4.936X12+0.023 2X2-1.688,R2=0.937;3) the mathematical model of shear rate with shaking time and shear stress is Y=0.005 192 X13-0.140 73X12+1.249 045X1+ 0.036 546 X2-3.644 29,R2=0.954 3;4) the effects of pH value on the rheological properties in the supernatant of peach gum are comparatively complicated with a varying range of 3-11 and the shear rate shows a change trend of saddle model;5) the mathematical model of shear rate with the concentration of NaCl and shear stress is Y=-0.037 44X1+0.012 93 X2,R2=0.998;6) the mathematical model of shear rate with the concentration of CaCl2 and shear stress is Y=0.025 789X1+0.016 19X2,R2 =0.999;and 7) the mathematical model of shear rate with the concentration of sorbic acid potassium and shear stress is Y=0.079 5X1+0.017 3X2,R2=0.998.The results show that the material ratio,temperature,shaking time,pH value significantly affect the rheological properties in the supernatant of peach gum,and the concentrations of NaCl and CaCl2 also significantly affect the rheological properties expect the concentration of sorbic acid potassium.
摘要：
The cold hardiness of a landscape plant is an important factor in regulating its introduction and cultivation. Thankfully, unsaturated fatty acids in a plant can be used as a determinant of its cold hardiness. The quantities of fatty acids in the leaves of Ligustrum quihoui were analyzed using CHCl 3-CH3OH mixed solvent distilling, pentadecanoic acid internal standard, KOH-CH3OH-BF3 esterify, silica gel discoloration, and finally, gas chromatography. The results concluded that myristic acid was not detectable, but the quantities of palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, and eleosetearic acid could be found. The relative response factor for each of the fatty acids was 1.000, 0.8886, 0.9998, 0.8684, 0.7551 and 0.5334, respectively. The linear correlative coefficient of each of the relative response factors was 0.9998, 0.9984, 0.9993, 0.9979, 0.9968 and 0.9947. The relative standard deviations were 2.52, 3.98, 3.18, 2.71, 2.39 and 1.62%. The recovery rates were 96.97, 107.52, 88.67, 91.32, 94.22 and 92.48%. All the linear correlative coefficients of the relative response factors of various fatty acids were over 0.99. The relative standard deviations were less than 5.0%. The recovery rates ranged from 88.67 to 107.52%. This data indicates that the quantitative analysis of trace elements can be conducted using this method.
摘要：
This study explores the sprouting characteristics of an evergreen broad-leaved forest after clear-cutting based on a survey of 1,893 stumps of 62 tree species in Okinawa, Japan. The sprouting capabilities of the stumps varied among tree species. The stumps of 60 species could produce sprouts, while those of the other two species could not. In 10 of the sprouting species, the mean sprout-stem number was higher than 4.0 stems per stump; nine sprouting species showed low sprouting capabilities. Additionally, Castanopsis sieboldii and Schima wallichii, the dominant species, exhibited high sprouting capabilities. Further, the sprouting capabilities varied with stump diameter at breast height (DBH). Stumps with a larger DBH tended to have a higher mean number of sprout stems per stump, higher DBH, and higher tree height than the smaller stumps. The forest stands regenerated by sprouting might recover into a tree community similar to that before clear-cutting.
摘要：
The effects of three storage temperatures (1, 3, and 5 °C) were determined on the quality of the edible mushroom Agrocybe chaxingu stored in modified atmosphere packages (MAP) with and without (control) silicon gum film windows. Results showed that the storage temperature had clear effects on headspace gas concentrations of O2, CO2 and ethylene, sensory characteristics, respiration rate, ascorbic acid content, soluble solid content and electrolyte leakage. The higher storage temperature (5 °C) resulted in more rapid changes in the different quality parameters for the stored mushroom except in the case of storage at 1 °C where chilling injury occurred. The MAP with silicon gum film windows at 3 °C provided the best atmosphere for mushroom A. chaxingu as shown by a fact that the MAP packs with windows at 3 °C had better quality than the control.
作者机构：
[张琳; 谭晓风; 袁德义] College of Resources and Environment, Central South University of Forestry and Technology;[周建] Botanical Garden Institute,Henan Institute of Science and Technology;[何小勇] Lishui Popular Science Station of Zhejiang Province;[胡姣; 龙洪旭] Co
摘要：
The efforts to genetically improve teaoil camellia, Camellia oleifera Abel, started more than two thousand years ago when forest dwellers chose to use seeds to extract table oil and later selectively planted teaoil camellia trees. Since the 1970s, China has sponsored many national-level projects on genetics studies and selective breeding of this taxon. So far, over 200 superior cultivars, families, clones, and hybrids have been selected, and those varieties have markedly improved the productivity of teaoil by renovation of low-yielding plantations and application of superior new varieties. The analysis of present production status and the situation of genetic improvement in teaoil indicate that mutation breeding and biotechnological improve-ment should be emphasized based on conventional breeding methods. Rich germplasm resources should benefit a molecular breeding program.
作者机构：
[Caihong Chen] Faculty of Resources and Environment, Central South University of Forestry and Technology, Changsha, China;[Mitsunori Aramoto] Tropical Biosphere Research Centre, University of the Ryukyus, Okinawa, Japan;[Takakazu Shinzato] Faculty of Agriculture, University of the Ryukyus, Nishihara, Okinawa, Japan;[Lichao Wu] Faculty of Resources and Environment, Central South University of Forestry and Technology, Changsha, China<&wdkj&>Tropical Biosphere Research Centre, University of the Ryukyus, Okinawa, Japan
通讯机构：
[Lichao Wu] F;Faculty of Resources and Environment, Central South University of Forestry and Technology, Changsha, China<&wdkj&>Tropical Biosphere Research Centre, University of the Ryukyus, Okinawa, Japan
摘要：
This study explores the sprouting characteristics of an evergreen broad-leaved forest after clear-cutting based on a survey of 1,893 stumps of 62 tree species in Okinawa, Japan. The sprouting capabilities of the stumps varied among tree species. The stumps of 60 species could produce sprouts, while those of the other two species could not. In 10 of the sprouting species, the mean sprout-stem number was higher than 4.0 stems per stump; nine sprouting species showed low sprouting capabilities. Additionally, Castanopsis sieboldii and Schima wallichii, the dominant species, exhibited high sprouting capabilities. Further, the sprouting capabilities varied with stump diameter at breast height (DBH). Stumps with a larger DBH tended to have a higher mean number of sprout stems per stump, higher DBH, and higher tree height than the smaller stumps. The forest stands regenerated by sprouting might recover into a tree community similar to that before clear-cutting.
摘要：
The diurnal variations of photosynthesis on Magnolia grandiflora and M. denudata have been studied under the same natural conditions using a Li-6400 portable photosynthesis system in China to provide foundational data on the physiological ecology in Magnolia plants for its introduction, cultivation and design. Samples of 3 leaves were taken from 6 trees each to determine their diurnal characteristics. All data was analyzed using SPSS. The results showed that the curves of diurnal variations of net photosynthetic rate (Pn) on the two plants were different. The diurnal variation of Pn on M. grandiflora was a midday depression pattern and had two peaks. The first peak, which occurred in the morning, lasted longer than the second peak, which occurred in the afternoon. The stomatal conductance (Cond) and the transpiration rate (Tr) were closely related to photosynthesis, which showed an obvious midday decline while the intercellar CO(2) concentration (Ci) was slightly increased, so the mid-depress of Pn on M. grandiflora was mainly caused by non-stomatal limited elements, i.e., photo inhibition and photo respiration. The M. denudata diurnal variations on the Pn curves had a single peak that appeared in the morning with a slow decline lasting into the afternoon. The Tr was correlated to photosynthesis closely by the similar change trends they exhibited while the diurnal variations of Cond was different. The Cond also affected Ci and Tr to some degree. The vapor pressure deficit (Vpd) was attributes to PAR and air temperature. The water utilization efficiency (WUE) in M. grandiflora was higher than that of M. denudata. The analysis of stepwise multi-regression and partial correlation of Pn and other factors showed that the diurnal variation of Pn had closer relations with the elements as Cond, Tr, Vpd, the relative humidity of the air (RH) and PAR, which were the main limiting factors for M. grandiflora and M. denudata. This excludes PAR, which has no obvious relation with M, denudata.
作者机构：
[Zhang Yangli; Wu Xiaofu; Zhou Hailan; Zhao Fang; Chen Mingli; Zhao Chong] Cent S Univ Forestry & Technol, Coll Resource & Environm, Changsha 410004, Hunan, Peoples R China.;[Wu Xiaofu] Cent S Univ Forestry & Technol, Coll Resource & Environm, Shaoshan S Rd, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Wu Xiaofu] C;Cent S Univ Forestry & Technol, Coll Resource & Environm, Shaoshan S Rd, Changsha 410004, Hunan, Peoples R China.
摘要：
Experiments were conducted to investigate influence of different factors on the adsorption of Zn2+ and Cd2+ ions from aqueous solution onto vermiculite. The ratio of the initial concentration of ions, C0, to the adsorbent concentration, W0, was shown to be the key factor determining the equilibrium ion adsorption density, qe. Subject to the magnitude of C0/W0, the value of qe could either attain its maximum level, qm (the maximum adsorption density), when the solid surface was fully saturated, or approach its critical limit, qc (the C0/W0 ratio), when the ions in the bulk solution had been completely removed. The main mechanism for adsorption in the systems studied was ion-exchange. An increase in Zn2+ or Cd2+ ion adsorption from the single metal ion solution resulted in an increase in the concentrations of unadsorbed K+, Na+, Ca2+ and Mg2+ ions remaining in the bulk solution. Competition between adsorbing ions was observed in the mixed K+-Zn2+-Cd2+ ion system. Although temperature had a positive effect upon the adsorption of Zn2+ and Cd2+ ions, its effect was statistically negligible over the range 15-45°C. The negative effect of decreasing pH values on the adsorption process was only significant below a pH value of 4.0, indicating that the adsorption of Zn2+ and Cd2+ ions would be significantly depressed when high amounts of H+ ions are present in the system.
