Effect of60Co gamma radiation on the rice weevil,Sitophilus oryzae (L.)

The effect of gramma radiation on the rice weevil,Sitophilus oryzae (L.) was studied. Adults were subjected to 12 doses ranging from 0 to 180 Gy of gamma radiation from a⁶⁰Co source. The time to onset of death and the duration of the period of mortality were investigated. Survival of the adults was decreased with increase of the doses. LD₅₀ and LD_99,9 values were calculated.With one figure and one table     

地方特色植物在昆明的适应性调查研究

通过世博园中国园区在设计及建设中地方特色植物的应用分析，得出了地方特色植物在造园时均受到重视的结论，并实际调查造园植物的生长状况，初步掌握各省区地方特色植物在昆明的适应性。经植物区系分析，探讨地方特色植物的异地利用问题，为昆明园林建设中观赏植物的应用提供借鉴和参考。     

Evaluation of Air Pollution Burden from Contribution of Motorcycle Emission in Bangkok

This study investigated the relationship between exhaust emission from motorcycles and ambient air quality in Bangkok Metropolitan Region (BMR). The test result revealed that averagepollutant concentrations of the test motorcycles in terms of hydrocarbon, carbon monoxide and nitrogen dioxide were 8.38, 16.69 and 0.04 g km^-1, respectively. The finding also indicated that two-stroke motorcycles emitted 1.5 and 5 times more carbon monoxide and hydrocarbon emission, respectively perkilometer driven than do four-stroke motorcycles. Four air sampling stations were strategically established to evaluate the air pollution problems in Bangkok arising from vehicle exhaust emission. Investigation was carried out to determine the correlation between average air pollutant concentration with different traffic configuration in each traffic zone of Bangkok Metropolitan Region (BMA) during peak/non peak hours, day/night times and weekday/weekend. The average concentrationsof PM₁₀ particulate matter, carbon monoxide, nitrogen dioxide and sulphur dioxide in Bangkok street air were found tobe 84.33 μg m^-3 (24 hr ave.), 7.05 mg m^-3 (8 hr ave.), 56.74 μg m^-3 (1 hr ave.) and 9.60 μg m^-3 (24 hr ave.), respectively.     

Planting spacing affects canopy structure,biomass production and stem roundness in poplar plantations

To improve the productivity and wood quality of poplar plantations, effects of four planting spacing on canopy characteristics, biomass production and stem roundness in poplar plantations were evaluated over 8 years. Planting spacing influenced canopy characteristics of the plantations, and further affected the understory vegetation and plantation productivity. Understory vegetation biomass and Shannon-Wiener index were negatively correlated with leaf area index, but both diversity indexes and aboveground biomass of understory vegetation were higher in stands with a wider spacing. Tree diameter growth increased with increasing planting spacing, while the increment in plantations of square configurations (5?×?5 m and 6?×?6 m) was higher than those with rectangular configurations (3?×?8 m, 4.5?×?8 m). The highest poplar biomass production was achieved in the plantation with 5?×?5 m spacing at age 8. Moreover, poplar trees showed a tendency with better stem roundness in a square configuration. The results suggest that planting spacing not only affect canopy characteristics, understory vegetation and tree growth but also wood quality, and square configurations (5?×?5 m and 6?×?6 m) could be a better option for poplar plywood timber production at similar sites.     

控制光照下土庄绣线菊的生理生态响应和适应

本研究以一年生灌木土庄绣线菊(Spiraea pubescens Turcz.)幼苗为研究对象,人工设置相对透光率100%、50%、25%和12.5%四种控制光照水平,测量幼苗存活率以及在生理生态特征上的响应和适应性,从而加深我们对灌木幼苗的生理需求和生态特征的认识。结果表明,土庄绣线菊幼苗的存活率未受控制光照处理影响。遮阴处理导致最大净光合速率和蒸腾速率显著降低,叶绿素a和b含量显著升高,但气孔导度和类胡萝卜素含量未变化。同时,在25%和12.5%相对透光率水平下,土庄绣线菊幼苗的苗高和比叶面积显著高于100%相对透光率下幼苗,而根、茎和总生物量积累在12.5%下受到严重抑制。遮阴处理使得土庄绣线菊幼苗表现出地上生物量分配增大地下减少的一般趋势。以上结果说明土庄绣线菊幼苗对遮阴环境具有一定的生理生态响应和适应性。     

Synthesis and characterization of boron doped alumina stabilized zirconia fibers

Boron doped PVA/Zr-Al acetate nanofibers were prepared by electrospinning using PVA as a precursor. The effect of calcination temperature on morphology and crystal structure was investigated at 250, 500, and 800 °C. The study also establishes the effect of boron doping on the morphology of PVA/Zr-Al acetate nanofibers at various calcination temperatures. The measurements showed that the conductivity, pH, viscosity and the surface tension of the hybrid polymer solutions have increased with boron doping. In addition, the fibers were characterized by FTIR, DSC, XPS, XRD and SEM techniques. The addition of boron did not only increase the thermal stability of the fibers, but also increased the average fiber diameters, which gave stronger fibers. The DSC results indicated that the melting temperature (Tm) of the fibers was increased from 256 to 270 °C with the addition of boron. XRD peak patterns showed that after further heat treatment at 800 °C, zirconia exists in two phases of tetragonal and monoclinic modifications. Moreover, alumina does not transform into the γ-Al₂O₃ and θ-Al₂O₃ phase at 800 °C. The SEM appearance of the fibers showed that the addition of boron resulted in the formation of crosslinked bright surfaced fibers.     

Preparation and dielectric properties of polyvinyl alcohol (Co,Zn Acetate) Fiber/n-Si and polyvinyl alcohol (Ni,Zn Acetate)/n-Si Schottky diodes

Dielectric properties and ac electrical conductivity (σ _ac ) of Au/PVA(Co, Zn acetate)/n-Si and Au/PVA(Ni, Zn acetate)/n-Si Schottky diodes (SDs) have been investigated in dark and under illumination by using experimental capacitance-voltage (C-V) and conductance-voltage (G/ω-V) measurements at 1 MHz and room temperature. Experimental results indicate that the change in dielectric constant (ɛ′), dielectric loss (ɛ″), loss tangent (tanδ), the real (M′) and imaginary (M″) parts of electric modulus and ac electrical conductivity (σ _ac ) with illumination were found to change linearly with illumination level (P). On the other hand, the ɛ′, ɛ″, tanδ and σ _ac vs P have positive slope while the M′ and M″ vs P have negative slope. Such behavior of dielectric properties and σ _ac can be attributed to illumination induced electron-hole pairs under illumination effect in the depletion region of SDs. The obtained results under illumination suggest that these devices can be used as a sensor in optical applications.     

青贮疯草及其颗粒饲料对绵羊的增重效果及安全性评价

疯草为豆科多年生草本植物,具有营养价值高的特点,是一种可利用的潜在牧草资源。为了开发疯草作为牧草资源利用的可能性,探讨了含10%疯草青贮饲料和10%疯草颗粒饲料对绵羊的增重效果及安全性。试验选择90只临床健康绵羊,随机分为3组,每组30只。对照组饲喂常规饲料,青贮组饲喂含10%青贮疯草饲料,颗粒组饲喂含10%疯草颗粒饲料;试验期间每天观察受试绵羊的临床表现,定期进行空腹称重,并采集血液做生化指标检测。结果表明,试验期间,各试验组绵羊均未出现明显的疯草中毒症状;青贮疯草组绵羊体重与对照组比较增加24.66%,平均日增重高出对照组78.26%;10%疯草颗粒组与对照组比较无显著差异。青贮疯草组血清ALB、ALP水平降低,AST水平升高。10%疯草颗粒组AST、ALP、CRE、BUN水平升高。10%青贮疯草及其颗粒饲料对绵羊有一定的增重效果,且比较安全,可作为饲料资源开发利用。     

Insecticide resistance inFrankliniella occidentalis: Corroboration of laboratory assays with field data and cross-resistance in a cypermethrin-resistant strain

Field efficacy of five insecticides to a greenhouse strain ofFrankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) of known resistance status was studied. In a greenhouse trial, the mortality of aF. occidentalis strain (Uncali) which exhibited resistance only against cypermethrin in laboratory assays, reached 56%, 68%, 82%, 94% and 99%, 24 h after application of abamectin, cypermethrin, endosulfan, malathion and methomyl, respectively. In the laboratory, for larval mortality equal to that achieved in the field, much lower doses — half of the field dose of cypermethrin and endosulfan, and one-third and one-sixth of malathion and methomyl, respectively, were required in topical application. Because of differences between laboratory and field responses ofF. occidentalis to insecticides, a sound resistance evaluation program to determine field efficacy of insecticides is needed. Resistance increased 28.0- and 139.3-fold at LC₅₀ in theF. occidentalis strain subjected to 27 and 44 cycles of cypermethrin selection, respectively. A slight cross-resistance of two- to threefold was found with endosulfan, malathion and methomyl and no cross-resistance was observed with abamectin. http://www.phytoparasitica.org posting August 4, 2008.     

北京2008奥运绿化新举措对周边地区的影响

随着北京市成功申办2008年奥运会落下惟幕,北京市的生态建设与绿化新举措将全面实施。通过全面分析北京城市绿化树种应用的现状和存在问题及其绿化新举措对周边地区的影响,就北京未来城市绿化树种的发展趋势及周边地区应采取的对策进行了分析。认为发展乡土树种,加强选种、育种工作,积极开展特色植物引种驯化,是北京城市绿化工作的重点,周边地区也应抓紧此契机,积极调整苗木产业结构,制定新的发展战略,以发展自己和支持北京绿化。