开展“草根化”校本研究，促进学校和谐发展

我校是江苏省教科研基地，多次被评为苏州市教科研先进单位。面对基础教育课程改革新的形势和要求，如何在较高层次上进行科研创新，打造品牌学校，进一步提高办学质量，充分发挥实验小学示范、辐射功能，促进教师专业发展?为此，我们申报立项了省教育科学“十五”规划重点课题“草根化校本研究”，试图以课题研究为抓手，促进学校和谐发展和教师专业发展，形成课题带动和科研联动的新局面。

“草根化”的新媒体 网络视频业正举起融合大旗

自从网络作为一种新媒体形式出现以来，网络媒体的内容由于其多元化的特点，总被人冠以“非主流”、“边缘化”的印象。尤其是当视频类网站出现后，各种参差不齐的节目内容让互联网新媒体更加“草根化”。但实际上，网络媒体作为现代传媒的真正作用并未完全发挥出来。

Optimization of Genetic Transformation System of Tobacco K326 Mediated by Agrobacterium

[Objective]The aim was to optimize genetic transformation system in tobacco K326 mediated by Agrobacterium.[Method]The leaf of tobacco aseptic seedling was taken as explants to study the optimization of Agrobacterium-mediated genetic transformation system.[Result] The highest transformation efficiency was obtained when the explants were pre-cultured in the medium of MS ＋ 2 mg/L 6-BA ＋ 0.2 mg/L IAA for 2 d,and then infected with Agrobacterium GV3101（OD600 =0.6） for 5 min.The PCR detection proved that npt II gene had been integrated into the regenerated tobacco plants.[Conclusion]A highly efficient genetic transformation system of tobacco leaf mediated by Agrobacterium was established.

Solving the Sod Shock Tube Problem Using Localized Differential Quadrature (LDQ) Method

The localized differential quadrature (LDQ) method is a numerical technique with high accuracy for solving most kinds of nonlinear problems in engineering and can overcome the difficulties of other methods (such as difference method) to numerically evaluate the derivatives of the functions.Its high efficiency and accuracy attract many engineers to apply the method to solve most of the numerical problems in engineering.However,difficulties can still be found in some particular problems.In the following study,the LDQ was applied to solve the Sod shock tube problem.This problem is a very particular kind of problem,which challenges many common numerical methods.Three different examples were given for testing the robustness and accuracy of the LDQ.In the first example,in which common initial conditions and solving methods were given,the numerical oscillations could be found dramatically;in the second example,the initial conditions were adjusted appropriately and the numerical oscillations were less dramatic than that in the first example;in the third example,the momentum equation of the Sod shock tube problem was corrected by adding artificial viscosity,causing the numerical oscillations to nearly disappear in the process of calculation.The numerical results presented demonstrate the detailed difficulties encountered in the calculations,which need to be improved in future work.However,in summary,the localized differential quadrature is shown to be a trustworthy method for solving most of the nonlinear problems in engineering.

Phytoremediation of PAH-Contaminated Sediments by Potamogeton Crispus L. with Four Plant Densities

In order to investigate the effect of plant density ofPotamogeton crispus L. on the remediation of sedi- ments contaminated by polycyclic aromatic hydrocarbons, a 54-day experiment with four plant densities （642, 1 604, 2 567 and 3 530 plants/m^2） was conducted. The results showed higher plant density with slower plant growth rate. Surface area per plant was the most sensitive root parameter to plant density. At the end of the 54-day experi- ment, planting P. crispus enhanced the dissipation ratios of phenanthrene and pyrene in sediments by 6.5%-26,2% and 0.95%-13.6%, respectively. The dissipation increment increased with increasing plant density. Plant uptake accounted for only a small portion of the dissipation increments. Furthermore, P. crispus could evidently improve sediment redox potentials, and strong positive correlations between root surface area and the redox potential as well as between the redox potentials and the dissipation ratios of phenanthrene and pyrene were obtained, indicating that the oxygen released by the roots ofP. crispus might be the main mechanism by which P. crispus enhanced the dis- sipation of PAHs in sediments.

Liposoluble chemical constituents from the fibrous root of Ophiopogonjaponicas

We investigated the chemical constituents of the fibrous root of Ophiopogon japonicus and their cytotoxicities against Hela and Hep2 cells.Ten compounds were purified by various chromatographic techniques.Their structures were identified as 2 - hydroxylophiopogonone A（1）,5,8-dimethoxy-6-methyl-7-hydroxy-3-（2 -hydroxy-4 -methoxybenzyl） chroman-4-one（2）,5,7- dihydroxy-6,8-dimethyl-3-（4 -hydroxybenzyl） chroman-4-one（3）,7,4 -dihydroxy-5-methoxyflavanone（4）,N-trans-coumaroyltyramine （5）,N-trans-coumaroyloctopamine（6）, N-trans-feruloyltyramine （7）, 4-hydroxycinnamic acid （8）, caffeic acid （9）, and ferulic acid （10） on the basis of spectroscopic analyses. Compounds 4, 6, 7, 9, 10 were obtained from this genus for the first time. The cytotoxic activities of 1, 2, 4, 5, 6, 7, 9 and 10 against Hela and Hep2 cells are described.

Vetiver Grass and Micropollutant Leaching Through Structured Soil Columns Under Outdoor Conditions

In Burkina Faso, significant amounts of endosulfan are applied to cotton fields; in addition, urban vegetable agriculture is often characterised by high fertiliser inputs, such as urban solid wastes containing heavy metals(e.g., Cu and Cd). Thus, the relevance of surrounding cotton and urban vegetable plots with vetiver(Vetiveria zizanioides) hedges to reduce environmental pollution by micropollutants was investigated using a leaching experiment, with outdoor lysimeters filled with two representative agricultural soils of Burkina Faso: Vertisol and Lixisol. After 6 months, little Cu was found in the leachates(< 0.010% of the applied amount) due to its high adsorption coefficient and its tendency to remain at the soil surface. Despite leachate and bromide recoveries being greater in soils planted with vetiver grass than in the bare soils, smaller amounts of endosulfan and Cd were found in the effluents from the planted soils(0.01% to 0.70% of the applied amount) than in those from the bare soils(0.01% to 1.48% of the applied amount), in agreement with their adsorption coefficients. These results may also be explained by a greater degradation of endosulfan in planted soils compared to bare soils and the absorption of Cd by vetiver. Thus, vetiver may decrease the risk of groundwater contamination,especially for Cd and endosulfan, which are more mobile than Cu. In addition, despite the smaller amounts of endosulfan and Cd measured in the Vertisol leachates(0.01% and 0.04% of the applied amount, respectively) compared to the Lixisol leachates, vetiver was more effective in decreasing the leaching of micropollutants if planted on Lixisol rather than on Vertisol. Further field monitoring is necessary to demonstrate the effectiveness of vetiver under the climatic conditions of Burkina Faso.