浙江典型海塘实时安全监测分析

海塘是浙江沿海及海岛抵御台风暴潮的第一道防线。针对海塘跨域大、台风期恶劣气候影响严重以及海塘外部影响对内部响应变化速度快的特点,提出了大范围、分布式、集中管理的远程实时动态海塘安全监测技术,并对钱塘江海宁盐仓段标准塘和浙东海塘舟山万丈塘进行实时监测。监测结果表明海塘内部渗压水位与潮位有较好的相关性,潮位涨落对海塘渗流影响由海塘外侧至内侧逐渐减弱;海塘内部水力坡降均小于允许坡降,海塘渗透稳定满足要求。在潮涌作用下,海塘将产生mm级水平变形,随着潮位涨落,海塘内部水平位移呈周期性变化;水平位移沿深度分布呈现上部大、下部小的特点。研究成果为海塘的日常维护和应急抢险提供技术支撑。     

SMP+CPTU孔压静力触探试验简述

静力触探试验是土体原位测试的一种,在工程勘察中应用较多。介绍了荷兰Geomil公司生产的一种SMP+CPTU孔压静力触探探头的组装、仪器的调试、探头的饱和及静力触探试验过程,并根据现场试验总结了在静力触探试验贯入过程中的注意事项。     

吹填土真空预压工程中孔压计改进埋设方法的研究

介绍了吹填土真空预压工程中孔隙水压力计(以下简称"孔压计")的传统钻孔埋设方法和改进埋设方法—插板机埋设,对使用改进埋设方法的监测数据进行了分析,并与钻孔埋设方法的监测数据进行比较。分析表明,采用插板机埋设的孔压计中产生明显超静孔隙水压力,且深部测点超静孔隙水压力消散所需时间较钻孔埋设的长;对于浅层深度的孔压计可采用插板机埋设,节省施工成本,方便快捷,而超过15m深度的孔压计埋设则需采用常规钻孔。     

普通和高性能排水板在海堤施工中的效果对比分析

海堤一般修筑在深厚的软土地基上,施工中常打设排水板加固软土地基。针对海堤施工中普通排水板和高性能排水板的复合体及滤膜进行对比分析,同时在整个预压过程中对采用2种排水板处理的地基进行4次取样检测及十字板剪切试验,并对试验成果进行分析研究,得出了在处理的初期高性能排水板区块土体的物理指标及强度增长比普通排水板更显著;同时,随着深度的增加,高性能排水板区块土体十字板强度及地基承载力增长更明显。     

Mutagenic Effects of BM302：GO112 Induced by Low-Energy Ion Beam Implantation

Mutant strains of GO112 and BM302 with a high 2-keto-L-gulonic acid （2KLG） transformation rate induced by ion beam implantation were separately and combinatorially compared with the original strains GO29 and BM80 to study the mutagenic effects of ion beam implantation. Both the sole GOl12 and mixed BM302：GOl12 demonstrated improved SNDH activity and 2KLG yield compared to the original strains. The mutant combinations of BM302：GOl12 showed a longer stationary phase and higher biomass than BM80：GO29. The mutant BM302 exhibited a stronger capacity to maintain a stable pH environment at mixed fermentation with Gluconobacter oxydans （G. oxydans） for 2KLG transformation and facilitated the growth of G. oxydans compared with the original strain BM80. The promotive capacity to L-sorbosone dehydrogenase （L-SNDH） from the supernate of BM302 was 1.6-fold higher than that of BM80. Genes encoded SNDH in GO29 and GOl12 were amplified and sequenced, and mutations including three transitions （CG →TA, CG →TA, GC → AT） and one transversion （AT→ TA） were confirmed from GO29 to GOl12. The corresponding amino acid was changed as Leu →Phe, Arg → Gln and Asn → Lys.     

Bioeffects of Low Energy Ion Beam Implantation： DNA Damage, Mutation and Gene Transter

Low-energy ion beam implantation （10 - 200 keV） has been proved to have a wide range of biological effects and is broadly used in the breeding of crops and micro-organisms.To understand its mechanisms better and facilitate its applications, the developments in the bioeffects of low energy ion beam implantation in the past twenty years are summarized in this paper.     

静态强磁场(SMFs)对小麦花粉母细胞(PMCs)的遗传毒性研究

研究了静态强磁场(Static magnetic fields,SMFs)对小麦花粉母细胞的影响,以评价环境中这种非电离辐射可能的遗传毒性.将小麦种子暴露于不同磁场强度(1、3、5、7T)/5h及进行不同时间(1、3、5h)/7T的处理,取其幼穗进行常规制片.以微核、染色体桥、落后染色体、断片、非四极分裂等的频率作为DNA损伤的指标来评价SMFs的遗传毒性作用.结果表明,5T以下剂量,暴露组与对照组之间在畸变频率上无统计学意义上的差别,5T场强下染色体桥、7T场强下落后染色体、三极分离、微核的频率则有显著的提高.剂量-效应呈现出剂量依赖的非线性关系,表明5T以上静态强磁场可能对生物体具有某种遗传损伤效应.     

Purification and Properties of a New L-Sorbose Dehydrogenase Accelerative Protein from Bacillus megaterium Bred by Ion-Beam Implantation

Bacillus megaterium BM302 bred by ion-beam implantation produces L-sorbose dehydrogenase accelerative protein （SAP） to accelerate the activity of L-sorbose dehydrogenase （SDH） of Gluconobacter oxydans in the 2-keto-L-gulonic acid （2KLG） fermentation from L-sorbose by the mixed culture of B. megaterium BM302 and G. oxydans. The SAP purified by three chromatographic steps gave 35-fold purification with a yield of 13% and a specific activity of 5.21 units/mg protein. The molecular weight of the purified SAP was about 58 kDa. The SDH accelerative activity of SAP at pH 7 and 50℃ was the highest. Additionally, it retained 60% activity at a pH range of 6.5 ～ 10 and was stable at 20℃ ～ 60℃. After 0.32-unit SAP was added to the single cultured G. oxydans strains, the SDH activity was apparently accelerated and the 2KLG yield of GO29, GO112, GO and GI13 was enhanced 2.1, 3.3, 3.5 and 2.9 folds respectively over that of the strains without the addition of SAP.