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971.
972.
《Soil Science and Plant Nutrition》2013,59(5):575-584
Abstract The phylogenetic positions of bacterial communities in manganese (Mn) nodules from subsoils of two Japanese rice fields were estimated using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis followed by sequencing of 16S rDNA. The DGGE band patterns and sequencing analysis of characteristic DGGE bands revealed that the bacterial communities in Mn nodules were markedly different from those in the plow layer and subsoils. Three out of four common bands found in Mn nodules from two sites corresponded to Deltaproteobacteria and were characterized as sulfate-reducing and iron-reducing bacteria. The other DGGE bands of Mn nodules corresponded to sulfate and iron reducers (Deltaproteobacteria), methane-oxidizing bacteria (Gamma and Alphaproteobacteria), nitrite-oxidizing bacteria (Nitrospirae) and Actinobacteria. In addition, some DGGE bands of Mn nodules showed no clear affiliation to any known bacteria. The present study indicates that members involved in the reduction of Mn nodules dominate the bacterial communities in Mn nodules in rice field subsoils. 相似文献
973.
974.
孔祥伟 《农业机械化与电气化》2008,(1):35-36,39
在农网或城网民用低压供电系统中,三相间不平衡电流普遍存在。调整三相不平衡电流装置的研究,解决了三相四线制低压系统中有功电流不平衡的技术难题,并得到实际应用和验证。 相似文献
975.
The effects of waves with a uniform current on marine aquaculture gravity-type cages were analyzed using a numerical model previously validated by physical model tests. The present analysis employs a numerical algorithm to study the dynamic behaviors of the net-cage system when impinged upon by surface waves from various angles over a uniform current. The maximum tension of the mooring lines and the minimum volume reduction coefficients of the rearing system were analyzed. We found that the current-induced effects on the net-cage system were more important than those due to waves only. We conclude that farming sites should not be situated in areas where the current speed exceeds 1 m/s, unless technological devices are available to overcome serious net-cage volume deformation. Furthermore, we recommend that, whenever possible, the combined effects of various oblique waves and currents be carefully examined before a system is installed. Finally, the ideal range of water depth for net-cage implementation in the open sea is between 30 and 50 m. 相似文献
976.
烟草作为一具有种特殊的农作物,要达到质量效益的最大化,需要应用现代的作物生产管理方法.粗糙集理论对不完备决策表的处理优势,可以解决在生产过程中无法获得完备信息的问题.在限制容差关系模型下,以扩充分明矩阵为基础,提出了不完备决策表属性约简算法,实现了对不完备决策表的直接处理.通过属性约简获取决策规则,可以有效地指导生产管理. 相似文献
977.
柳建闽 《福建农业大学学报(哲学社会科学版)》2008,(6):65-68
以国有股为代表的上市公司非流通股的解禁与减持,对我国证券市场的持续、稳定发展有着重要的影响。本文从分析上市公司非流通股的解禁与减持对当前我国证券市场走势的影响入手,在阐述上市公司非流通股疯狂持减原因的基础上,提出应遵循公平原则来进行机制重塑,以规范上市公司非流通股减持。 相似文献
978.
The simplified method, in which second-order elasticity analysis having undergone stiffness reduction is employed to research into sway frames' second order effect, has begun to be accepted by Chinese Standard. In the proper ascertainment of the value of stiffness reduction factor considering non-elastic characteristic, it is advisable to properly choose the checking computation method of the stiffness reduction on the basis of a comprehensive analysis of RC frame. Combined with a contrastive analysis of the present schemes in USA and New Zealand, a scheme to ascertain the RC frames component's stiffness reduction is proposed for the revision of the Chinese Standard. 相似文献
979.
The slag samples that have some titanium oxide reduction grade are reduced with blast furnace slag taken from Pan Zhi Hua Iron & Steel (Group) Co. in site. Then the viscosity and free running temperature of slag samples were measured in laboratory. With the increasing of reduction grade the viscosity and free running temperature of slags would have rising tendency. The mineral structure of the samples is observed in optical microscope, and quantitative analysis of TiC, TiN in the slag samples is made with image analysiser. The results show that the thickening of titanium slag has relationship with the amount of TiC, TiN, which was reduced from titania. So the usage of titanium oxide reduction grade as the index of thickening in blast furnace process is reasonable, and which could represent characteristic of the blast furnace smelting iron ore bearing titanium and vanadium. 相似文献
980.
自激振动深松机减阻试验研究 总被引:22,自引:6,他引:16
为了研究在土壤深松过程中深松机产生自激振动的原因及振动减阻机理,作者应用机械振动原理和信号测试技术,借助电测仪器与设备对由1SQ-127型全方位深松机所组成的自激振动式深松机系统进行了耕深、土壤阻力以及拖拉机牵引阻力等随机信号的测试及数据处理分析。系统地研究了“拖拉机-深松机-土壤”系统的动态特性,探讨深松机减阻节能的技术途径与方法。 相似文献