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111.
何建明 《宁波大学学报(理工版)》2006,19(3):340-345
通过正交试验法探索管桩最佳离心工艺,找出了离心工序影响混凝土密实度的主要因素,从而优化了离心工艺参数,保证了管桩质量,提高劳动生产率,降低生产成本,同时为优化管桩离心工艺提供1种方法和经验. 相似文献
112.
首先对原应用于高应变测试分析中的CAPWAP/C算法进行改进使其适用于低应变反射波法基桩完整性分析,然后利用基于该算法所编制的程序对基桩测试中常见的疑难问题进行了理论模型分析,得到了一些有应用价值的结论,并将其用于指导工程检测实践,取得了较好的效果. 相似文献
113.
Jing Xin Meng Ying Ma Xin Xin Xu Yang Guang Li En Bo Wang~* Key Laboratory of Polyoxometalate Science of Ministry of Education Department of Chemistry Northeast Normal University Ren Min Street No. Changchun Jilin PR China 《中国化学快报》2007,18(1):81-84
A new heteropolytungstate,[H_2bpy]_3[SiMnW_(11)O_(39)].1.25H_2O(1),has been prepared under mild hydrothermal conditions and structurally characterized by single crystal X-ray diffraction.It is the first characterized compound containing 1D zigzag chain of transition metal substituted Keggin heteropolytungstate,which is connected through a common oxygen atom.The elemental analysis and IR of it are also described. 相似文献
114.
Y K Agarwal C V K Baba D R Chakrabarty V M Datar D A Gothe H C Jain A Roy M K Sharan 《Pramana》1990,35(1):49-65
An array of seven hexagonal NaI(Tl) detectors has been set up for measuringγ-ray spectra in the energy region 5 MeV ≤E
γ ≤ 40 MeV with good accuracy. This is in contrast to earlier set ups which mostly used one large sized (about 10 inchesφ × 15 inches long)NaI(Tl) detector. This set up has been made for the study ofγ decay of GDR based on high spin states and ultra-dipole radiations.
The array has been provided with the following features: a) TOF discrimination against neutrons, b) pile up detection and
elimination, c) active and passive shielding to cut down background and d) an array of trigger counters for multiplicity dependence
measurements. The well known program EGS4 has been used to determine the response of the array forγ-rays in the energy region 5–40 MeV and several test measurements have been carried out to confirm the validity of the calculated
response functions. Some typicalγ-ray spectra fromα and16O induced reactions measured at VECC, Calcutta and Pelletron accelerator at TIFR are also shown. 相似文献
115.
河北省宽城县遵(化)—小(寺沟)铁路穿越一个体积约77×104m3的古滑坡体,因在滑坡前缘以路堑方式穿过,开挖施工导致古滑坡复活。为保障未来铁路的运营安全,需要对其进行彻底治理。在现场地质调查及试验,以及分别对沿复活滑坡体新滑面和古滑面在不同工况下的稳定性计算的基础上,结合复活滑坡体的具体特征,提出2种治理方案,即"抗滑桩"方案和"削方+抗滑桩+桩间挡土墙"方案。通过综合比选确定后者为采用方案,并具体进行了削方、抗滑桩、截排水系统和坡面防护等设计。 相似文献
116.
117.
Using nonequilibrium Green?s functions in combination with the density functional theory, we investigated the electronic transport behaviors of zigzag graphene nanoribbon (ZGNR) heterojunctions with different edge hydrogenations. The results show that electronic transport properties of ZGNR heterojunctions can be modulated by hydrogenations, and prominent rectification effects can be observed. We propose that the edge dihydrogenation leads to a blocking of electronic transfer, as well as the changes of the distribution of the frontier orbital at negative/positive bias might be responsible for the rectification effects. These results may be helpful for designing practical devices based on graphene nanoribbons. 相似文献
118.
本文用第一性原理中的局域密度近似方法,计算了锯齿型单壁硅纳米管(single-walled silicon nanotubes,SWSiNTs)的能带结构、态密度、吸收谱及反射谱.计算结果表明当n=6~9时,带隙为0,该组SWSiNTs具有金属性;当n=10~21时,能带图出现带隙,该组SWSiNTs具有半导体性;当n=13~21时,该组SWSiNTs的带隙以3组手性指数为周期减小;并在吸收谱和反射谱都会在一些相似频率值附近产生峰值. 相似文献
119.
The foundation structure with piles and slab is widely used in offshore wind farm construction in shallow water. Experimental studies on the hydrodynamic loads acting on the piles and slab under irregular waves and currents are summarized with discussion on the effects of pile grouping on the wave forces and wave impact loads on the slab locating near the free surface. By applying the theoretical solution of the wave diffracted by the slab and using the Morison equation to evaluate the wave force on the piles, the effects of the slab on the wave forces acting on the piles are analyzed. Based on the Reynolds-averaged Navier-Stokes (RANS) equations and the volume of fluid (VOF) method, a numerical wave basin is developed to simulate the wave-structure interaction. The computed maximum wave force on the foundation structure with piles and slab agrees well with the measured data. The violent deformation, breaking, and run-up of the wave around the structure are presented and discussed. Further work on the turbulent flow structures and large deformation of the free surface due to interaction of the waves and foundation structures of offshore wind farms needs more efficient approaches for evaluating hydrodynamic loads under the effects of nonlinear waves and currents. 相似文献
120.