短碳纤维增强金刚石钻头铁基胎体性能的研究     

沈立娜  阮海龙  欧阳志勇  吴海霞  李春 《探矿工程》2014,41(3):77-79

设计了粉末冶金法制备短碳纤维增强金刚石钻头铁基胎体材料,通过分析不同碳纤维添加量对胎体烧结性能的影响,得出在本实验制备条件下,短碳纤维对铁基胎体材料性能的影响规律,并对该结果进行了讨论分析,在此基础上,提出了制造更加优良短碳纤维增强铁基胎体材料的可能性。  相似文献   

光纤光栅应变传感器在地质灾害上的应用     

曾克 《物探与化探》2014,(1):142-144,156

根据光纤光栅传感的原理,提出了光纤光栅式封装应变传感器,对其传感特性进行了研究,并进行了室内实验。结合光栅传感监测滑坡的应用实例,探讨了光纤布拉格光栅传感元件在滑坡体上的布设工艺及监测过程。分析初期的监测结果,针对监测系统可能出现的问题提出了解决途径。  相似文献   

物联网技术在水资源管理中的应用探索     

周美华  程铄  周先平  肖粤桧 《地下水》2014,(5):146-148

分析物联网技术的相关概念及其关键技术以及目前物联网技术在水资源管理方面的初步应用,提出＂水资源智慧网络＂的概念。＂水资源智慧网络＂由感知（节点信息采集层）、传输（信息传输层）、应用（应用平台层）3个层面的系统组成。探索实现＂水资源智慧网络＂所需要的传感技术、无线组网、应用支撑平台等技术。分析＂水资源智慧网络＂在水环境智能监测、计量、调度和管理方面的具体应用。指出物联网在＂水资源智慧网络＂构建中所面临的困难和挑战。  相似文献   

新型低弹模混凝土性能研究     

张宇亭  ;左殿军  ;陈文亮 《岩土工程技术》2014,(3):131-136

聚丙烯纤维低弹模混凝土以其优良的工作性能和力学性能成为近年来我国水利工程大坝防渗墙采用的主要材料之一.在室内试验的基础上,对聚丙烯低弹模混凝土的强度、塌落度特性进行了研究;开发了一套混凝土耐久性渗透水采集仪,对聚丙烯低弹模混凝土的渗透性和耐久性进行了研究,试验结果表明：与传统低弹模混凝土相比,聚丙烯低弹模混凝土的抗压、弹模变化不大,抗拉强度有提高,抗渗性能明显改善,渗透系数降低了一个数量级左右,耐久性年限可以进一步提高,研究结果为聚丙烯低弹模混凝土大坝防渗墙的工程应用提供了技术支撑.  相似文献   

云光学厚度对华北地区夏季边界层臭氧模拟影响评估     

姚石泉  王自发  李杰 《成都信息工程学院学报》2014,29(5)

为评估云光学厚度(CLDOPD)在空气质量数值模式中对边界层臭氧浓度的模拟影响,利用中国科学院大气物理研究所自主研发的嵌套网格空气质量预报模式系统(NAQPMS),对中国华北京津冀地区2013年6月夏季臭氧浓度进行模拟。结果表明:NAQPMS对极端对流性天气下的CLDOPD模拟偏低,结合观测数据对CLDOPD进行修正后,边界层臭氧浓度的模拟误差在一定程度上有所减小。此外,除极端性天气外模式对高CLDOPD值情况下的边界层臭氧浓度的模拟能力要优于低值情况。  相似文献   

Characterization of Stratospheric Aerosol Distributions during the Volcanically Quiescent Period of 1998–2004          下载免费PDF全文

YANG Jing-Mei  ZONG Xue-Mei  WANG Pu-Cai 《大气和海洋科学快报》2014,(4):291-296

The Stratospheric Aerosol and Gas Experiment （SAGE） II aerosol extinction profiles at 1020 nm were used to study the distribution characteristics of stratospheric aerosols during the volcanically quiescent period of 1998-2004. The stratospheric aerosol distributions exhibited hemispheric asymmetry between the Northern Hemisphere （NH） and the Southern Hemisphere （SH）. In the lower stratosphere below 20 km, the zonal averaged aerosol optical depths in the NH were higher than those of the corresponding SH; whereas at higher altitudes above 20 km, the optical depths in the SH-- except the equatorial region--were higher than those of the NH. At 0-10°N and 10-20°N, the stratospheric aerosol optical depth （SAOD） exhibited larger values in boreal winter and lower values in the spring and summer; at 0-10°S and 10-20°S, the SAOD presented small seasonal variations. At 30-40°N, the SAOD presented larger values in the boreal fall and winter and lower values in the spring and summer; while at 30-40°S, the SAOD exhibited larger values in the austral winter and early spring and lower values in the summer and fall. These characteristics can mainly be attributed to the seasonal cycle of the dynamic transport, and the effects of the buildup and breakdown of the polar vortex. At 50-60°S, the SAOD exhibited extremely high values during austral winter associated with the Antarctic polar vortex boundary; at 50-60°N, the SAOD also exhibited larger values during the boreal winter, but it was much less obvious than that of its southern counterpart.  相似文献   

影响振筒式气压传感器精度的因素及其提高精度的方法     

刘希林 《气象研究与应用》2014,(1):88-90

对影响振筒式气压传感器精度的因素进行,提出提高传感器精度应采取的措施.  相似文献   

新一代天气雷达测试仪表使用解析     

刘永亮  李强  於莹 《气象研究与应用》2014,(1):94-96

介绍新一代天气雷达功率计和示波器的基本操作方法、注意事项和衰减值的计算方法,以利于保证仪表安全和排除故障.  相似文献   

Characterization of the solar light field within the ocean mesopelagic zone based on radiative transfer simulations     

《Deep Sea Research Part I: Oceanographic Research Papers》2014

The solar light field within the ocean from the sea surface to the bottom of the mesopelagic zone was simulated with a radiative transfer model that accounts for the presence of inelastic radiative processes associated with Raman scattering by water molecules, fluorescence of colored dissolved organic matter (CDOM), and fluorescence of chlorophyll-a contained in phytoplankton. The simulation results provide a comprehensive characterization of the ambient light field and apparent optical properties (AOPs) across the entire visible spectral range within the depth range 200–1000 m of the entire mesopelagic zone for varying chlorophyll-a concentration and seawater optical properties in the mixed surface layer of the ocean. With increasing depth in the mesopelagic zone, the solar irradiance is reduced by ~9–10 orders of magnitude and exhibits a major spectral maximum in the blue, typically centered around a light wavelength of 475 nm. In the green and red spectral regions, the light levels are significantly lower but still important owing to local generation of photons via inelastic processes, mostly Raman scattering and to a lesser extent CDOM fluorescence. The Raman scattering produces a distinct secondary maximum in irradiance spectra centered around 565 nm. Comparisons of our results with light produced by the radioactive decay of the unstable potassium isotope contained in sea salt (⁴⁰K) indicates that the solar irradiance dominates over the ⁴⁰K-produced irradiance within the majority of the mesopelagic zone for most scenarios considered in our simulations. The angular distribution of radiance indicates the dominance of downward propagation of light in the blue and approach to uniform distribution in the red throughout the mesopelagic zone. Below the approximate depth range 400–500 m, the shape of the angular distribution is nearly invariant with increasing depth in the green and red and varies weakly in the blue. The AOPs at any light wavelength also assume nearly constant values within the deeper portion of the mesopelagic zone. These results indicate that the mesopelagic light field reaches a nearly-asymptotic regime at depths exceeding ~400–500 m.  相似文献   

Spike in phytoplankton biomass in Greenland Sea during 2009 and the correlations among chlorophyll-a,aerosol optical depth and ice cover     

瞿波  路海浪  林道荣 《中国海洋湖沼学报》2014,32(2):241-254

The distributions and correlations of chlorophyll-a(Chl-a),aerosol optical depth(AOD)and ice cover in the southeast Arctic Ocean-Greenland Sea(10°W–10°E,70°–80°N)between 2003 and 2009 were studied using satellite data and statistical analyses.Regression analysis showed correlations between Chl-a and AOD,Chl-a and ice cover,and AOD and ice cover with different time lags.The time lag of Chl-a and AOD indicated their long-term equilibrium relationship.Peaks in AOD and Chl-a and generally occurred in May and July,respectively.Despite the time lag,the correlation between Chl-a and AOD in the study region was as high as 0.7.The peak gap between Chl-a and AOD shifted for about 6 weeks during 2003–2009.In the summer and autumn of 2009,Chl-a and AOD levels were much higher than during the other years,especially in the northern band of the study region(75°–80°N).The driving forces for this localized increase in phytoplankton biomass could be mainly attributed to the very high rate of ice melting in spring and early summer and the high wind speed in autumn,together with the increased deposition of aerosol throughout the year.The unusually high AOD in the spring of 2003 was mainly due to a massive fi re in Russia,which occurred in the fi rst half of the year.Over the 7 years of the study,the sea surface temperature generally decreased.This may have been due to the release of dimethylsulfi de into the air,excreted in large amounts from abundant phytoplankton biomass,and its subsequent reaction,form large amounts of aerosol,and resulting in regional cooling.  相似文献