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831.
鄂西北南化塘地区中元古界武当山岩群由三个岩段组成,其原岩分别以火山角砾岩、岩屑凝灰岩及晶屑凝灰岩为主。它们的空间展布与上覆上元古界耀岭河岩群高角度相交,三岩段所显示出早期褶皱也只限于武当山岩群内部,与上覆岩群的构造轮廓极不谐调,耀岭河岩群没有经历过这一期变形。因此,武当山岩群与耀岭河岩群之间最初存在着明显的角度不整合接触。该区域不整合面的厘定和早晋宁运动的确认将改变以往关于扬子地块北缘构造层的划分及构造演化历史的认识,对研究秦岭造山带的造山过程具有重要意义。 相似文献
832.
Accurate evaluation of soil productivity has been a long-standing challenge. Although numerous models for productivity assessment exist, most are cumbersome to use and require substantial parameter inputs. We developed a new empirical soil productivity model based on field investigations of soil erosion, soil physicochemical properties, and crop yields in the dry-hot valleys (DHVs) in China. We found that soil pH, and organic matter and available potassium contents significantly affected crop yields under eroded conditions of the DHVs. Moreover, available potassium content was the key factor affecting soil productivity. We then modified an existing soil productivity model by adding the following parameters: contents of effective water, potassium, organic matter, and clay, soil pH, and root weighting factor. The modified soil productivity model explained 63.5% of the crop yield. We concluded that the new model was simple, realistic, and exhibited strong predictability. In addition to providing an accurate assessment of soil productivity, our model could potentially be applied as a soil module in comprehensive crop models. 相似文献
833.
本文介绍一种无线数据传接口及控制装置。装置中采用计算机软件实现串—并、并—串变换及频率调制、其硬件成本低廉,工作可靠,可用于速率为50、300、600或1200bps的数传通信。 相似文献
834.
董黎明,李向明,冯长春ASTUDYONREGIONALDIFFERENCEOFCHINA'SPAIDURBANLANDUSESYSTEMANDGRADING¥DongLiming;LiXiangming;FengChangchun(PekingUni... 相似文献
835.
ZHANG Junyan CHENG Genwei LI Yongfei 《山地科学学报》2006,3(2):125-130
Introduction Landscape evolution in glaciated high mountains environment in southwestern China is undergoing the coupled processes of monsoon- induced denudation and active tectonic. The debris fan development, in particular sediment transfer, is most int… 相似文献
836.
1 INTRODUCTION δ13C in organic matters from lacustrine sedi- ments varies with several factors including aquatic plants, vegetation type in the catchment, atmos- pheric CO2 concentration, climate (temperature and precipitation), and properties of water, … 相似文献
837.
1 INTRODUCTION In southern high latitudes, recent observations have shown a standing mode of ACW (Antarctic Circumpolar Wave) with eastward propagation across the Southern Ocean of the Antarctic in co- varying SST (sea surface temperature) and SLP (sea le… 相似文献
838.
淄川区位于山东省淄博市中部,矿产资源丰富,现已发现24种矿产。其中,已探明储量的矿产有16种,主要为煤、地热、铁、铝土矿、耐火粘土、制碱用灰岩、溶剂用灰岩,水泥用灰岩、石英砂岩、高岭土、花岗岩、石膏、砖瓦用粘土、地下水、矿泉水;已发现但尚未探明储量的矿种有:白云岩、磷矿、砚石等。矿业的发展为全区经济和社会的发展做出了巨大的贡献,同时也存在着诸多问题,如粗放经营,资源破坏浪费严重,资源家底不清,矿产储量耗竭过快,偷逃矿产资源补偿费等。为此,淄川区国土资源局用近两年时间对全区矿山企业占用储量进行了检测,基本摸清了淄川区矿产资源家底,并在此基础上对全区矿山企业占用资源储量进行了登记,从而基本建立起了矿山矿产资源储量动态管理制度。 相似文献
839.
Based on in-situ observation, satellite and reanalysis data, responses of the western North Pacific subtropical ocean(WNPSO) to the slow-moving category 5 super typhoon Nanmadol in 2011 are analyzed. The dynamical response is dominated by near-inertial currents and Ekman currents with maximum amplitude of 0.39 m/s and 0.15 m/s, respectively. The near-inertial currents concentrated around 100 m below the sea surface and had an e-folding timescale of 4 days. The near-inertial energy propagated both upward and downward, and the vertical phase speed and wavelength were estimated to be 5 m/h and 175 m, respectively. The frequency of the near-inertial currents was blue-shifted near the surface and redshifted in ocean interior which may relate to wave propagation and/or background vorticity. The resultant surface cooling reaches -4.35℃ and happens when translation speed of Nanmadol is smaller than 3.0 m/s.When Nanmadol reaches super typhoon intensity, the cooling is less than 3.0℃ suggesting that the typhoon translation speed plays important roles as well as typhoon intensity in surface cooling. Upwelling induced by the slow-moving typhoon wind leads to typhoon track confined cooling area and the right-hand bias of cooling is slight. The mixed layer cooling and thermocline warming are induced by wind-generated upwelling and vertical entrainment. Vertical entrainment also led to mixed layer salinity increase and thermocline salinity decrease, however, mixed layer salinity decrease occurs at certain stations as well. Our results suggest that typhoon translation speed is a vital factor responsible for the oceanic thermohaline and dynamical responses, and the small Mach number(slow typhoon translation speed) facilitate development of Ekman current and upwelling. 相似文献
840.