Y/JTG-1下架式陀螺全站仪快速定向

快速精确定向是现代陀螺定向测量的重要研究方向。本文利用下架式陀螺全站仪跟踪测量法精确测定了仪器分划板格值τ和悬带零位系数λ两个重要参数,从而使悬带零位改正更加可靠。并基于下架式陀螺全站仪跟踪测量法进一步提出采用连续采样跟踪法实现快速定向。利用跟踪一个周期的数据进行定向测量,耗时仅需12min左右,定向精度与积分法相当。     

青藏高原东北缘武山盆地中中新世炭屑记录及其古气候意义

火是生态系统中的重要因子,是反映古气候和环境变化的重要标志。因此,重建火活动历史可以帮助我们理解过去的气候变化和火活动的机制,但是目前在全球范围内十分缺少对中新世时期高分辨率的火活动记录的研究。炭屑已被证明是重建火活动历史的有效替代性指标,基于青藏高原东北缘武山盆地中中新世时期高分辨率的炭屑记录,重建了研究区天然火活动历史,结合现有资料,探讨了火-植被-气候之间的关系以及研究区火活动对全球变化的响应。结果表明：（1） 15.30~13.60 Ma时期,炭屑总浓度变化范围为59~4324粒·g^-1,平均浓度为835粒·g^-1。炭屑形状以次圆形为主,且几乎所有的炭屑粒径都小于50 μm,反映出研究区天然火活动是以乔木植物燃烧的森林火活动为主,主要是区域性火活动。根据炭屑总浓度的变化趋势,将研究区天然火活动历史分为2个主要阶段。阶段Ⅰ（15.30~14.00 Ma）：炭屑总浓度逐步增加,平均浓度为866粒·g^-1。其中,阶段Ⅰ又可以细分为3个次要阶段,Ⅰa（15.30~14.38 Ma）：炭屑总浓度最低,平均浓度为693粒·g^-1;Ⅰb（14.38~14.20 Ma）：炭屑总浓度快速减少,平均浓度为1140粒·g^-1;Ⅰc（14.20~14.00 Ma）：炭屑总浓度急剧增加,平均浓度为988粒·g^-1。阶段Ⅱ（14.00~13.60 Ma）：炭屑总浓度急剧减少,平均浓度为777粒·g^-1。（2） 孢粉数据重建的研究区的植被和气候变化结果表明,15.30~14.38 Ma时期为开阔的森林植被,湿度较低;14.38~14.00 Ma时期乔木增加,湿度增加;14.00~13.60 Ma时期乔木属种显著减少,湿度降低。（3） 经过对比分析,炭屑总浓度变化趋势与乔木类花粉百分比趋势相近,次圆形炭屑浓度趋势与阔叶类植物花粉的百分比趋势显著正相关,认为武山盆地中中新世的天然火活动与森林植被的盖度（尤其是阔叶林的盖度）有较强联系,在气候温暖湿润的时期,炭屑浓度高。此外,通过对比炭屑总浓度趋势和深海底栖有孔虫氧同位素的变化,可以推测,全球温度变化可能通过影响研究区植被变化来对天然火活动产生重要影响。     

可控源法在海阳市郭城地区鑫泰金矿床成矿规律中的应用

可控源音频大地电磁法(CSAMT法)是一种利用人工场源研究地层、构造等深部地质特征问题的新技术新方法。在山东省海阳市郭城地区鑫泰金矿床的应用研究表明,CSAMT法可以较好地用于确定矿体的产状和大致地层结构,在矿体成矿规律研究方面具有较为突出的应用效果。     

中国水土保持研究回顾

The preservation and sustainable development of soil and water resources is one of the basic principles for the development of China. Throughout the course of history, all the social improvement and economic development are deeply concerned with soil loss and ecological environmental protection. It is now a common sense that soil and water conservation is the safety insurance for national ecology and its development. For the past long period of time, soil and water loss has been recognized as “the No. 1 killer“ to the ecological environment. The nation is on the stage of the critical conditions for its development. China has massive mountain and upland area with complicated geological conditions and accelerated human destruction and serious soil and water loss.Based on rich historical documents, renovating experience and detailed analysis of the data collected in field experiments and field surveys for soil and water conservation, this paper aims to review the general characteristics of soil and water loss, to explore the relationship between soil and water conservation and sustainable economic development, and to provide relevant strategies for soil and water conservation in China.     

On improving tropical cyclone track forecasts using a scale-selective data assimilation approach: a case study

A dynamical downscaling approach based on scale-selective data assimilation (SSDA) is applied to tropical cyclone (TC) track forecasts. The results from a case study of super Typhoon Megi (2010) show that the SSDA approach is very effective in improving the TC track forecasts by fitting the large-scale wind field from the regional model to that from the global forecast system (GFS) forecasts while allowing the small-scale circulation to develop freely in the regional model. A comparison to the conventional spectral-nudging four-dimensional data assimilation (FDDA) indicates that the SSDA approach outperforms the FDDA in TC track forecasts because the former allows the small-scale features in a regional model to develop more freely than the latter due to different techniques used. In addition, a number of numerical experiments are performed to investigate the sensitivity of SSDA’s effect in TC track forecasts to some parameters in SSDA, including the cutoff wave number, the vertical layers of the atmosphere being adjusted, and the interval of SSDA implementation. The results show that the improvements are sensitive in different extent to the above three parameters.     

Lead isotope geochemical characteristics of Pb-Zn-Cu deposits on the southwestern margin of Tarim, and their significance

The polymetallic(Pb,Zn,Cu,etc) ore belt on the southwestern margin of Tarim is one of the major regions with the greatest prospecting potential in Xinjiang.Reported in this paper are the lead isotope data for 66 sulfide samples(including 50 galena samples,15 chalcopyrite samples and 1 pyrite sample) collected from such representative deposits as Tamu,Tiekelike,Kalangu,Abalieke,etc.in this ore belt.The Pb isotopic ratios of 206 Pb/204 Pb,207 Pb/204 Pb and 208 Pb/204 Pb in the galena samples range from 17.931 to 18.176,15.609 to 15.818 and 38.197 to 38.944,with the average values of 18.017,15.684 and 38.462,respectively.Those in the chalcopyrite samples range from 17.926 to 18.144,15.598 to 15.628 and 38.171 to 38.583,with the average values of 18.020,15.606 and 38.262,respectively.The pyrite sample has the Pb isotopic ratios of 206 Pb/204 Pb,207 Pb/204 Pb and 208 Pb/204 Pb to be 17.980,15.604 and 38.145,respectively.In combination with the previous Pb isotope data for sulfides,it is found that there is only a slight variation in the Pb isotopic composition of galena,chalcopyrite,sphalerite and pyrite in the ore belt.However,there is some difference in Pb isotopic characteristics between galena and chalcopyrite,especially the Pb isotopic composition of galena shows an obvious linear correlation with some other relevant parameters(e.g.β and γ).The comprehensive analysis suggested that lead in galena(maybe including sphalerite and pyrite) was derived principally from wall rocks and underlying basement,and that in chalcopyrite only originated from the basement.The single-stage model ages of these sulfides couldn’t indicate the time limit of metallogenesis(Pb,Zn,Cu,etc.),and the positive linear correlations for the Pb isotopic composition of galena are of no single-stage and two-stage Pb-Pb isochron significance.Furthermore,there are significant differences in Pb isotopic composition characteristics between the genetic type of deposits in this polymetallic ore belt and the Mississippi Valley type(MVT).In addition,the authors also pointed out that there is a phenomenon of differentiation(not paragenesis) for lead and copper elements during the process of metallogenesis in this ore belt.     

峡东埃迪卡拉系陡山沱组稳定碳同位素记录及其年代地层意义

基于峡东秭归青林口、泗溪和宜昌晓峰河埃迪卡拉系下部陡山沱组剖面岩石、层序和精细的碳同位素地层研究,在埃迪卡拉系下部陡山沱组底部、下部、中部、上部和顶部分别识别出5次以灰岩出现或黑色页岩增厚为标志的海侵事件,划分出5个可以进行区域对比的三级层序,自下而上分别命名为BDSS,LDSS,MDSS,UDSS和TDSS。以层序界面为对比标志,峡东埃迪卡拉纪不同古地理部位碳同位素组成变化的对比显示峡东埃迪卡拉系陡山沱组中内部发育5次可以进行区域乃至全球对比的碳同位素负异常,分别是分布在BDSS下部的SN1,LDSS上部的SN2,MDSS上部和顶部的SN3和SN4,以及分布在UDSS上部的SN5。其中SN1和SN4碳同位素负偏离最为明显,最小δ13C分别达到-4‰~-5‰和-9‰~-10‰,分别与Marinoan冰期上覆盖帽白云岩以及Gaskier冰碛沉积上、下地层中的碳同位素组成特点接近。SN4是埃迪卡拉系最晚冰期的产物。与SN1是埃迪卡拉系底界划分对比的标志相对比,SN4的出现应该是埃迪卡拉系内部再划分中另一个不可忽视的界线标志。     

西大别南缘印支期吕王-高桥-永佳河构造混杂岩带的厘定及其构造意义

在西大别造山带的区调工作中,新识别出一系列中元古代末-新元古代的岩石-构造单元,它们沿着吕王-高桥-永佳河一线展布,并构成一条NNW-SEE向展布的构造混杂岩带.该混杂岩带主要由超镁铁质-镁铁质岩、硅泥质岩、石英质岩、大理岩、含碳陆源碎屑岩、双峰式火山岩以及卷入其中的榴辉岩等多种变质岩块(片)共同组成,并赋存于一套遭受了强烈剪切变形的泥质片岩之中.混杂岩带内各岩块(片)的原岩年龄跨度较大(>4亿年),分别集中在1 200～1 100 Ma和800～700 Ma之间.锆石记录的变质年龄和云母的冷却年龄则主要集中在240～200 Ma之间.结合接触关系、岩性组合、年代学及地球化学数据的综合研究认为,混杂岩带的物质来源既包括中元古代末-新元古代早期的弧-弧后盆地系统的沉积岩-火山岩-侵入岩;也包括叠置其上的新元古代中-晚期大陆裂解期的沉积岩-火成岩.这些不同时代、不同性质岩石在三叠纪不同程度地卷入了华南陆块北缘向华北陆块之下的俯冲,而后快速折返,最终沿着区域上折返断裂(桃花-七角山断裂)就位于西大别造山带之中,形成一条包含高压-超高压变质岩的三叠纪构造混杂岩带.混杂岩带内新厘定的中元古...     

基于PS-InSAR的输电塔结构及沿线地质监测技术

我国电力建设发展迅速,电力输送设施建设通常会跨越恶劣地质条件区域,这些区域易发生地质灾害,从而引起输电铁塔基础结构产生形变,严重威胁高压输电线路的运行安全.本文使用合成孔径雷达影像,应用永久散射体差分干涉测量(PS-InSAR)技术对高压输电塔结构及其沿线地表进行形变监测.使用相干系数阈值法来确定研究区域的永久散射体点...     

Effects of inhibitors on ferricyanide uptake and assimilation by plants

Effects of inhibitors on uptake and assimilation of ferricyanide by different plants were investigated. Detached roots of plants were kept in a closed-dark hydroponic system with ferricyanide solution amended with various inhibitors. Dissociation of ferricyanide to free cyanide and iron in solution was negligible. The application of inhibitors affected both botanical assimilation and uptake of ferricyanide. Of the inhibitors tested, silver nitrate showed a significantly inhibitory effect on ferricyanide uptake by rice, soybean and maize (P < 0.01), while a negligible effect was found in willows spiked with the same inhibitor (P > 0.05). However, lanthanum chloride showed the most severe effect on botanical assimilation of ferricyanide by maize and rice (P < 0.01), whereas silver nitrate and tetraethylammonium chloride were the most sensitive inhibitors to soybean and willows, respectively (P < 0.01). Botanical assimilation of ferricyanide was observed positively in responses to temperatures, in which maize was more susceptible than other selected plants. In conclusion, application of inhibitors has a substantial influence on the uptake and assimilation of ferricyanide by plants, and the inhibitory efficiency is highly dependent on the species of inhibitors applied.