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51.
大桂林旅游资源开发研究   总被引:8,自引:0,他引:8  
旅游资源是一个地区旅游业发展的重要基础,尤其是对桂林这样一个资源驱动型的旅游地来说,旅游资源开发利用与合理保护直接到其旅游业发展的兴衰。文章在对大桂林旅游资源的实地考察和文献分析基础上,首先对桂林市旅游资源的开发利用现状进行评价,并对桂林资源的区际比较优势与劣势进行了分析,接着找出了其在开发利用与保护过程中存在的问题,最后针对发现的问题提出相应的对策建议。  相似文献   
52.
由于桂林地区地基GNSS站并未配置气象传感器,致使大量GNSS观测数据无法在大气水汽(PWV)监测中发挥作用.针对这一情况,本文将欧洲中期天气预报中心(ECMWF)最新发布的ERA5再分析资料中测站处的气压和温度气象数据加入到GNSS水汽反演中,并将反演结果与利用地面气象站反演的GNSS水汽做对比,以此评估ERA5在桂林地区反演GNSS水汽的精度和适用性.结果表明:1)以桂林地区2017年10个地面气象站的实测气压和温度数据为参考值,ERA5地表气压和温度的年均偏差分别为-0.35 hPa和0.86 K,年均均方根误差(RMSE)分别为0.65 hPa和1.66 K,该精度可用于GNSS水汽反演;2)以2017年6—7月GNSS利用地面气象站反演的PWV为参考值,ERA5反演的GNSS PWV的偏差和RMSE分别为0.17 mm和0.35 mm,且两者具较好的相关性和一致性.由此表明,ERA5地表温压产品可应用于桂林地区GNSS水汽反演,这些研究结果可为桂林地区的GNSS水汽反演及数据源的选用提供重要的参考依据.  相似文献   
53.
利用多参数自动记录仪对桂林岩溶试验场的降水量、水位、水温、pH值和电导率进行了监测,数据采集间隔根据参数变化的程度由2min到1h不等。结果发现,岩溶裂隙水在洪水期间pH值呈降低趋势,而电导率呈升高的不寻常变化。与此相反,对于岩溶管道水,同样是在洪水期间,它的pH值是升高的,而电导率呈正常的降低。考虑到Ca2 和HCO-3分别为地下水中主要的阴阳离子(>90%),及它们与电导率的线性关系,计算得到了洪水期间方解石的饱和指数(SIc)和水的CO2分压(Pco2)的变化情况。发现洪水时裂隙水的Pco2高于正常情况的Pco2,而它的SIc值比正常情况低。与此相对,对于管道水,尽管同一洪水期间其SIc降低,但Pco2也降低。从这些结果,可以推断,至少有两个关键的过程控制着洪水期间的水化学变化。一个是雨水的稀释作用,另一个是水-岩-气的相互作用。然而,对于裂隙水来说,后者的作用可能更重要,即在洪水期间,高浓度的土壤CO2溶解于水中,则更具侵蚀性的水能溶解更多的石灰岩,从而增强水的电导率。而对于管道水,雨水的稀释作用更重要,因为研究区较高的pH和低电导率的雨水能更快地通过管道流出,所以,要了解岩溶系统水化学的变化,仅考虑水-岩相互作用是不够的,我们还必须重视CO2气体对岩溶系统中水化学变化的影响。总之,水-岩-气相互作  相似文献   
54.
桂林市地热资源成热地质条件及其开发区预测分析   总被引:1,自引:0,他引:1  
:本文着重研究了桂林市地热的大地构造背景,已知温泉水文地质特征,以及地层岩性、断裂构造及岩浆活动等与成热的密切关系,进而提出了加强对已知温泉开发和加强桂林市城区及近围地热勘查工作等四点建议。  相似文献   
55.
土地利用总体规划是保证区域人口、资源、环境和社会经济持续协调发展的重要措施,而土地质量评价又是规划的基础和使规划达到理想效果的前提。对桂林市土地质量评价的系统、单元、参评因子及分级和权重等探讨,并指出土地利用总体规划时应重视的问题。  相似文献   
56.
The time sequence of paleoclimatic changes from 245.2 to 147.9 ka B.P. has been established by high precision U-series dating by Thermal Ionization Mass Spectrometry and the analysis of the oxygen isotopes from a stalagmite of Shuinan Cave in Guilin. The oxygen isotope pattern is divided into three main intervals. The top part of the stalagmite (interval C) displays mainly relatively heavy oxygen isotopes, mostly −7 to −5‰VPDB, but at a depth of 86.5 cm below the top, there is a sharp change to values lighter than −8 ‰. This boundary, dated at 192.6 ±3.9 ka B.P. is correlated with the boundary between marine oxygen isotope stages 6 and 7. The underlying interval B has δ18O values consistently between −7.5 and −8.5‰ until 271 cm depth when there is a sharp rise in δ18O values towards values as heavy as −5‰. The upper position of this change is dated at 242.5±6.4 ka B.P. and is correlated with the boundary between marine isotope stages 7 and 8. Carbon isotope values lie between −8.5 and −11‰ and are not uniquely high or low in the three intervals, but also show rapid changes at the boundaries between intervals in the same sense as the shifts in δ18O. The pronounced shifts in δ18O are attributed to changes in the paleo-monsoon intensity which reflect major reorganizations of the climate system, but some regional characteristics are also present. The results are also consistent with previous studies of climate proxies from loess-palaesol sequences in northern China. These characteristics show that paleo-climate evolution since the late stage of the middle Pleistocene Epoch in the Guilin area not only follows the global characteristics, but also has the strong district or regional patterns.  相似文献   
57.
《China Geology》2018,1(1):17-27
On the basis of proposing the existence of a karst carbon cycle and carbon sink at a watershed scale, this paper provides four pieces of evidence for the integration of geology and ecology during the carbon cycle processes in the karst dynamic system, and estimated the karst carbon sink effect using the methods of comparative monitoring of paired watersheds and the carbon stable isotope tracer technique. The results of the soil carbon cycle in Maocun, Guilin, showed that the soil carbon cycle in the karst area, the weathering and dissolution of carbonate rocks under the soil, resulted in a lower soil respiration of 25% in the karst area than in a non-karst area (sandstone and shale), and the carbon isotope results indicated that 13.46% of the heavy carbon of the limestone is involved in the soil carbon cycle. The comparative monitoring results in paired watersheds, suggesting that the HCO3- concentration in a karst spring is 10 times that of a rivulet in a non-karst area, while the concentration of inorganic carbon flux is 23.8 times. With both chemical stoichiometry and carbon stable isotopes, the proportion of carbon in karst springs derived from carbonate rocks was found to be 58.52% and 37.65% respectively. The comparison on carbon exchange and isotopes at the water-gas interface between the granite and carbonate rock basins in the Li River showed that the CO2 emission of the karst water is 10.92 times that of the allogenic water from the non-karst area, while the carbon isotope of HCO3- in karst water is lighter by 8.62‰. However, this does not mean that the karst water body has a larger carbon source effect. On the contrary, it means the karst water body has a greater karst carbon sink effect. When the karst subterranean stream in Zhaidi, Guilin, is exposed at the surface, carbon-rich karst water stimulated the growth of aquatic plants. The values of carbon stable isotopes in the same species of submerged plants gradually becomes heavier and heavier, and the 512 m flow process has a maximum range of 15.46‰. The calculation results showed that 12.52% of inorganic carbon is converted into organic carbon. According to the data that has been published, the global karst carbon sink flux was estimated to be 0.53-0.58 PgC/a, equivalent to 31.18%-34.41% of the global forest carbon sink flux. In the meanwhile, the karst carbon sink flux in China was calculated to be 0.051 PgC/a, accounting for 68% of its forest carbon sink flux.  相似文献   
58.
利用1981~2015年桂林气象观测站地面气象资料、PM2.5资料,分析桂林霾日变化的影响因子。结果表明:桂林霾日数在过去35年呈明显上升趋势,气候倾向率为24.6d/10a,在1995年经历过一次明显突变,这种变化主要原因有人类活动和气象因子的变化。各因子中PM2.5浓度影响着霾日数的月、日分布,1月和7月是桂林PM2.5高值、低值月份,也是霾出现最多、最少月份。PM2.5浓度和霾出现频率日变化趋势相似,均为双峰型。各气象因子中,降水量≥0.1mm、最大风速≥5m/s日数的减少以及年均相对湿度下降是霾增加的重要原因,逆温也影响霾日、月分布,用逆温层厚度和高度能较好的反映出霾期间PM2.5浓度水平。  相似文献   
59.
High‐resolution measurements of rainfall, water level, pH, conductivity, temperature and carbonate chemistry parameters of groundwater at two adjacent locations within the peak cluster karst of the Guilin Karst Experimental Site in Guangxi Province, China, were made with different types of multiparameter sonde. The data were stored using data loggers recording with 2 min or 15 min resolution. Waters from a large, perennial spring represent the exit for the aquifer's conduit flow, and a nearby well measures water in the conduit‐adjacent, fractured media. During flood pulses, the pH of the conduit flow water rises as the conductivity falls. In contrast, and at the same time, the pH of groundwater in the fractures drops, as conductivity rises. As Ca2+ and HCO3? were the dominant (>90%) ions, we developed linear relationships (both r2 > 0·91) between conductivity and those ions, respectively, and in turn calculated variations in the calcite saturation index (SIC) and CO2 partial pressure (P) of water during flood pulses. Results indicate that the P of fracture water during flood periods is higher than that at lower flows, and its SIC is lower. Simultaneously, P of conduit water during the flood period is lower than that at lower flows, and its SIC also is lower. From these results we conclude that at least two key processes are controlling hydrochemical variations during flood periods: (i) dilution by precipitation and (ii) water–rock–gas interactions. To explain hydrochemical variations in the fracture water, the water–rock–gas interactions may be more important. For example, during flood periods, soil gas with high CO2 concentrations dissolves in water and enters the fracture system, the water, which in turn has become more highly undersaturated, dissolves more limestone, and the conductivity increases. Dilution of rainfall is more important in controlling hydrochemical variations of conduit water, because rainfall with higher pH (in this area apparently owing to interaction with limestone dust in the lower atmosphere) and low conductivity travels through the conduit system rapidly. These results illustrate that to understand the hydrochemical variations in karst systems, considering only water–rock interactions is not sufficient, and the variable effects of CO2 on the system should be evaluated. Consideration of water–rock–gas interactions is thus a must in understanding variations in karst hydrochemistry. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
60.
文章对桂林市七星区五个采样片区的土壤热释汞含量、部分样品汞的赋存形式以及其污染性状进行了分析,并对主要相态汞的来源进行了简单的分析。结果发现:桂林市七星区部分区段土壤汞存在轻度的污染,污染主要源于原始岩石背景含量较高;区内土壤中汞的赋存方式多种多样,组成差异也较大,其中以硫酸汞为主的高温热态汞含量最高,其次为硫化物形态汞,再次为以氧化物形态为主的中温热态汞,而吸附态汞和低温热态亚汞及低温热态汞含量较低,所占总汞含量小于10%。  相似文献   
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