钻孔应变观测技术发展方向探讨     

池顺良  艾学民 《地震地磁观测与研究》1998,19(5):23-29

从大地测量技术、地震观测技术和钻孔应变观测技术３种地面运动观测方法在观测频频带和观测精度方面的互补性,探讨了钻孔应变观测技术的发展方向,指出钻孔应变观测应将观测重点放在周期数十秒到数十天的短临信息频段,同时指出,钻孔应变观测可以同时用于声和高频地震观测,以获取更多的短临信息。  相似文献   

Platinum-Group Element Geochemical Certified Reference Materials (GPt1-7)   总被引：2，自引：0，他引：2  

Mingcai Yan  Chunshu Wang  Tiexin Gu  Qinghua Chi  Zhong Zhang 《Geostandards and Geoanalytical Research》1998,22(2):235-246

Unlike the situation for other elements, few reference materials certified for the platinum-group elements are currently available. Therefore, the GPt1-7 series of PGE geochemical CRMs, prepared by the IGGE, represent an important addition and comprise a range of matrix types, including a soil, stream sediment, Mg-rich ultramafic rock, Fe-rich ultramafic rock, platinoid ore depleted in Cu, Ni and Fe, and a chromitite. The concentration of PGE in these samples ranges over 4-5 orders of magnitude and the samples were shown to have good homogeneity as assessed by a variance test. Analytical methods based on different principles were used in sample certification, including several fire assay and wet chemical procedures used for decomposition and preconcentration. Certified values for the elements Pt, Pd, Os, Ru, Ir, Rh and Au were determined by AAS, catalytic colourimetry (COL), catalytic polarography (POL), atomic emission spectrometry (AES), ICP-MS and NAA. Recently, the GPt1-7 samples were approved as national primary CRMs by the State Bureau of Technical Supervision of China.  相似文献   

Storm‐event rainfall–runoff modelling approach for ungauged sites in Taiwan     

Yu‐Chi Wang  Shien‐Tsung Chen  Pao‐Shan Yu  Tao‐Chang Yang 《水文研究》2008,22(21):4322-4330

This work develops a top‐down modelling approach for storm‐event rainfall–runoff model calibration at unmeasured sites in Taiwan. Twenty‐six storm events occurring in seven sub‐catchments in the Kao‐Ping River provided the analytical data set. Regional formulas for three important features of a streamflow hydrograph, i.e. time to peak, peak flow, and total runoff volume, were developed via the characteristics of storm event and catchment using multivariate regression analysis. Validation of the regional formulas demonstrates that they reasonably predict the three features of a streamflow hydrograph at ungauged sites. All of the sub‐catchments in the study area were then adopted as ungauged areas, and the three streamflow hydrograph features were calculated by the regional formulas and substituted into the fuzzy multi‐objective function for rainfall–runoff model calibration. Calibration results show that the proposed approach can effectively simulate the streamflow hydrographs at the ungauged sites. The simulated hydrographs more closely resemble observed hydrographs than hydrographs synthesized using the Soil Conservation Service (SCS) dimensionless unit hydrograph method, a conventional method for hydrograph estimation at ungauged sites in Taiwan. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Impact of climate change on hydrological processes over a basin scale in northern Taiwan     

Pao‐Shan Yu  Yu‐Chi Wang 《水文研究》2009,23(25):3556-3568

This study investigates the impact of climate change on rainfall, evapotranspiration, and discharge in northern Taiwan. The upstream catchment of the Shihmen reservoir in northern Taiwan was chosen as the study area. Both observed discharge and soil moisture were simultaneously adopted to optimize the HBV‐based hydrological model, clearly improving the simulation of the soil moisture. The delta change of monthly temperature and precipitation from the grid cell of GCMs (General Circulation Models) that is closest to the study area were utilized to generate the daily rainfall and temperature series based on a weather generating model. The daily rainfall and temperature series were further inputted into the calibrated hydrological model to project the hydrological variables. The studies show that rainfall and discharge will be increased during the wet season (May to October) and decreased during the dry season (November to April of the following year). Evapotranspiration will be increased in the whole year except in November and December. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Effects of spectral composition,photoperiod and light intensity on the gonadal development of Atlantic salmon Salmo salar in recirculating aquaculture systems (RAS)     

仇登高  徐世宏  宋昌斌  迟良  李贤  孙国祥  刘宝良  刘鹰 《中国海洋湖沼学报》2015,33(1):45-56

Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using standard lighting technology,sexual maturation is not suppressed.In this study,an L_9(3~3) orthogonal design was used to determine the effects of three factors(spectral composition,photoperiod,and light intensity) on the gonadal development of Atlantic salmon in RAS.We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity.The photoperiod had a significant effect on the secretion of sex steroids and melatonin(P0.05),and a short photoperiod delayed sex steroid and melatonin level increases.The three test factors had no significant effects on the survival rate,specific growth rate,relative weight gain,and male Fulton condition factor(P0.05).The optimum lighting levels in female and male Atlantic salmon were LD 8:16,455 nm(or 625 nm),8.60 W/m~2;and LD 8:16,8.60 W/m~2,455 nm respectively.These conditions not only delayed gonadal development,but also had no negative effects on Atlantic salmon growth in RAS.These results demonstrate that a combination of spectral composition,photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.  相似文献   

基于WRF/CALMET的近地面精细化风场的动力模拟试验研究   总被引：2，自引：1，他引：1  

张弛  王东海  巩远发 《气象》2015,41(1):34-44

本文利用中尺度动力模式 WRF和诊断模式CALMET对琼州海峡的两次冷空气过程的近地层风场进行模拟和诊断,所用的资料是美国NCEP再分析FNL资料。WRF模式第一至第四层网格的水平距离分别是27、9、3和1 km,并用WRF-1 km场以单向嵌套模拟方式降至200 m,同时以 WRF-1 km 预报场作为 CALMET 初猜场降尺度诊断至200 m。分别用CALMET-200 m风场、WRF-1 km风场和 WRF-200 m风场,3个风场的风速、风向与沿琼海海峡分布的21个测站（其中6个测风塔）观测资料进行检验比较分析。主要结论是：（1）CALMET-200 m的风速RMSE明显小于另外两组试验,风向RMSE总体上差异不大;在60～80 m高度上也没有明显差异。（2）在0～8 m·s－1风速,10 m高度上CALMET-200 m风场诊断结果最好,风速平均偏差值从4～0 m·s－1,WRF的两组试验平均偏差值比CALMET-200 m结果大约2 m·s－1,风向上表现为偏差的分布更加集中;60～80 m高度上,CALMET-200 m 诊断效果与 WRF-1 km 模拟效果相当,但是冷空气时段内 WRF-200 m的风速要远远差于另外两组试验;而3组试验的风向并无大的差异。（3）WRF／CALMET模式系统在非冷空气活动时段内的风速风向模拟诊断偏差更小,说明其在层结相对较稳定时模拟诊断的准确度更高。  相似文献   

Asteroseismic modelling of the solar-like star β Hydri     

G. Doğan  I. M. Brandão  T. R. Bedding  J. Christensen-Dalsgaard  M. S. Cunha  H. Kjeldsen 《Astrophysics and Space Science》2010,328(1-2):101-104

We present the results of modelling the subgiant star β Hydri using seismic observational constraints. We have computed several grids of stellar evolutionary tracks using the Aarhus STellar Evolution Code (ASTEC, Christensen-Dalsgaard in Astrophys. Space Sci. 316:13, 2008a), with and without helium diffusion and settling. For those models on each track that are located at the observationally determined position of β Hydri in the Hertzsprung-Russell (HR) diagram, we have calculated the oscillation frequencies using the Aarhus adiabatic pulsation package (ADIPLS, Christensen-Dalsgaard in Astrophys. Space Sci. 316:113, 2008b). Applying the near-surface corrections to the calculated frequencies using the empirical law presented by Kjeldsen et al. (Astrophys. J. 683:L175, 2008), we have compared the corrected model frequencies with the observed frequencies of the star. We show that after correcting the frequencies for the near-surface effects, we have a fairly good fit for both l=0 and l=2 frequencies. We also have good agreement between the observed and calculated l=1 mode frequencies, although there is room for improvement in order to fit all the observed mixed modes simultaneously.  相似文献   

Scientific Objectives of China-Russia Joint Mars Exploration Program YH-1     

Ji Wu  Guang-Wu Zhu  Hua Zhao  Chi Wang  Lei Li  Yue-Qiang Sun  Wei Guo  Cheng-Li Huang 《Chinese Astronomy and Astrophysics》2010

Compared with other planets, Mars is a planet most similar with the earth and most possible to find the extraterrestrial life on it, and therefore especially concerned about by human beings. In recent years, some countries have launched Mars probes and announced their manned Mars exploration programs. China has become the fifth country in the world to launch independently artificial satellites, and the third country able to carry out an independent manned space program. However, China is just at the beginning of deep space explorations. In 2007, China and Russia signed an agreement on a joint Mars exploration program by sending a Chinese micro-satellite Yinghuo-1 (YH-1) to the Mars orbit. Once YH-1 enters its orbit, it will carry out its own exploration, as well as the joint exploration with the Russian Phobos-Grunt probe. This paper summarizes the scientific background and objectives of YH-1 and describes briefly its payloads for realizing these scientific objectives. In addition, the main exploration tasks of YH-1 and a preliminary prospect on its exploration results are also given.  相似文献   

呼伦贝尔地区土地荒漠化动态变化   总被引：6，自引：0，他引：6  

徐驰  姜琦刚  李远华  邢宇 《世界地质》2010,29(1):160-167

呼伦贝尔地区是中国重要的天然草原和畜牧基地, 随着该地区经济和社会的发展及人类对资源的不合理利用, 土地荒漠化现象加重。笔者应用RS和GIS技术, 以1970 年MSS、2000 年ETM和 2007年CBERS数据为数据源, 主要采用人工目视解译方法, 并辅助野外调查验证, 获得三期解译数据, 并利用空间分析、网格剖分方法, 对呼伦贝尔地区荒漠化的时空变化情况进行研究。结果表明: 近40年来, 该地区土地荒漠化总面积不断增加, 1970 年该地区土地荒漠化面积为7408.76 km2 , 2000年为7 539.52 km2 , 2007年增加到7 852.12 km2 , 共增加面积443.36 km2。1970-2000年间, 沙漠化减轻、盐碱化加重的面积为134.09 km2 , 沙漠化加重、盐碱化减轻的面积为53.35 km2 ; 2000- 2007年间, 沙漠化减轻、盐碱化加重的面积为41.71 km2 , 沙漠化加重、盐碱化减轻的面积为172.8 km2。  相似文献   

孑遗植物四合木(Tetraena mongolica)异地保护条件下的气候生物学特征与光合效率     

智颖飙  杨持  李红丽  张荷亮  华宇鹏  赵凯  路战远  红鸽  旺扎拉  王强 《中国沙漠》2014,34(1):88-97

为了廓清异地保护条件下孑遗濒危植物四合木(Tetraena mongolica)的气候生物学特征、光合生理生态适应性及生境适宜性,应用1971—2011年的地面气象资料进行了不同试验区的气候生物图解与分析,测定了四合木及其伴生种白刺(Nitraria tangutorum)的叶片气体交换参数及光合效率。结果表明:①四合木自然分布区(内蒙古乌海地区)与异地保护区的气候生物学特征存在明显分异;②当年种植的四合木实生苗的生长量大小依次为:乌海四合木核心区实生苗鄂尔多斯实生苗阿拉善实生苗;③自然条件下,5个处理的净光合速率(Pn)依次为阿拉善移植的四合木成株(24.05±1.68μmol·m-2·s-1)乌海客土栽培的四合木(19.97±1.05μmol·m-2·s-1)乌海栽培的四合木实生苗(18.96±1.04μmol·m-2·s-1)鄂尔多斯栽培的四合木实生苗(16.64±0.92μmol·m-2·s-1)阿拉善栽培的四合木实生苗(16.48±0.13μmol·m-2·s-1);异地保护试验区栽培的四合木实生苗的Pn没有明显差异(p≥0.05),即原生境条件下栽培的四合木实生苗的Pn较高。同时,异地保护栽培四合木实生苗中,鄂尔多斯栽培的四合木实生苗的Pn阿拉善栽培的四合木实生苗。从四合木光合作用特征中的Pn、蒸腾速率、气孔导度和胞间CO2浓度、气候生物学特征和生长量等综合研究结果可以推断,从原生境区东移的实生苗迁地保护,使四合木具有更高的生理生态适宜性和环境适应性。  相似文献