重轨星载InSAR形变监测中一种改进的大气延迟相位校正方法     

祝杰  李瑜  王坦  常占强  于文  韩宇飞  王阅兵  刘洋洋 《大地测量与地球动力学》2020,40(11):1164-1169

在传统空间辐射计方法基础上,将对流层中水汽垂直分层效应集成到校正模型中,提出一种改进的InSAR大气延迟相位校正方法。为验证改进方法的可行性,利用MERIS近红外水汽产品去除北京地区地面沉降InSAR监测中的大气延迟相位。以陆态网络GNSS站点监测结果为基准,验证改进的大气校正方法的监测精度。改进的大气校正方法、空间辐射计校正法和未校正的InSAR监测结果与陆态网络GNSS站点监测结果对比显示,均方根误差分别为0.388 cm、0.603 cm、0.685 cm,表明改进的方法相比于未校正和传统方法具有更高的精度,能有效削弱干涉图中的大气延迟相位误差。  相似文献   

Reducing the Common Environmental Effect on Litopenaeus vannamei Body Weight by Rearing Communally at Early Developmental Stages and Using a Reconstructed Pedigree     

Zhangwei Kong  Jie Kong  Dongchun Hao  Xia Lu  Tan Jian  Xianhong Meng  Kun Luo  Baoxiang Cao  Juan Sui  Xupeng Li  Sheng Luan 《中国海洋大学学报(英文版)》2020,19(4):923-930

Heritability estimates may be severely biased when a large common environmental effect on a family arises from a longlasting separate rearing at early stages(SRES) in traditional selective breeding programs, especially when bred populations have weak genetic ties. Communal rearing at early stages(CRES) may reduce common environmental effect since all families are reared in the same environment immediately after hatching. Here, we compared the effects of CRES and SRES strategies on genetic parameter estimation for harvest body weight in a selective breeding population of Litopenaeus vannamei with a small number of half-sib families. Genetic parameters of each strategy were estimated by using animal models excluding and including the common environmental effect(Model 1 and Model 2, respectively). Heritability estimates for body weight were 0.21 ± 0.06(P 0.05) and 0.69 ± 0.09(P 0.05) for CRES and SRES, respectively, in Model 1, and 0.21 ± 0.06(P 0.05) and 0.52 ± 0.27(P 0.05) in Model 2. The ratio of common environmental variance to phenotypic variance was 0.002 ± 0.000 and 0.071 ± 0.112 for CRES and SRES, respectively. Neither strategy precisely partitioned the common environmental variance according to likelihood ratio test. Lower heritability for body weight in CRES than in SRES implied that a large common environmental variance was confounded with additive genetic variance and was not effectively partitioned in SRES. Moreover, genetic correlation of body weight between the two strategies was 0.75 ± 0.15, indicating that family rankings truly changed. The CRES should be followed in the selective breeding program of shrimp, especially in a population with a shallow pedigree and weak genetic ties between families.  相似文献   

High mortality and poor growth of green mussels, <Emphasis Type="Italic">Perna viridis</Emphasis>, in high chlorophyll-<Emphasis Type="Italic">a</Emphasis> environment     

Tan Kar Soon  Delta Jenetty Denil  Julian Ransangan 《Ocean Science Journal》2016,51(1):43-57

The current study was carried out from May 2014 to April 2015 to estimate the stock status of P. viridis in Marudu Bay. The gonad development was monitored by histological examination, while the population parameters including asymptotic length (L_∞), growth coefficient (K), mortality rate (Z, F and M), exploitation level (E) and recruitment of P. viridis were estimated using the lengthfrequency data. Results of the current study demonstrated that P. viridis in Marudu Bay spawned throughout the year with two major peaks, one in April to May and another one in October to December. The recruitment pattern was continuous with the peak in May to June 2014, which corresponded to the first spawning peak in April. However, no significant recruitment was observed from the second spawning peak due to the difference in spawning timing between male and female populations. The estimated asymptotic length (L_∞), growth coefficient (K), total mortality (Z), natural mortality (M), fishing mortality (F) and growth performance (ф) of P. viridis in Marudu Bay were estimate to be 117 mm, 0.97 yr^-1, 4.39 yr^-1, 1.23 yr^-1, 3.16 yr^-1 and 4.123, respectively. The exponent b of the lengthweight relationship was 2.4 and exploitation level (E) was 0.72. The high mortality, low condition indices and negative allometric of P. viridis in Marudu Bay is caused by a lack of suitable food in the surrounding water.  相似文献   

High-resolution simulations for Vietnam - methodology and evaluation of current climate     

Jack Katzfey  Kim Nguyen  John McGregor  Peter Hoffmann  Suppiah Ramasamy  Hiep Van Nguyen  Mai Van Khiem  Thang Van Nguyen  Kien Ba Truong  Thang Van Vu  Hien Thuan Nguyen  Tran Thuc  Doan Ha Phong  Bang Thanh Nguyen  Tan Phan-Van  Trung Nguyen-Quang  Thanh Ngo-Duc  Long Trinh-Tuan 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(2):91-106

To assist the government of Vietnam in its efforts to better understand the impacts of climate change and prioritise its adaptation measures, dynamically downscaled climate change projections were produced across Vietnam. Two Regional Climate Models (RCMs) were used: CSIRO’s variable-resolution Conformal-Cubic Atmospheric Model (CCAM) and the limited-area model Regional Climate Model system version 4.2 (RegCM4.2). First, global CCAM simulations were completed using bias- and variance-corrected sea surface temperatures as well as sea ice concentrations from six Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate models. This approach is different from other downscaling approaches as it does not use any atmospheric fields from the GCMs. The global CCAM simulations were then further downscaled to 10 km using CCAM and to 20 km using RegCM4.2. Evaluations of temperature and precipitation for the current climate (1980-2000) were completed using station data as well as various gridded observational datasets. The RCMs were able to reproduce reasonably well most of the important characteristics of observed spatial patterns and annual cycles of temperature. Average and minimum temperatures were well simulated (biases generally less than 1oC), while maximum temperatures had biases of around 1oC. For precipitation, although the RCMs captured the annual cycle, RegCM4.2 was too dry in Oct.-Nov. (-60% bias), while CCAM was too wet in Dec.- Mar. (130% bias). Both models were too dry in summer and too wet in winter (especially in northern Vietnam). The ability of the ensemble simulations to capture current climate increases confidence in the simulations of future climate.  相似文献   

Experimental study on the solar reflectance of crushed rock layer with different sizes     

Yinghong Qin  Kanghao Tan  Jia Liang  Yunfeng Li  Fanghua Li 《Environmental Earth Sciences》2016,75(9):817

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Nonlinear fault detection threshold optimization method for RAIM algorithm using a heuristic approach     

He  Pan  Liu  Gang  Tan  Chun  Lu  Yan-e 《GPS Solutions》2016,20(4):863-875

GPS Solutions - The threshold value used in receiver autonomous integrity monitoring algorithms to identify faults has a significant impact on positioning integrity and GPS/GNSS availability. The...  相似文献   

A diagnostic method for aircraft turbulence based on high-resolution numerical weather prediction products     

Xiao-kang Shi  Jian-wen Liu  Yao-dong Li  Bing Huang  Yong-qiang Tan 《Natural Hazards》2015,77(2):867-881

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The oxidation state and microstructural environment of transition metals (V,Co, and Ni) in magnetite: an XAFS study     

Xiaoliang Liang  Zisen He  Wei Tan  Peng Liu  Jianxi Zhu  Jing Zhang  Hongping He 《Physics and Chemistry of Minerals》2015,42(5):373-383

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Analysis of infiltration of 2D trickle irrigation under multiple‐line sources     

Jiann‐Mou Chen  Yih‐Chi Tan  Yu‐Zhang Wu 《水文研究》2008,22(14):2657-2666

The analysis of infiltration of 2D trickle irrigation under multiple‐line sources, governed by the celebrated Richards equation, is performed, aiming at determining the efficiency of trickle irrigation so as to reduce the water demand. A closed‐form solution is explicitly obtained by utilizing the Fourier integral transformation, and this serves as a means to compute the distribution of volumetric water content during trickle irrigation. Results for the infiltration of 2D trickle irrigation under single line and multiple‐line sources are presented, which illustrate the distribution of infiltration water that diffuses into the soil, and make it possible to calculate the period of time required for trickle irrigation for different plants. The results can be applied to verify complicated solutions from other numerical models. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Reply to comment on ‘C.‐P. Tung,N.‐M. Hong,C.‐H. Chen,and Y.‐C. Tan. 2004. Regional daily baseflow prediction. Hydrological Processes 18: 2147–2164’     

Nien‐ming Hong  Chu‐hui Chen  Ching‐pin Tung  Yi‐chi Tan 《水文研究》2008,22(6):887-889

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