滆湖人工放流技术的改进及其效益分析

本文研究了滆湖1986—1988年人工放流主要鱼类的年龄组成、生长速度、肥满度、回捕率及其经济效益。青鱼、草鱼和团头鲂等主要放流种类的回捕率为23.85％—39.88％;鲢鳙鱼为8.20％—19.63％;中华绒螫蟹苗和蟹种分别为2.69％和48.57％。人工放流的产量效益平均为14.3倍,经济效益早均为9.6倍。     

青海湖盆地35万年来的植被演化及环境变迁

本文依据青海湖南岸二郎剑阶地QH-86孔(深155m)中200余个孢粉样品的分析资料,将该孔深78m以上的孢粉图式,从下至上划分出七个区域性孢粉带,并结合铀系法测年数据,论述了350ka B.P.来的湖区植被和环境演变。其气候曲线与毗邻的柴达木盆地,甚至与深海钻孔及洛川黄土,具有可对比性。     

河套灌区食用向日葵空壳率高的原因及对策

食用向日葵生产已经成为河套灌区农民经济收入的支柱产业,但是在生产中,普遍存在着空壳率高的问题,这是生产中急待解决的问题。本文就影响食用向日葵空壳率高的主要原因进行了分析,并针对此问题提出了应对的对策。     

呼和浩特地区一次对流天气过程分析

利用多普勒雷达资料的强度场、速度场、垂直累积液态水含量等资料,对2009年7月29日呼和浩特市及以西地区的1次中到大雨天气过程进行了分析。结果表明:由不同仰角的PPI图和多普勒雷达径向速度场的变化来判断未来雷达回波的强度及移动方向,对临近预报有重要作用;观测垂直累积液态含水量VIL值的变化可以预报对流天气形成的可能性。     

Installation effects of the post-grouted micropile in marine soft clay

The grouted steel pipe micropile is widely used as structural support and in situ improvement in China. This paper presents measurement of the radial soil stress and excess pore water pressure during the construction processes of the grouted steel pipe micropile (with an enlarged driving shoe) embedded in marine soft clay. Comparative analysis was conducted between the predictions by cavity expansion method (CEM) and maximum stress values in situ. The results show that the existence of the enlarged driving shoe has an effect on the stress change in the surrounding soils during penetration. The maximum radial total stress and excess pore water pressure generated during micropile penetration are approximately 4–6σ_v0′ and 1.5–2.5σ_v0′, respectively. The maximum radial total stress and excess pore water pressure, which appeared near the pile wall during the process of post-grouting, are approximately 5–7c_u and 4–6c_u, respectively. The predictions of CEM for pore water pressure during micropile penetration and post-grouting are in reasonable agreement with the field test data.

     

A p–y curve model for laterally loaded XCC pile in soft clay

Acta Geotechnica - This paper presents a p–y curve model for laterally loaded X-sectional cast-in-place concrete (XCC) piles, which are a type of non-circular cross-sectional pile, in soft...     

A technique for prediction of SPEs from solar radio flux by statistical analysis,ANN and GA

Solar Radio Flux (SRF) is the significant index in easily evaluating everyday solar activities. From the statistical analysis of SRF at 2800 MHz, 1415 MHz and 610 MHz from 1976 to 1994, and only 111 Solar Proton Events (SPEs) occurring in the same period, we have given the statistical relation between them. In fact, there occurred a total of 131 SPEs in the same period, but we dealt with only 111 SPEs of them, because of lack of SRF data in SGD (2800 MHz, 1415 MHz and 610 MHz). We also discussed the possible parameters of SRF at 2800 MHz, 1415 MHz and 610 MHz for prediction of SPEs by statistical analysis, Artificial Neural Network (ANN) and Genetic Algorithm (GA) using MATLAB. In this study, we used some parameters: the daily total SRF, the overall rate of increase of SRF and SPEs.     

Morphology and Structure of High-redshift Massive Galaxies in the CANDELS Fields

Using the multi-band photometric data of all five CANDELS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey) fields and the near-infrared (F125W and F160W) high-resolution images of HST WFC3 (Hubble Space Telescope Wide Field Camera 3), a quantitative study of morphology and structure of mass-selected galaxies is presented. The sample includes 8002 galaxies with a redshift 1 < z < 3 and stellar mass M_*> 10¹⁰M_⊙. Based on the Convolutional Neural Network (ConvNet) criteria, we classify the sample galaxies into SPHeroids (SPH), Early-Type Disks (ETD), Late-Type Disks (LTD), and IRRegulars (IRR) in different redshift bins. The findings indicate that the galaxy morphology and structure evolve with redshift up to z ～ 3, from irregular galaxies in the high-redshift universe to the formation of the Hubble sequence dominated by disks and spheroids. For the same redshift interval, the median values of effective radii (r_e) of different morphological types are in a descending order: IRR, LTD, ETD, and SPH. But for the Sérsic index (n), the order is reversed (SPH, ETD, LTD, and IRR). In the meantime, the evolution of galaxy size (r_e) with the redshift is explored for the galaxies of different morphological types, and it is confirmed that their size will enlarge with time. However, such a phenomenon is not found in the relations between the redshift (1 < z < 3) and the mean axis ratio (b/a), as well as the Sérsic index (n).     

Genetic improvement on Chinese shrimp （Fenneropenaeus chinensis）： growth and viability performance in F1 hybrids of different populations

Fenneropenaeus chinensis distributed in the Yellow Sea and Bohai Sea of China and the west coast of the Korean Peninsula. Different geographical populations represent potentially different genetic resources. To learn further the characteristics of different geographical population, crosses among two wild and three farmed populations were produced. The two wild populations were from the Yellow Sea and Bohai Sea （WYP）, and the west coast of the Korean Peninsula and coast （WKN）. The three farmed populations included the offspring of first generation of wild shrimp from coast in Korea （FKN）, the Huang Hai （the Yellow Sea in Chinese） No.1 （HH1）, and JK98. The phenotypes growth and survival rates of these populations were compared to confirm the feasibility for crossbreeding. The body length （BL）, carapace length （CL）. carapace width （CW）, height of the second and third abdominal segment （HST）, width of the second and third abdominal segment （WST）, length of the first abdominal segment （LF）, length of the last abdominal segment （LL）, live body weight （BW）, and survival rate were measured, Different combinations were statistically performed with ANOVA and Duncan＇s Multiple Range Test. The results show that the survival rate of JK98（♀）×WKN（♂） was the highest, followed by WYP（♀）×WKN（♂）, FKN（♀）×WYP（♂）, FKN（♀）×HHI（♂） and WYP（♀）×FKN（♂）; the body weight of FKN（♀）×HHI（♂） was the highest, followed by FKN（♀）×WYP（♂）, WYP（♀）×WKN（♂）, WYP（♀）×FKN（♂） and JK98（♀）×WKN（♂）; the total length had the same ranking as the body weight. All growth traits in hybrids JK98（♀）×WKN（♂） were the lowest among all combinations. F1 hybrids had significant difference （P〈0.05） in BL, CL, HST, LL, and BW; and insignificant difference （P〉0.05） in other growth traits and survival rate. The results of Duncan＇s Multiple Range Test are that BL and CL of J     

新型紫外光致发光图像高速采集装置的研制及其在筛分天然钻石中的应用

为了提高批量小颗粒钻石的筛查效率和准确性,研制了一种新型紫外光致发光图像高速采集装置——珠宝首饰观察鉴定仪(DDO),通过对激发光波长、工业相机等的选用和结构设计技术突破,以及对发光现象采集方式进行创新,实现了批量观察不同宝石间的光致发光现象和发光延迟现象差异等,从而实现对宝石高效检测。对20 000粒以上无色天然钻石、合成钻石和钻石相似品进行的DDO测试结果表明,98%~99%的无色天然钻石在紫外光激发光停止后的0.1~10 ms内可观察到的碧蓝色磷光现象,为天然钻石典型特征,合成钻石和其他无色宝石的发光特征(发光颜色、强度、持续时间、结构分区)明显区别于天然钻石,由此建立了一种通过观测包括荧光、衰减时间在100 ms内的连续发光(磷光)特征差异性作为筛分条件快速、准确筛分无色天然钻石的新方法。本装置提高了钻石鉴定的准确度和检测效率,对天然钻石的筛查通过率可高达99%,对合成钻石和仿钻石的筛查准确性可达100%。