基于恒虚警检测的图像声呐目标跟踪

无人化、智能化的目标探测与跟踪是未来水下探测的必然趋势。针对水下移动小目标,通过固定位置的声呐接收的角度与距离二维信息,提出了一套自动跟踪方法。首先,对图像声呐进行恒虚警处理,同时引入时域参量,通过在门限计算中增加之前时间的权重,抑制位置恒定的静态强背景干扰。之后,基于空间上目标的连续运动,提出了小目标的自动跟踪算法。湖试数据实验处理表明：该方法能有效抑制干扰,实现水下小目标的自动探测跟踪。     

黄河入海口径流量和输沙量对黄河三角洲生态环境的影响

20世纪后期黄河入海口的径流量减少和多次断流。这对流域下游地区的经济发展、尤其是农业产生明显影响。特别应注意的是,与径流量减少的同时,输沙量也明显减少,致使20世纪90年代以来入海口造陆面积锐减,在1996年和1997年甚至造陆停滞、出现海侵。黄河入海口的径流量、输沙量减少可能引发的一系列生态环境问题中,造陆面积的减少和海水的侵入可能关系到黄河三角洲的经济发展前途,近期则危及胜利油田的安全,应引起有关部门的关注。文中还探讨了用地球物理测井方法检测生态环境的变化。     

西太平洋台风对上海地区钻孔应变的低频扰动特征分析

基于上海佘山台四分量钻孔应变仪在6次西太平洋台风期间的观测记录,利用小波分解、优势振动方向等处理方法提取出台风所激发的显著低频扰动信号,并详细分析扰动信号在时频域及空间域的表现特性.结果显示:在低频区间,台风激发的扰动信号优势周期为2～4 min,信号能量随台风进程而变化,并主要与台风量级、台风中心的位置(海上或陆域)...     

Levels and patterns of genetic variation in Pampus minor:Assessment of a mitochondrial DNA control region sequence

Pampus minor is an important commercial fish. Due to the similarity of external morphological characteristics among the genus Pampus species, P. minor has often been identified as the juvenile group of both P. cinereus and P. argenteus. While little genetic background on this species is known, this study was based on control region sequences and provided the first evaluation of the genetic signature of 264 individuals of P. minor from 11 populations along the coasts of China and Malaysia. The results indicate high genetic haplotype diversity and low nucleotide diversity in this species. Additionally, two differentiated haplotype lineages were identified in the P.minor populations. However, phylogenetic structures corresponding to the geographical locations were unable to be established. Analysis of molecular variance identified a vast majority of the genetic variation occurring within populations. F-statistic test value(FST) of pairwise indicated that great differences existed between the Chinese and Malaysian P. minor populations. For the Chinese populations, the genetic differences were insignificant with the exception of the Xiamen population, which is a marginal population. During the late Pleistocene, a population expansion of P. minor occurred. These expanded populations originated from the glacial refugium in the South China Sea and then rapidly occupied and adapted to their new habitat. The results of this study provide genetic information for ensuring the protection and management of P. minor resources.     

北京怀柔云蒙山地区花岗岩风化过程的地球化学基因

地球化学基因是近两年提出的一种新的地球化学示踪技术,本文选择北京怀柔云蒙山地区两个邻近的花岗岩风化剖面(编号为B和C)来分析岩性地球化学基因和金矿化地球化学基因的属性特征.剖面B样品的化学蚀变指数CIA变化为51.3～58.9,WIG的范围为89.4～68.6,属于初始风化程度;剖面C样品的CIA变化为52.4～78....     

中国老龄事业发展水平时空演化及其与经济发展水平的空间匹配

基于“积极老龄化”理论框架,从健康、参与和保障三大维度构建中国老龄事业发展水平评价指标体系。以中国大陆31个省（自治区、直辖市）为研究对象,运用数理统计、重心和空间重叠性、空间错位分析和计量经济模型等方法,分析了2004—2016年中国老龄事业发展水平的时序变化、空间格局、错位特征及其影响机制。结果表明：① 2004—2016年,中国老龄事业发展水平整体快速增长,区域差异逐渐缩小,但区域失衡特征不容忽视。东部地区整体水平高于中部、西部及东北地区,并伴有“西部崛起,中部及东北地区塌陷”特征。东部地区呈现“两极化”现象。② 中国老龄事业基本处于低水平发展阶段,空间分布由西南-东北辐射递减模式转变为显著的“中部塌陷”式,形成一条由北向南的低值集聚带,纵贯中国中部,与区域经济发展存在错位关系。③ 负向错位区主要分布在黄河、长江中上游地区,正向错位区主要集中在东部沿海、长城以北等地区。空间错位强度存在显著的地域差异性,其中西部地区尤为显著。④ 老龄事业发展水平的动态变化是多因素交互作用的结果。经济发展水平、政府政策和行政导向及产业结构的时空分异对其产生正向影响。市场经济规模扩大和人口老龄化未对老龄事业发展起推动作用,与理论预期不符。家庭规模小型化的倒逼作用不显著。     

Base cation concentrations in forest litter and topsoil have different responses to climate and tree species along elevational gradients

The forest litter is an essential reservoir of nutrients in forests, supplying a large part of absorbable base cations(BC) to topsoil, and facilitating plant growth within litter-soil system. To characterize elevational patterns of base cation concentrations in the forest litter and topsoil, and explore the effects of climate and tree species, we measured microclimate and collected the forest litter and topsoil(0-10 cm) samples across an elevational range of more than 2000 m(1243 ～ 3316 m a.s.l.),and analyzed the concentrations of BC in laboratory. Results showed that: 1) litter Ca concentration displayed a hump-shaped pattern along the elevational gradients, but litter K and Mg showed saddle-shaped patterns. Soil Ca concentration increased with elevation, while soil K and Mg had no significant changes. 2) Ca concentration in the forest litter under aspen(Populus davidiana) was significantly higher than that in all other species, but in topsoil, Ca concentration was higher under coniferous larch and fir(Larix chinensis and Abies fargesii). Litter K and Mg concentrations was higher under coniferous larch and fir, whereas there were nosignificant differences among tree species in the concentrations of K and Mg in topsoil. 3) Climatic factors including mean annual temperature(MAT), growing season precipitation(GSP) and non-growing season precipitation(NGSP) determined BC concentrations in the forest litter and topsoil. Soil C/N and C/P also influenced BC cycling between litter and soil. Observation along elevations within different tree species implies that above-ground tree species can redistribute below-ground cations, and this process is profoundly impacted by climate. Litter and soil Ca, K and Mg with different responses to environmental variables depend on their soluble capacity and mobile ability.     

促精宝汤治疗弱精症65例临床观察

目的：探讨促精宝汤治疗弱精症的临床疗效及其作用机制。方法：将131例弱精症患者随机分为2组,治疗组65例采用促精宝汤治疗,对照组66例采用复方玄驹胶囊治疗。结果：总有效率治疗组为90.8%,对照组为81.8%,组间比较,差异有统计学意义（P<0.05）;治疗组在改善患者精液量、精子密度、精子活率、a级精子和b级精子、精浆超氧化物歧化酶同工酶（SOD）、丙二醛（MDA）、一氧化氮（NO）含量等方面均明显优于对照组,差异均有统计学意义（P<0.05）。结论：促精宝汤治疗弱精症的临床疗效显著,其作用机制可能与提高SOD含量、降低MDA与NO的表达有关。     

Interactive Effects of Ultraviolet Radiation and Dissolved Organic Carbon on Phytoplankton Growth and Photosynthesis in Sanya Bay,Northern South China Sea

Ocean Science Journal - The effects of a simulated climate change scenario, i.e., increased ultraviolet radiation (UVR) and dissolved organic carbon (DOC), on the growth and photosynthesis of...     

Primary molecular basis of androgenic gland endocrine sex regulation revealed by transcriptome analysis in Eriocheir sinensis

In crustaceans, the male sexual dif ferentiation and maintenance are specially regulated by androgenic gland(AG). However, little is known about the genes involved in the regulation process.RNA-Seq was performed on AG with ejaculatory duct(AG_ED) and ejaculatory duct(ED) as control in Eriocheir sinensis, one of the most important economic and ?shery crabs with typically sex dimorphism. A total of 925 unigenes were identi?ed as dif ferentially expressed genes(DEGs) and the expression of nine genes randomly selected was con?rmed by qRT-PCR. 667 unigenes were up-regulated in AG_ED, being supposed to be AG preferential genes. Among them, the full length of i nsulin-like androgenic gland factor( IAG) cDNA named as Es-IAG was obtained as a logo gene of AG, which together with the genes i nsulin-like receptor( INR), and s ingle insulin binding domain protein( SIBD), might constitute the sex regulation pathway. Several sex related genes were identi?ed, and their function will have to be investigated. Also,the identi?cation of j uvenile hormone epoxide hydrolase 1( JHEH1), ecdysteroid 22-hydroxylase( DIB) and e cdysone receptor( ECR) preliminarily clari?ed the molecular regulation mechanism of eyestalk-AG-testis axis, which plays important roles in molting and reproduction. The results will enhance our understanding for the molecular basis of the AG involved in male sex regulation in crabs.