基于CORS的智能手机高精度定位平台研究

以智能手机为载体,研究了连续运行参考站(CORS)和智能手机相结合高精度导航定位关键技术,形成了基于江苏省连续运行参考站(JS-CORS)的移动终端高精度导航定位解决方案.同时,开发了相应软件系统,包含一套移动端手机软件(APP)和一套位置管理平台.基于CORS的智能手机高精度定位平台的建设,对于延伸智能手机在地理测绘...     

Spermatozoid life-span of two brown seaweeds, Saccharina japonica and Undaria pinnatifida, as measured by fertilization efficiency

During sexual reproduction of seaweeds, spermatozoid (sperm) discharge is triggered by chemical messengers (pheromones) released by the female gametes. The chemotactic ability of the sperm ensures fertilization success. Using unialgal male and female gametophyte material under designated standard gametogenesis testing (SGT) conditions, the potential life-span of the sperm of two seaweeds, Saccharina japonica and Undaria pinnatifida, was assessed by their ability to fertilize eggs. Results show that within 20-30 min after being discharged, sperm of both species could complete fertilization without an apparent decline in fertilization rate. Although fertilization rate 60–120 min after sperm discharge dropped significantly in both species, some sperm were viable enough to fertilize the eggs. In S. japonica, at 12°C, some sperm were able to fertilize eggs up to 12 h after discharge. In both species, egg discharge rates (EDR) in the male and female mixed positive controls were significantly higher than those of all the sperm-testing groups. Doubling the seeded male gametophytes of S. japonica in the SGT tests significantly increased the EDR, further confirming the effect of the presence of the male on the female in terms of facilitating egg discharge from oogonia.     

Periodic exposure to ambient solar irradiance benefits the growth of juvenile seedlings of Hizikia fusiformis

In our trials, from 2007 to 2008, of mass production of seedlings of Hizikia fusiformis using synchronization techniques, problems of a dark thalli phenomenon and epiphytes contamination severely threatened the health of juvenile seedlings. In this investigation, we optimized conditions for improving the growth of juvenile seedlings. Seven string collectors were seeded with zygotes and a series of experiments were conducted including direct exposure to solar irradiance, co-culture with Ulva spp. and treatme...     

Zoospore-derived monoecious gametophytes in Undaria pinnatifida (Phaeophyceae)

The annual life cycle of the brown seaweed Undaria pinnatifi da(Harvey)Suringer comprises a macroscopic diploid sporophyte stage and a microscopic haploid gametophyte stage.In 2011,an unusual zoospore-derived monoecious gametophyte isolate(designated as line 10-5-3)of U.pinnatifi da was observed.To understand this phenomenon,a comprehensive screening of eighty-two previously identifi ed male gametophyte cultures,isolated from three randomly selected cultivars(lines 10,7,and 5)was performed.Thirty-six of the isolates developed both antheridia and oogonia on the same fi lamentous fragment in a standard gametogenesis test(SGT: 18°C,60 μmol photons/(m 2·s)).Selfi ng of the monoecious gametophyte or crossing it with a normal male gametophyte both gave rise to morphologically normal sporophytic offspring.However,crossing resulted in a much higher fertilization rate(89.7%).The hybrid and selfed sporophytic offspring were grown to maturity in fl ow tanks at an ambient temperature of 10–18°C over a period of 69 days.Active zoospores were released from both types of mature sporophylls.The majority of these developed into male gametophytes,while 15%–20% developed into the observed monoecious structures on the same fi lament.Using PCR amplifi cation it was found that all the monoecious gametophyte isolates and the sporophytic offspring resulting from the selfi ng and crossing lacked the femalelinked microsatellite sequence(a part of the locus Up-AC-2A8,GenBank accession No.AY738602.1),indicating their male nature.U.pinnatifi da is an invasive species in some regions and the implications of the above fi ndings for this species in nature are briefl y discussed.     

日照水库及周边区域综合地质条件分析

日照水库是1959年建成的一座大(二)型水库,位于日照市东港区驻地以西16 km处的付疃河中游,控制流域面积548 km2,是日照城市及国民经济发展的最重要水源保障。近年来日照市经济社会飞速发展,特别随着"山东精品钢基地"等大项目的开工建设,供水安全形势愈发严峻,如何维护日照水库和保护这一水源地更是被提到了重要的议事日程。先行研究分析流域地质条件,是做好日照水库保护建设工作的重要基础。     

一种双向测距与时间同步系统的设计与分析

在研究双向单程伪距测量原理的基础上,设计了双向测距与时间同步（DRTS）终端系统总体构架,阐述了在系统中使用的技术,并搭建了基于DSP＋FPGA的双向测距与时间同步系统软硬件平台。实验结果表明,此系统的码速率为5MHz、中心频率为15MI-Iz时,测距和时间同步的分辨率可达0．15cm和5ps（@1S）,采用不同频率源时测距和时间同步的精度分别为1．038m和3．46ns,采用相同频率源时分别为0．28cm和9．43ps（参考频率稳定度1×10^-10／d量级）。与国外同类产品相比具有测量精度优势,但考虑通用性,此系统的硬件仍需进一步优化,软件上需要做到码速率可调。     

星间链路对地伪距观测量历元归算及分析

对历元偏差引起的伪距变化量逐项分解,总结历元偏差引起的伪距各误差项的偏差典型值,使用多项式插值法进行历元归算,并进行仿真分析,最后以星间链路体制下的星地伪距观测量为实例进行方法验证。仿真分析结果表明当数据采样间隔不大于5 min时,若选取合适的插值阶数,使用多项式插值法能得到优于1 mm的历元归算精度;实测数据结果表明基于多项式插值的历元归算方法是有效的,能够完成星间链路对地伪距观测量的历元归算需求,历元归算造成的误差远小于伪距本身的观测噪声。     

面向5G网络应用的精确时间同步协议测试与分析

随着5G的普及和基站建设,对基站间时间同步精度提出了更高的要求．目前,精确时间同步协议(PTP)只能达到几十纳秒,且频率分布效果差,将其结合同步以太网(SyncE)技术后可以实现网络上所有时钟的频率与时钟源同步．WR(White Rabbit)技术在PTP+SyncE的基础上加入了全数字双混频鉴相器(DDMTD),对节点间相位差进行调整补偿,消除由相位噪声长时间累积引起的不同步,动态实现了整个网络节点的时钟同步．本文分别介绍了将SyncE与PTP结合的同步方法和WR同步方法的原理及实现过程,最后构建实验平台验证同步过程,测试证明可以分别达到百皮秒和几十皮秒的抖动,同步精度分别能达到纳秒和亚纳秒级别.      

煤炭产业经济走势及煤炭企业对策研究

煤基固体废弃物的清洁利用是矿区生态建设亟待解决的问题,重金属的结构形态是煤基固废清洁利用的关键。以安徽淮南矿区潘一矿煤矸石、粉煤灰为研究对象,利用XRF、XRD、SEM和FTIR等微区方法对煤基固废进行表征分析,探讨其精细化学结构及重金属嵌布方式,并结合RAC(Risk Assessment Code)生态风险评价对重金属潜在风险进行评估。结果表明,煤矸石主要粒径以黏粒(0~5 μm)和粗粉砂(10~50 μm)为主,粒度不规则,空间分布间距较大,主要矿物为石英(SiO₂),IR谱线辅助验证了AlO₄和SiO₄的弯曲振动。粉煤灰粒径以粗粉砂(10~50 μm)和砂砾石(50~250 μm)为主,表面以球状包裹体和多孔颗粒组成,粒径大小不一,主要矿物相是莫来石(Al₆Si₂O₁₃),IR谱线发现其存在有机硅Si-O-Si对称伸缩和反对称伸缩。煤矸石中Ni、Pb以有机结合态和铁锰氧化物结合态为主,Cr、Cd、As的赋存形态主要是残渣态;粉煤灰中As主要以残渣态和有机结合态存在,其余重金属元素均以残渣态存在。RAC生态风险评价结果表明,煤矸石和粉煤灰中Cr、As属于低风险水平,其余重金属均无风险。研究结果对煤基固废资源化利用及矿区生态环境保护具有重要的现实意义。