和田玉的鉴定与评估

新疆和田玉是世界软玉品种中最好的一种,有“玉王”之称。该文对和田玉的矿物组成、化学成分及物理性质进行了鉴定分析,提出了和田玉原料及玉器的评估方法。     

Formation and early development of tetraspores of Polysiphonia urceolata （Rhodomelaceae, Rhodophyta）

Polysiphonia urceolata is one type of potential commercial red seaweeds used for breeding and cultivation, because of its significant biochemical and biomedical application. However, the information of breeding and seedling incubation for cultivation is limited, especially the early development. In this study, tetrasporohyte and gametophyte of P. urceolata were taken as the study materials in Huiquan Bay, Qingdao, China. The cleaned and sterilized tetrasporophytes and gametophytes were pre-cultured in sterilized seawater, then nurtured at 18°C, 25 μmol photons m⁻² s⁻¹ in 12:12 h (light:dark) photoperiod. Continuous observation under microscope showed that the early development consists of bipolar division stage and seedling stage. In the division stage, tetraspores germinate into bipolar sporelings that further differentiate into a colorless rhizoidal portion and a lightly pigmented upright shoot. The lightly pigmented rhizoidal cell develops to a rhizoid and the larger pigmented cell transforms to an erect axis. In the seedling stage, several quasi-protuberances appear on the erect axis and form juvenile seedlings. The results demonstrate the culture of P. urceolata from tetraspores under laboratory conditions. Supported by National Key Technology Support Program, Development Program of China (No.2006AA09Z21), National Natural Science Foundation of China (No. 40618001 and N_CUHK438/06) and Shandong Agricultural Seed Stock Breeding Project     

Ab initio prediction of 29Si-NMR chemical shifts

The ability of several ab initio models to predict experimental ²⁹Si-NMR chemical shift is examined. The shielding values of trimethylsilyl chloride (A), t-butyldimethylsilyl chloride (B) and allytrimethylsilane (C) are calculated by GIAO, CSGT and IGAIM methods, using HF/6–31G^*, B3LYP/6-31G^*, HF/6–311+G^**, B3LYP/6–311+G^** and MPW1PW91/6–311+G^** models respectively. The ²⁹Si chemical shifts calculated by GIAO method using HF/6–311+G^** model are highly in agreement with those obtained experimentally. All of the models above reproduce the trends of chemical shifts in all cases studied, suggesting that the models are of practical value.     

Numerical simulation of the Kuroshio using nested model of three-dimensional baroclinic circulation

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差分InSAR处理及其应用分析

本文结合实例分析和介绍了影响In SAR处理结果的几个重要环节。如: 数据源及像对选择 ;影响In SAR处理的因素等。目前有4～5种雷达卫星数据可以用于In SAR的处理,ERS-1/2卫星数据效果最好; 差分In SAR处理的工作步骤中,亚像元精度的配准、相干性分析、全相位恢复等是其中的关键技术。In SAR的精度和噪声水平是In SAR能否实用的重要条件,噪声影响地物的相干性,噪声较大部位相干性消失,在整幅图像中噪声区域不大于30% ,将不影响整体的In SAR测量结果。     

东秦岭石界河群中石榴石成分环带所记录的PTt轨迹

位于河南省西峡县北部地区的石界河群榴云片岩中的石榴石发育有很好的结构和成分环带。本文应用微分热力学方法对其环带成分进行计算,确定出一条顺时针方向的PTt轨迹。该轨迹与应用矿物共生组合世代关系确定的PTt轨迹十分吻合。     

SEA LEVEL RISE OF THE ZHUJIANG RIVER DELTA AND NEOTECTONICS

A linear regression analysis of 28 selected tide-gauge stations of the Zhujiang Estuary shows that there has been a tendency of local sea level rise at a rate of 2.028 mm per year. The origin of the variation is significantly attributed to the local tectonic movement of discrepant fault-block. Based on this, four types of relative local sea level changes are classified. According to calculation, half of the fertile land, or 800 km2 of the delta plain will have been submerged by sea water by about 2040. This will yield a significant influence on the economic construction and human activities.     

长春双阳地震台数字水管仪倾斜潮汐观测质量评定

对双阳地震台DSQ型水管倾斜仪2001～2006年倾斜潮汐观测资料作了质量评定,检定结果显示:观测资料连续,仪器观测状况稳定,年零漂、年变幅小,噪声水平低.     

f-3项与投影函数对电离层延迟的影响

依据Chapman正常电离层理论,构造Chapman剖面函数加权投影函数,给出VTEC三角多项式模型,并以武汉站2005年1月1日观测数据进行实例解算,分析电离层延迟f-3项、电离层单层高度、电离层投影函数形式等对电离层延迟的影响.     

地震电磁卫星星座轨道优化设计

根据地震监测任务对电磁卫星的需求．利用点数字仿真方法和遗传算法优化设计了电磁卫星星座。由4颗卫星组成的电磁卫星星座之空间分辨率约为700km．覆盖全球的观测用时周期为12小时。