A COMBINED REFRACTION-DIFFRACTION-DISSIPATION MODEL OF WAVE PROPAGATION

A numerical model based on the mild-slope equation of water wave propagation over complicated bathymetry,taking into account the combined effects of refraction,diffraction and dissipation due to wavebreaking is presented.Wave breaking is simulated by modifying the wave height probability density func-tion and the wave energy dissipation mechanism is parameterized according to that of the hydraulic jumpformulation.Solutions of the wave height,phase function,and the wave direction at every grid point areobtained by finite difference approximation of the governing equations,using Gauss-Seidel Iterative Method(GSIM)row by row.Its computational convenience allows it to be applied to large coast regions tostudy the wave transformation problem.Several case studies have been made and the results compare verywell with the experiment data and other model solutions.The capability and utility of the model forreal coast areas are illustrated by application to a shallow bay of northeast Australia.     

甘肃桦树沟铁铜矿床地球化学及成因

甘肃桦树为铁铜矿床地质、同位素地球化学、包裹体地球化学、同位素年代学研究表明，该矿床形成于震旦纪裂陷海盆环境，矿床成因属典型的热水沉积成矿。     

Detection of trends in precipitation extremes in Zhejiang, east China

Extreme weather exerts a huge impact on human beings and it is of vital importance to study the regular pattern of meteorological and hydrological factors. In this paper, a selection of seven extreme indices is used to analyze the trend of precipitation extremes of 18 meteorological stations located in Zhejiang Province, east China using the Mann–Kendall test. Then the precipitation trends in the plum season (from May to July) and typhoon season (from August to October) are studied separately. The results show that the precipitation trend varies from east to west. There is a positive trend in the east and a negative one in the west. The largest part of Zhejiang Province shows a positive trend in heavy precipitation and the most significant upward trend is detected in Dinghai with 3.4?mm/year for precipitation on very wet days. Although the upward trend of extreme precipitation is not prevailing, the range of increase in specific areas is apparent, like Dinghai with 1.3?mm/year. Precipitation intensity exhibits an upward trend in most areas and a typical upward trend can be found in Dachendao, Tianmushan, and Yuhuan with 0.04, 0.02, and 0.05?mm/year respectively. Precipitation intensity in both plum and typhoon seasons has increased too, especially for the coastal stations.     

苹果套袋栽培中的气象条件与管理措施

苹果套袋初期,高温易发生果实日灼现象,果实膨大期适温为20-27℃,成熟采收期为13-20℃;花芽分化期土壤保持最大含水量的60%为宜,果实膨大期需水量350 mm左右,成熟期连阴雨天气影响果实着色和采收;日照时数多,光照强,光质好,利于花芽分化、果实糖分积累和着色.摘袋时间因品质不同而异,应在阴天或多云天摘袋;若晴天摘袋,宜在10-14时进行.     

Experimental evidence for eukaryotic fossil preservation: Onion skin cells in silica solution

Research on the origin of eukaryotes often focuses on the exceptional preservation found in silicified Precambrian fossils. Nuclei like subcellular structures in well-preserved fossil becomes confusion and arguments, which focus on whether the partial degradation of prokaryotes produces artifacts that resemble a ‘nucleus’, or fossilized nuclei of eukaryotes. In order to understand the mechanisms of silicification and identify the fossilized subcellular and microstructures in rocks, a series of laboratory controlled experiments were performed for simulating the silicification process. The effects of different silica solutions in eukaryote fossilization were studied in our experiments by exposing onion skin cells (epidermis) to silica solutions. Onion skin provides a good experimental model because of its well characterized cellular structures which are easily observed. The designed experiments revealed that the possibility of onion cell preserved as a “fossil” with nuclear structures, the first week fossilization, or mineralization as rapid as 1 week is important. And the experiment also revealed interactions between silica and the onion skin cell wall surface functional groups were weak. The preservation of nuclei in the onion skin model was due to precipitation in highly supersaturated silica solutions rather than simply the high silica concentration. When the silica gel precipitates slowly at low supersaturation states, the nuclei were not well preserved, but the rapid precipitation at high supersaturated silica conditions preserved nuclear structures. A better understanding of the processes involved in onion skin fossilization will further contribute to issues concerning the silicification of other eukaryotic materials.     

海藻中类胡萝卜素的提取及含量测定

许多研究已经表明，类胡萝卜素是分布最广泛、最重要的一类光辅助合成色素。类胡萝卜素具有多种生物学功能：作为化学保护剂可抵抗由植物自身叶绿素的光敏氧化作用引起的有害作用，给人体补充β-胡萝卜素可有效降低心血管疾病和癌症的发生概率，高摄入富含类胡萝卜素的饮食和降低白内障发生的危险之间有重要联系(Bendich，1993)。海藻中含有丰富的类胡萝卜素，从结构类型说，通常可以分为三类：胡萝卜素、叶黄素和类胡萝卜素酸。海藻中还含有多种特有的类胡萝卜素，如褐藻黄素、甲藻黄素、硅藻黄素等。直到目前为止，海藻中类胡萝卜素的组成与生理学功能尚没有明确的结论，因而对我国丰富的海藻资源中的类胡萝卜素进行较为系统和全面的化学及生物活性研究已成为摆在我们面前的一个重要课题。本研究选取我国青岛海滨三类大型经济海藻——红、绿、褐藻中资源量丰富的代表性种类作为实验材料，较系统地测定了其中类胡萝卜素的含量，并运用经典的柱层析法对各类胡萝卜素组分进行了分离，通过薄层分析和可见光谱扫描对各分离组分进行了定性、定量分析。     

桂中坳陷环江凹陷上古生界海相页岩储层孔隙结构和分形特征研究

通过有机地化分析、全岩X衍射矿物分析、甲烷等温吸附及低压氮气吸附实验,本文对桂中坳陷环江凹陷上古生界页岩样品的孔隙结构及分形特征进行了研究.结果表明:研究区页岩总有机碳含量(TOC)平均为2.40%,热成熟度(Ro)平均为2.65%,处于过成熟演化阶段.页岩主要的矿物组成为石英和黏土.页岩的比表面积平均为5.86 m2/g,孔容平均为0.014 9 mL/g,平均孔径为11.2 nm.页岩中发育大量的中孔,主要呈两端开口的圆筒形孔或四边开放的平行板状孔.页岩中TOC含量和石英含量越多,微-中孔越发育、比表面积和孔容越大,而平均孔径则变小.通过Frenkel-Halsey-Hill (FHH)模型和氮气吸附实验数据计算得到孔隙表面分形维数D1(平均为2.428 4)和孔隙结构分形维数D2(平均为2.622 2),对应的相对压力(P/P0)分别是0~ 0.45和0.45 ~ 0.99.分形维数D1、D2随着比表面积、孔容的增加而增加,而平均孔径随着前者的增加而减小.分形维数D1、D2、TOC含量、石英含量和甲烷吸附量之间呈现较好的正相关性,但随着黏土矿物含量的增多而减小.分形维数D1与Langmuir压力存在弱负相关性,分形维数D2随Langmuir压力增大有变大的趋势.桂中坳陷西北部页岩分形维数越大,孔隙结构越复杂,其对天然气的吸附和存储能力越强.     

Assessment of PPP integer ambiguity resolution using GPS,GLONASS and BeiDou (IGSO,MEO) constellations

Although integer ambiguity resolution (IAR) can improve positioning accuracy considerably and shorten the convergence time of precise point positioning (PPP), it requires an initialization time of over 30 min. With the full operation of GLONASS globally and BDS in the Asia–Pacific region, it is necessary to assess the PPP–IAR performance by simultaneous fixing of GPS, GLONASS, and BDS ambiguities. This study proposed a GPS + GLONASS + BDS combined PPP–IAR strategy and processed PPP–IAR kinematically and statically using one week of data collected at 20 static stations. The undifferenced wide- and narrow-lane fractional cycle biases for GPS, GLONASS, and BDS were estimated using a regional network, and undifferenced PPP ambiguity resolution was performed to assess the contribution of multi-GNSSs. Generally, over 99% of a posteriori residuals of wide-lane ambiguities were within ±0.25 cycles for both GPS and BDS, while the value was 91.5% for GLONASS. Over 96% of narrow-lane residuals were within ±0.15 cycles for GPS, GLONASS, and BDS. For kinematic PPP with a 10-min observation time, only 16.2% of all cases could be fixed with GPS alone. However, adding GLONASS improved the percentage considerably to 75.9%, and it reached 90.0% when using GPS + GLONASS + BDS. Not all epochs could be fixed with a correct set of ambiguities; therefore, we defined the ratio of the number of epochs with correctly fixed ambiguities to the number of all fixed epochs as the correct fixing rate (CFR). Because partial ambiguity fixing was used, when more than five ambiguities were fixed correctly, we considered the epoch correctly fixed. For the small ratio criteria of 2.0, the CFR improved considerably from 51.7% for GPS alone, to 98.3% when using GPS + GLONASS + BDS combined solutions.     

GLONASS phase bias estimation and its PPP ambiguity resolution using homogeneous receivers

Integer ambiguity resolution (IAR) appreciably improves the position accuracy and shortens the convergence time of precise point positioning (PPP). However, while many studies are limited to GPS, there is a need to investigate the performance of GLONASS PPP ambiguity resolution. Unfortunately, because of the frequency-division multiple-access strategy of GLONASS, GLONASS PPP IAR faces two obstacles. First, simultaneously observed satellites operate at different wavelengths. Second and most importantly, distinct inter-frequency bias (IFB) exists between different satellites. For the former, we adopt an undifferenced method for uncalibrated phase delay (UPD) estimation and proposed an undifferenced PPP IAR strategy. We select a set of homogeneous receivers with identical receiver IFB to perform UPD estimation and PPP IAR. The code and carrier phase IFBs can be absorbed by satellite wide-lane and narrow-lane UPDs, respectively, which is in turn consistent with PPP IAR using the same type of receivers. In order to verify the method, we used 50 stations to generate satellite UPDs and another 12 stations selected as users to perform PPP IAR. We found that the GLONASS satellite UPDs are stable in time and space and can be estimated with high accuracy and reliability. After applying UPD correction, 91 % of wide-lane ambiguities and 99 % of narrow-lane ambiguities are within (?0.15, +0.15) cycles of the nearest integer. After ambiguity resolution, the 2-hour static PPP accuracy improves from (0.66, 1.42, 1.55) cm to (0.38, 0.39, 1.39) cm for the north, east, and up components, respectively.