Paleoclimate implication of oxygen and carbon isotopic composition from diagenesis coral

Oxygen and carbon isotopic compositions of diagenesis? coral samples from NY-1 core at the depth of 22 to 50 m, together with mineral compositions of transitive coral samples of 17 to 18 m at the depth, were meas ured. The data exhibited that when aragonite changed to calcite, its oxygen and carbon isotopic compositions dropped roughly on a linear trend. The linear trend implies that the oscillation pattern of the origin oxygen and carbon isotopic ratios of the aragonite could probably be retained after they diageneticly changed into calcite. Oxygen isotopic stratigraphy for the NY-1 core at the depth between 22 and 50 m was determined according to the δ⁸O ratios of the calcite coral. The oxygen stratigraphy provided an age of about 289 ka for 45 m of the NY-1 core, which agreed with that by paleomagnetic stratigraphy.     

夏季鄱阳湖水体温度场及其气温效应

１９８７年和１９８８年７、８月在鄱阳湖中心的棠荫岛进行了小气候考察，资料分析表明，夏季鄱阳湖水体气温效应，阴天和晴天的夜间表现为正效应，晴天的白天（０９－１８时）为负效应；夏季水上点气温比陆上点高，宏观上鄱阳湖水体呈现为热源。      

江西大吉山钨矿床不同成矿阶段稳定同位素地球化学

大吉山钨矿床是一个著名的石英脉型钨矿床。该矿床主成矿阶段成矿作用是在物理化学条件稳定、同位素平衡交换条件下进行的，而碳酸盐阶段的成矿作用则是在低温条件下大气降水与花岗岩相互作用过程中进行的     

Temporal variability of tsunami arrival detection distance revealed by virtual tsunami observation experiments using numerical simulation and 1-month HF radar observation

The combination of a high-frequency ocean surface radar and a tsunami detection method should be assessed as the onshore-offshore distribution of tsunami detection probability, because the probability will vary in accordance with the signal-to-noise ratio (SNR) and the tsunami magnitude in addition to the radar system specifications. Here, we statistically examine the tsunami detection distance based on virtual tsunami observation experiments by using signals received by a high-frequency radar in February 2014 installed on the southern coast of Japan and numerically simulated velocities induced by a Nankai Trough earthquake. In the experiments, the Doppler frequencies associated with the simulated velocities were superimposed on the receiving signals of the radar, and the radial velocities were calculated from the synthesized signals by the fast Fourier transform. Tsunami arrival was then detected based on the temporal change in the cross-correlation of the velocities, before and after tsunami arrival, between two points 3 km apart along a radar beam. We found that the possibility of tsunami detection primarily depends on the kinetic energy ratio between tsunami current and background current velocities. The monthly average detection probability is over 90% when the energy ratio exceeds 5 (offshore distance: 9 km ≤ L ≤ 36 km) and reduces to 50% when the energy ratio is approximately 1 (L = 42 km) over the shelf slope. The ratio varied with the background current physics and SNR, which was mainly affected by ocean surface wave heights and ionospheric electron density.     

面向知识层次的主动式航海图书保障模式设计

针对当前航海图书产品应用领域的不断拓展及其在不同应用领域的多样化需求,以及新的技术条件下海图制图手段的飞速发展,探讨了航海图书产品保障模式的转变,提出了构建面向知识层次的主动式保障模式的思想;从保障产品的多样性、快速保障的可行性以及远程保障的必要性等方面,研究了航海图书产品保障的发展趋势,为下一步海图制图与应用的发展提出了新的构想。     

一种纸质海图条形码自动生成方法

条形码是正式出版海图的身份标识,表明海图产品合法性。针对当前纸质海图中条形码的生成仍采用手工方式的不足,在分析条形码编码规则基础上,提出了一种基于MicroStationV8的条形码自动生成方法,并实验开发了相应的条形码生成模块,从而验证了所提方法的有效性和优越性。     

全空间中空腔内壁点电源场电位的边界元算法及其应用

本文应用边界元数值计算法对全空间中空腔内壁点电源场的电位求解。并将其有效地应用于井下电阻率法三维模拟计算中，从理论上给出了巷道电阻率法中正常背景场与异常场的某些基本规律以及实际资料解释中所需注意的问题。     

Hydrogen and oxygen isotopic compositions of meteoric waters in the eastern part of China

42 meteoric water samples were analyzed for their δ¹⁸O and δD values. It can be seen that both δ¹⁸O and δD values vary synchronously with latitude along our investigation-tour route from Guangxi (22.7 NL°) to Heilongjiang (48.8 NL°). Their relationship is presented as follows: δ¹⁸O(‰)=?0.24 NL° + 0.04 and δD(‰)=?1.84 NL° + 6.88. The relationship between δ¹⁸O, δD and altitude in the southeastern part of the Guizhou Plateau is: $$ - \delta ^{1{\rm B}} O(\% o) = 0.003H(m) + 5.24 and - \delta D(\% o) = 0.0134H(m) + 39.8.$$