新型Boussinesq方程的进一步改善

基于传统的Ｂｏｕｓｓｉｎｅｓｑ方程,通过速度变换及在方程中加入高阶项的方法,给出了进一步改善线性色散关系及变浅作用系数的方程,其线性色散关系及变浅作用系数的精度均为Ｏ（β８）（β＝ｈ０／Ｌ,Ｌ为特征波长,ｈ０为特征水深）．     

光合细菌在海湾扇贝人工育苗中应用的研究

光合细菌是一类组份较全且营养价值较高的细菌。在缺氧弱光条件下，具有处理低分子有机物、净化水质等显著功效。本研究利用了光合细菌所具有的独特生理功能和生态习性，在海湾扇贝人工升温育苗过程中，以单胞藻为基础饵料适当添加光合细菌，增强了海湾扇贝整体营养水平和改善了育苗水体生态环境条件，促进了亲贝性腺发育，提高了幼虫生长率。亲贝性腺指数平均日增长达２％以上，幼虫日平均增长１３．８５μｍ，同时，光合细菌可降低     

含强水流高阶Boussinesq水波方程

采用摄动法并利用已建立的纯波情况下高阶Boussinesq方程,建立了可以考虑强水流与波浪相互作用的高阶Boussinesq方程.水流速度与波浪群速具有相同量级,且随时间和空间的变化尺度远大于波浪周期和波长.方程色散性近似到[4/4]阶Pade展开,对浅水情况方程可以是完全非线性的,可适用于波流相互作用的强非线性问题.通过将水流存在时波长和波幅的结果与一阶斯托克斯波结果对比,讨论了具有不同近似程度的3种含波流相互作用的Boussinesq方程的适用性.     

Numerical model for solving Bousiinesq-type equations: comparison and validation

ＮｕｍｅｒｉｃａｌｍｏｄｅｌｆｏｒｓｏｌｖｉｎｇＢｏｕｓｉｉｎｅｓｑ－ｔｙｐｅｅｑｕａｔｉｏｎｓ：ｃｏｍｐａｒｉｓｏｎａｎｄｖａｌｉｄａｔｉｏｎＺｏｕＳｈｉｌｉａｎｄＸｕＢｅｎｈｅ（ＲｅｃｅｉｖｅｄＭａｙ２０,１９９７;ａｃｃｅｐｔｅｄＡｕｇｕｓｔ１...     

川西南陆内俯冲造山带地质特征及金成矿作用

川西南地区北起青川,向南西至云南丽江发育着一条长达800余公里的燕山晚期-喜马拉雅期陆内俯冲造山带.其中央地带的地质构造特征主要表现为由主滑脱-俯冲带、超壳断裂和次级滑脱带组成的一套巨型推覆构造体系,伴随构造活动发育有从绿片岩相到角闪岩相的动力变质作用;仰冲块体地质构造特征主要表现为由前俯冲阶段的边缘海沉积物仰冲并褶皱变质形成复合山链,而在俯冲阶段则于山链间形成山间断陷盆地并接受磨拉石建造红层沉积.形成特征的岩浆活动分带;俯冲块体上则只有大型断陷盆地内的典型红色沉积,而不发育岩浆活动.陆内俯冲造山带的央央巨型推覆构造带和仰冲块体是金矿成矿的重要大地构造环境,形成了各具特色的金矿床.中央地带主要表现为断裂构造系统中不同层次、类型和性质的构造对金矿成矿的控制,矿床类型主要为蚀变岩型;在仰冲块体上,与复杂的构造-岩浆活动相伴,金矿类型多样,成因复杂.金矿成矿可以划分为2个系列和6个亚系列.陆内俯冲造山带内的这种金矿成矿特点可用陆内俯冲造山成矿模式进行解释.     

高湿地区强震仪小型室外加速度计观测罩

为解决强震仪在较恶劣环境下的使用问题,浙江省地震局结合本省强震仪观测环境特点,研制小型室外加速度计观测罩,保障强震仪土层自由场观测。该技术目前已由浙江省十多个地震台站安装使用,实例证明,该观测罩具有体积小、制造方便、使用寿命长、防水隔震等优点,可为强震仪提供良好的工作环境。     

A Study on the Seismic Velocity Changes before and after the 2016 MS6.4 Menyuan Earthquake Using the Active Source Data in the Qilian Mountain

The Qilian Mountain active source network data was processed using the methods of stacking, cross-correlation and interpolation, and the airgun travel time variation characteristics of P and S waves around the January 21, 2016 M_S6.4 Menyua, Qinghai earthquake. The results show that about 6 months before the earthquake, the relative travel time of three stations near the epicenter showed a declined change (travel time decrease), and such a change of low value anomaly was recovered about 3 months before the earthquake. The travel time decrease then appeared again, and the earthquake occurred during the recovery process. The maximum decrease of the S-wave travel time was 18ms, and the change in travel time returned to normal after the earthquake. The variation trend of the 3 stations is consistent, including the S-wave travel time change of station ZDY38, which is nearest to the epicenter and changed obviously, and the variation range of the travel time is smaller at the stations afar. This variation pattern is related to the position of the seismic source. The shorter travel time means the velocity increase, which may be related to the regional stress accumulation.     

长薄鳅耗氧率与窒息点的研究

太湖位于太湖流域中央,对汛情起着控制作用,通过分析近４０年来太湖流域梅雨期,太湖水位,环太湖进出水量的时空分布,得出梅雨决定太湖主汛期,东太湖泄洪能力降低,围湖减少蓄水,淤滩影响泄洪,太浦河．望虞河通而不畅的现实是太湖汛期水们居高不下的重要原因,提出预降太湖水位,加快工程建设,加强工程管理是太湖安全渡汛的主要措施。     

大口鲇幼鱼摄食、生长及驯化的初步研究

根据1991年1～12月的调查,陆水水库的浮游植物共8门118属,以绿藻、硅藻、蓝藻门的种类为主,占总属数的86.44％;浮游动物198种,其中原生动物38种、轮虫68种、枝角类61种、桡足类31种。浮游植物年平均数量和生物量分别为3.1449×10~6cell/L和1.937mg/L,数量以蓝藻、隐藻、硅藻最多,占总数量的91.33％,生物量以隐藻、硅藻、绿藻最大,占总生物量的85.03％,浮游植物初级毛产量为3.4gO_2/m~2·d。浮游动物年平均数量和生物量分别为2323.8ind/L和1.4837mg/L,数量以原生动物和轮虫最多,占96.89％,生物量以枝角类和桡足类为主,占79.94％.陆水水库浮游生物种类组成和现存量在不同的水域差异较大,季节变化明显。按水化学分析结果及浮游生物特征判定,陆水水库的营养类型为中营养型。还讨论了环境因子对水库浮游生物的影响。     

Statistics for sample splitting for the calibration and validation of hydrological models

Hydrological models have been widely applied in flood forecasting, water resource management and other environmental sciences. Most hydrological models calibrate and validate parameters with available records. However, the first step of hydrological simulation is always to quantitatively and objectively split samples for use in calibration and validation. In this paper, we have proposed a framework to address this issue through a combination of a hierarchical scheme through trial and error method, for systematic testing of hydrological models, and hypothesis testing to check the statistical significance of goodness-of-fit indices. That is, the framework evaluates the performance of a hydrological model using sample splitting for calibration and validation, and assesses the statistical significance of the Nash–Sutcliffe efficiency index (E_f), which is commonly used to assess the performance of hydrological models. The sample splitting scheme used is judged as acceptable if the E_f values exceed the threshold of hypothesis testing. According to the requirements of the hierarchical scheme for systematic testing of hydrological models, cross calibration and validation will help to increase the reliability of the splitting scheme, and reduce the effective range of sample sizes for both calibration and validation. It is illustrated that the threshold of E_f is dependent on the significance level, evaluation criteria (both regarded as the population), distribution type, and sample size. The performance rating of E_f is largely dependent on the evaluation criteria. Three types of distributions, which are based on an approximately standard normal distribution, a Chi square distribution, and a bootstrap method, are used to investigate their effects on the thresholds, with two commonly used significance levels. The highest threshold is from the bootstrap method, the middle one is from the approximately standard normal distribution, and the lowest is from the Chi square distribution. It was found that the smaller the sample size, the higher the threshold values are. Sample splitting was improved by providing more records. In addition, outliers with a large bias between the simulation and the observation can affect the sample values of E_f, and hence the output of the sample splitting scheme. Physical hydrology processes and the purpose of the model should be carefully considered when assessing outliers. The proposed framework in this paper cannot guarantee the best splitting scheme, but the results show the necessary conditions for splitting schemes to calibrate and validate hydrological models from a statistical point of view.