振动系统的逆与优化问题(Part-Ⅱ)部分边界值再构内部场(I)理论(英文)

研究由一振动体的部分边界测量数据再构振动体内部场的逆问题。提出基于偏微分方程控制方法的一种算法 ,并证明原用于处理散射问题的 Null- field method可用来求解优化问题的随伴问题。     

水下声传输数据通讯技术研究

本文介绍了水下声传输数据通讯的原理、功能作用及关键技术研究。     

胶州湾菲律宾蛤仔死壳分布与生态环境关系的研究

胶州湾菲律宾蛤仔栖息地带由于近年受拖耙捕生产，底质遭到频繁骚动。同时沿岸带局部水域环境污染严重，以及河口盐度突发性骤降等因素，直接影响了蛤仔的存活率。因而蛤仔死壳逐年增多。据１９９０年调查，９月份幼蛤和成蛤死壳平均密度比同年４月分别增加３．５倍和１．８倍，蛤仔资源量亦受一定损失。     

饵料中添加锰对中国对虾的影响

报道了在以花生饼、鱼粉、玉米粉和麸皮为基本原料,加入不同浓度梯度的锰所配制的人工饵料饲喂中国对虾(Penaeus chinensis),对其增长、增重和存活率均无明显的影响,但添加适量的锰对其肝胰脏申的羧肽酶A具有激活作用。据此认为,利用上述原料生产的配合饵料可以不添加锰,但饵料中即使含锰量较高,对对虾的生长、成活也没有害处。     

Photometric Follow-up Transit (Primary Eclipse) Observations of WASP-43 b and TrES-3b and A Study on Their Transit Timing Variations

Two photometric follow-up transit (primary eclipse) observations on WASP-43 b and four observations on TrES-3 b are performed using the Xuyi Near-Earth Object Survey Telescope. After differential photometry and light curve analysis, the physical parameters of the two systems are obtained and are in good match with the literature. Combining with transit data from a lot of literature, the residuals (O ? C) of transit observations of both systems are fitted with the linear and quadratic functions. With the linear fitting, the periods and transit timing variations (TTVs) of the planets are obtained, and no obvious periodic TTV signal is found in both systems after an analysis. The maximum mass of a perturbing planet located at the 1:2 mean motion resonance (MMR) for WASP-43 b and TrES-3 b is estimated to be 1.826 and 1.504 Earth mass, respectively. By quadratic fitting, it is confirmed that WASP-43 b may have a long-term TTV which means an orbital decay. The decay rate is shown to be P? = (?0.005248 ± 0.001714) s·yr^?1, and compared with the previous results. Based on this, the lower limit of the stellar tidal quality parameter of WASP-43 is calculated to be ${Q^{\prime }}_{*}\ge 1.5\times {10}^5$, and the remaining lifetimes of the planets are presented for the different ${Q^{\prime }}_{*}$ values of the two systems, correspondingly.     

Leak-off mechanism and pressure prediction for shallow sediments in deepwater drilling

Deepwater sediments are prone to loss circulation in drilling due to a low overburden gradient. How to predict the magnitude of leak-off pressure more accurately is an important issue in the protection of drilling safety and the reduction of drilling cost in deep water. Starting from the mechanical properties of a shallow formation and based on the basic theory of rock-soil mechanics, the stress distribution around a borehole was analyzed. It was found that the rock or soil on a borehole is in the plastic yield state before the effective tensile stress is generated, and the effective tangential and vertical stresses increase as the drilling fluid density increases; thus, tensile failure will not occur on the borehole wall. Based on the results of stress calculation, two mechanisms and leak-off pressure prediction models for shallow sediments in deepwater drilling were put forward, and the calculated values of these models were compared with the measured value of shallow leak-off pressure in actual drilling. The results show that the MHPS (minimum horizontal principle stress) model and the FIF (fracturing in formation) model can predict the lower and upper limits of leak-off pressure. The PLC (permeable lost circulation) model can comprehensively analyze the factors influencing permeable leakage and provide a theoretical basis for leak-off prevention and plugging in deepwater drilling.     

Immunohistochemical identification of dynorphin A and Kappa opioid receptor-1 in the digestive system of scallop Chlamys farreri

Journal of Oceanology and Limnology - Little is known about the roles of dynorphin and Kappa opioid receptor (KOR) in mollusks. In this study, we aim to determine the distribution of dynorphin A...     

低速十字路口交通流模型相图

研究由两个单车道构成低速十字路口交通流模型.模型中两车道上的车辆更新遵循无交通灯管制下的并行规则.依据构建相图的原则并采用局部占有概率方法,建立相图,给出相图中的各部分区域的流量表达式.两车道均采用周期边界条件和确定性FI模型进行数值模拟,模拟结果与理论分析精确一致.模型中两条车道的行车规则更接近实际道路交通,该结果为交通管理提供一定的指导作用.     

Accurate ab initio study of low-lying electronic states of phosphorus nitride radical

This paper employs the highly accurate valence internally contracted multireference configuration interaction method to investigate the potential energy curves (PECs) for the ground state (X¹Σ⁺) and two low-lying excited states (A¹Π and D¹Δ of phosphorus nitride (PN) radical with the correlation-consistent basis set, aug-cc-pV6Z, in the valence range. Relativistic effects are considered in these calculations. The spectroscopic constants of the X¹Σ⁺ and A¹Π states are calculated based on the PECs, and the results are in good accord with the available experimental data. The first 30 vibrational states for the A¹Π state and the first 40 vibrational states for the A¹Π state are determined when J=0. For each vibrational state, molecular constants G(υ), B(υ) and D(υ) are also attained.     

Research on the panel adjustment method of an active main reflector for a large radio telescope

The surface accuracy of a large parabolic antenna is an important indicator to evaluate the quality of the antenna.It not only directly affects the antenna’s aperture efficiency,thereby determining the shortest wavelength that the antenna can work,but also affects the main lobe width and side lobe structure of the antenna pattern.Microwave holography is an important method for parabolic antenna profile detection.In this article we adopt a new algorithm to adjust the panels for the large radio telescope with an active main reflector through the TM65 m antenna’s aperture phase profile.The panels of the TM65 m radio telescope is in a radial pattern with 14 rings.Each corner of the panel is fixed on the screw of the actuator to move up and down,and the adjacent corners of the four panels share an actuator.We use the method of plane fitting to calculate the adjustment value of every panel’s corner.But one actuator,which simultaneously controls the common corner of the adjacent panels,will have different adjustment values according to the different plane fitting equation based on adjacent panels.In this paper,the adjustment value of the adjacent panels’crosspoints are constrained to be equal to the constraint condition to calculate each actuator’s adjustment value of the TM65 m radio telescope.Through multiple adjustments and application of the new algorithms,the accuracy of the TM65 m antenna reflector profile has been improved from the original 0.28 mm to the current 0.19 mm.