计算区带油气聚散量的物质平衡方法

区带油气聚散是一个多因素的、极为复杂的地质历史过程,油气的最终聚集量更是人们极为关注的问题。本文提出一整套实用的油气聚集、散失量计算方法:区带供油气计算;油在运载层中残留量计算;气在运载层中被岩石吸附量计算;气在储集层中扩散量计算。通过对比供油气量、油气总散失量及圈闭容积三者的关系,建立起计算区带油气聚集量平衡方程,从而为盆地数值模拟的软件设计及油气资源评价提供一条切实可行的途径。     

成油气系统综合分析模拟的思路和方法

成油气系统作为控制油气形成与赋存的地质单元,其概念已为国内外油气地质家普遍接受。成油气系统与盆地数值模拟的关系十分密切。本文论述成油气系统数值模拟综合分析的内容和方法,以及应注意的问题。     

Covalently bonded two spin centers of paramagnetic metallofullerene dimer

Nano Research - Paramagnetic endohedral metallofullerenes with well protected unpaired spin have potential applications in molecular-scale qubit processing and magnetoreception system. In this...     

Improved Stable Indocyanine Green (ICG)‐Mediated Cancer Optotheranostics with Naturalized Hepatitis B Core Particles

In recent years, hepatitis B core protein virus‐like particle (HBc VLP) is an impressive biomaterial, which has attracted considerable attention due to favorable properties such as structural stability, high uptake efficiency, and biocompatibility in biomedical applications. Heretofore, only a few attempts have been made to apply it in physical, chemical, and biological therapy for cancer. In this study, a tumor‐targeting RGD‐HBc VLP is first fabricated through genetic engineering. For image‐guided cancer phototherapy, indocyanine green (ICG) is loaded into RGD‐HBc VLP via a disassembly/reassembly pathway and electrostatic attraction with high efficiency. The self‐assembled stable RGD‐HBc VLP significantly improves body retention (fourfold longer), aqueous stability, and target specificity of ICG. Remarkably, these positive reformations promote more accurate and sensitive imaging of U87MG tumor, as well as prolonged tumor destruction in comparison with free ICG. Moreover, the photothermal and photodynamic effect on tumors are quantitatively differentiated by multiple linear regression analysis. Overall, less‐potent medicinal ICG can be perfectly rescued by bioengineered HBc VLP to realize enhanced cancer optotheranostics.     

Heat-treatable Mg-9Al-6Sn-3Zn extrusion alloy

Mg-9Al-6Sn-3Zn (wt%) alloy was extruded and heat treated in T5 and T6 conditions, and its mechanical properties and microstructures were investigated. The extruded product can be slightly strengthened by the T5 treatment as a result of sparse and heterogeneous precipitation. Significant increase in strength is achieved by the T6 treatment, and this is mostly attributed to the formation of lamellar discontinuous Mg₁₇Al₁₂ precipitates. The segregation of Al and Zn at grain boundaries is responsible for the discontinuous Mg₁₇Al₁₂ nucleation. The T6-treated alloy exhibits a tensile yield strength of 341 MPa and an ultimate tensile strength of 409 MPa, together with an elongation to fracture of 4%.     

Conceptual design of a Moon-based Earth radiation observatory

An Earth radiation observatory on the nearside of the Moon could provide long-term measurements complementary to the satellite-based Earth radiation observation data. This study is intended as a preliminary step towards the design of a Moon-based Earth Radiation Observatory (MERO) and its instrumentation. Based on the analysis of data from the JPL Horizons Ephemeris System for an 18.6-years precession cycle, we show that due to the irregularities of the lunar orbit, for a MERO to maintain an all-time whole Earth disk coverage, it needs to be located within the region of 80.5º W–80.5º E and 81.5º S–81.5º N on the nearside of the Moon and requires a minimum angular instantaneous field of view of 2.07º. Additionally, it should have a 360º horizontally and 15.5º vertically orientation adjustability. On one hand there is a risk for a MERO instrument to receive direct sunlight which might excess the radiation allowance of the sensor; on the other hand, a MERO would have a better polar coverage than does a low orbit spacecraft borne Earth observatory. Within the deployable region, a multi-station MERO network may increase the instantaneous spatial coverage by up to around 10% with abundant overlaps to facilitate inter calibration and validation.     

A Straightforward Direct Traction Boundary Integral Method for Two-Dimensional Crack Problems Simulation of Linear Elastic Materials

This paper presents a direct traction boundary integral equation method (DTBIEM) for two-dimensional crack problems of materials. The traction boundary integral equation was collocated on both the external boundary and either side of the crack surfaces. The displacements and tractions were used as unknowns on the external boundary, while the relative crack opening displacement (RCOD) was chosen as unknowns on either side of crack surfaces to keep the single-domain merit. Only one side of the crack surfaces was concerned and needed to be discretized, thus the proposed method resulted in a smaller system of algebraic equations compared with the dual boundary element method (DBEM). A new set of crack-tip shape functions was constructed to represent the strain field singularity exactly, and the SIFs were evaluated by the extrapolation of the RCOD. Numerical examples for both straight and curved cracks are given to validate the accuracy and efficiency of the presented method.