Analytic solution to the magnetotelluric response over anisotropic medium and its discussion

In the present paper,from the second order partial differential equations for solving the magnetotelluric(MT) fields of general anisotropic medium,we first obtained the second order partial differential equations for some anisotropic media with special conductivity(e.g.diagonal anisotropy,transverse anisotropy,azimuthal anisotropy,etc.) by simplifying the electrical conductivity tensor of anisotropic medium.And then we obtained the analytic solutions to MT fields for the case of transverse and azimuthal anisotropy through converting the conductivity parameter based on that of diagonal anisotropy.We further discussed the influence of the selection of integral limit and step length on precision in solving the analytic solutions for MT fields of isotropic medium.Finally,we presented the MT responses of two transverse and azimuthal anisotropic media as well as some applications of the analytic solutions to MT fields of anisotropic medium.     

珠江三角洲地区城镇化与生态韧性的耦合协调研究

Urban resilience is an emerging research topic of urban studies, and its essence is described by the ability of cities to resist, recover, and adapt to uncertain disturbances. This paper constructs a "Size-Density-Morphology" urban ecological resilience evaluation system, uses a coupling coordination degree model to measure the degree of coupling coordination between urbanization and ecological resilience in the Pearl River Delta from 2000 to 2015, and conducts an in-depth discussion on its spatiotemporal characteristics. The results show the following.(1) From 2000 to 2015, the urbanization level of cities in the study area generally increased while the level of ecological resilience declined. The coupling coordination degree between the two systems decreased from basic coordination to basic imbalance.(2) In terms of spatial distribution, the coupling coordination degree between urbanization and ecological resilience of cities presented a circular pattern that centered on the cities at the estuary of the Pearl River and increased toward the periphery.(3) Ecological resilience sub-systems played variable roles in the coupling coordination between urbanization and ecological resilience. Specifically, size resilience mainly played a reverse blocking role;the influence of morphology resilience was generally positive and continued to increase over time;the effect of density resilience was positive and continued to decline and further became negative after falling below zero. The main pathways for achieving coordinated and sustainable development of future urbanization and ecological resilience in the Pearl River Delta include: leading the coordinated development of regions with new urbanization, improving ecological resilience by strictly observing the three areas and three lines, adapting to ecological carrying capacity, and rationally arranging urban green spaces.     

Discussion on the Scenario of Salt Accumulation in Yarkand Basin during Late Cretaceous

正Large-scale accumulation of salt and formation of potash concentrated in Tethys domain during late Mesozoic to early Cenozoic.These events were typified by the formation of Laos-Thailand and Lanping-Simao     

Geological Characteristics and Petrogenesis of Syenites in Bengge Gold Deposit, Yunnan

Please refer to the attachment(s) for more details     

上海天文台白天人卫激光测距的强光保护

在进行白天激光测距实验中，太阳及其附近的强背景光会损坏测距系统的光电接收器件。本讨论了由本站自行设计并已在实际测距工作中使用的软件和硬件保护措施，同时给出了一个软件保护的图形实例，从显示的图形实例和实际使用都证明了所采用的保护措施是有效的。     

Diversity and distribution of bacterial community in the coastal sediments of Bohai Bay, China

In order to understand the diversity and distribution of the bacterial community in the coastal sediment of the Bohai Bay,China,high-throughput barcoded pyrosequencing of the 16 S r RNA gene was used.Metagenomic DNA was extracted from the sediment samples,and was sequenced using a 454 GS FLX Titanium system.At 97%similarity,the sequences were assigned to 22 884 operational taxonomic units(OTUs) which belonged to 41 phyla,84 classes,268 genera and 789 species.At the different taxonomic levels,both the dominants and their distribution varied significantly among the six coastal sediments.Proteobacteria was the first dominant phylum across all the six coastal sediments,representing 57.52%,60.66%,45.10%,60.92%,56.63% and 56.59%,respectively.Bacteroidetes was the second dominant phylum at Stas S1,S2 and S4,while Chloroflexi was the second dominant phylum at Stas S3,S5 and S6.At class level,γ-Proteobacteria was the first dominant class at Stas S1,S2,S4 and S6,while δ-Proteobacteria became the first dominant class at Stas S3 and S5.In addition,a large proportion of unclassified representatives have distributed at the different taxonomic levels.Canonical correspondence analysis(CCA) results indicated that the sediment texture,water depth(D),dissolved oxygen(DO),total nitrogen(TN) and nine EPA priority control polycyclic aromatic hydrocarbons(PAHs) including naphthalene,acenaphthylene,acenaphthene,fluorine,phenanthrene,fluoranthene,pyrene,benzo[a]anthracene and indeno[1,2,3-cd]pyrene were the important factors in regulating the bacterial community composition.Those results are very important to further understand the roles of bacterial community in the coastal biogeochemical cycles.     

Development and application of simulation technique for hydrokinetic hammer

The computer simulation is an important method for hydrokinetic hammer design. Various kinds of simulation measures with their technical characters and applications being taken during the computer aided design are enumerated. Computer simulation supports plenty of valuable references to the designer. Each type of simulation process is used to explore the exact aspect of the performance of hydrokinetic hammer and each type of simulation method has its own excellences and deficiencies. Thus the integrative simulation methods based on modern computational technology are brought forward to obtain the perfect capability of the whole product. Along with the development of computer hardware and software, various kinds of platforms have been provided to different simulation methods that can be carried out with distinct working flows. The jet flow element is the core part of the hydrokinetic hammer. We can build the ideal simulation model of it by means of CFD (computational fluid dynamics) technology. On the other hand, to set up the digital model of piston and hammer, the best way is to build the virtual prototype using automatic dynamic analysis of mechanical system. As a result of the argumentation, we think the technique of Virtual Prototype and CFD are the prime way to process the combined computer simulation for hydrokinetic hammer.     

Development of experimental apparatus about reverse circulation bit

A set of experimental apparatus on reverse circulation bit are developed, in order to lucubrate the mechanism of the new type reverse circulation bits, and the structure of the bits influencing the ability of taking core and carrying powder. Both the major structure of the equipment and the procession of experiment are described.