Analytical study of ground motion caused by seismic wave propagation across faulted rock masses

Studying seismic wave propagation across rock masses and the induced ground motion is an important topic, which receives considerable attention in design and construction of underground cavern/tunnel constructions and mining activities. The current study investigates wave propagation across a rock mass with one fault and the induced ground motion using a recursive approach. The rocks beside the fault are assumed as viscoelastic media with seismic quality factors, Q_p and Q_s. Two kinds of interactions between stress waves and a discontinuity and between stress waves and a free surface are analyzed, respectively. As the result of the wave superposition, the mathematical expressions for induced ground vibration are deduced. The proposed approach is then compared with the existing analysis for special cases. Finally, parametric studies are carried out, which includes the influences of fault stiffness, incident angle, and frequency of incident waves on the peak particle velocities of the ground motions.     

The mass ratio of Charon to Pluto from Hubble Space Telescope astrometry with the fine guidance sensors

The mass ratio of Charon to Pluto is a basic parameter describing the binary system and is necessary for determining the individual masses and densities of these two bodies. Previous measurements of the mass ratio have been made, but the solutions differ significantly (Null et al., 1993; Young et al., 1994; Null and Owen, 1996; Foust et al., 1997; Tholen and Buie, 1997). We present the first observations of Pluto and Charon with a well-calibrated astrometric instrument—the fine guidance sensors on the Hubble Space Telescope. We observed the motion of Pluto and Charon about the system barycenter over 4.4 days (69% of an orbital period) and determined the mass ratio to be 0.122±0.008 which implies a density of 1.8 to 2.1 g cm⁻³ for Pluto and 1.6 to 1.8 g cm⁻³ for Charon. The resulting rock-mass fractions for Pluto and Charon are higher than expected for bodies formed in the outer solar nebula, possibly indicating significant postaccretion loss of volatiles.     

BORDER PORT MANZHOULh URBAN FUNCTION AND SPACE DEVELOPMENT

Manzhouli is the largest land port city on the Sino-Russia border, transit cargo through the land port amount-ed to 5.95 million tons, transit tourists were 304 500 in 2000. It stands at the joint place of China, Mongolia and Russi-a, faces to Siberia area of Russia, receives direct support from the Northeast China and Bohai Sea Rim Area, and possess-es priorities in geographical location, land port infrastructure, water resources, coal resources, tourist resources andgreat potentiality in economic cooperation with Russia. The future urban function is a key port on the First Eurasia Continen-tal Bridge. Manzhouli Port will keep its first place between China and Russia land transport, and it is forecasted that thetransit amount through Manzhouli Port will go up to 10 million tons in 2005 and 20 million tons in 2010. It will be construct-ed to be a trade center of the peripheral area extending to Russia and Mongolia, a key export-oriented processing industri-al zone supported by industries such as export processing industries, export agriculture, trade services, technology trad-ing and the other service industries. It keeps being a well-known touring city for trade, shopping, sightseeing, vocation,local food, recreation and cultural events. To build Manzhouli Export Processing Industry Zone will improve city econom-ic structure, and the main sectors are organic food processing, livestock products processing, garment and furniture indus-try. Moreover, Manzhouli Export Processing Industry Zone will eventually be upgraded to be a border free trade zone.The city functional transition will inevitably affect urban spatial restructure and its expansion. The city space transforma-tion will develop as such: one development axis of No. 301 highway paralleling with Bin - Zhou(Harbin - Manzhouli) rail-way which cuts through central part of Manzhouli City, and links Zhalainuocr District with central city; three urban unitsincluding central city, Zhalainuocr District and Manzhouli Interchange Trade Zone; cohesion with Aoerjin and Cuogangpastures; regional dual-nuclei structure of Hailaer City and Manhzouli City; and the Manzhouli-Zabaykalsk Free TradeZone.     

Spectroscopic studies of three novae

We present our spectroscopic observations of the novae V1425, V1493, and V1494 Aql carried out with the 125-cm telescope at the Crimean Station of the Sternberg Astronomical Institute in the wavelength range 4000–11000 Å. We measured the emission-line intensities, determined the nova shell expansion velocities from the line profile FWHMs and components, and estimated the interstellar reddening from the first members of the Balmer series. The chemical composition of the nova shells is analyzed. Nitrogen and oxygen were found to be overabundant in V1425 and V1494 Aql; the helium abundance turned out to be normal in the two stars.     

Pulsar magnetic field for an infinitely conductive accretion disk

The magnetic-field distribution outside a flat, infinitely conductive unbounded disk in the field of a point magnetic dipole is determined. A relationship is established between the problem of magnetic-field determination and the problem of the flow of an ideal incompressible fluid around an infinitely thin disk.     

An expansion of the Voigt function

The Voigt function and its derivatives are represented by means of series in Hermite polynomials. The equations obtained can be used both for numerical calculations of these functions and for analytical research.Translated from Astrofizika, Vol. 39, No. 4, pp. 619–625, October–December, 1996.