Many open-pit mines are gradually converted to underground mining, the problem of roadway surrounding rock damage caused by expansive soft rock is becoming increasingly problematic. To study the seasonal evolution of expansive rock mass containing clay minerals, an underground mine transferred from an open-pit was selected as the experimental mine. The experimental results of SEM electron microscopy and X-ray diffraction confirmed that the surrounding rock of the main haulage roadway contains a large number of expansive clay minerals. The expansive grade of the main transport roadway’s surrounding rock could then be identified as the medium expansive rock mass, which has a large amount of exchangeable cation and strong water absorption capacity, based on the combined test results of dry saturated water absorption and free expansion deformation. The water swelling can cause the roadway to considerably deform, and then the surrounding rock will have strong rheological characteristics. From the research results in the text, the seasonal evolution law of the main haulage roadway in the experimental mine was obtained, and the deformation law of the expansive rock mass under different dry and wet conditions was revealed. The research results provide a reference for studying the stability evolution law of expansive soft rocks in underground mines.

This paper addresses the questions that were left unanswered in my previously published works on the Mongolian translations of the Aṣṭasāhasrikā Prajñāpāramitā. It shows that the five earliest Mongolian translations of the sutra were based on the Tibetan version known as gzo sbyangs, suggesting that in the first half of the 17th century the gzo sbyangs version, which is a rarity today, dominated the transmission of the Aṣṭasāhasrikā in Mongolia and was later replaced by the widely spread phreng ba can version. Two of the early Mongolian translations have preserved a rare Tibetan colophon. Currently this colophon is known to have survived in a unique Tibetan manuscript kept at the Otani University, Japan. The colophon declares that the sutra was edited by several figures of the snga dar period, whose identities are under question.

In recent years, fractional slot concentrated winding permanent magnet synchronous motors (FSCW PMSMs) have become a hotspot in the research field. Due to the unique inductance characteristics of the FSCW PMSM, a fast and accurate calculation of the d/q-axis inductance and saliency ratio is necessary. In this paper, a method is proposed to calculate the d/q-axis reactance of the FSCW SPMSM, which constructs the equivalent magnetic circuit model of the d/q-axis armature reaction flux separately, and the saliency ratio characteristics of the FSCW SPMSM were demonstrated. In addition, to meet the high requirements of the modern industries, especially in servo systems, accurate consideration of the effect of stator resistance on torque and electromagnetic performance is important and more applicable. According to the relationship between the vector parameter, the explicit expression of the d/q-axis currents that consider the stator resistance is obtained, and the prediction of load angle at maximum electromagnetic torque is achieved. Then, combined with the finite element method, the influence mechanism of stator resistance on the motor steady-state performance is revealed. Finally, the experimental data are compared with the calculation data, and the correctness of the models and analysis was verified.

This paper contains thsults of hydrological and hydrochemical investigations carried out in the basin of Werenskiöld Glacier against the background of determining climate elements. It also gives chosen elements of the water balance and mass balance determined from year-long investigations of the polar hydrological year 1979-1980.

In the mid-1980s the French and British scientists warned of adverse effects of tin paint used in hull coating on marine environment. The International Convention on he Control of Harmful Anti-Fouling Systems on Ships (AFS 2001) entered into force in 2008. At present there are 56 states parties to the Convention, which represent almost 80% of total shipping tonnage. Poland has ratified the AFS Convention in 2004. The European Union has implemented it in 2008.