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111.
Power Technology and Engineering - The paper presents the results of developing a high-speed semiconductor transformer voltage regulator (STVR) intended for a real-time voltage regulation of 0.4 kV...  相似文献   
112.
1.  The number of hydraulic (including hydropower) structures in our country, the standard operating life of the mechanical equipment of which expired long ago, is considerably more than 100. It is necessary to immediately and seriously undertake their reconstruction and to update their mechanical equipment.
2.  Timely and thorough preparation for reconstruction of structures and replacement (wherever this is necessary) of mechanical equipment will eliminate the negative effect of the reconstruction process on the structure and its functional characteristics while performing these works.
3.  The use of a heavy-freight floating crane, despite the high cost of its rental for the time of replacing the mechanical equipment, is justified from the viewpoint of economy and quality of the works.
Send orders for performing works (turnkey) on inspection of structures, designing, reconstruction, manufacture, and replacement of mechanical equipment and its testing (after reconstruction) and adjustment works to:  相似文献   
113.
1.  The use of the results of on-site investigations of an irregular wave load on slopes of structures makes it possible to increase the reliability of designing structures.
2.  A differentiated consideration of the wave load according to probability in storms represented by corresponding quasi-steady wave systems can substantially reduce the cost of construction and installation works on objects of various classes and technical purposes.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 12, pp. 24–27, December, 1989.  相似文献   
114.
1.  Despite their openness, transverse discontinuous structures have a jetty effect.
2.  Discontinuous structures formed by two rows of rectangular support masses connected by longitudinal beams have the strongest effect on the dynamics of a pebble beach.
3.  It can be recommended to use circular supports with a diameter of not more than 2 m arranged in one row at a distance of at least 6 m from one another for constructing hydraulic structures intersecting pebble beaches.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 5, pp. 23–25, May, 1989.  相似文献   
115.
1.  The side curtains as necessary cutoff elements of the al-Qadisiyah hydro development were made in an optimal design variant, on time, and with a high quality. A considerable technical and economic effect was obtained by eliminating excessive volumes of works specified by the original design as a result of a combined analysis of the data of engineering surveys, investigations of experimental grouting works, and optimization of the grouting technology.
2.  The index of unit cement absorption in the control holes used as the criterion of sufficiency of grouting on the side curtains should be used everywhere where the purpose of grouting works is to detect and eliminate large cavities and fissures.
3.  Grouting works on elimination of karst cavities and large fissures, being in essence infill grouting, require the development of an industrial technology of the works with the use of considerable volumes of grouts (concretes) and use of a large number of machines and mechanisms (concrete plants, mixers, concrete pumps, etc.).
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 1, pp. 45–50, January, 1989.  相似文献   
116.
The use of the main methods of calculating Kc in practice guarantees an accuracy of the calculation within
  相似文献   
117.
1.  Borehole bench marks I–VI practically work just as the settlement marks of the dam and surface cliff bench marks located near the dam. Consequently, with such a scheme of embedding the bench marks it was not possible to fall outside the zone of formation of settlement, and the given borehole bench marks cannot serve as a reliable, independent reference for determining dam settlements.  相似文献   
118.
1.  During operation of large multipurpose reservoirs their unsatisfactory sanitary and engineering state, ineffective use of their water and biological resources, and unfavorable ecological conditions were revealed, which requires their immediate improvement.
2.  There are real ways of improving these sanitary state and use of the water and biological resources of reservoirs, which were established when drawing up the schemes.
3.  A thorough elaboration of ecological problems of the examined reservoirs aimed at an improvement of the ecological conditions on each reservoir and on the territories adjacent to them is required.
4.  To solve the stated problem it is necessary to implement a number of coordinated measures. For this purpose, a scientifically founded approach based on a prediction of the results of their accomplishment is required. The interrelatedness and interdetermination of these measures with respect to increasing the effectiveness of using water, land, and biological resources should be based on scientific approaches of aquatorial regionalization and planning of reservoirs. Such an approach, unfortunately, is absent in many schemes.
5.  The investments and expenditures being provided for the indicated purposes should be aimed at achieving priority goals on improving the sanitary state of reservoirs, water quality, and effective use of their resources. The investments provided for in the schemes should be based on real sources of financing and should be coordinated with the plan of the concerned organizations, which are the title holders of the objects planned for construction.
Deceased  相似文献   
119.
1.  For a porosity of about 5% the quality indices of APC are at the level of the requirements of the existing specifications P20-85:K F0.85,R 20>3 MPa,R 50>1.2 MPa,K th>2.5–3.
2.  The experiments on the impermeability of APC showed that material with a porosity of 4–5% withstands a water pressure of 0.2–0.3 MPa without its infiltration through the specimens.
3.  The results obtained give grounds to revise the traditional requirements imposed on the residual porosity — not more than 3% — of APC-base structural members. Compaction of asphaltic and asphaltic polymer-impregnated concrete mixes to a residual porosity of 4–5% will make it possible to reduce expenditures on compaction. In this case, variants of compacting mixes to various residual porosities are possible in combination with surface treatment of the material with sealing compositions (for example, with a bitumen-polymer binder) which must be substantiated by technical and economic calculations for the particular conditions of conducting works on constructing watertight facings of hydraulic structures.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 28–30, November, 1988.  相似文献   
120.
1.  Polymer-cement shotcrete (gunite) has a number of advantages in comparison with ordinary shotcrete — increased elasticity (low modulus of deformation), high impermeability and adhesiveness to rocks and concrete, resistance to corrosive effects, nontoxicity of the polymer used, and simplicity of the technology of adding latex to the coating material.
2.  The addition of polymer makes it possible to reduce the thickness of the coating by at least half while preserving the strength and operating characteristics of the support, which provides a high cost effectiveness of using polymer-cement shotcrete.
3.  It is expedient to recommend the wide use of highly effective polymer-cement compositions on a base of synthetic latex SKS-65GP in hydrotechnical construction.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 7, pp. 18–22, July, 1988.  相似文献   
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