ISSN:0021-8979    

DOI:10.1063/1.1712794

出版商:AIP    

年代:1940

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1712795

出版商:AIP    

年代:1940

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1712796

出版商:AIP    

年代:1940

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1712797

出版商:AIP    

年代:1940

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1712798

出版商:AIP    

年代:1940

数据来源: AIP

摘要:

A modified Kapitza method used in the study of conditions favorable to the growth of single crystals of zinc (99.99+percent pure), shows that the ratio of the temperature gradient (across the interfacial boundary between the liquid and solid phases) to the rate of growth of the crystal must be maintained within an optimum range of values, depending on the angle of orientation. Optically mosaic crystals give no indication of a preferred region of growth and can be obtained over a much wider range of conditions.

ISSN:0021-8979    

DOI:10.1063/1.1712799

出版商:AIP    

年代:1940

数据来源: AIP

摘要:

Recent developments of engines and turbines for producing low temperatures have emphasized the necessity of improved heat interchangers for further progress in the field. The present report covers an experimental investigation of heat interchanger design and operation intended primarily to cover those applications most likely to occur in the experimental rather than in the commercial laboratory.

ISSN:0021-8979    

DOI:10.1063/1.1712800

出版商:AIP    

年代:1940

数据来源: AIP

摘要:

Kozeny's approximate solution to the problem of fluid flow through porous media is developed and the result is checked by experimental data on air flow through plugs of cotton, wool, rayon, and glass wool fibers. The solution givesWA=k&ggr;02&mgr;&tgr;&sgr;2(1−c)3c2−&dgr;p2&dgr;xfor the isothermal linear flow of a gas.W/Ais the macroscopic flux density; &mgr;, the viscosity; &ggr;0, the density of the gas at unit pressure; &tgr;/&sgr;, the volume of fibers divided by their surface area;c, the fraction of space occupied by fibers; &dgr;p2/&dgr;x, the macroscopic gradient of the square of the pressure; andkis a numerical constant which depends on the shape and orientations of the fluid passages.kwas found experimentally to be 0.18, which is in approximate agreement with the value found for flow through media made up of spherical particles. The dependence of the flow on the factorcwas checked over the approximate range fromc=0.1 toc=more than 0.5. &tgr;/&sgr; andchave values for fineness and density of samples of fibers in fair agreement with independent determinations.

ISSN:0021-8979    

DOI:10.1063/1.1712801

出版商:AIP    

年代:1940

数据来源: AIP

摘要:

A general formulation of the problem of transfer of power from the electron beam to an oscillating circuit by moving charged particles is given. The method is applied specifically to calculation of the behavior of the klystron oscillator in making approximations analogous to those made by Webster in his treatment of the same problem.

ISSN:0021-8979    

DOI:10.1063/1.1712802

出版商:AIP    

年代:1940

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1712803

出版商:AIP    

年代:1940

数据来源: AIP