[An approach to the pathogenetic mechanisms of the glaucomato-cyclitic crisis (author's transl)].
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to Y T Feng.
Explore the source record for details and available documents.
The heart of the library lies in its collections, and collections have to be built continuously. Budgetary constraints perforce stress the need for better defined collection development policy, although the ultimate goal should be an improvement of library service rather than any reduction of library cost. A written collection development policy facilitates a consistent and balanced growth of library resources, and a dynamic policy is one that evolves as the institution grows. Such a policy is based on the understanding of the needs of the community it serves and seeks to define and delimit the goals and objectives of the institution. A collection development statement is not a substitute for book selection; it charts the forest but does not plant the trees. It should be used as a guidepost, not a crutch. Book selection requires judgment and the courage to choose. A sound collection development policy, on the other hand, provides the necessary rational without which a collection may grow amoebalike, by means of pseudopodia.
Explore the source record for details and available documents.
Experimental studies were devoted to the effect of structural parameters, i.e., tube diameter and density, on the field electron emission characteristics of carbon nanotubes. Thermal chemical vapor deposition system was employed to synthesize carbon nanotubes. Nanotubes with different diameters and densities were obtained by adjusting the thickness of the iron (Fe) catalyst film. The morphologies of the Fe and carbon nanotube film were characterized by scanning electron microscopy respectively. Further field emission measurement confirmed that the tube diameter and density could significantly affect the electron emission properties of the carbon nanotube. Possible physical reasons for the effect are discussed.