Three-dimensional map construction     

Jenks GF  Brown DA 《Science (New York, N.Y.)》1966,154(3751):857-864

Three-dimensional maps are useful tools which have been neglected for some time. They shouldbe more commonly used, and familiarity with the techniques discussed in this article should dispel any qualms anyone might ve about needing artistic talent to nstruct them. The saving in time esulting from the use of an anamorphoser provides a further incentive. The anamorphoser transformations discussed above were all prepared by using straight slits, oriented at right angles to each other and placed so that all planes of the elements were parallel to each other. It is possible to vary these conditions in an infinite number of ways and thereby produce nonparallel tranceformations. Some of these variations are illustrated in Fig. 10. All the illustrations in Fig. 10 are transformations of the planimetric weather map shown in Fig. 8A. The variations used for the maps of Fig. 10 are as follows. (A) All planes parallel, with a curved rear slit; (B) all planes parallel, with curved slits front and rear; ( C) all planes parallel, with S-shaped rear slit; (D) all planes parallel, with an undulating rear slit; (E) all planes parallel, with curved front and undulating rear slit; (F) plane of the original rotated on the horizontal axis-both slits curved; (G) plane of the original rotated on thevertical axis- both slits curved; (H) plane of the original rotated on the horizontal axis -both slits straight. These are only a few of the many transformations which can be made with an anamorphoser, butthey do point toward some interesting possibilities. For example, it appears that maps based onone projection might be altered to satisfy the coordinates of a completely different projection. Note, for example, the change of parallels from concave to convex curves (Figs. 8A and 10A) and the change from converging meridians to diverging meridians (Figs. 8A and l0G). Similarly, the grids of maps B, F, and H of Fig. 10 approximate projections which are quite different from the original. Other possible, and noncartographic, uses also come to mind. For example, transformations offront and side views of architectural and engineering drawings could be made to show views fromdifferent elevations and orientations. Or a geologist might be able to illustrate folding of sedimentary strata by preparing a drawing of a series of horizontal beds and then using an anamo-rephoser with an undulating slit to alter the beds to any degree of folding desired. With a movie camera and a moving lens mount this "folding" process could be photographed with different settings, so that the parallel beds would gradually and continuously change to irregularly folded beds. The transformations shown in Fig. 10 resulted from uncontrolled experimentation with the anamorphoser, and as yet no geometric solutions for setting up the transformation elements are available. Similarly, the suggested uses are mere flights of fancy, and no claim is made for theirpracticality. It is hoped, however, that they will stimulate the reader's imagination and lead him to look for uses of the anamorphoser in fields other than cartography (9).  相似文献   

Extended family system in a communal bird     

Brown JL  Brown ER 《Science (New York, N.Y.)》1981,211(4485):959-960

The genealogical structure of an extended family system in a nonprimate species is described. In Mexican jays, social units are more complex genealogically than in most other communal birds and may contain grandparents, uncles, aunts, and cousins in addition to parents and older siblings. The average relatedness within the units varies greatly, and is lower than would be expected for a highly social bird.  相似文献   

Postsynaptic transmission block can cause terminal sprouting of a motor nerve     

R L Holland  M C Brown 《Science (New York, N.Y.)》1980,207(4431):649-651

Sprouting of mouse soleus motor nerve terminals can be evoked by daily intramuscular injections of purified alpha-bungarotoxin. This finding supports the hypothesis that an important stimulus to terminal sprouting in partial denervation and presynaptic nerve blockade is a product of inactive muscle fibers.  相似文献   

Seasat synthetic aperture radar: ocean wave detection capabilities   总被引：1，自引：0，他引：1  

Gonzalez FI  Beal RC  Brown WE  Deleonibus PS  Sherman JW  Gower JF  Lichy D  Ross DB  Rufenach CL  Shuchman RA 《Science (New York, N.Y.)》1979,204(4400):1418-1421

A preliminary assessment has been made of the capability of the Seasat synthetic aperture radar to detect ocean waves. Comparison with surface and aircraft measurements from five passes of the satellite over the Gulf of Alaska indicates agreement to within about - 15 percent in wavelength and about +/- 25 degrees in wave direction. These results apply to waves 100 to 250 meters in length propagating in a direction predominantly across the satellite track, in sea states with significant wave height (H((1/3))) in a range of 2 to 3.5 meters.  相似文献   

Planetary magnetic fields and rotation     

Brown RT  Van Allen JA 《Science (New York, N.Y.)》1967,158(3801):674

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THE SCIENTIFIC WORK OF THE GOVERNMENT     

Pegram GB  Compton AH  Davis B  Sinclair D  Brown WF 《Science (New York, N.Y.)》1933,78(2015):122-123

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Tandem duplication of D-loop and ribosomal RNA sequences in lizard mitochondrial DNA   总被引：18，自引：0，他引：18  

C Moritz  W M Brown 《Science (New York, N.Y.)》1986,233(4771):1425-1427

Some Cnemidophorus exsanguis have mitochondrial DNA's (mtDNA's) that are 22.2 kilobases (kb) in size, whereas most have mtDNA's of 17.4 kb. Restriction site mapping, DNA transfer hybridization experiments, and electron microscopy show that the size increment stems from the tandem duplication of a 4.8-kb region that includes regulatory sequences and transfer and ribosomal RNA genes. This observation is notable in that sequences outside of the control region are involved in major length variation. Besides revealing a novel form of mtDNA evolution in animals, these duplications provide a useful system for investigating the molecular and evolutionary biology of animal mtDNA.  相似文献   

Computer vision and natural constraints     

Brown CM 《Science (New York, N.Y.)》1984,224(4655):1299-1305

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Personality's role in moral action     

Spezio ML  Peterson GR  Brown WS  Reimer KS  van Slyke J 《Science (New York, N.Y.)》2011,332(6036):1380-1381

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Atomistic Processes in the Early Stages of Thin-Film Growth     

Z Zhang  MG Lagally 《Science (New York, N.Y.)》1997,276(5311):377-383

Growth of thin films from atoms deposited from the gas phase is intrinsically a nonequilibrium phenomenon governed by a competition between kinetics and thermodynamics. Precise control of the growth and thus of the properties of deposited films becomes possible only after an understanding of this competition is achieved. Here, the atomic nature of the most important kinetic mechanisms of film growth is explored. These mechanisms include adatom diffusion on terraces, along steps, and around island corners; nucleation and dynamics of the stable nucleus; atom attachment to and detachment from terraces and islands; and interlayer mass transport. Ways to manipulate the growth kinetics in order to select a desired growth mode are briefly addressed.  相似文献