Acidic deposition: What is fact,what is speculation,what is needed?     

N. W. Foster 《Water, air, and soil pollution》1989,48(1-2):299-306

In this presentation research findings from the symposium and from the literature are utilized to examine some of the major hypotheses that link acidic deposition with impairment of forest health and productivity in central Europe and eastern North America. Although unequivocal evidence of acid rain damage may be lacking, there is a considerable body of knowledge that implicates air pollutants in recent interference with forest nutrition and health. The nature of the evidence and the inferences that can be drawn from it are still being vigorously debated. The problem of verifying the mechanisms by which air pollutants affect forests still remains. Reports that climatic irregularities have acted as inciting or triggering factors in forest declines are relevant to understanding regional damage. More emphasis on experimental studies that assess interactions of air pollutants and natural stresses with forests is needed.  相似文献   

Equation-solving programs for the personal computer     

Foster KR 《Science (New York, N.Y.)》1988,240(4857):1353-1358

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Long-range electronic perturbations caused by defects using scanning tunneling microscopy     

Mizes HA  Foster JS 《Science (New York, N.Y.)》1989,244(4904):559-562

Real-space observations of long-range electronic perturbations caused by defects have been made with scanning tunneling microscopy. The defects are isolated adsorbed molecules on the surface of graphite. These defects perturb the charge density, giving periodic oscillations similar to Friedel oscillations. The oscillations have a wavelength radical3 times that of the graphite lattice, and the symmetry of the oscillations reflects the nature of the defect.  相似文献   

Hemolysin production in the development of staphylococcal lesions   总被引：3，自引：0，他引：3  

E A Foster 《Science (New York, N.Y.)》1965,149(690):1395-1396

The presence of hemolysin in staphylococcal lesions of the rabbit kidney was detected by overlaying sections of kidney with blood agar. Hemolytic activity against rabbit, human, sheep, calf, and guinea pig erythrocytes was present and was not abolished by heating the sections to 60 degrees C for 30 minutes. In developing lesions, hemolytic activity appeared before necrosis or exudation.  相似文献   

Paleomagnetic study of antarctic deep-sea cores   总被引：1，自引：0，他引：1  

Opdyke ND  Glass B  Hays JD  Foster J 《Science (New York, N.Y.)》1966,154(3747):349-357

The magnetic inclinations and inten sities of about 650 samples from seven deepsea cores taken in the Antarctic were measured on a spinner magnetometer. This series of measurements provided a magnetic stratigraphy, based on zones of normally or reversally polar ized specimens for each core, which was then correlated with the magnetic stra tigraphy of Cox et al. (1). One core (V16-134) gave a continuous record of the paleomagnetic field back to about 3.5 million years. When selected samples were subject ed to alternatingfield demagnetization, most were found to have an unstable component that was removed by fields of 150 oersteds; all samples from two cores were partially demagnetized in a field of 150 oersteds. The average inclination in these two cores was then in good agreement with the average inclination of the ambient field for the latitude of the core site. It was also found that the intensities of the samples decreased at the points of reversal; this finding is to be expected if, as has been postulated by the dynamo theory, the intensity of the dipole field decreases to zero and builds again with opposite polarity. We believe that the magnetiza tion of the cores results from the pres ence of detrital magnetite, although other magnetic minerals also may be present. Four faunal zones (, X, , and ) have been recognized in these Antarctic cores on the basis of upward sequential disappearance of Radiolaria. The faunal boundaries and reversals consistently have the same relations to one another, indicating that they are both timedependent phenomena. Using previously determined times of reversal, one may date the following events in the cores: 1) Radiolarian faunal boundaries:-X, 2 million years; X-, 0.7 million years; -, 0.4 to 0.5 million years. These dates are in good agreement with ages previously extrapolated from radio metric dates. 2) Initiation of Antarctic diatom ooze deposition, approximately 2.0 mil-lion years ago. 3) First occurrence of ice- rafted detritus, approximately 2.5 million years ago. One can also calculate rates of sedi mentation, which vary in the cores studied from 1.1 to about 8.0 millimeters per 1000 years. Sedimentation rates for the Indian Ocean cores are higher than for the Bellingshausen Sea cores. The near coincidence of faunal changes and reversals in the cores suggests but does not prove a causal relation. We conclude from this study that paleomagnetic stratigraphy is a unique method for correlating and dating deep sea cores, and that future work with such cores may provide a complete or nearly complete record of the history of the earth's magnetic field beyond 4 million years.  相似文献   

A FURTHER NOTE ON POLYRADIATE CESTODES     

Foster WD 《Science (New York, N.Y.)》1916,44(1133):388-389

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"Bound water" in barnacle muscle as indicated in nuclear magnetic resonance studies     

Resing HA  Foster KR  Garroway AN 《Science (New York, N.Y.)》1977,198(4322):1181-1182

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Microwave hearing: evidence for thermoacoustic auditory stimulation by pulsed microwaves     

K R Foster  E D Finch 《Science (New York, N.Y.)》1974,185(147):256-258

Acoustic transients can be thermally generated in water by pulsed microwave energy. The peak pressure level of these transients, measured within the audible frequency band as a function of the microwave pulse parameters, is adequate to explain the "clicks" heard by people exposed to microwave radiation.  相似文献   

Spatial patterns in the distribution of tropical tree species   总被引：1，自引：0，他引：1  

Condit R  Ashton PS  Baker P  Bunyavejchewin S  Gunatilleke S  Gunatilleke N  Hubbell SP  Foster RB  Itoh A  LaFrankie JV  Lee HS  Losos E  Manokaran N  Sukumar R  Yamakura T 《Science (New York, N.Y.)》2000,288(5470):1414-1418

Fully mapped tree census plots of large area, 25 to 52 hectares, have now been completed at six different sites in tropical forests, including dry deciduous to wet evergreen forest on two continents. One of the main goals of these plots has been to evaluate spatial patterns in tropical tree populations. Here the degree of aggregation in the distribution of 1768 tree species is examined based on the average density of conspecific trees in circular neighborhoods around each tree. When all individuals larger than 1 centimeter in stem diameter were included, nearly every species was more aggregated than a random distribution. Considering only larger trees (>/= 10 centimeters in diameter), the pattern persisted, with most species being more aggregated than random. Rare species were more aggregated than common species. All six forests were very similar in all the particulars of these results.  相似文献   

Service-oriented science   总被引：1，自引：0，他引：1  

Foster I 《Science (New York, N.Y.)》2005,308(5723):814-817

New information architectures enable new approaches to publishing and accessing valuable data and programs. So-called service-oriented architectures define standard interfaces and protocols that allow developers to encapsulate information tools as services that clients can access without knowledge of, or control over, their internal workings. Thus, tools formerly accessible only to the specialist can be made available to all; previously manual data-processing and analysis tasks can be automated by having services access services. Such service-oriented approaches to science are already being applied successfully, in some cases at substantial scales, but much more effort is required before these approaches are applied routinely across many disciplines. Grid technologies can accelerate the development and adoption of service-oriented science by enabling a separation of concerns between discipline-specific content and domain-independent software and hardware infrastructure.  相似文献