- 行业: Printing & publishing
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- Company Profile:
McGraw Hill Financial, Inc. is an American publicly traded corporation headquartered in Rockefeller Center in New York City. Its primary areas of business are financial, publishing, and business services.
Naturally occurring stishovite, SiO<sub>2</sub>, is a mineral formed under very high pressure with the silicon atom in sixfold, or octahedral, coordination instead of the usual fourfold, or tetrahedral, coordination. It was discovered in the same type of Coconino sandstone from the Meteor Crater of Arizona. Stishovite has since been found in rocks from the Ries Crater of Germany. The presence of stishovite indicates formation pressures in excess of 10<sup>6</sup> lb/in.<sup>2</sup> (7.5 gigapascals). The possibility of the existence of stishovite at great depths strongly influences the interpretations of geophysicists and solid-state physicists regarding the phase transitions of mineral matter, as well as the interpretation of seismic data in the study of such regions of the interior of the Earth.
Industry:Science
Nuclear structure studies with electrons have entered a new phase of development. In addition to an ongoing program of selected experiments at very high energy at the Standard Linear Accelerator Center (SLAC), an 800-MeV continuous-beam microtron is in operation at Mainz, Germany, with a complement of spectrometers for detecting the scattered electrons and a tagged-photon facility. The Bates Laboratory at the Massachusetts Institute of Technology in Cambridge, where pioneering studies in this field have been carried out since the early 1970s, now has a storage ring where large circulating currents can be directed on a variety of thin gas targets. This configuration has led to an entirely new class of experiments, as first demonstrated in Novosibirsk, Russia, and at the NIKHEF Laboratory in Amsterdam.
Industry:Science
Space flight in 2005 made a number of significant strides in both human and robotic activities, moving ahead in its increasingly dominant theme: progress toward human exploration ventures outside the Earth's boundaries. But based on the number of launches to orbit and the number of launched satellite payloads, the utilization of space in 2005, which had reached its lowest level in 2004 since 1961, remained on that level without showing signs of reversing this trend. For the second consecutive year, the number of space launches attempted worldwide totaled 55 (including three failed). However, in terms of commercial satellite sales, with 19 geostationary-orbit commercial communications satellites (comsats) ordered worldwide, 2005 brought a significant improvement over the 12 satellites ordered in 2004.
Industry:Science
Lasers can be used both to initiate chemical reactions and to control their rates and product distributions. The frequency, intensity, and phase properties of a laser beam are used to great advantage in controlling the motion of nuclei and electrons. For example, infrared radiation is used to excite specific vibrational modes of a molecule, whereas visible radiation and ultraviolet radiation are used to induce electronic transitions. The tunability and narrow bandwidth (that is, sharp wavelength) of a laser permit very precise selection of the desired transition. The high intensity achievable with pulsed lasers promotes multiphoton or overtone transitions. Finally, the phase coherence of a laser exploits the quantum-mechanical properties of matter in ways that are inaccessible by conventional methods.
Industry:Science
Paleoecology is a discipline that deals with interactions of fossil organisms in their ancient environments. However, current research indicates that paleoecological data (the fossil record) are inherently different from neoecological data (the present-day world). Due to postmortem processes, such as transport by water currents or reworking by burrowing organisms, skeletal remains of various ages are often mixed together during their fossilization. Thus, in contrast to the living organisms studied by ecologists, individual fossils found preserved together in geological strata are not necessarily contemporaneous. As in human cemeteries, fossiliferous horizons mix together remains of organisms that lived at different times and never interacted with one another. The fossil record tends to be time-averaged.
Industry:Science
Prion diseases have been recognized in several animal species and include scrapie in sheep, bovine spongiform encephalopathy (BSE or “mad cow disease”) in cattle, chronic wasting disease (CWD) in deer and elk, and transmissible mink encephalopathy (TME) in mink. In humans, the most common form of prion disease is Creutzfeldt-Jakob disease (CJD). A new form of CJD in humans called variant CJD (vCJD) has been linked with exposure to BSE-contaminated materials. Thus, animal prion diseases have become a significant public health issue and have raised concerns about food safety. In light of the fact that BSE has caused a new form of prion disease in humans, as well as continuing uncertainty as to whether or not other animal prions may do the same, it is critical to understand how animal prions infect humans.
Industry:Science
Influenza is a viral disease that strikes many different types of animals, including birds, pigs, horses, and humans. Canine influenza is considered an emerging disease, and resulted from a mutation in a previously existing equine influenza virus strain known as H3N8. Prior to this development, influenza A virus strains were unable to spread easily within canine populations. After the development of this new canine strain, outbreaks of canine influenza were reported for the first time in greyhound kennels and at greyhound racetracks in 2004. Serological studies indicate that the virus may have been present in greyhounds as early as 1999. Although canine influenza first appeared in greyhounds, it now causes respiratory illness in a variety of breeds, and all dogs are considered to be at risk of infection.
Industry:Science
Over the past century the technological means of communication have expanded to include the telegraph, telephone, facsimile machine, data modem, and the Internet. The modalities of communication have also expanded to include the transmission of voice, data, document images, graphics, and video. Meanwhile, the computer has evolved from a device suitable for large computations, to a manipulator of large bodies of information (enabled by mass-storage technologies), and then to a tool for communications (enabled by computer networking). Looking to the future, depending on the perspective chosen, there will be a strong trend toward incorporating communications as an integral part of computing applications, or incorporating information access and manipulation as an integral part of communications applications.
Industry:Science
Molecular imprinting is a highly attractive approach for producing binding sites in polymeric materials. It can be described as a way of making artificial locks for molecular keys. With this technique, lock-building elements are assembled in the presence of a molecular key and subsequently are made transfixed by cross-linking. The prepared lock becomes selective for the chosen molecular key and will not effectively recognize other keys. The molecular key may, in principle, be any type of molecule—from small molecules such as drug substances, amino acids, or steroid hormones to large molecules such as nucleic acids or proteins. Molecular assemblies such as cells and viruses can also be perceived. The lock-building elements consist of different monomers capable of forming three-dimensional network polymers.
Industry:Science
Nitrogen-containing compounds are widespread in nature, are pharmacologically interesting compounds, and are used in the synthesis of fine chemicals. Because of their pervasiveness in the chemical industry, the selective generation of amines remains of fundamental importance to the synthetic organic chemist. Among the standard methods for their synthesis, <i>N</i>-alkylation of ammonia, reductive amination of aldehydes or ketones, reduction of amides, and aminations of olefins using stoichiometric promoters are the most common. Although these routes are well developed, they are often not implemented when large amounts of amines are needed. These reactions suffer from the production of vast amounts of by-products created during the process, the elimination of which is costly and environmentally unfriendly.
Industry:Science
