- 行业: Printing & publishing
- Number of terms: 178089
- Number of blossaries: 0
- 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.
The family of emergent methods that imitate human intelligence have formed a new subject area called soft computing. Since the development of artificial intelligence, there have been many attempts to create devices that mimic intelligent behavior. The goal is to make tools provided with some humanlike capabilities (such as learning, reasoning, and decision making) to solve complex problems, not to build machines with the capacity to compete with humans. Soft computing replaces the traditional time-consuming and complex techniques of programming with more intelligent processing techniques. Soft computing uses the human mind as a model and aims to formalize the cognitive processes used to accomplish daily tasks.
Industry:Science
The distribution and physiology of plants are constantly changing over different time scales as the plants are affected by changes and fluctuations in the environment. Recently, climate change has received much attention, and there is increasing evidence that it is already having an effect on some species, not only on their distribution but also on the timing of key events, such as leafing and flowering. With global temperatures predicted to increase by 1.4–5.8°C (2.5–10.4°F) over the period 1990–2100, and global precipitation predicted to increase (but with regional variation), it is important to assess the implications of such changes and to identify which ecosystems and plants might be particularly vulnerable.
Industry:Science
The branch of geology that deals with study and interpretation of deformation of the Earth's crust. Deformation brings about changes in size (dilation), shape (distortion), position (translation), or orientation (rotation). Evidence for the changes caused by deformation are commonly implanted into geologic bodies in the form of recognizable structures, such as faults and joints, folds and cleavage, and foliation and lineation. In fact, geologic structures exist because the rock bodies in which they are found were forced to undergo such changes. The geologic record of structures and structural relations is best developed and most complicated in mountain belts, the most intensely deformed parts of the Earth's crust.
Industry:Science
The incorporation of molecular water into a complex with the molecules or units of another species. The complex may be held together by relatively weak forces or may exist as a definite compound. Many salts form solid hydrates when exposed to water vapor under certain conditions of temperature and pressure. Copper sulfate, for example, forms a monohydrate (CuSO<sub>4</sub> · H<sub>2</sub>O) when exposed at 25°C (77°F) to water vapor at a pressure of 0.8 mm of mercury (1100 pascals). At higher pressures other hydrates are formed. Water is lost from these compounds when they are heated or when the water vapor pressure falls below a minimum value. Solids forming hydrates at low pressures are used as drying agents.
Industry:Science
The investigation of the effects of the laws of quantum mechanics on the propagation and absorption of sound. At the present stage of development of physical science, quantum mechanics is the most fundamental theory of physical phenomena. However, for many applications in the everyday world, a sufficiently accurate description of nature is provided by classical mechanics. Quantum acoustics refers to acoustic experiments that are carried out under conditions such that the results can be understood only in terms of quantum theory. As a general tendency, quantum effects become more important in acoustic experiments that are performed with higher-frequency sound waves or that are carried out at lower temperatures.
Industry:Science
The automatic maintenance of a nearly constant output level of an amplifying circuit by adjusting the amplification in inverse proportion to the input field strength, also called automatic volume control (AVC). Almost all radio receivers in use employ AGC. In broadcast receivers AGC makes it possible to receive incoming signals of widely varying strength, yet have the sound remain at nearly the same volume. In communications receivers a type of AGC circuit called a squelch circuit is used to prevent noise during periods of no transmission, such as in the reception of on-off keying, frequency-shift keying, and phone. AGC is also useful in accelerating the switching action between receivers in diversity connection.
Industry:Science
The controlled induction of a grand mal seizure under anesthesia for treating individuals suffering from certain psychiatric illnesses. Electroconvulsive therapy (ECT) was introduced as a treatment for psychiatric disorders by the Italian neurologist Ugo Cerletti in 1938. Cerletti developed a method of electrically inducing seizures in laboratory animals as a means of studying epilepsy. Aware of the observation that individuals with epilepsy and depression experienced an improvement in mood following a seizure, he postulated that inducing a seizure in a depressed individual might improve his or her condition. In 1938 he reported the first case of a psychiatric patient treated with ECT with dramatic, positive results.
Industry:Science
The growth and maintenance of a single species in isolation, free from foreign or contaminating species. Isolation is usually achieved by growing the species in an environment that was previously sterilized, and was thereby rid of contaminating organisms. Since, from a practical viewpoint, the contaminating organisms usually encountered are microorganisms, axenic cultures, whether of invertebrates (for example, nematodes) or vertebrates (for example, rodents), are often referred to as germ-free. Indeed, the terms axenic and germ-free are occasionally used interchangeably. Gnotobiotic is also often used interchangeably with axenic; however, in common practice gnotobiotic specifically refers to germ-free conditions.
Industry:Science
The common name for a malignant neoplasm or tumor. Neoplasms are new growths and can be divided into benign and malignant types, although in some instances the distinction is unclear. The most important differentiating feature is that a malignant tumor will invade surrounding structures and metastasize (spread) to distant sites whereas a benign tumor will not. Other distinctions between benign and malignant growth include the following: malignancies but not benign types are composed of highly atypical cells; malignancies tend to show more rapid growth than benign neoplasms, and are composed, in part, of cells showing frequent mitotic activity; and malignant tumors tend to grow progressively without self-limitation.
Industry:Science
Study of the development and function of the nervous system, with emphasis on how nerve cells generate and control behavior. The major goal of neurobiology is to explain at the molecular level how nerve cells differentiate and develop their specific connections and how nerve networks store and recall information. Ancillary studies on disease processes and drug effects in the nervous system also provide useful approaches for understanding the normal state by comparison with perturbed or abnormal systems. The functions of the nervous system may be studied at several levels: molecular, subcellular (organelle), cellular, simple multicellular interacting systems, complex systems, and higher functions (whole animal behavior).
Industry:Science
