| 释义 |
concentration
con·cen·tra·tion C0543600 (kŏn′sən-trā′shən)n.1. a. The act or process of concentrating, especially the fixing of close, undivided attention.b. The condition of being concentrated.2. Something that has been concentrated.3. Chemistry The amount of a specified substance in a unit amount of another substance.concentration (ˌkɒnsənˈtreɪʃən) n1. intense mental application; complete attention2. the act or process of concentrating3. something that is concentrated4. (Chemistry) the strength of a solution, esp the amount of dissolved substance in a given volume of solvent, usually expressed in moles per cubic metre or cubic decimetre (litre). Symbol: c 5. (Chemistry) the process of increasing the concentration of a solution6. (Military) military a. the act of bringing together military forcesb. the application of fire from a number of weapons against a target7. (Economics) economics the degree to which the output or employment in an industry is accounted for by only a few firms8. (Card Games) another name (esp US) for Pelmanismcon•cen•tra•tion (ˌkɒn sənˈtreɪ ʃən)
n. 1. the act of concentrating or the state of being concentrated. 2. exclusive attention to one object; close mental application. 3. something concentrated: a concentration of stars. 4. (in a chemical solution) a measure of the amount of dissolved substance contained per unit of volume. [1625–35] con·cen·tra·tion (kŏn′sən-trā′shən) The amount of a particular substance in a given amount of another substance, especially a solution or mixture.Concentration a concentrated collection or mass; a distillate.Examples: concentration of broken beams, 1634; of lunar beams, 1691; of related species, 1881; of hostile tribes, 1841; of forces, 1804.concentrationA measure of the quantity of solute dissolved in a solution at a given temperature.Thesaurus| Noun | 1. | concentration - the strength of a solution; number of molecules of a substance in a given volumeproperty - a basic or essential attribute shared by all members of a class; "a study of the physical properties of atomic particles"titer, titre - the concentration of a solution as determined by titrationhydrogen ion concentration - the number of moles of hydrogen ions per cubic decimetermolal concentration, molality - concentration measured by the number of moles of solute per kilogram of solventmolar concentration, molarity, M - concentration measured by the number of moles of solute per liter of solution | | 2. | concentration - the spatial property of being crowded togethercompactness, denseness, density, tightnessspatial arrangement, spacing - the property possessed by an array of things that have space between themdispersion, distribution - the spatial or geographic property of being scattered about over a range, area, or volume; "worldwide in distribution"; "the distribution of nerve fibers"; "in complementary distribution" | | 3. | concentration - strengthening the concentration (as of a solute in a mixture) by removing diluting materialstrengthening - the act of increasing the strength of somethingpervaporation - the concentration of a colloidal solution whose colloid will not pass through a semipermeable membrane; solution is placed in a bag of the membrane and the solvent is evaporated offdilution - weakening (reducing the concentration) by the addition of water or a thinner | | 4. | concentration - increase in densityincrease - a change resulting in an increase; "the increase is scheduled for next month"compaction, compression, densification, concretion - an increase in the density of somethingrarefaction - a decrease in the density of something; "a sound wave causes periodic rarefactions in its medium" | | 5. |  concentration - complete attention; intense mental effortengrossment, immersion, absorptionattention - the faculty or power of mental concentration; "keeping track of all the details requires your complete attention"centering, focus, focusing, focussing, focal point, direction - the concentration of attention or energy on something; "the focus of activity shifted to molecular biology"; "he had no direction in his life"specialism - the concentration of your efforts on a particular field of study or occupationstudy - a state of deep mental absorption; "she is in a deep study" | | 6. | concentration - bringing together military forcesgathering, assemblage, assembly - the social act of assembling; "they demanded the right of assembly" | | 7. |  concentration - great and constant diligence and attentionassiduity, assiduousnessindustriousness, diligence, industry - persevering determination to perform a task; "his diligence won him quick promotions"; "frugality and industry are still regarded as virtues"intentness, engrossment - the quality of being intent and concentrated; "the intentness of his gaze"singleness - the quality of concentrating on one central objective; "his singleness of purpose" |
concentrationnoun1. attention, application, absorption, single-mindedness, intentness His talking kept breaking my concentration.
attention distraction, disregard, inattention, absent-mindedness2. focusing, centring, consolidation, convergence, bringing to bear, intensification, centralization This concentration of effort and resources should not be to the exclusion of everything else.3. convergence, collection, mass, cluster, accumulation, aggregation The area has one of the world's greatest concentrations of wildlife.
convergence scattering, spreading-out, diffusion, dispersalconcentrationnoun1. A converging at a common center:confluence, conflux, convergence.2. Concentration of the mental powers on something:attention, attentiveness, consideration, heedfulness, regardfulness.Translationsconcentrate (ˈkonsəntreit) verb1. to give all one's energies, attention etc to one thing. I wish you'd concentrate (on what I'm saying). 集中注意力 集中，专心 2. to bring together in one place. He concentrated his soldiers at the gateway. 使集中於一點 使集中于一点3. to make (a liquid) stronger by boiling to reduce its volume. 濃縮 浓缩ˈconcentrated adjective (of a liquid etc) made stronger; not diluted. concentrated orange juice. 濃縮的 浓缩的ˌconcenˈtration nounShe lacks concentration – she will never pass the exam. 集中力 集中，专心 concentration
concentration, in chemistry, measure of the relative proportions of two or more quantities in a mixturemixture,
in chemistry, a physical combination of two or more pure substances (i.e., elements or compounds). A mixture is distinguished from a compound, which is formed by the chemical combination of two or more pure substances in a fixed, definite proportion.
..... Click the link for more information. . The concentration of a solute is very important in studying chemical reactions because it determines how often molecules collide in solution and thus indirectly determines the rates of reactions and the conditions at equilibrium (see chemical equilibriumchemical equilibrium,
state of balance in which two opposing reversible chemical reactions proceed at constant equal rates with no net change in the system. For example, when hydrogen gas, H2, and iodine gas, I2
..... Click the link for more information. ). Concentration may be expressed in a number of ways. The simplest statement of the concentrations of the components of a mixture is in terms of their percentages by weight or volume. Mixtures of solids or liquids are frequently specified by weight percentage concentrations, such as alloys of metals or mixtures used in cooking, whereas mixtures of gases are usually specified by volume percentages. Very low concentrations may be expressed in parts per million (ppm), as in specifying the relative presence of various substances in the atmosphere. In addition to these means of expressing concentration, several others are defined especially for describing solutionssolution,
in chemistry, homogeneous mixture of two or more substances. The dissolving medium is called the solvent, and the dissolved material is called the solute. A solution is distinct from a colloid or a suspension.
..... Click the link for more information. : molarity, molality, mole fraction, formality, and normality. Some of these define the concentration of the solute in reference to the amount of solvent, others in reference to the total amount of solution. The molarity of a solution is the number of molesmole,
in chemistry, a quantity of particles of any type equal to Avogadro's number, or 6.02×1023 particles. One gram-molecular weight of any molecular substance contains exactly one mole of molecules.
..... Click the link for more information. of solute per liter of solution; e.g., a solution of glucose in water containing 180.16 grams (1 gram-molecular weight, or mole) of glucose per liter of solution is referred to as one molar (1 M). The molality of a solution is the number of moles of solute per 1,000 grams of solvent; a solution prepared by dissolving 180.16 grams of glucose in 1,000 grams of water is one molal (1 m). The mole fraction of a solution is the ratio of moles of solute to the total number of moles in the solution. Since ionic compounds, such as sodium chloride, NaCl, do not occur as molecules, their concentrations cannot be expressed in terms of molarity, molality, or mole fraction. Instead, the concentration of an ionic compound in solution may be given by its formality, the number of gram-formula weights of the compound per liter of solution; e.g., a solution containing 58.44 grams (one gram-formula weight) of NaCl per liter of solution is one formal (1 F). In considering the reactions of certain solutions in combination, for example the neutralizationneutralization,
chemical reaction, according to the Arrhenius theory of acids and bases, in which a water solution of acid is mixed with a water solution of base to form a salt and water; this reaction is complete only if the resulting solution has neither acidic nor basic
..... Click the link for more information. of acids and bases, a useful expression of the concentration is the normality of each solution, the number of gram-equivalent weights of solute per liter of solution (see equivalent weightequivalent weight.
The equivalent weight of an element or radical is equal to its atomic weight or formula weight divided by the valence it assumes in compounds. The unit of equivalent weight is the atomic mass unit; the amount of a substance in grams numerically equal to the
..... Click the link for more information. ); e.g., a solution containing 49.04 grams (one gram-equivalent weight) of sulfuric acid, H2SO4, per liter of solution is one normal (1 N). Concentrations of solutions may also frequently be given in terms of the weight of solute in a given volume of solvent or solution. concentration The diameter of the telescopic image of a point-source of light, such as a star. The image is increased from point size by unavoidable optical effects in the telescope, specifically diffraction (see Airy disk), and for ground-based telescopes it is further increased by distortion due to atmospheric conditions at the time of observation, i.e. by the seeing.Concentration in chemistry, the value representing the relative quantity of a given component (independent constituent) in a physicochemical system (mixture, solution, melt). The most commonly used methods of expressing concentration are (1) mass fraction—the ratio of the mass of the given component to the mass of the entire system; this ratio multiplied by 100 yields the concentration in weight percent; (2) atomic, or mole, fraction—the ratio of the number of gram atoms (moles) of a given component to the total number of gram atoms (moles) of the system; this ratio multiplied by 100 yields the concentration in atom (mole) percent; and (3) volume fraction—the ratio of the volume of the given component to the total volume of the system; this ratio multiplied by 100 yields the concentration in volume percent. The concentration of liquid systems is often expressed by the weight of the substance dissolved in 100 g (sometimes in 1 l) of solvent or by the number of moles of substance per 1,000 moles of solvent. In the study of solutions, the concepts of molarity (the number of moles of solute per 1 l of solvent) and molality (the number of moles of solute per 1,000 grams of solvent) are often used. In volumetric analysis, the concentration is expressed by normality (the number of gram equivalents of the active constituent per 1 l of solution) and by titer (the number of grams of active substance or the substance being determined per 1 ml of solution). In practice, concentration is determined using both the standard methods of quantitative analysis and certain instrumental methods, which make it possible to perform rapid and sufficiently accurate calculations of the content of the main component (for example, determination of the concentration of aqueous solutions of acids, alkalis, salts, and ethyl alcohol by measuring density with the aid of a hydrometer). REFERENCESAnosov, V. Ia, and S. A. Pogodin. Osnovnye nachalafizikokhimicheskogo analiza. Moscow-Leningrad, 1947. Pages 81–83.
Terminologiia termodinamiki; sborniki rekomenduemykh terminov, fasc. 7. Edited by A. M. Terpigorev. Moscow, 1952.
Kireev, V. A. Kurs fizicheskoi khimii. Moscow, 1955. Pages 340–44.
Vinogradov, G. V. Nomogrammy perescheta kontsentratsii. Moscow-Leningrad, 1948.S. A. POGODIN concentration[‚kän·sən′trā·shən] (chemistry) In solutions, the mass, volume, or number of moles of solute present in proportion to the amount of solvent or total solution. (hydrology) The ratio of the area of the sea covered by ice to the total area of sea surface. (mathematics) An operation that provides a relatively sharp boundary to a fuzzy set; for a fuzzy set A with membership function mA, a concentration of A is a fuzzy set whose membership function has the value [mA (x)]αfor every element x, where α is a fixed number that is greater than 1. (mining engineering) Separation and accumulation of economic minerals from gangue. concentration1. Chemistry the strength of a solution, esp the amount of dissolved substance in a given volume of solvent, usually expressed in moles per cubic metre or cubic decimetre (litre). 2. Economics the degree to which the output or employment in an industry is accounted for by only a few firms 3. another name (esp US) for PelmanismconcentrationIn communications, the combining of multiple channels into one.concentration
concentration [kon″sen-tra´shun] 1. increase in strength by evaporation.2. the ratio of the mass or volume of a solute to the mass or volume of the solution or solvent.3. intense mental focus.hydrogen ion concentration see hydrogen ion concentration.mass concentration the mass of a constituent substance divided by the volume of the mixture, as milligrams per liter (mg/l).mean corpuscular hemoglobin concentration (MCHC) the average hemoglobin concentration in erythrocytes, conventionally expressed in “per cent,” meaning grams per deciliter of red blood cells, obtained by dividing the blood hemoglobin concentration (in g/dl) by the hematocrit (in l/l): MCHC = Hb/Hct.minimal alveolar concentration (MAC) the concentration of anesthetic that at a pressure of 1 atmosphere produces immobility in 50 per cent of subjects exposed to a noxious stimulus.minimal bactericidal concentration (MBC) the lowest concentration of a given antibiotic required to kill a specific organism.minimal inhibitory concentration (MIC) the lowest concentration of a given antibiotic that inhibits the growth of a specific organism.molar concentration the concentration of a substance expressed in terms of molarity" >molarity.concentration test a test of renal function based on the patient's ability to concentrate urine; see also fishberg concentration test.con·cen·tra·tion (c), (kon'sen-trā'shŭn), 1. A preparation made by extracting a crude drug, precipitating it from the solution, and drying. 2. Increasing the amount of solute in a given volume of solution by evaporation of the solvent. 3. The quantity of a substance per unit volume or weight. In renal physiology, symbol U for urinary concentration, P for plasma concentration; in respiratory physiology, symbol C for amount per unit volume in blood, F for fractional concentration (mole fraction or volume per volume) in dried gas; subscripts indicate location and chemical species. [L. con-, together, + centrum, center] Chemistry The ratio of a mass or volume of a solute to the mass or volume of a solvent
Epidemiology The density of a population in a particular demographic region
Lab medicine The proportion of one molecule or substance to its diluent
Neurology The degree of mental focus required to carry out a task
Respiratory medicine The amount of a particular gas—CO2, O2—in a sampling of air from a patientconcentration Epidemiology The density of a population in a particular demographic region Lab medicine The proportion of one molecule or substance to its diluent. See Blood alcohol concentration, Critical concentration, Critical dissolved oxygen concentration, Derived air concentration, Minimum bactericidal concentration, Minimum effective concentration, Minimum inhibitory concentration, Passive concentration, Peak serum concentration, Potentially toxic concentration, Serum concentration, Steady-state serum concentration, Total drug concentration, Trough serum concentration Neurology A general term for the degree of mental focus required to carry out a task Toxicology The ratio of a mass or volume of a solute to the mass or volume of a solvent. See Lethal concentration, Median lethal concentration, Minimum detectable concentration. con·cen·tra·tion (c) (kon'sĕn-trā'shŭn) 1. A preparation made by extracting a crude drug, precipitating from the solution, and drying. 2. Increasing the amount of solute in a given volume of solution by evaporation of the solvent. 3. The quantity of a substance per unit volume or weight. 4. physiology Symbol U for urinary concentration, P for plasma concentration. 5. respiratory physiology Symbol C for amount per unit volume in blood, F for fractional concentration (mole fraction or volume per volume) in dried gas. [L. con-, together, + centrum, center]ConcentrationRefers to the amount of solute present in a solution, compared to the total amount of solvent.Mentioned in: Diabetes Insipiduscon·cen·tra·tion (kon'sĕn-trā'shŭn) A preparation made by extracting a crude drug, precipitating it from the solution, and drying it. [L. con-, together, + centrum, center]Patient discussion about concentrationQ. Where to concentrate on while losing weight and how? a strongest muscle and largest muscle reduction will help me in losing weight. Where to concentrate on while losing weight and how?A. why not do a sport that activates more muscles then just one..? running or swimming? those actions work on groups of big muscles and on your heart and lungs system that is very important in order to get in shape. Q. Does anyone have ideas for ways to overcome concentration problems without depending on medications? I'm reallllllly trying hard to study for my final exams and my ADD seems to bother me every time I touch the desk. Sometimes my thoughts fly out when I only think of how much I still have to study today!!! please- help if you can... I really don't want to start with meds...A. Omega-3 fatty acids, phosphatidylserine, zinc and magnesium may have benefits with regard to ADD symptoms. i take omega-3 fatty acids every day for the past year and it helped me go threw a ruff year of studying. More discussions about concentrationFinancialSeeMACAcronymsSeeconcentratedconcentration
Synonyms for concentrationnoun attentionSynonyms- attention
- application
- absorption
- single-mindedness
- intentness
Antonyms- distraction
- disregard
- inattention
- absent-mindedness
noun focusingSynonyms- focusing
- centring
- consolidation
- convergence
- bringing to bear
- intensification
- centralization
noun convergenceSynonyms- convergence
- collection
- mass
- cluster
- accumulation
- aggregation
Antonyms- scattering
- spreading-out
- diffusion
- dispersal
Synonyms for concentrationnoun a converging at a common centerSynonyms- confluence
- conflux
- convergence
noun concentration of the mental powers on somethingSynonyms- attention
- attentiveness
- consideration
- heedfulness
- regardfulness
Synonyms for concentrationnoun the strength of a solutionRelated Words- property
- titer
- titre
- hydrogen ion concentration
- molal concentration
- molality
- molar concentration
- molarity
- M
noun the spatial property of being crowded togetherSynonyms- compactness
- denseness
- density
- tightness
Related Words- spatial arrangement
- spacing
Antonymsnoun strengthening the concentration (as of a solute in a mixture) by removing diluting materialRelated Words- strengthening
- pervaporation
Antonymsnoun increase in densityRelated Words- increase
- compaction
- compression
- densification
- concretion
- rarefaction
noun complete attentionSynonyms- engrossment
- immersion
- absorption
Related Words- attention
- centering
- focus
- focusing
- focussing
- focal point
- direction
- specialism
- study
noun bringing together military forcesRelated Words- gathering
- assemblage
- assembly
noun great and constant diligence and attentionSynonymsRelated Words- industriousness
- diligence
- industry
- intentness
- engrossment
- singleness
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