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| 释义 | betabe·taB0212600 (bā′tə, bē′-)beta(ˈbiːtə)Beta(ˈbiːtə)be•ta(ˈbeɪ tə; esp. Brit. ˈbi-)n., pl. -tas, adj. n. Be•ta(ˈbeɪ tə; esp. Brit. ˈbi-) Trademark.beta
betabetabeta(bay -tă, bee -) (β) The second letter of the Greek alphabet, used in stellar nomenclature usually to designate the second-brightest star in a constellation or sometimes to indicate a star's position in a group.Beta(beets), a genus of annual, biennial, and perennial plants of the family Chenopodiaceae. There are 13 species, of which 11 are wild and two are cultivated. The five species found in the USSR include the two cultivated species. Wild species include B. procumbens, B. macrorhiza, B. lomatogona, B. intermedia, B. trigyna, B. maritima, and B. patula. Wild beets grow in the Mediterranean Region, the Middle East, Transcaucasia, the Crimea, and the Balkans. They are distributed as far east as India and as far west as France, Great Britain, and Scandinavia. The two cultivated species, Swiss chard (B. cicla) and the common beet (B. vulgaris), are biennials. The latter species is divided into European and Asian subspecies. The European subspecies include varieties of garden, feed, and sugar beets. The Asian subspecies include predominantly inferior varieties with weakly developed roots. Numerous varieties of cultivated beets have been developed by breeding. The flower-bearing stem, which is grassy, erect, and very heavily branched, appears in biennial and perennial species in the second season. The large, smooth or wavy leaves are triangular, lingulate, or cordate. The basal leaves have long petioles, and upper leaves are short-petioled and almost sessile. The bisexual green or whitish flowers have a pentamerous cup-shaped perianth, five stamens, and one pistil; they are gathered into long leafy inflorescences and often are in sessile groups. The plants are cross-pollinated by small insects. The kidney-shaped fruits grow together as they mature, forming clusters of two to six. The seeds are enclosed in a shell. The first sugar beet with a one-seeded fruit cluster, or seedball, was developed in the USSR. The spindle-shaped root of wild beets and leaf beets becomes woody and is entirely underground. The common garden beet has a fleshy, succulent root, which emerges to the soil surface in most varieties. The wild beet has been used as food since prehistoric times. In the first or second millennium B.C. the chard was brought under cultivation, presumably on islands in the Mediterranean Sea, as a medicinal and vegetable plant. Cultivated forms of the common beet appeared by the beginning of the Common Era. They were known in Kievan Rus’ in the tenth or 11th century and in Western Europe in the 13th or 14th century. The differentiation of the common beet into garden and feed varieties occurred in the 16th or 17th century. The sugar beet was isolated from hybrid forms of feed beets in the 18th century. Since the late 19th and early 20th centuries beet cultivation has spread to all continents. The garden beet, also called table beet or red beet, forms during the first season an oblate-spherical, ovate-spherical, or flattened tuber, weighing 0.4–0.9 kg, and a top of red-veined green or red leaves. The tuber, which has dark red, claret, or red violet flesh, contains 13–20 percent dry matter, including 9–16 percent sugar, 1.8–3 percent protein, up to 0.5 percent organic acid, 0.7–1.4 percent cellulose, and 0.8–1.3 percent mineral salts. It also contains vitamins C, B, P, and PP. The tubers and the young plants are used as food. Garden beets are raised on all continents. They are cultivated in all the agricultural zones of the USSR: in 1973 garden beets occupied roughly 50,000 hectares (ha) and yielded 400–500 quintals per ha (maximum, 1,000 quintals). In 1974 there were 21 regionalized varieties; the best included Bordeaux 237, Nesravnennaia A-463, Gribovskaia ploskaia A-473, and Podzimniaia A-474. Garden beets are planted in rotation with cabbage, tomatoes, and cucumbers. At least 30 tons/ha of humus are applied during autumn plowing; on acid soils 5–10 tons/ha of lime are also applied. The beets are sown in the spring or autumn in double rows or with wide spacing between rows (33 cm). The rate of sowing is 16–20 kg/ha, with the seeds placed at a depth of 2–3 cm. Crop management involves the use of herbicides (spraying with pyramine), thinning twice, topdressing, soil loosening, and watering (in hot summers and in regions of irrigation farming). The tubers are gathered by beet pullers and, after leaf removal, are stored in root cellars. In the first season the feed beet, which is commonly called the mangel-wurzel, forms a large tuber, weighing up to 10–12 kg and varying in shape (saclike, oval-conical, cylindrical, spherical) and color (yellow, white, red). Its green top leaves are used as succulent feed, including silage. One hundred kilograms of tubers contain 12.2 feed units and 0.9 kg of digestible protein, 100 kg of leaves contain 10.2 feed units and 1.8 kg of digestible protein. Mangel-wurzels have been raised in what is now the USSR since the 18th century. They are cultivated (1973) in many European countries, the United States, Canada, Brazil. Australia, New Zealand, Algeria, Tunisia, and elsewhere. In the USSR mangel-wurzels occupied roughly 800,000 ha in 1973; the average yield of tubers was 300–400 quintals per ha. The primary regions of cultivation are the Ukrainian Poles’e, the central regions of the nonchernozem zone of. the RSFSR, the Volga Region, Byelorussia, and Lithuania. As of 1974 there were 25 regionalized varieties; the best included Ekkendorfskaia Zheltaia, Arnim krivenskaia, Barres, Pobeditel’, and Polusakharnaia Belaia. Certain varieties of sugar beets, for example, Sakharnaia Okruglaia 143, are also raised for feed. In feed crop rotation, mangel-wurzels are planted after annual green fodder mixtures, potatoes, and silage corn. Fertilizer dosages are 30–40 tons/ha of organic fertilizer and 60–120 kg/ha of NPK. The beets are planted in wide rows and single-drill rows 45–60 cm apart, with a sowing rate of 15–25 kg and 8–12 kg of seed per ha, respectively. The seed is sown at depths of 2.5–4 cm. Crop management is similar to that for garden beets. Feed beets are harvested by potato pickers, potato-harvesting combines, and beet pullers. They are stored in piles or root cellars. During the first season the sugar beet develops an elongated, sugar-rich (up to 23 percent) tuber, which weighs an average of 300–600 g. It has white flesh and a top of light green leaves. The growing season is 100 to 170 days in the first year and 100 to 125 days in the second year. The sugar beet deviates more from the two-year cycle of development than other forms of beets with respect to flowering in the first season and not flowering in the second. These attributes are related to varietal characteristics and conditions of cultivation and storage of the tubers. The sugar beet thrives on heat, light, and moisture, although it also has comparatively high drought and salt resistance. The optimum temperature for seed germination is 10°-12°C; the optimum temperature for growth and development is 20°-22°C. The sprouts are sensitive to frost and die at a temperature of – 4° or – 5°C. The sugar content of the tubers depends on the number of sunny days between August and October. The plant consumes the greatest amount of moisture in July and August—the period of intensive tuber growth. The sugar beet is particularly productive on chernozems. The sugar beet is an important industrial crop; it provides raw material for the sugar industry. By-products include pulp residue (used for livestock feed), molasses (a food product), and defecation slime (a lime fertilizer). In 1747 the German chemist A. S. Marggraf proposed that beets with white tubers could expediently be used to obtain crystalline sugar. Later in the century his countryman F. C. Achard selected and bred beets with increased sucrose content and obtained large amounts of beet sugar at his factory. The scientific selection of sugar beets was begun in the mid- 19th century in France by L. Vilmorin. In 1900 sugar beets were planted on 497,500 ha in Russia; in 1913 the figure had risen to 676,000 ha, with an average yield of 168 quintals per ha. The industrial characteristics of the raw material were improved through selection work, better seed-raising, and improved cultivation. In 1811 the sugar content of the beets was no greater than 6–7 percent; by 1908 the sugar content had been increased to an average of 18.5 percent. Since 1900 sugar beets have been raised primarily in countries with temperate climates. For statistics on world sugar beet production see Table 1. In 1973 the highest sugar beet yields in the USSR were obtained in Kirghizia (387 quintals/ha), Georgia (331 quintals/ha), and the Ukraine (279 quintals/ha). The principal areas of cultivation are the Ukraine, the central chernozem regions, the Northern Caucasus, Moldavia, Kazakhstan, and Kirghizia. Domestically bred varieties and hybrids exclusively are planted in the USSR. In 1974, 30 varieties (including six one-seeded varieties) and ten hybrids (seven one-seeded hybrids) were regionalized. They comprised heavy-producing (sugar content 17.9–18.3 percent; yield 48–51 quintals/ha), high-sugar (sugar content 18.7–19 percent; yield 43–44 quintals/ha), and combination heavy-producing and high-sugar (sugar content 18.5–18.7 percent; yield 47–49 quintals/ha) varieties and hybrids. The best are Ramonskaia 06, Ramonskaia 100, Ialtushkovskaia Odnosemiannaia. Ialtushkovskii hybrid, and Belotserkovskii Polyhybrid 1 and 2. In 1974, one-seeded varieties constituted 60 percent of the sugar beet plantings of the USSR (75 percent in the Ukraine). The goal of selection in the USSR is to breed highly productive varieties and hybrids (including one-seeded polyhybrids), which have excellent industrial characteristics and which are disease and pest resistant, responsive to large doses of fertilizer and to irrigation (for irrigation regions), fast-maturing, and nonflowering in the first season. In crop rotation, sugar beets are usually planted after winter wheat followed by perennial grasses and bare and occupied fallow. The primary soil tillage involves scuffling stubble and deep (28–32 cm) autumn plowing. Approximate fertilizer norms are 20–30 tons/ha of manure, 30–60 kg/ha of N, 30–90 kg/ha of P2O5, and 45–60 kg/ha of K2O. It is most efficient to apply fertilizer in the drills with the seeds and as topdressing. Sugar beets are planted by the wide-row and single-seed methods, with interrow spaces of 45–60 cm. The seeds, which have been graded by size, treated, and coated, are sown at a rate of 10–28 kg/ha at depths of 2–5 cm. Field management involves pregermination and postgermination harrowing, blocking and subsequent thinning out, loosening the interrow soils, topdressing, and watering (in Kirghizia, Kazakhstan, and other regions with inadequate moisture). The plants are harvested when they have reached the greatest sugar content in the tubers. The tubers are stored in underground and surface pits. Full mechanization of sugar beet cultivation in the principal beet-growing regions of the USSR involves special machinery (sugar-beet drills, thinning machines, cultivator-feeders), in addition to general-purpose machinery and implements. Sugar beets are gathered primarily by beet-harvesting combines, which use either the continuous or two-stage method. With the first method, the beets are transported from the combine to a processing plant or storage area. The two-stage method involves dumping the beets from the combine into piles at the edge of the field or some special area and then loading them onto a transport vehicle. In swath harvesting two combines work in the field simultaneously; the first cuts the tops and the second digs up the tubers. On small and uneven plots, sugar beets are harvested by beet pullers. Sugar beet pests include the flea beetle, the beet weevil, the beet leaf miner, the sugar-beet root aphid, and the beet bug. Diseases include black root, cercosporosis, nematode diseases, powdery mildew, and leaf mosaic.
In the USSR sugar beet seeds are raised by selection-testing stations (where varieties are developed), special elite seed-growing sovkhozes, and regular seed-growing sovkhozes. The last raise the seeds that are used in agriculture. REFERENCESKrasochkin, V. T. Svekla. Moscow-Leningrad, 1960.Karpenko, P. V. Sveklovodstvo, 3rd ed. Moscow, 1964. Sortoopisanie ovoshchnykh bakhchevykh kul’tur i kormovykh korneplodov. Moscow, 1965. Biologiia i selektsiia sakharnoi svekly. Moscow, 1968. Kul’turnaia flora SSSR, vol. 19: Korneplodnye rasteniia. Leningrad, 1971. I. F. BUZANOV and S. I. KUZMICH beta[′bād·ə]BETA(1)Mjolner Informatics ApS, Aarhus, implementations for Mac, Sun,HP, Apollo. E-mail: Mailing list: ["Object-Oriented Programming in the BETA ProgrammingLanguage", Ole Lehrmann et al, A-W June 1993, ISBN0-201-62430-3]. beta(2)See beta conversion, beta test. betabeta[ba´tah]Because of their effects on the heart, these agents are used to treat angina pectoris, hypertension, and cardiac arrhythmias. And, because they decrease the workload of the heart, they are effective in reducing the long-term risk of mortality and reinfarction after recovery from the acute phase of a myocardial infarction. They are an important adjunct in treatment of heart failure and are also used for prophylaxis of migraine. Nonselective beta-adrenergic blocking agents affect both types of receptors and can produce bronchospasm in patients with asthma or chronic obstructive pulmonary disease. If such patients need one of these drugs, they should be given a cardioselective one that preferentially blocks the β1-receptors in the heart. Nonselective agents include propranolol" >propranolol (Inderal), used for treatment of angina, hypertension, arrhythmias, and migraine and for prophylaxis after the acute phase of a myocardial infarction; nadolol" >nadolol (Corgard), used for treatment of angina and hypertension; and timolol" >timolol, used as an ophthalmic preparation (Timoptic) for treatment of glaucoma and as an oral preparation (Blocadren) for treatment of hypertension and for prophylaxis after the acute phase of a myocardial infarction. Cardioselective beta-adrenergic blocking agents are used for treatment of hypertension and include atenolol" >atenolol (Tenormin) and metoprolol" >metoprolol (Lopressor). βIn typography, do not substitute the German compound letter β for this Greek letter.be·ta (β),(bā'tă), In typography, do not substitute the German compound letter β for the Greek letter β.betaMedspeakThe second letter in the Greek alphabet. The term is included here to flag the differences in pronunciation between British and American English. Medspeak-UK: pronounced, BEE tuh. Medspeak-US: pronounced, BAY tuh. Statistics The probability of a Type-II false-negative error. In hypothesis testing, beta is the probability of concluding incorrectly that an intervention is not effective when it has true effect. 1-b is the power to detect an effect of an intervention if one truly exists betaβ The second letter of the Greek alphabet; Statistics The probability of a Type II–false-negative error. See Type II error. Cf Alpha.βbe·ta(β) (bā'tă)betaThe second letter of the Greek alphabet, often used to denote the order in a sequence.beta
Words related to beta
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英语词典包含2567994条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。
Beta - beets 
beta - preliminary or testing stage of a software or hardware product; "a beta version"; "beta software"