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geometric     
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  几何
     Geometric Constraints in Image Sequence and Their Applications
     序列图象的几何约束及其应用
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     Researches on Image Representation and Geometric Constraints in Video Coding
     图像表述及视频编码中的几何约束研究
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     Study on Theories and Methods of Geometric Tolerance Design Based on Variational Geometric Constraints Network
     基于变动几何约束网络的形位公差设计理论与方法的研究
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     A Study on Geometric Mircrostructure and Mechanical Performances of 4-directional Rectangular Braided Composites
     四向矩形编织复合材料几何细观结构和力学性能研究
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     The Problem of Geometric Continuity in NURBS Surfaces Reconstruction
     NURBS曲面重构中的几何连续性问题
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  几何的
     WFA ALGORITHM BASED ON FRACTAL GEOMETRIC FOR APPLICATION OF IMAGE COMPRESSION
     基于分形几何的WFA算法在图像压缩中的应用
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     This paper studys some problems about pure states D~1(H) in density states D(H) from the geometric point of view.
     本文主要从几何的角度讨论了密度态空间D(H)中纯态D~1(H)的一些问题。
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     Study of Nonlinear Strain Geometry of Vessels with Initial Geometric Imperfections
     有初始几何缺陷的压力容器非线性应变几何的研究
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     The classical differential geometry curve theory and Lyapunov stability theory are combined to create a new robust geometric approach to the missile guidance problem.
     针对平面拦截问题 ,将基于微分几何的导弹制导与基于李雅普诺夫稳定理论的鲁棒控制方法结合起来 ,提出一种新的鲁棒制导算法———鲁棒几何制导 .
短句来源
     Recently, L~p — pinching problem has become an important new subject in differential geometry, which mainly studies the geometric structure and topological structure of manifolds under L~p — pinching condition.
     最近,L~p-pinching问题已经成为研究微分几何的一个重要的新课题,它主要研究流形在L~p-pinching条件下的几何结构和拓扑结构。
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  几何学的
     The studies in the thesis centered on the following:The elementary analysis on the triple screw geometry includes basic structure, geometry configuration and the relationship between geometric parameter and performance.
     (1) 三螺杆几何学的初步分析,其中包括三螺杆挤出机的基本结构和几何构型、几何参数与性能的分析研究。
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     Through necessary proof and using geometric methods, this paper presents some conclusions about orthougraphics, projective characteristics and positions in space both of oblique line and plane with equal dip angles to the planes of projection.
     本文运用几何学的方法,通过必要的证明,对一般位置等倾直线和等倾平面的投影图形、投影特性及空间位置得出了结论。
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     Methods An ideal aortic valve model was established, and the force on the valvular surface in different situations were analyzed with geometric method.
     方法 建立理想的主动脉瓣模型,用几何学的方法对不同瓣叶情况下的瓣膜受力情况进行分析。
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     fractal geometry enables students to have better understanding of the new development of geometry and exploit new space of geometric thinking;
     分形几何学使得学生能更多地了解几何学的新发展,开拓几何思维的新空间。
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     The relative motion of crustal blocks in China and surounding area has been investigated using a geometric method, which was engaged in study of plate motion by Minster & Jorden (1978).
     本文利用板块几何学的方法研究中国及邻区地块间的相对运动,用数值方法计算了地块运动的角速度及边界断层的滑动速率。
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  几何图形的
     This paper defines fuzzy sets, researches some problems of fuzzy mathematic and discusses the subjects of geometric figure with the concept of convex sets.
     定义了 Fuuzy集 ,研究了 Fuzzy数学中的几个问题 ,用凸集概念讨论了几何图形的题目
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     MATCHING RECOGNITION OF GEOMETRIC GRAPHICS
     几何图形的匹配识别
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     A study of the first sampling part of irregular geometric figures was conducted in the experimental method.
     用实验方法对不规则几何图形的取样首视点进行研究。
短句来源
     Friedman test and Kendall's Coefficient of Concordance test showed that the sampling order for irregular geometric figure recognition was generally stable, it was accorded with the degree of the difference among the sampled-features.
     Friedman双向方差分析和Kendall一致性系数检验的结果表明 :不规则几何图形的信息取样优先序有按取样特征信息差异度序进行编排的趋势。
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     Simply Analyse the Application of the Geometric Figure in Higher Mathematics Teaching
     浅析高等数学教学中几何图形的应用
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  geometric
As in the case of Mumford's geometric invariant theory (which concerns projective good quotients) the problem can be reduced to the case of an action of a torus.
      
Using related sequences of Lucas numbers, other 3-manifolds are constructed, their geometric structures determined, and a curious relationship between the homology and the invariant trace-field examined.
      
In [Ka1] its geometric counterpart was applied to construct contractible smooth affine varieties non-isomorphic to Euclidean spaces.
      
We also study the structure of the exceptional?-graded transitive Lie superalgebras and give their geometric realization.
      
Geometric construction of the global base of the quantum modified algebra of
      
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(Consisting of two articles, the first one was published in 1938 in the Singchow Semi-monthly Singapore, the second is a much more detailed one written in 1957. Followingis a general sketch of both the two articles.) Ⅰ. What is the Malayan Stock? In common sense, Malayan stock means the Malayan race or Brown race, which isone of the five human races of the world. The classic method of the classification ofhuman races according to their skin colour gave the Malayans the pseudo-scientific name"Brown race" which...

(Consisting of two articles, the first one was published in 1938 in the Singchow Semi-monthly Singapore, the second is a much more detailed one written in 1957. Followingis a general sketch of both the two articles.) Ⅰ. What is the Malayan Stock? In common sense, Malayan stock means the Malayan race or Brown race, which isone of the five human races of the world. The classic method of the classification ofhuman races according to their skin colour gave the Malayans the pseudo-scientific name"Brown race" which has made the ethnic position of the Malayans as well as the ethnicrelationship between the Malayans and the other related peoples unclear scientifically. Therecent anthropological studies revealed the close ethnic relation between the brown raceand the yellow race, hence the Malayan stock is regarded as one branch of the Mongo-loids and given a new term "Oceanic Mongoloid". The Malayan stock now stands closelywith its two brothers the Northern Mongoloid and the Southern Mongoloid. The term "Malayans" is used here in its broader meaning which includes all thepeoples in Malaysia with a physical characteristics mostly of yellowish-brown colour.brachycephalie (broad) head form, black and straight hair, scanty beard, Malayan eye.medium stature and speaking branches of Malayo-Polynesian language which is agglutina-tive in its nature. Scientifically, both the "proto-Malays" and the "deutero-Malays", orboth the "true Malays" (Orang Malayu) and the other Malayans outside of it are to beconsidered here as the Malayan stock. Generally speaking, largest part of the peoplesliving in Malaya, Indonesia, Philippines and other islands bear this common name inscientific sense. Within the country of Indonesia the term Indonesians is most usuallyused, but in this article, the Indonesians is also included in the term Malayan stockbecause the latter is larger in its scope and more generally used in science. The Malayan stock is not a pure, single race but one of many elements intermixedtogether. The first element is the Oceanic Mongoloid which came from the north, pro-bable Chinese continent, its physical characteristics survived are the black, straight hair,broad head, yellowish-brown colour, medium stature and certain degree of Mongolian eye(narrow eye with Mongolian fold which covers the upper eye-lid). The second elementis the Indonesian stock, (This is used in scientific, narrower meaning instead of thatused in common sense) and early branch of the Caucasian race, originated in westernAsia and migrated eastward to Malaysia through Indo-China; it gives the present people the physical characteristics of Malayan eye, (broad eye without Mongolian fold hence theeye-lashes and a concave line on the eye-lid can be seen clearly) a certain degree of doli-chocephalie (long) head together with the agglutinative Malayo-Polynesian language. Thethird element is the Oceanic Negroid whose part contributed to the Malayans is not solarge that it still has pure descendants in present day viz. the Negritoes and the Papuans;while the fourth element is the Veddas came from India. The third and fourth one arri-ved earliest in probably Palaeolithic age, but played no important role in ethnic composi-tion of the Malayan stock because of their small number in population. The second onereached Malaysia after the above two probably in early period of Neolithic age, while thefirst one arrived latest in later period of Neolithic age. Though later in time, the OceanicMongoloids and Indonesians came in large numbers hence they formed the two principalelements of the Malayan stock. As the outcome of the intermixing of blood there appea-red a great mixed racial stock which looks different from its original elements, conseq-uently the original names are no longer suitable to be used. The term Indonesian is usedhere in its original meaning which is different from that of the so-called "Indonesians"in present day use. The mixed stock is no more called Indonesian but Malayan stock inthis article. Ⅱ. Is there Any Connection Between the Malayan Stock and the Ancient Peoples in Southern China? The cradle of the mix-blooded Malayan stock may be in the meeting point of the twoprincipal elements. Indo-China, a necessary meeting point on their ways, was naturally thecradle of the Malayan stock. From Indo-China floods of racial migration appeared fromtime to time and peopled the islands of Malaysia from west to east. As the Oceanic Mongoloid might be originated in the east Asia continent and mig-rated southward to Indo-China, naturally there must be a time in which they lived insouthern China as well as in Indo-China. Furthermore, the ancient peoples in SouthernChina consisted of various aboriginal tribes different from the Chinese Proper, it seemsnot very unreasonable to suggest that besides the Mongoloids there might existed too acertain primitive branch of Caucasian race or even Negroid race in southern China eventhough in small number before the Chinese Proper migrated southward. Possessing theability of migrating southward by the difficult way of water, why the Indonesians couldor would not proceed further eastward from Indo-China by an easier way of land tosouthern China During or preceding Chow dynasty (before 250 B. C.) in the coastal regions of sout-hern China (Chekiang, Fukien, Kwangtung, Kiangsi, Kwangsi provinces) there existedan ancient aboriginal stock with the name of "Yueh" which was looked by the Chineseproper as a different race because they lived in different way, followed their own queerhabits and customs and spoke in a different tongue. This stock was indeed more strangethan the other aboriginal stocks in southem China. The formation of such a stock mightbe the outcome of blending of the Mongoloids arrived from the north with some other peoples came from the southwest. As there really existed a different people-the In-donesians-migrated from the west and the blending of the two races-the Indonesiansand the Mongoloids-was actually taking place in Indo-China, it is far from impossiblethat such a phenomenon might extend and appear also in southem China. Being theproduct of mixing blood of the two principal races-the Mongoloids and the Indonesians-the Yueh stock might be in the same condition as the Malayan. If the intermixing of the Mongoloids with the Indonesians really took place in sout-hern China, the ancient people Yueh then was the brother of the Malayan stock. At thebeginning they might resemble to each other, but in later days both of them lived indifferent places and mixed with more other peoples, hence appeared also different fromeach other. Since the Chin dynasty (220 B. C.) the Yueh stock began to be assimilatedby the Chinese Proper from the north; the process of assimilation of culture and theblending of blood reached its conclusion in about 6th century. Later on no survivor ofYueh stock with pure blood or tribal name ever appeared in China. Their mix-bloodedoffspring, however, have existed up to present time as the population of the southeastcoastal region viz. Chekiang, Fukien, Kwangtung Provinces. Ⅲ. Three Evidences From the historical and geographical point of view, we get the above hypothesis ofthe ethnical Connection between the Malayan and the Yueh stock in southern China. Ifthis is true there must be, between them, physical and cultural resemblances which aresound enough as the evidence. Three sorts of facts, as I seek, may do this service: (1) Resemblances in Physical Characteristics--Though there is still no enoughamount of prehistoric skeletons of both the Indonesians and the Oceanic Mongoloidsunearthed in Malaysia and southern China for scientific research, the Iiving offsprings ofboth the two ancient races may give us some hints about this question,. It is often observedthat the physical characteristics of the southern Chinese of present day are different insome respects from the northern ones although basically they are of the same type viz.the Chinese type. Among them, the peoples of Kwangtung and Fukien have espicially adifferent appearence: Firstly, the eyes of them are broader and less in degree of Mongolian fold on theupper eye-lid. The eye of this type is the medium form between the Mongolian and theMalayan eye, and may be called Half-Malayan eye. Generally most of the Mongol Properand the northern Chinese have the Mongoian eye, while the Malayans have the Malayaneye. The intermediate eye suggests that the human group possessing it must be the mixedblood of the two kinds of peoples with these two sorts of eyes. Wherefrom did the sout-hern Chinese get the half-Malayan eye? Unless they had as one part of their compositeelement a sort of people with Malayan eyes, it is quite impossible to explain the derivationof this eye form. this eye form, therefore, tells us that the southern Chinese, especiallythat of Kwangtung, Fukien and perhaps Chekiang provinces had as one part of theirancestors a people with Malayan eyes. The Malayans may get their malayan eye from the Indoncsians, because the Indonesians belong to the Caucasian race whose eye is calledEuropean eye which is the same as the Malayan one. In fact, the European eye formappeared on the Malayan face is called Malayan eye. The eyes of the southern Chinesetherefore might he derived from the same way as the Malayans. Secondly, the stature of the southern Chinese especially those of Kwangtung andFukien is generally lower than that of the northern Chinese; while compared with theMalayans, they are nearly the same with each other. Thirdly, some of the faces of the southern Chinese looks different from the northernones but appears resembling the Malayans. The Southerns have a shorter face while thenortherners have a longer one. As the physical characteristics of both the southem Chinese and the Malayans resem-bling each other, it is hardly possible to distinguish some Chinese in Malayan costumesand vice versa. The Chinese new comers in Malaysia are often astonished to find thatthe so-called strangers or foreigners viz. the Malayans, look quite like themselves in theirphysical respect. Sometimes it is not easy too for the Europeans to distinguish betweenthe Chinese and the Malayans, because most of the Chinese immigrated to Malaysiancountries were from the southeastern coastal regions which was the home country of theancient Yueh people. (2) Resemblances in Early Cultural Respects--Of course the cultural life ofthe southern Chinese and the Malayans in present day are different to each other, butthe historical records about the ancient Yueh people reveal that the Yueh stock had intheir material life, social customs and languages some points suggesting the connectionwith the Malayans. These may be enumerated as the following: 1, Hair cutting: The ancient northern Chinese never cut their hair, the Miao stockbound their hair too, only the Yueh people was noted for their hair cutting. The primitivebranches of the present Malayan also cut their hair, the early Malayans probably had thiscustom in ancient times too. 2, Tattooing: The Yueh was also well-known for their tattooing which made themlook quite wonderful to the other Chinese, The Malayans of today still have kept thiscustom in Borneo, Philippines etc. 3, Snake worship: The Yueh worshipped the snakes and those in Fukien even tookthe snake as their totem. The aborigines in Taiwan province, which belong to Malayanstock too, still preserve the remnant of such belief, Snake worship is not unknown tothe Malayans in Malaysia too. 4, Pile-house: At present the pile-houses of the Malayans is quite well-known forits specialty; such form of building, however, was also adopted by the ancient southernChinese because it is recorded that the Yueh lived in nest, and the later southern peopleslived actually in the pile-houses which was called "kan-lan". 5, Naked foot: The Yueh's naked foot custom was also noted in ancient times.while the Malayans in history also kept their feet naked even though they were officersin the kings courts. 6, Agglutinative language: The Yueh spoke in a different and queer tongue fromthe Chinese Proper and even the other peoples in ancient times, the translation of Yuehwords gave the Chinese Proper a hard question; to denote the sound of a Yueh word,one Chinese word is not enough, while two or three words sound too much. Thiscondition suggests that though the Chinese language was isolating in its nature, that ofthe Yueh might belong to agglutinative one, because one agglutinative word usually pro-nounces just like two or more isolating words connected. Heine-Geldern and other scholarealso suggested that the Malayo-Polynesian or Austro-Asiatic language was originated inthe continent. The present south-eastern Chinese still speak in different dialects whichproves that the ancient Yueh language was quite strange to the northern Chinese. Thedifficulty to compare the ancient Yueh language with the Malayan one lies in the factthat both the present tongues used by the modern Malayans and the southern Chinesehave been changed by nearly two thousand years' assimilation with other languages. (3) Resemblances of Prehistoric Remains--Before the prehistoric archaeologicaldiscoveries took place in southern China, the question of the derivation or origin of someprehistoric objects in malaysia and even Polynesia had been very hard to be solved. Poly-nesia is famous for one special type of stone implements viz. the tanged adze or steppedadze, the origin of it was traced to that unearthed in Philippines; the derivation of thestepped adze of Philippines, however, was also very hard to be traced. Since about 1930the prehistoric findings began to take place in southern Chinese continent. the newmaterials enable the old questions easier to be solved. The prehistoric remains are difte-rent to those found in northern China, the latter consists of the painted pottery, blackpottery, thick stone axe, holed stone axe etc., whilc the former consists of the pressedgeometric-designed pettery, the stepped adze, the shouldered axe etc.. Strange to say thatthe southern prehistoric objects of China really resemble those of Malaysia and evenPolynesia. These objects may be pointed as the following: 1, Stepped stone adze: Stepped adze is found in large numbers in the south-easternregions viz. Fukien, Kwangtung, Chekiang, Kiangsi, Kiangsu etc., but appears veryrare in the eastern part of northern China and is entirely unknown in the western partof it. The shape suggests that it was developed in three stages just like that of Phi-lippines and Polynesia. Furthermore, the stepped adze of primary and intermediate stagesappeared more in number in south-eastern China, while that of the higher stage appearedmore in Philippines and Polynesia; such a condition reveals that the stepped adze of Phi-lippines and Polynesia was derived from south-eastern China. The way of transmigrationof the stepped adze is probably through Taiwan, Philippines and other islands. 2, Shouldered stone axe: The shouldered axe appeared in Indo-China. Malay pe-ninsula, Philippines etc., but was not found in the intermediate islands viz Sumatra,Java etc.. It was unearthed in Taiwan and Hainan islands too. In the southern part ofthe Chinese continent it appeared less in number but more will be found in future. Inthe north-eastern China very rare was obtaine(?) too. The shouldered axe might be ori-ginated in Indo-China and then spreaded eastward to the south-eastern coastal region of Chinese continent, therefrom it crossed the sea and arrived in Philippines through Tai-wan island, On the way a northward route led it to the north-eastern region. Anotherroute led it southward to Malay Peninsula. Shouldered axe is also an object of evidenceshowing the relation of the Malayans and the southern Chinese, because the prehistoricpeoples in Indo-China was the Malayans instead of the Annamese etc.. 3, Pressed geometric-designed pottery: In southern, especially south-eastern China,the prehistoric pottery was that with geometric designs pressed with pottery prints, thisis quite different to the painted pottery of north-western China and the black pottery ofnorth-eastern China. In Malaysia and Indo-China the prehistoric potteries found resembleto that of south China, some of the shape of the potteries as well as the pressed designsare quite like each other. Some potteries of this type were actuaily found in Indo-China,Java and Sulawesi, which are comparable with that of south China. This kind of potteryalso suggests the prehistoric connection between Malayans and the southern Chinese. Ⅳ. Conclusions (1) The Malayan stock is a mixed blood of chiefly the Oceanic Mongoloid raceand the Indonesians which is an early branch of the Caucasian race. These two raceshave been blended to such a degree that a new stock appeared which is called the Ma-Jayan stock, and the two elements have no more pure offsprings survived. The presentMalayans show more Mongolian physical features than the Indonesian ones, hencs it istaken as a branch of Mongoloids. (2) The Oceanic Mongoloid came from southern China, hence these should beethnic connection. between the Malayans and the ancient southern Chinese. Moreover,the other two elements of the Malayans, the Indonesians and the Negritoes probablyalso arrived and lived in southern China earlier than the Mongoloids and became partof the ethnical elements of the southern Chinese in later days, therefore the Malayansand the southern Chinese may have the same ethnical element. (3) The present southern Chinese, especially the south-eastern ones have some phy-sical characteristics like the Malayans, their ancestor Yueh stock had some customs andlanguage showing some resemblances to the Malayans, finally, the prehistoric discoveriesalso show the relationship between these two races. (4) The processes of the formation of the Malayan stock might proceeded in Indo-China and southern China. Since Neolithic age the Malayans migrated step by step toMalaysian islands, while those remained in Indo-China and southern China were assimi-lated by the Chinese Proper, Annamese, Siamese and Burmese. The ancient Yueh stockin southern China might have nearly the same ethnic composition as the Malayans, butwas assimilated by the Chinese Proper since two thousand years ago. (5) There might be two routes of southward migration of the Malayans. The firstand principal one was the west route which started from Indo-China, penetrated Suma-tra, Java and Borneo, and finally reached Philippines; the evidences are the pressedgeometric designed pottery and the shouldered axe. The second was the east route whichstarted from the south-eastern coast of Chinese continent, passed Taiwan and other islets,finally reached Philippines, Sulawesi and eastern Borneo. The stepped adze, the shoul-dered axe, and the pressed geometric-designed pottery are the eviden

林惠祥同志三十多年来除了对人类学(包括古学、民族学)进行系统的研究,并获得很大的成就和贡献外,他一生对南洋问题的研究,也曾下过工夫,做过不少工作和贡献。“南洋马来族与华南古民族的关系”这篇论文是林惠祥同志关于南洲问题最后的遗著。前篇于一九三八年以“马来人与中国东南方人同源说”为题曾在南洋发表过,后篇是他二十年后对这问题进一步深入研究的成果,提出更丰富、更可靠的有关人类学(包括考古学、民族学)的材料和证据,把我国和南洋民族的历史关系以及将东南亚这一大片地方过去被遗忘的历史补充起来,这是他三十年多年来对南洋研究的重要贡献,也是他一生对南洋问题研究总结的一部份。

The wearing angles of the travellers while running at spindle speeds between 13000-15000 r. p. m. and the depth and length of wear of rings and travellers were measured. Various type of rings and travellers were used in these tests, including anti-wedge rings and travellers made in Shanghai. The results show that the wearing angles of travellers are 14°30', 22.25' to the coordinate plane XOY, YOZ respectively. From a simple analysis of the moments acting on the traveller, the cause. of wedging of traveller is...

The wearing angles of the travellers while running at spindle speeds between 13000-15000 r. p. m. and the depth and length of wear of rings and travellers were measured. Various type of rings and travellers were used in these tests, including anti-wedge rings and travellers made in Shanghai. The results show that the wearing angles of travellers are 14°30', 22.25' to the coordinate plane XOY, YOZ respectively. From a simple analysis of the moments acting on the traveller, the cause. of wedging of traveller is discussed, the most serious one being probably the inclined angle A within XY plane. Experiments showed that the working life of travellers are widely different on different rings. Some travellers worked as long as 449 hours, while others had been changed 19 times within the same period. Measurements on those rings and travellers showed that the longer the working life, the greater the ratio of T/t (T-the distance between horns of traveller, and t-the width of the ring web.) and the longer the wearing length. Therefore it is considered that the geometric shape of ring and traveller should suit each other. As an example a ring flange is redesigned under certain simplifications. The author concluded that travellers could run at higher speeds without abnormal wear, burning or wedge, under following conditions: 1. The contact surface between ring and traveller should be larger than those used under ordinary speeds. 2. The center of gravity of the traveller should be low. 3. The contact position on the ring flange should be higher. 4. The space between top surface of the ring and traveller should be large enough to allow yarn to pass through. 5. It is better to use a narrower width of flange. 6. The width of ring web should be narrow. The distance between the horns ends of traveller should be kept at a proper ratio to the flange width of the ring. 7. The sharp angle of the flange curve should be avoided.

通过作用在钢絲圈上各力矩的分析,得出鋼絲圈在运动中是要产生偏斜的。这种偏斜与鋼絲圈重心位置与其在鋼令上接触点的高度有关。由于这种偏斜的产生,且达到使鋼絲的外脚碰及钢令外側壁时,即引起了楔住。認为在子午面中的倾斜是引起楔住的最大原因。除了楔住是运轉上的麻烦外,另一点是钢絲圈在高速下的过快磨損。了对这二点作了討論,提出了在設計鋼领与鋼絲圈的弧形时以及它們相互配合上所应遵循的几点条件。最后,簡單地举例說明了钢令弧形的设計。

This paper pressents a discussion on the subject based upon the concept of the cemented granular structure of the concrete. It is shown that the effect of infiltrating water through the concrete consists of three types of forces: 1) the buoyant force, 2) the hydrodynamic force, and 3) the surface force.A thorough investigation of the stresses in a gravity dam subject to infiltrating water includes the above mentioned forces. In the geometric method of stress analysis, these forces can be taken into account...

This paper pressents a discussion on the subject based upon the concept of the cemented granular structure of the concrete. It is shown that the effect of infiltrating water through the concrete consists of three types of forces: 1) the buoyant force, 2) the hydrodynamic force, and 3) the surface force.A thorough investigation of the stresses in a gravity dam subject to infiltrating water includes the above mentioned forces. In the geometric method of stress analysis, these forces can be taken into account more convinently in the equations of equilibrium of the block.However, in the modern design of a concrete gravity dam, a less permeable layer and a drainage system are installed close to the upstream face of the dam. These make the seepage line lower inside the dam and the hydrodynamic force insignificant. Under this condition, the application of the method of gravity analysis, in which the water pressure is considered to be acting on the upstream face of the dam and the uplift of seepage water is aken to be an external force, will not bring in considerable error.With the same point of view, this paper further analizes and investigates the principal stress parallel to the upstream face of the modern concrete gravity dam and shows that, the well-known formula still gives a better approximation and lies on the safe side.

本文首先略述近若干年来考虑混凝土壩壩內渗透压力作用的设计假定及存在问题乇鹬赋隽芯S条件的不合理性,并指出目前某些規范要求部分滿足列維条件也是根据不足的。由于壩身混凝土是由骨料顆粒經水泥結石胶結而成的不均質多孔固体,当水透入混凝土时能产生以下三种作用力: ①浮力W_(BZB)=γ_B(n_s-n_v),力的方向鉛直向上; ②渗透动压力W_Φ=γ_BJn_s,力的方向与流线相切; ③表面作用力pΦ=p(1-n_s),力的方向垂直于壩面。正確的考虑渗透压力作用的壩身应力的計算必須包括上述这三种力。当用“小块法”計算霸身应力时,将它們考虑进去并没有什么困难。就力的性質来說,在霸內分布的浮力及渗透动压力都是体积力,在下游壩体內的渗透动压力的水平分量极易引起拉应力,对霸内应力十分不利。文中并指出:由于現代修建的混凝土壩在其上游面矷栌锌股炷敛慵芭潘苣?霸內等水头綫向上游密集;排水管后壩体的浸潤綫限低,浸潤线下的孔隙水压力也常很小,因此按照通常“重力分析法”認为外水压力作用在壩面,并将揚压力靦为外力,所算得的壩身应力分布并没有很大的誤差。最后,根据同样的論点,对于近年来国內爭論較多的上游壩面主应力的計算问题作了分析,...

本文首先略述近若干年来考虑混凝土壩壩內渗透压力作用的设计假定及存在问题乇鹬赋隽芯S条件的不合理性,并指出目前某些規范要求部分滿足列維条件也是根据不足的。由于壩身混凝土是由骨料顆粒經水泥結石胶結而成的不均質多孔固体,当水透入混凝土时能产生以下三种作用力: ①浮力W_(BZB)=γ_B(n_s-n_v),力的方向鉛直向上; ②渗透动压力W_Φ=γ_BJn_s,力的方向与流线相切; ③表面作用力pΦ=p(1-n_s),力的方向垂直于壩面。正確的考虑渗透压力作用的壩身应力的計算必須包括上述这三种力。当用“小块法”計算霸身应力时,将它們考虑进去并没有什么困难。就力的性質来說,在霸內分布的浮力及渗透动压力都是体积力,在下游壩体內的渗透动压力的水平分量极易引起拉应力,对霸内应力十分不利。文中并指出:由于現代修建的混凝土壩在其上游面矷栌锌股炷敛慵芭潘苣?霸內等水头綫向上游密集;排水管后壩体的浸潤綫限低,浸潤线下的孔隙水压力也常很小,因此按照通常“重力分析法”認为外水压力作用在壩面,并将揚压力靦为外力,所算得的壩身应力分布并没有很大的誤差。最后,根据同样的論点,对于近年来国內爭論較多的上游壩面主应力的計算问题作了分析,認为对于現代修建的混凝土壩,由于在其上游面有可靠的排水和防渗层,通常用N′_1=(σ′_Y-pcos~2α)/sina~2α計算上游霸面主应力仍是比較适宜,而且是偏于安全的。

 
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