2023年全國碩士研究生考試考研英語一試題真題(含答案詳解+作文范文)_第1頁
已閱讀1頁,還剩11頁未讀, 繼續(xù)免費(fèi)閱讀

下載本文檔

版權(quán)說明:本文檔由用戶提供并上傳,收益歸屬內(nèi)容提供方,若內(nèi)容存在侵權(quán),請進(jìn)行舉報(bào)或認(rèn)領(lǐng)

文檔簡介

1、<p><b>  一、原文</b></p><p>  building types and design</p><p>  A building is closely bound up with people,for it provides with the necessary space to work and live in .</p>

2、<p>  As classified by their use ,buildings are mainly of two types :industrial buildings and civil buildings .industrial buildings are used by various factories or industrial production while civil buildings are

3、those that are used by people for dwelling ,employment ,education and other social activities .</p><p>  Industrial buildings are factory buildings that are available for processing and manufacturing of vari

4、ous kinds ,in such fields as the mining industry ,the metallurgical industry ,machine building ,the chemical industry and the textile industry . factory buildings can be classified into two types single-story ones and mu

5、lti-story ones .the construction of industrial buildings is the same as that of civil buildings .however ,industrial and civil buildings differ in the materials used and in the w</p><p>  Civil buildings are

6、 divided into two broad categories: residential buildings and public buildings .residential buildings should suit family life .each flat should consist of at least three necessary rooms : a living room ,a kitchen and a t

7、oilet .public buildings can be used in politics ,cultural activities ,administration work and other services ,such as schools, office buildings, parks ,hospitals ,shops ,stations ,theatres ,gymnasiums ,hotels ,exhibition

8、 halls ,bath pools ,and so on .all of the</p><p>  Housing is the living quarters for human beings .the basic function of housing is to provide shelter from the elements ,but people today require much more t

9、hat of their housing .a family moving into a new neighborhood will to know if the available housing meets its standards of safety ,health ,and comfort .a family will also ask how near the housing is to grain shops ,food

10、markets ,schools ,stores ,the library ,a movie theater ,and the community center .</p><p>  In the mid-1960’s a most important value in housing was sufficient space both inside and out .a majority of familie

11、s preferred single-family homes on about half an acre of land ,which would provide space for spare-time activities .in highly industrialized countries ,many families preferred to live as far out as possible from the cent

12、er of a metropolitan area ,even if the wage earners had to travel some distance to their work .quite a large number of families preferred country housing to suburban</p><p>  Before any of the building can b

13、egin ,plans have to be drawn to show what the building will be like ,the exact place in which it is to go and how everything is to be done.</p><p>  An important point in building design is the layout of roo

14、ms ,which should provide the greatest possible convenience in relation to the purposes for which they are intended .in a dwelling house ,the layout may be considered under three categories : “day”, “night” ,and “services

15、” .attention must be paid to the provision of easy communication between these areas .the “day “rooms generally include a dining-room ,sitting-room and kitchen ,but other rooms ,such as a study ,may be added ,and there m

16、ay</p><p>  It is also essential to consider the question of outlook from the various rooms ,and those most in use should preferably face south as possible .it is ,however ,often very difficult to meet the o

17、ptimum requirements ,both on account of the surroundings and the location of the roads .in resolving these complex problems ,it is also necessary to follow the local town-planning regulations which are concerned with pub

18、lic amenities ,density of population ,height of buildings ,proportion of green space </p><p>  There is little standardization in industrial buildings although such buildings still need to comply with local

19、town-planning regulations .the modern trend is towards light ,airy factory buildings .generally of reinforced concrete or metal construction ,a factory can be given a “shed ”type ridge roof ,incorporating windows facing

20、north so as to give evenly distributed natural lighting without sun-glare .Assessment of natural radioactivity levels and radiation hazards due to cement industry Abstr</p><p>  The cement industry is consid

21、ered as one of the basic industries that plays an important role in the national economy of developing countries. Activity concentrations of 226Ra, 232Th and 40K in Assiut cement and other local cement types from differe

22、nt Egyptian factories has been measured by using γ-ray spectrometry. From the measured γ-ray spectra, specific activities were determined. The measured activity concentrations for these natural radionuclides were compare

23、d with the reported data for ot</p><p>  1. Introduction</p><p>  The need for cement is so great. That it considered a basic industry. Workers exposed to cement or its raw materials for a long

24、time especially in mines and at manufacturing sites as well as people, that spend about 80% of their time inside offices and homes (Mollah et al., 1986; Paredes et al., 1987) result in exposure to cement or its raw mater

25、ials being necessary reality so we should know the radioactivity for cement and its raw material. There are many types of cements according to the chemi</p><p>  The radiological impact from the natural radi

26、oactivity is due to radiation exposure of the body by gamma-rays and irradiation of lung tissues from inhalation of radon and its progeny (Papastefanou et al., 1988). From the natural risk point of view, it is necessary

27、to know the dose limits of public exposure and to measure the natural environmental radiation level provided by ground, air, water, foods, building interiors, etc., to estimate human exposure to natural radiation sources

28、 (UNSCEAR, 1988</p><p>  The concentration of radio-elements in building materials and its components are important in assessing population exposures, as most individuals spend 80% of their time indoors. The

29、 average indoor absorbed dose rate in air from terrestrial sources of radioactivity is estimated to be 70 nGy h?1. Indoors elevated external dose rates may arise from high activities of radionuclides in building material

30、s (Zikovsky and Kennedy, 1992). Great attention has been paid to determining radionuclide concentr</p><p>  Because of the global demand for cement as a building material, the present study aims to: </p&g

31、t;<p>  (1) Assess natural radioactivity (226Ra, 232Th and 40K) in raw and final products used in the Assiut cement factory and other local factories in Egypt. </p><p>  (2) Calculate the radiological

32、 parameters (radium equivalent activity Raeq, level index Iγr, external hazard index Hex and absorbed dose rate) which is related to the external γ-dose rate.</p><p>  The results of concentration levels and

33、 radiation equivalent activities are compared with similar studies carried out in other countries.</p><p>  2. Experimental technique</p><p>  2.1. Sampling and sample preparation</p><

34、;p>  Fifty seven samples of raw materials and final products used in the Assiut cement factories were collected for investigation. Twenty five samples of raw materials were taken from (Limestone, Clay, Slag, Iron oxid

35、e, gypsum) which are all the raw material used in cement industry, 20 samples of final products were taken from Assiut cement (Portland, El-Mohands, White, and Sulphate resistant cement (S.R.C)). For comparison with prod

36、ucts from other factories, 8 samples were taken from the ordinary Po</p><p>  2.2. Instrumentation and calibration</p><p>  Activity measurements were performed by gamma ray spectrometry, employ

37、ing a 3″×3″scintillation detector. The hermetically sealed assembly with a NaI(Tl) crystal is coupled to a PC-MCA (Canberra Accuspes). Resolution 7.5% specified at the 662 keV peak of 137Cs. To reduce gamma ray back

38、ground a cylindrical lead shield (100 mm thick) with a fixed bottom and movable cover shielded the detector. The lead shield contained an inner concentric cylinder of copper (0.3 mm thick) to absorb lead X-rays. In </

39、p><p>  3. Conclusion</p><p>  The natural radionuclides 226Ra, 232Th and 40K were measured for raw materials and final products used in the Assiut cement factory in Upper Egypt and compared with t

40、he results in other countries. The activity concentration of 40K is lower than all corresponding values in other countries. The activity concentration of 226Ra and 232Th for all measured samples of Portland cement are co

41、mparable with the corresponding values of other countries. The obtained results show that the averages of radiatio</p><p>  Prestressed Concrete</p><p>  Concrete is strong in compression , but

42、weak in tesion : its tensile strengh varies from 8 to 14 percent of its compressive strength . Due to such a low tensile capacity , flexural cracks develop at early stages of loading . In order to reduce or prevent such

43、cracks from developing , a concentric or eccentric force is imposed in the longitudinal direction of the structural element . This force prevents the cracks from developing by eliminating or considerably reducing the ten

44、sile stresses at the</p><p>  Such an imposed longitudinal force is called a prestressing force , i.e. , a compressive force that prestresses the sections along the span of the structual element prior to the

45、 application of the transverse gravity dead and live loads or transient horizontal live loads . The type of prestressing force involved , together with its magnitude , are determined mainly on the basis of the type of

46、system to be constructed and the span length and slenderness desired . Since the prestressing force is </p><p>  Tension caused by the load will first have to cancel the compression induced by the prestressi

47、ng before it can crack the concrete. Figure 4.39a shows a reinforced concrete simple-span beam cracked under applied load. At a relative low load, the tensile stress in the concrete at the bottom of the beam will reach t

48、he tensile strength of the concrete , and cracks will form. Because no restraint is provided against upward extension of cracks, the beam will collapse.</p><p>  Figure 4.39b shows the same unloaded beams w

49、ith prestressing forces applied by stressing high strength tendons. The force, applied with eccentricity relative to the concrete centroid, will produce a longitudinal compressive stress distribution varying linearly f

50、rom zero at the top surface to a maximum of concrete stress, = , at the bottom, where is the distance from the concrete centroid to the bottom beam, and is the moment of the inertia of the cross-section, is the dep

51、th of the beam. </p><p>  Figure 4.39c shows the prestressed beams after loads have been applied. The loads cause the beam to deflect down, creating tensile stresses in the bottom of the beam. The tension fr

52、om the loading is compensated by compression induced by the prestressing. Tension is eliminated under the combination of the two and tension cracks are prevented. Also, construction materials (concrete and steel) are use

53、d more efficiently.</p><p>  Circular prestressing , used in liquid containmeng tanks , pipes , and pressure reactor vessels , essentially follows the same basic principles as does linear prestressing . The

54、circumferential hoop . or “hugging” stress on the cylindrical or spherical structure , neutralizes the tensile stresses at the outer fibers of the curvilinear surface caused by the internal contained pressure . </p>

55、;<p>  From the preceding discussion , it is plain that permanent stresses in the prestressed structural member are created before the full dead and live loads are applied in order to eliminate or considerably red

56、uce the net tensile stresses caused by these loads . With reinforced concrete , it is assumed that the tensile strength of the concrete is negligible and disregarded . This is because the tensile forces resulting from th

57、e bending moments are resisted by the bond created in the reinforcement pr</p><p>  The reinforcement in the reinforced concrete member does not exert any force of its own on the member , contrary to the act

58、ion of prestressing steel . The steel required to produce the prestressing force in the prestressed member actively preloads the member , permitting a relatively high controlled recovery of cracking and deflection . Once

59、 the flexural tensile strength of the concrete is exceeded , the prestressed member starts to act like a reinforced concrete element .</p><p>  Prestressed members are shallower in depth than their reinforce

60、d concrete counterparts for the same span and loading conditions . In general , the depth of a prestressed concrete member is usually about 65 to 80 percent of the depth of the equivalent reinforced concrete member . Hen

61、ce , the prestressed member requires less concrete , and about 20 to 35 percent of the amount of reinforcement. Unfortunately , this saving in material weight is balanced by the higher cost of the higher quality mater<

62、;/p><p>  In spite of these additional costs, if a large enough number of precast units are manufactured, the difference between at least the initial costs of prestressed and reinforced concrete systems is usua

63、lly not very large. And the indirect long-term savings are quite substantial, because less maintenance is needed, a longer working life is possible due to better quality control of the concrete, and lighter foundations a

64、re achieved due to the smaller cumulative weight of the superstructure.</p><p>  Once the bean span of reinforced concrete exceeds 70 to 90 feet (21.3 to 27.4 m), the dead weight of the beam becomes excessiv

65、e, resulting in heavier membersand,consequently,greater long-term deflection and cracking. Thus,for larger spans,prestressed concrete becomes mandatory since arches are expensive to construct and do not perform as well d

66、ue to thesevere long-term shrinkage and creep they undergo.Very large spans such as segmental bridges or cable-stayed bridges can only be constructed thro</p><p>  Prestressed concrete is not a new concept,

67、dating back to 1872,when P.H. Jackson ,an engineer from California, patented a prestressing system that used a tie rod to construct beams or arches from individual block. After a long lapse of time during which little pr

68、ogress was made because of the unavailability of high-strength steel to overcome prestress losses, R.E. Dill of Alexandria, Nebraska , recognized the effect of the shrinkage and creep(transverse material flow) of concret

69、e on the loss of </p><p>  Linear prestressing continue to develop in Europe and in France,in particular through the ingenuity of Eugene Freyssinet,who proposed in 1923-28 methods to overcome prestress losse

70、s through the use of high-strength and high-ductility steels.In1940,he introduced the now well-known and well-accepted Freyssinet system.</p><p>  P.W. Abeles of England introduced and developed the concept

71、of partial prestressing between the 1930s and 1960s . F. Leonhardt of Germany , V. Mikhailov of Russia, and T.Y. Lin of the United States also contributed a great deal to the art and science of the design of prestressed

72、concrete .Lin's load-balancing method deserves particular mention in this regard, as it considerably simplified the design process, particularly in continuous structures. These twentieth-century developments have led

73、 to </p><p>  Ordinarily, concrete of substantially higher compressive strength is used for prestressed structures than for those constructed of ordinary reinforced concrete. There are several reasons for th

74、is:</p><p>  (1) High-strength concrete normally has a higher modulus of elasticity. This means a reduction in initial elastic strain under application of prestress force and a reduction in creep strain, whi

75、ch is approximately proportional to elastic strain. This results in a reduction in loss of prestress.</p><p>  (2) In post-tensioned construction, high bearing stresses result at the end of beams where the p

76、restressing force is transferred from the tendons to the anchorage fittings, which bear directly against concrete. This problem can be met by increasing the size of the anchorage fitting or by increase the bearing capaci

77、ty of the concrete by increasing its compressive strength. The latter is usually more economical.</p><p>  Today prestressed concrete is used in building , underground structures, TV towers , floating storag

78、e and offshore structures, power stations , nuclear reactor vessels, and numerous types of bridge systems including segmental and cable-stayed bridges. They demonstrate the versatility of the prestressing concept and its

79、 all-encompassing application. The success in the development and construction of all these structures has been due in no small measures to the advances in the technology of materi</p><p><b>  二、譯文<

80、/b></p><p><b>  建筑類型和設(shè)計(jì)</b></p><p>  大樓與人民息息相關(guān),因?yàn)樗峁┍匾目臻g,工作和生活中。</p><p>  由于其使用的分類,建筑主要有兩種類型:工業(yè)建筑和民用建筑各工廠或工業(yè)生產(chǎn)中使用的工業(yè)大廈,而那些居住,就業(yè),教育和其他社會(huì)活動(dòng)的人使用的民用建筑。</p><p&

81、gt;  工業(yè)樓宇廠房可用于加工和制造各類采礦業(yè),冶金工業(yè),機(jī)械制造,化學(xué)工業(yè)和紡織工業(yè)等領(lǐng)域??煞譃閮煞N類型的單層和多層的廠房,民用建筑,工業(yè)建筑是相同的。然而,工業(yè)與民用建筑中使用的材料,在使用它們的方式不同。</p><p>  民用建筑分為兩大類:住宅建筑和公共建筑,住宅建筑應(yīng)滿足家庭生活應(yīng)包括至少有三個(gè)必要的房間:每個(gè)單位。一個(gè)客廳,一個(gè)廚房和廁所,公共建筑,可以在政治文化活動(dòng),管理工作和其他服務(wù),如學(xué)

82、校,寫字樓,公園,醫(yī)院,商店,車站,影劇院,體育場館,賓館,展覽館,洗浴池,等等,他們都有不同的功能,這在需要以及不同的設(shè)計(jì)類型。</p><p>  房屋是人類居住。房屋的基本功能是提供遮風(fēng)擋雨,但今天人們需要更他們的住房,一個(gè)家庭遷入一個(gè)新的居民區(qū)知道,如果現(xiàn)有住房符合其標(biāo)準(zhǔn)安全,健康和舒適。附近的房屋是如何糧店,糧食市場,學(xué)校,商店,圖書館,電影院,社區(qū)中心,家庭也會(huì)問。</p><p&

83、gt;  在60年代中期最重要的住房價(jià)值足夠空間的內(nèi)部和外部。多數(shù)首選的一半左右1英畝的土地,這將提供業(yè)余活動(dòng)空間單戶住宅的家庭。在高度工業(yè)化的國家,許多家庭寧愿住盡量盡可能從一個(gè)大都市區(qū)的中心,“打工仔”,即使行駛一段距離,他們的工作。不少家庭的首選國家住房郊區(qū)住房的大量的,因?yàn)樗麄兊闹饕康氖沁h(yuǎn)離噪音,擁擠,混亂。無障礙公共交通已不再是決定性因素,在住房,因?yàn)榇蠖鄶?shù)工人開著自己的車上班的人。我們主要感興趣的安排和房間的大小和臥室數(shù)目

84、。</p><p>  在建筑設(shè)計(jì)中的一個(gè)重要的一點(diǎn)是,房間的布局,應(yīng)提供有關(guān)它們目的,最大可能的便利,在住宅,布局可根據(jù)三類認(rèn)為:“天”,“夜必須注意“和”服務(wù)“。支付提供這些地區(qū)之間容易溝通?!碧臁暗姆块g,一般包括用餐室,起居室和廚房,但其他房間,如一項(xiàng)研究,可能會(huì)補(bǔ)充說,可能有一個(gè)大廳,客廳,通常是最大的,往往是作為一個(gè)餐廳,也或廚房,可有一個(gè)用餐涼亭。“夜”的房間,臥室組成。 “服務(wù)”,包括廚房,衛(wèi)生間,

85、儲(chǔ)藏室,廚房和儲(chǔ)藏室的水廁。連接天與客房的服務(wù)。</p><p>  這也是必須考慮的前景問題,從不同的房間,和那些在使用中最應(yīng)該盡可能最好朝南。,然而,它往往很難達(dá)到最佳的要求,同時(shí)對環(huán)境的考慮和位置,的道路。在解決這些復(fù)雜的問題,它也必須遵循當(dāng)?shù)氐某鞘幸?guī)劃與公共設(shè)施,人口密度,建筑高度,綠地比例的住房,建筑線,一般的外觀有關(guān)的法規(guī)鄰里關(guān)系的新特性,依此類推。</p><p>  標(biāo)準(zhǔn)化

86、是在工業(yè)大廈內(nèi)的小雖然這些建筑物仍然需要遵守當(dāng)?shù)氐某鞘幸?guī)劃法規(guī),現(xiàn)代趨勢是朝著輕,通風(fēng)的廠房。一般的鋼筋混凝土或金屬建筑,工廠可以給出一個(gè)“棚”類型脊屋頂,將朝北的窗口,給均勻分布沒有自然采光,陽光刺眼。</p><p>  由于水泥行業(yè)的天然放射性水平和輻射危害的評(píng)估抽象被視為水泥行業(yè)的基礎(chǔ)產(chǎn)業(yè),對發(fā)展中國家的國民經(jīng)濟(jì)中起著重要的作用之一。 226Ra的活度濃度,232Th和40K亞西烏特水泥和其他地方的水泥類

87、型,從不同的埃及工廠已經(jīng)使用γ射線光譜測量。從測得的γ射線譜,具體活動(dòng)進(jìn)行了測定。這些天然放射性核素的活度濃度與其他國家報(bào)告的數(shù)據(jù)進(jìn)行比較。獲得226Ra的,232Th和40K的活度濃度的平均值,在不同類型的水泥比報(bào)道科委出版物的全球相應(yīng)值低。生產(chǎn)操作減少輻射危害的參數(shù)。水泥不構(gòu)成重大建筑施工中使用時(shí)的輻射危害。</p><p><b>  1。介紹</b></p><p

88、>  對水泥的需求是如此巨大。它認(rèn)為一個(gè)基本的行業(yè)。作業(yè)工人,尤其是在地雷和生產(chǎn)基地以及人們在很長一段時(shí)間,大約80%的時(shí)間花在辦公室和家庭內(nèi)(Mollah等人,1986年。帕雷德斯等人,1987年水泥或原料曝光水泥或它是必要的現(xiàn)實(shí),所以我們應(yīng)該知道的水泥及其原料的放射性原料)的結(jié)果。根據(jù)化學(xué)成分和每一個(gè)水力特性,有許多類型的水泥。波特蘭水泥是最普遍的一種。中226Ra,232Th和40K的原材料和加工的內(nèi)容可以有很大的不同取決于

89、其地質(zhì)源和地球化學(xué)特征。因此,在這些材料中的放射性知識(shí)是重要的,估計(jì)對人體健康的放射性危害。</p><p>  從天然放射性輻射影響,是由于身體接觸輻射伽瑪射線和肺組織的照射吸入氡及其子體(Papastefanou等,1988)。從自然風(fēng)險(xiǎn)的角度來看,它是必要了解公眾照射劑量限值和測量地面,空氣,水,食品,建筑內(nèi)飾等提供天然環(huán)境輻射水平,估計(jì)人體暴露于自然輻射來源(科委,1988年)。低級(jí)別的伽瑪射線熒光光譜儀

90、是適用于環(huán)境中的伽瑪射線發(fā)射核素(IAEA,1989)定性和定量測定。</p><p>  建材及其組件的無線電元素濃度在人口風(fēng)險(xiǎn)評(píng)估是重要的,因?yàn)榇蠖鄶?shù)人花費(fèi)80%的時(shí)間是在室內(nèi)。平均室內(nèi)從地面的放射性源的空氣中吸收劑量率估計(jì)為70 NGY H?1。室內(nèi)升高,可能出現(xiàn)的外部劑量率從高建筑材料放射性核素(Zikovsky和肯尼迪,1992年)的活動(dòng)。已支付的高度重視,以確定在許多國家建筑材料放射性核素濃度(Amr

91、ani和Tahtat,2001;佐等,2001; Kumar等。,2003年。Tzortzis等,2003)。但這些材料在埃及的放射性的信息是有限的。知識(shí)的發(fā)生與濃度等重要材料的天然放射性是一般檢查其質(zhì)量和對周圍環(huán)境,特別是水泥生產(chǎn)工廠明知其效果的關(guān)鍵。</p><p>  由于全球水泥作為建筑材料的需求,本研究的目的是:</p><p> ?。?)評(píng)估在艾斯尤特水泥工廠和在埃及其他地方的

92、工廠使用的原材料和最終產(chǎn)品的天然放射性(鐳,釷和40K)。</p><p>  (2)計(jì)算的放射性參數(shù)(相當(dāng)于鐳活動(dòng)Raeq,水平指數(shù)Iγr,外部危險(xiǎn)指數(shù)六角和吸收劑量率),這是關(guān)系到外部的γ劑量率。</p><p>  與其他國家進(jìn)行類似的研究,濃度和輻射相當(dāng)于活動(dòng)的結(jié)果進(jìn)行了比較。</p><p><b>  2。實(shí)驗(yàn)技術(shù)</b></

93、p><p>  2.1。取樣和樣品制備</p><p>  在艾斯尤特水泥工廠使用的原材料和最終產(chǎn)品的57個(gè)樣品進(jìn)行了調(diào)查收集的。 25個(gè)樣品取自原材料(石灰石,粘土,礦渣,氧化鐵,石膏),這是在水泥行業(yè)中使用的所有原材料,最終產(chǎn)品的樣品取自20艾斯尤特水泥(波特蘭,EL-Mohands,白,耐硫酸鹽水泥(SRC)的)。與其他工廠的產(chǎn)品進(jìn)行比較,8個(gè)樣品取自普通硅酸鹽水泥(赫勒萬基納,EL-k

94、awmya,托拉)和白水泥(西奈半島和赫勒萬),4個(gè)樣本。每個(gè)樣品重約1公斤,蒸餾水洗滌和干燥烤箱約110°C,以確保徹底清除水分,對樣品進(jìn)行粉碎,均質(zhì),并通過200目,這是最佳的篩分在重礦物富集的大小。加權(quán)樣本被放置在聚乙烯燒杯中,體積350立方厘米。完全密封的燒杯4周,以達(dá)到長期平衡氡子體衰變率等于母公司。這一步是必要的,以確保氡氣被局限在體積和樣品中的女兒也將保持。</p><p>  2.2。儀

95、器儀表和校準(zhǔn)</p><p>  活度測量進(jìn)行伽瑪射線光譜儀,采用3“×3”閃爍探測器。密封裝配用的NaI(Tl)晶體耦合的PC-MCA(坎培拉Accuspes)。分辨率7.5%,在662 keV峰的137Cs指定。為了減少伽瑪射線背景圓柱底部固定和移動(dòng)蓋(100毫米厚的鉛屏蔽)屏蔽探測器。鉛屏蔽含有銅的同心圓筒內(nèi)部(0.3毫米厚),X射線吸收鉛。為了確定探測器周圍環(huán)境中的背景分布,一個(gè)空的密封燒杯計(jì)算

96、以同樣的方式,在相同的幾何形狀的樣品?;顒?dòng)或背景的測量時(shí)間為43 200秒。背景光譜被用來糾正的凈峰面積測量同位素的γ射線。一個(gè)專用的軟件程序(2000)從堪培拉精靈分析每個(gè)測量γ射線譜。</p><p><b>  3。結(jié)論</b></p><p>  在上埃及的的艾斯尤特水泥工廠使用,并與其他國家的結(jié)果相比,原材料和最終產(chǎn)品的天然放射性核素鐳,釷和40K測定。 4

97、0K的活度濃度低于所有其他國家的相應(yīng)值。硅酸鹽水泥的所有測量樣品中226Ra和232Th的活度濃度與其他國家的相應(yīng)值相媲美。所獲得的結(jié)果表明,輻射危險(xiǎn)參數(shù)的平均值為艾斯尤特水泥廠的鐳當(dāng)量Raeq的,1的水平的的指數(shù)Iγr,外部風(fēng)險(xiǎn)指數(shù)六角≤1和59(NGY?低于可接受水平的370貝克公斤1? 1)吸收劑量率。生產(chǎn)操作減少輻射危害的參數(shù)。因此,水泥制品不構(gòu)成重大建筑施工中使用時(shí)的輻射危害。在水泥的原料和最終產(chǎn)品的放射性變化,從一個(gè)國家到另

溫馨提示

  • 1. 本站所有資源如無特殊說明,都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請下載最新的WinRAR軟件解壓。
  • 2. 本站的文檔不包含任何第三方提供的附件圖紙等,如果需要附件,請聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
  • 3. 本站RAR壓縮包中若帶圖紙,網(wǎng)頁內(nèi)容里面會(huì)有圖紙預(yù)覽,若沒有圖紙預(yù)覽就沒有圖紙。
  • 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
  • 5. 眾賞文庫僅提供信息存儲(chǔ)空間,僅對用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理,對用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯,并不能對任何下載內(nèi)容負(fù)責(zé)。
  • 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容,請與我們聯(lián)系,我們立即糾正。
  • 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時(shí)也不承擔(dān)用戶因使用這些下載資源對自己和他人造成任何形式的傷害或損失。

評(píng)論

0/150

提交評(píng)論