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1.
雅鳖在具有排污设施的地上池培育。坚持每天排污,七天洗池;根据雅鳖不同时期对营养的不同要求,分别投喂一、二、三号饲料;坚持每五天用5ppm漂白粉消毒一次;精细饲养,培养七十天体重可由出壳时2-5g增到近50g,成活率93.6%。  相似文献   

2.
本研究采用26℃,32℃,38℃,44℃和50℃等5个恒定温度分别干燥西洋参,在干燥过程中每两天取样一次,测定淀粉和还原糖含量,以研究干燥温度对鲜西洋参糖类成分的影响。结果表明:用5个恒定(26℃,32℃,38℃,44℃和50℃)干燥西洋参,粗淀粉和还原糖含量总体上呈下降趋势;粗淀粉和还原糖的变化趋势相反;38℃处理整个干燥日程还原糖含量均最高,与其他处理相比差异极显著(P<0.01),而且淀粉含量相应地较其他处理低。  相似文献   

3.
城市生活垃圾筛上物的热解研究及实验   总被引:5,自引:0,他引:5  
对城市生活垃圾场筛上物垃圾进行热解实验,研究特定垃圾的热解过程及其规律.实验采用热解终温为550℃和700℃,热解物料为原始筛上物垃圾和加入热解残炭的筛上物垃圾,实验设备为间歇运行的固定床式热解炉.实验结果表明:热解终温700℃与550℃相比,热解产物中固体和液体的产率降低,瞬时产气速率和气体产率均升高;瞬时产气速率曲线与瞬时耗电量曲线形状一致,迟滞时间为5~10min;物料底部热解产物焦炭存在与否对热解得到的固液气产率、产气特性和能量消耗等方面几乎没有影响.  相似文献   

4.
首先采用磁控共溅射的方法在镀钼钠钙玻璃上制备了Cu-Zn-Sn三元金属预制层,再以硫粉为硫源,用快速退火处理(RTP)炉分别在200℃、250℃、300℃、350℃、400℃、450℃、500℃、550℃和600℃进行1 h快速热处理,得到不同温度硫化的薄膜,分别采用XRD、Raman、SEM进行物相和表面形貌的表征.结果表明,在硫化退火过程中,在250~300℃,首先形成的二元相有Cu2S、ZnS、SnS;在300~350℃,三元相Cu2SnS3形成;超过350℃时,晶粒尺寸较小的Cu2ZnSnS4(CZTS)开始形成;随着温度继续升高,CZTS的晶粒逐渐长大,杂相减少;当温度达到500℃时,表面形成结晶性好、晶粒尺寸大且无杂相的CZTS薄膜.通过对XRD和Raman图谱的分析,确立了各个温度区间发生相转变的化学反应方程式.  相似文献   

5.
热处理对多微孔活性硅胶吸附特性的影响   总被引:4,自引:0,他引:4  
本文采用溶胶-凝胶法在陶瓷薄片上制备多微孔活性硅胶膜。研究了热处理对活性硅胶表面结构和吸附性能的影响;测定了硅胶膜的比表面积,等温吸附曲线;并进行了热分析及红外光谱分析。结果表明:焙烧温度低于550℃时,热处理对硅胶膜的比表面积无影响;850℃时开始有熔结现象,随着焙烧温度的继续升高,比表面减少较快;硅胶膜的吸附量随焙烧温度的升高而减少。  相似文献   

6.
生物质油催化裂解精制中催化剂上焦炭前身物的分析   总被引:3,自引:0,他引:3  
采用热重、红外、核磁等分析手段,对生物质油催化裂解精制中使用的催化剂HZSM-5上的焦炭前身物进行了表征。沉积在催化剂表面上的焦炭前身物主要是短链饱和烃类化合物,沸点200℃以下;催化剂内部的结焦前身物主要为芳香族碳氢化合物,这些化合物的沸程为350~650℃。  相似文献   

7.
付彦海 《科技资讯》2006,(22):11-11
锅炉运行中,要求有良好的汽水品质,必须进行定时和不定时的排放汽包沉积的杂质,以提高炉水品质,防止结垢,利于锅炉的安全运行。我厂的锅炉炉水定期排污采用人工定期手动排污。即存在工作量大,排污时不能及时监视汽包水位等问题,又存在阀门漏泄人员易被烫伤的危险。所以,改进锅炉排污的可靠性和安全性势在必行。DCS为分散控制系统的英文缩写,它是计算机技术和自动化技术发展的结果,作为技术进步的体现,国内的电厂应用DCS已越来越广泛。它具有控制效果好、可靠性高、系统维护量小、易于组态等特点。在伊春市林都热电厂DCS改造项目中,将锅炉定期排污程控纳入DCS控制系统(以下简称定排程控)。  相似文献   

8.
从与排污有关的水垢、排污率的计算、排污余热利用三个方面用数字说明了排污与节能的关系,目的是把排污问题作为锅炉水质管理的一个重要环节,引起有关运行操作管理人员的高度重视。  相似文献   

9.
杭州市四堡排污工程浓度场计算   总被引:1,自引:0,他引:1  
根据钱塘江四堡河段潮流变化大、水深相对较小和江心排污的特点,采用一、二维相结合的两步计算模型,先对全域进行一维非恒定流计算,在获得近区计算边界条件的基础上,对近区采用完全深度平均紊动动能-耗散率(K-ε)紊流模型进行二维计算。与传统深度平均K-ε紊流模型相比,该模型反映了流速在深度方向分布不均匀的影响;计入了自由水面与水下地形的影响;采用了组合坐标系统。经观测资料验证表明,该计算模型能较好地描述复杂流动的浓度分布。  相似文献   

10.
研究了稳压器波动接管在有密封套管、无密封套管、无密封套管带排污孔以及无套管时,流体在上充和下充2种流劝模式下,Re从4500-750000变化时,各测试点的局部对流换热系数,实验结果得出:套管能够有效保护接管免受热冲击和由此带来的疲劳问题;有密封套管比无密封套管更能够使套管避免上述问题;套管保护的区域是在其使流体流动停止或流速降低的区域;套管的设计应考虑温度和流动2种因素。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

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