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1.
冷轧对Fe-32Ni-5Co合金热膨胀系数的影响日本电磁材料研究所和东北特殊钢公司详细研究了冷轧对超因瓦合金Fe—32Ni-5Co)的热膨胀系数各向异性的影响。合金原料为纯度99.97%的电解铁,99.98%的电解镍和99.55%的电解钻。将这些原料...  相似文献   

2.
淀粉—KI体系光度法测定微量铜(Ⅱ)的研究   总被引:1,自引:0,他引:1  
本文利用碘与淀粉的高灵敏显色反应,建立了光度法测定微量铜的新分析方法。该法简单易行,灵敏准确.Cu2+离子浓度在1.0×10-6~6.0×10-5mol.L-1区间符合比耳定律,检测限为5×10-7mol.L-1。对水样中微量铜的测定.回收率在98.2%~99.6%之间变化,RSD为2.2%和2.5%。  相似文献   

3.
酸式电解法处理废蓄电池泥渣新工艺的研究   总被引:3,自引:1,他引:3  
本文研究了一种从废蓄电池泥渣中湿法回收铅的新工艺,该工艺以K2CO3脱硫,以自研的复合还原剂还原,以氟硅酸作电解液电冶Pb.获得铅粉纯度达99.99%,电流效率>98%,铅直收率>95%,铅总回收率>98%,此外,工艺过程稳定,效率高,成本低,无环境污染。  相似文献   

4.
用线性电位滴定法分析抗坏血酸,抗坏血酸回收率为99.80%~101.5%,相对标准偏差为0.61%;分析维生素C片中的抗坏血酸,相当标示量为98.90%~100.5%,相对标准偏差不大于0.48%,说明线性电位滴定法分析维生素C片中的抗坏血酸含量是可行的。  相似文献   

5.
以椰壳活性炭和煤质活性炭颗粒为载体,通过溶胶-凝胶法制备了活性炭负载二氧化钛的复合光催化剂,并对其光催化降解亚甲基蓝的活性进行评价.结果表明:复合光催化剂的光催化降解效果比纯二氧化钛好.载体的结构显著影响着复合光催化剂的活性.椰壳活性炭因其具有更丰富的孔体积和更大的比表面积,对亚甲基蓝溶液的光催化降解率明显要高于煤质活性炭负载二氧化钛复合型光催化剂.随着煅烧温度的升高,复合光催化剂的效果越来越好.  相似文献   

6.
以椰壳活性炭和煤质活性炭颗粒为载体,通过溶胶-凝胶法制备了活性炭负载二氧化钛的复合光催化剂,并对其光催化降解亚甲基蓝的活性进行评价.结果表明:复合光催化剂的光催化降解效果比纯二氧化钛好.载体的结构显著影响着复合光催化剂的活性.椰壳活性炭因其具有更丰富的孔体积和更大的比表面积,对亚甲基蓝溶液的光催化降解率明显要高于煤质活性炭负载二氧化钛复合型光催化剂.随着煅烧温度的升高,复合光催化剂的效果越来越好.  相似文献   

7.
在硫酸介质中,Cr(Ⅵ)将5-溴水杨基荧光酮(5-BSAF)氧化成最大吸收峰为494nm的有色产物,其表观摩尔吸光系数为3.67×104L/(mol·cm),Cr(Ⅵ)量在0~15mg/25L范围内服从比耳定律。用此法测定了电镀废液中微量Cr,回收率为98.5%~103%,相对标准偏差为2.6%  相似文献   

8.
本研究是以活性炭做为光触媒(TiO2)的载体,利用活性炭的高吸附能力,将有机污染物质吸附于活性炭的表面与孔道中,再依附活性炭上的光触媒(TiO2),在紫外线照射下产生的电子-电洞,将有机污染物质有效分解,以探讨以活性炭为载体之光触媒的光催化特性,以便找出高分解效率之光触媒。本文以溶胶-凝胶(sol-gel)法制备纳米级的二氧化钛,再将其均匀分散于水中,并将活性炭浸于二氧化钛的水溶液中,使二氧化钛能均匀附着于活性炭中,并采用SEM观测吸附二氧化钛的活性炭,以便了解二氧化钛在活性炭上分布的情形,并以XRD观测吸附后的二氧化钛的结晶型态是否有改变;实验结果显示,二氧化钛在活性炭表面分布的相当均匀,且吸附后的二氧化钛仍然以锐钛矿晶型存在。实验结果显示以活性炭为载体的光触媒是值得开发的途径,且有可能成为新一代高效能的光催化剂,以解决日益严重的污染问题。  相似文献   

9.
本文研究了以铬天青S(CAS)-溴化十六烷基吡啶(CPB)一十二烷基硫酸钠(SDS)-铝多元体系吸光度法测定痕量铝的方法。本方法的最大吸收波长634um,表观摩尔吸光系数1.57x105L·mol-1cm-1.铝离子浓度在0-2.5ug/25mL范围符合朗伯比尔定律,加标回收率为97.6%-99.5%.  相似文献   

10.
用钌钛金属阳极在含有Cl—和Br-离子的酸性溶液中进行电解氧化联二脲制备偶氮二甲酰胺,获得产品得率为93—98%、纯度为99.6%、电流效率为88-92%。母液可循环使用,基本不产生废液.  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.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

14.
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   

15.
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   

16.
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   

17.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

18.
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   

19.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
1 Rise of studies on climate change's effects on biodiversity
Until the 1980s, climate change and biodiversity were studied as two independent disciplines for more than a century. In 1992, the Ecological Society of America's annual report named climate change, biodiversity, and the sustainable ecological system as the three major global environmental issues of the twenty-first century [1].  相似文献   

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