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1.
Ce-Co合金膜在乙酰胺-尿素-NaBr熔体中电化学制备的研究   总被引:1,自引:0,他引:1  
 应用循环曲线法研究了在353 K的乙酰胺-尿素-NaBr熔体中Co2+在Pt和Cu电极上的电化学行为,获知Co2+电还原为金属Co是一步不可逆过程,测得α为0.28,D0为4.65×10-5cm2/s;而Ce3+不能单独还原为Ce,但可以被Co(Ⅱ)诱导而共沉积;由恒电位电解法得到非晶态的Ce-Co合金,Ce-Co合金膜中Ce的质量分数随电位、时间和浓度的变化而变化,其合金膜中Ce的质量分数的最大值可达64.65%.  相似文献   

2.
固体超强酸催化制备丙烯酸十八酯   总被引:3,自引:0,他引:3  
 以丙烯酸和十八碳醇为原料,采用固体超强酸SO42-/TiO2为催化剂及直接酯化法制备丙烯酸十八酯.研究了丙烯酸与十八醇的摩尔比、催化剂和阻聚剂的质量分数、反应温度及反应时间对反应的影响,并用红外光谱对产物进行了表征.由实验得出的最佳合成条件是:丙烯酸与十八醇的摩尔比为1.2:1,固体超强酸及对苯二酚的质量分数分别为6%,0.8%,反应温度为120℃,反应时间为3 h,在此反应条件下,酯的产率可达97%.  相似文献   

3.
为开发新型储氢材料提供更为丰富的理论基础,采用B3LYP泛函在6-311++G(d,p)基组水平上对BLi6+超碱团簇和BLi72+超碱土团簇的稳定性结构、电荷分布等方面进行理论研究,进而研究团簇的储氢性能。结果表明:两个离子团簇均比它们所对应的中性团簇均具有较高的动力学稳定性。两个离子团簇中的每个Li原子同时有效吸附2个氢分子,BLi6+团簇中氢分子在团簇表面平均吸附能为0.969~2.162kCal/mol,储氢质量分数达31.56wt%。而BLi7+团簇中氢分子在团簇表面平均吸附能为1.764~3.714kCal/mol,储氢质量分数达32.21wt%。它们的储氢性能表明BLi6+团簇和BLi72+团簇均有望成为良好的储氢媒介。  相似文献   

4.
Al/Pb-WC-ZrO2复合电极材料的电化学性能研究   总被引:1,自引:0,他引:1  
 研究了电镀液中固体微粒质量浓度及工艺条件对Al/Pb-WC-ZrO2复合电极材料的表面化学组成及稳态析氧极化曲线的影响规律,对上述工艺条件进行了优化,优化后的工艺条件如下:WC:50 g/L,ZrO2:40g/L,温度:20℃,电流密度:1.5 A/dm2,电沉积时间:2 h.所获得Al/Pb-WC-ZrO2复合电极材料的析氧动力学参数为:a=771 mV,b=140 mV,i0=3.11×10-6A·cm-2,并且电极的析氧过电位为η=1 009 mV,复合镀层中WC和ZrO2质量分数分别为10.02%和3.55%.  相似文献   

5.
 采用生物膜填料塔净化SO2废气,研究结果表明:其最佳操作条件为入口气体质量浓度500~1 000mg/m3、气体流量100 L/h、循环液流量15 L/h,pH 1.0;当气体流量从100 L/h增加到300 L/h时,SO2净化效率由86.4%下降到73.2%;最佳操作条件下SO2净化效率可达98%以上.  相似文献   

6.
采用杂化密度泛函理论(DFT)的B3LYP方法,在6-311++G (d, p)基组水平上对Li3O 0, +超碱团簇的几何结构和稳定性进行理论计算,并研究了Li3O+团簇的储氢性能。结果表明,Li3O+团簇结构相比中性Li3O团簇结构的动力学稳定性要高。氢分子在Li3O+团簇表面能以介于物理吸附与化学吸附之间的形式吸附,每个Li原子最多可以有效吸附三个H2,储氢质量分数可达33.01 wt%。H2分子在Li3O+团簇表面的平均吸附能范围为1.959~3.591 kCal/mol,该吸附能满足在近室温条件下可逆吸放氢反应的热力学要求。  相似文献   

7.
采用自设固定源PM2.5稀释采集系统对陕西省关中地区多个燃煤电厂烟气中的颗粒物开展了现场实测与样品化学源组分分析。结果表明:4个燃煤电厂PM2.5、PM10占颗粒物比重差异较大(PM2.5占比范围为6.92%~54.34%,PM10占比范围为36.36%~73.02%);4个燃煤电厂数浓度水平最高值(2.0×104~4.0×105个/cm3)差异较大,相差约1个数量级;燃煤电厂PM2.5小粒径段颗粒物质量浓度占比大多较低,但其对PM2.5数浓度贡献却很大(最小值>95%),大粒径段颗粒物则相反;煤粉炉PM1/PM2.5较大,占比范围为35.29%~51.35%,循环流化床锅炉PM1/PM2.5较小,占比范围为16.62%~21.47%;SO42-是燃煤电厂PM2.5中最丰富的离子成分,各电厂SO42-占总离子浓度比重范围为50.02~65.52%,Na+和Ca2+位于第2或第3位;各燃煤电厂主要检出无机元素是Si、Al、Ca、Na、Fe、Na等地壳元素;燃煤电厂PM2.5、PM10和颗粒物的排放因子范围分别为0.001~0.028 kg/t、0.002~0.086 kg/t、0.003~0.236 kg/t;除尘设施组合越复杂先进,排放因子就可能越小。  相似文献   

8.
以聚乙烯醇(PVA)为基体,选用六方氮化硼纤维(BN fiber)作为导热填料,通过溶液共混的方法制备导热复合材料。结合X射线衍射仪(XRD)、扫描电子显微镜(SEM)以及导热测试结果,探究填料的微观形貌以及与基体的界面相容性对于提升复合材料导热性能的影响。结果表明:BN fiber对于提升复合材料的面内导热率有很好的效果,而且采用过氧化氢(H2O2)溶液进行表面改性,可以有效改善界面相容性;当经过1 400℃热处理再经过表面改性的BN fiber(BN fiber-1400-H2O2)的填充量为5%(质量分数)时,复合材料的面内导热率达到了1.32 W·m-1·K-1,为纯PVA体系的629%,相比于表面改性前提升了60%。  相似文献   

9.
采用密度泛函理论(B3LYP)方法,在6-311++G(d,p)基组水平上对NLi4超碱团簇和NLi4+超碱离子团簇的几何结构和稳定性等物理化学性质进行理论计算,进而研究NLi4团簇和NLi4+团簇的储氢性能。结果表明:NLi4团簇和NLi4+团簇结构稳定性均比较高,但是通过理论计算表明NLi4团簇不能有效吸附氢分子,而NLi4+团簇在吸附氢分子过程中不仅结构稳定,而且NLi4+团簇中的每一个锂原子均可有效吸附3个氢分子,氢分子平均吸附能为1.517~2.931 kCal/mol,储氢质量分数达36.67 wt%,合适的吸附能和较高储氢容量表明NLi4+团簇可有望成为良好的储氢材料。  相似文献   

10.
生物法同时脱除高温烟气中SO2和NOx的实验研究   总被引:1,自引:0,他引:1  
 对采用生物膜填料塔处理高温烟气中的SO2和NOx进行了实验研究,结果表明,生物膜填料塔能够有效地同时去除高温烟气中的SO2和NOx.在65 ℃,循环液流量4.0~7.0 L/h,pH=1.5,停留时间150 s,SO2进气质量浓度2 000~3 000 mg/m3,NOx进气质量浓度500~1 000 mg/m3的操作条件下,生物膜填料塔对SO2的去除率可达99.9%以上,对NOx的去除率为60.2%.  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.
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   

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.
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   

15.
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   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
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   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
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   

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