首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
通过差示扫描量热法(DSC)研究了环氧端基酚酞聚芳醚腈(简称E-PCE树脂)与几种常用固化剂的热效应,测算了E-PCE/DDS固化体系固化过程的表观活化能及反应级数。另外,通过DSC、TGA测试了固化后试样的热性能。  相似文献   

2.
环氧端基酚酞聚芳醚腈的合成及结构性能表征   总被引:1,自引:0,他引:1  
由酚酞和2,6-二氯苯甲腈经亲核缩反应制得了含-OK端基的聚醚腈低聚物,在碱金属碳酸盐K2CO3/H2O催化下,将其与环氧氯丙烷反应得到了含环氧端基醚醚腈(E-PCE)用FT-IR,^1HNMR和DSC等方法地E-PCE树脂的结构性能进行了表征,测定了E-PCE树脂的环氧值,溶解性,分子量及分子量分布,讨论了单体的摩尔比,反应温度,催化剂含量及水含量对产物的影响。  相似文献   

3.
本文采用种子乳液聚合技术,合成聚苯乙烯-聚丙烯酸酯复合乳液,用TEM电镜观察其乳液的形态,用GPC方法测定了乳胶聚合物的化学组成。  相似文献   

4.
用胶体化学方法制备了稀土铕(Eu)-苯甲酰甲烷(DBM)和氯化十六烷基吡啶(CPC)同粒水溶胶「Eu(DBM)3」.CPC通过光谱性质的测定,结合透射是镜(TEM)观测,研究了「Eu(DBM)3」.CPC超微粒的粒径对光谱的影响。结果表明:由于「Eu(DBM)3」.CPC超微粒的小尺寸效应,其光谱性质明显不同于体相材料,并初步地讨论了尺寸效应分子内能量传递的影响。  相似文献   

5.
合成了三元共聚物PEO-TPC-LDABS、MMEC-TPC-LDABS和MNEC-TPC-LDABS,可望成为一类新的高分子固体电解质材料  相似文献   

6.
加工番茄多聚半乳糖醛酸酶(PG)基因的cDNA克隆   总被引:1,自引:0,他引:1  
以加工番茄87-5为材料,运用反转录PCR(RT-PCR)技术成功地将PG基因的cDNA序列克隆到pGEM-T载体上,并利用酶切及PCR进行了初步鉴定。  相似文献   

7.
用胶体化学方法制备了稀土铕(Eu)二苯甲酰甲烷(DBM)和氯化十六烷基吡啶(CPC)超微粒水溶胶[Eu(DBM)3]·CPC,通过光谱性质的测定,结合透射电镜(TEM)观测,研究了[Eu(DBM)3]·CPC超微粒的粒径对光谱的影响.结果表明:由于[Eu(DBM)3]·CPC超微粒的小尺寸效应,其光谱性质明显不同于体相材料.并初步地讨论了微粒的尺寸效应对分子内能量传递的影响  相似文献   

8.
为研究Ha-ras和Ki-ras癌基因转染和细胞对小鼠细小病毒(MVM)杀伤敏感性间的关系,两个细胞株,即Ki-ras癌基因转株DT和Ha-ras癌基因转化细胞株REF4-3,被用来作为研究材料,体外细胞集落形成率和细胞在裸小鼠体内的成瘤能力测定显示,和对照细胞NIH/3T3相比之这REF4-3和DT对MVM的杀伤作用更敏感,同时,DNA杂交和蛋白免疫沉淀实验结果也显示,在REF4-3和DT细胞中  相似文献   

9.
本试验用哈磁化杯磁化ELCO种兔血清50-100分钟,立即测定血清淀粉酶(AMS)和血清γ-谷氨酰转移酶(γ-GT)的活性。结果表明:AMS酶磁化50分钟比磁化50分钟比磁化100分钟效果显著,与对照组有显著差异;γ-GT酶磁化100分钟比磁化50分钟效果显著,与对照组有极明显差异。  相似文献   

10.
可聚合性季铵盐及其聚合物的合成与表征   总被引:1,自引:1,他引:0  
合成了三种含不饱和双键和季铵盐:甲基丙烯酰氧乙基-苄基-二甲氯化铵(MB-DAC),甲基丙烯酰氧乙基-丁基-二甲基溴化铵(MBDAB)和甲基丙烯酰氧乙基-乙基-二甲基溴化铵(MEDAB),用红外光谱,元素分析,核磁共振谱对其结构进行了表征。用自由基聚合法合成了MBDAC的均聚物及其与甲基丙烯酸甲酯和苯乙烯的共聚物,并用元素分析、GPC,红外光谱等表征了聚合物的结构,用DSC和TG研究了其热稳定性,  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.
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   

15.
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   

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.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号