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1.
以KSCN饱和的NaOH溶液作预润胀剂和催化剂,以丙烯腈作醚化剂对漂白针叶木纤维进行氰乙基化改性.研究了氰乙基化改性过程中的相关工艺参数对纤维改性及其热塑性的影响.并利用FT-IR、SEM对氰乙基化改性产物的化学结构和微观形貌进行了表征.结果表明,打浆度为45°SR的1.0 g漂白针叶木纤维,经KSCN饱和的1.00 mol.L-1NaOH溶液预处理120 min,丙烯腈用量为6.85 g时,在40~50℃下静置反应120 min,可获得接枝率为67.0%~72.8%的氰乙基化改性产物.  相似文献   

2.
超声活化后的竹粉在微波辐射的作用下与丙烯腈反应制备氰乙基化竹粉,考察最佳用量和反应条件对氰乙基化反应的影响,并用电子显微镜、X-射线衍射分析(XRD)、红外(FTIR)和示差扫描量热分析(DSC)等对竹粉改性前后的微观结构和热塑性进行了初步研究.结果表明,1.5g竹粉在饱和KSCN的NaOH溶液的润胀作用下,超声活化10min后,与8mL丙烯腈微波辐射30min即可获得传统40℃水浴反应3h才能得到的增重率约为40%的氰乙基化竹粉.微波作用使竹粉的氰乙基化反应可以在非常温和的条件下(40℃)短时间内完成,减少了丙烯腈的水解和均聚等副反应.氰乙基化竹粉中竹纤维表面结构变得粗糙,管束结构消失,结晶度降低,并在145~290℃之间出现一个大的吸热峰.  相似文献   

3.
用无水三氯化铝作催化剂,在低温常压下,由对甲苯胺和丙烯腈合成N,N-二氰乙基对甲苯胺,研究了反应体系中各因素对反应的影响,实验结果表明:对甲苯胺双氰乙基化反应较适宜的工艺条件是:n(对甲苯胺):n(丙烯腈)=1:2.6,催化剂用量为对甲苯胺的30%,反应温度为85℃,反应时间为24h,目标产物产率高达89%。纯度高于96%。  相似文献   

4.
对红麻进行测定的结果说明,韧皮部纤维细长,形状和结构与针叶木相似;而木质部纤维粗短;韧皮部的综纤维素含量高于木质部,而1%NaOH溶液溶出物、木质素和戊聚糖低于木质部。红麻的综纤维素主要由萄葡糖基和木糖基组成,韧皮部纤维可代替针叶木制造优质纸浆。  相似文献   

5.
通过静态甲醛吸附实验,研究了本色与漂白针叶木硫酸盐浆(KP)、本色与漂白阔叶木KP、本色竹KP以及本色亚硫酸铵针叶木浆等9种浆的甲醛吸附速率,测定了11种不同纸浆在相同条件下的甲醛吸附量,并与两种市售吸附用活性炭进行了对比.实验结果表明:室温下9种浆的甲醛饱和吸附时间均小于3 h,多为2~3 h.本色针叶木和阔叶木KP对甲醛的吸附速率大于漂白针叶木和阔叶木KP.一般饱和吸附量越大,吸附速率也越快.实验条件下吸附4 h后纸浆的甲醛吸附量结果是本色亚硫酸铵针叶木浆最大(213 mg/kg),本色针叶木KP和本色桦木KP以及本色桉木KP次之,其甲醛吸附量在179~193 mg/kg之间;漂白针叶木KP和漂白阔叶木KP的甲醛吸附量较小,分别为135 mg/kg和126 mg/kg.本色烧碱–蒽醌麦草浆和本色高得率竹浆对甲醛的吸附性能与本色木材浆相近.冷碱浸渍能提高纸浆的吸附效果.有些纸浆的甲醛吸附效果可达到甚至超越一些吸附用活性炭的吸附效果.  相似文献   

6.
丙烯腈易与含活泼氢的化合物发生迈克加成反应,如与内二酸二乙酯及乙酰乙酸乙酯的氰乙基化反应,此类反应常使用的碱性催化剂是乙醇钠和季铵碱等,近年来,有人使用Fe(CO)_5l_2为催化剂进行氰乙基化反应,但其单氰乙基化率在55%左右。我们使用碳酸钾为催化剂,对内二酸二乙酯及乙酰乙酸乙酯的单氰乙基化反应,进行了温度、溶剂、碱等方面的探讨。结果表明:碳酸钾为减、乙酸乙酯为溶剂,温度40~50℃是适宜的单氰乙基化条件,产率分别达83%和57%。反应式如下:  相似文献   

7.
本文报告八种含有在氧及硫原子上带活泼氢的二茂铁衍生物进行氰乙基化反应的结果。作者发现它们同其苯的同类物一样,在适当条件下可很好地与丙烯腈发生反应。上述二茂铁衍生物的氰乙基化反应一般在室温或略高一点的温度,有一个碱性催化剂存在下进行,温度太高是不适宜的,因为那将使丙烯腈更易于聚合,丙烯腈的量应多一些,特别是在进行两个氢被取代的情况下。得到的八种氰乙基化产物都是新的,本文还将实验条件、产物的物理性质和产率在表中列出。  相似文献   

8.
木纤维改性对聚氯乙烯/木纤维力学性能的影响   总被引:9,自引:0,他引:9  
将木纤维先用一定质量分数的氢氧化钠(NaOH)溶液浸泡,再用硅烷偶联剂进行表面处理的两步改性方法,与只用硅烷偶联剂对木纤维进行表面改性相比,聚氯乙烯(PVC)/木纤维复合材料的界面黏合性提高,复合材料的力学性能如拉伸强度、冲击强度、断裂伸长率等有明显提高,改性效果显著  相似文献   

9.
采用微生物学的实验方法初步研究了氰乙基化废纸的生物降解性能,结果表明,氰乙基化废纸具有比废纸更佳的纤维素酶降解性,在里氏木菌纤维素酶降解192 h后,失重率为23.6 %.氰乙基化废纸在枯草芽孢杆菌亚种Bacillus subtilis (subsp)和苍白杆菌属 Ochrobactrum sp.的作用下具有较佳的生物降解性;在实验室最佳降解条件下:温度 35 ℃、pH值 11左右、接种量 25%~30%、底物质量浓度 50 g/L,降解菌降解氰乙基化废纸速度先增大后减小,在12~14 d后降解速度相对变缓;降解14 d氰乙基化废纸产生的还原糖质量浓度基本保持在0.030 mg/mL左右,失重率最高为29.57%.  相似文献   

10.
氰乙基化改性赋予天然材料稳定性强、耐酸碱、可生物降解等许多优良特性,被广泛应用于造纸、纺织、光电、文物保护等诸多领域.对淀粉、纤维素、壳聚糖、蛋白质材料氰乙基化改性及其应用进行了综述,并对其发展前景进行展望.  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   

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