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1.
改性草浆碱木素减水剂的制备与性能评价   总被引:1,自引:0,他引:1  
针对草浆碱木素化学改性,研究了引发氧化和磺化制备改性草浆碱木素减水剂(MLP)的工艺参数,通过测定MLP的红外光谱、MLP在水泥颗粒表面的吸附量、水泥ζ-电位、MLP水溶液的表面张力及掺MLP的水泥净浆流动性,对MLP进行了表征,并试验研究了掺MLP的混凝土性能.试验结果表明:通过对草浆碱木素进行氧化改性和磺化改性,可获得含有羟基、磺酸基等官能团的木质素磺酸盐减水剂,减水率达到15.2%;碱木素经改性后,表面活性提高,通过吸附一分散作用,降低水泥颗粒的ζ-电位,并可显著降低水的表面张力;掺MLP的混凝土性能符合高效减水剂国标要求.草浆碱木素经氧化和磺化改性后,不仅可代替木浆木质素磺酸盐使用,而且因其具有高效减水剂的性能指标,还可单独作为高效减水剂使用,或部分取代萘系高效减水剂.  相似文献   

2.
麦草碱木素在碱催化下经脱甲基改性可提高其反应活性.本文采用元素分析、扫描电镜、凝胶色谱、1HNMR和13CNMR波谱较系统地研究脱甲基改性麦草碱木素化学组成、微观表面形态和化学结构的变化.研究结果表明,脱甲基活化改性后,麦草碱木素的甲氧基含量由10.3%降至6.09%,而酚羟基和羧基含量分别由2.98%和4.58%增至5.51%和7.10%.脱甲基改性后氧元素含量下降,改性麦草碱木素的微观形态呈致密的球形,在尺寸上比未改性的麦草碱木素小.改性后麦草碱木素的平均相对分子质量(Mw)由6217降至5148,相对分子质量分布情况发生变化.脱甲基改性使苯环上的烷基芳基醚键断开,形成酚羟基,同时,在一定程度上也伴随木素结构单元间化学联接的断裂,体现在其核磁共振波谱和平均相对分子质量的变化.  相似文献   

3.
麦草碱木素在碱催化下经脱甲基改性可提高其反应活性。本文采用元素分析,扫描电镜,凝胶色谱,^1H-NMR和^13C-NMR波谱较系统地研究脱甲基改性麦草碱木素化学组成,向观表面形态和化学结构的变化。研究结果表明,脱甲基活化改性后,麦草碱木素的甲氧基含量由10.3%降至6.09%,而酚羟基和羧基含量分别由2.98%和4.58%增至5.51%和7.10%。脱甲基入性后氧元素含量下降,改性麦草碱木素的微观  相似文献   

4.
探讨了漆酶处理碱木素对其热塑过程中VOCs挥发量的控制作用.采用顶空气相色谱仪(HS-GC)和热重分析仪(TGA)对木素热塑过程中VOCs挥发量进行定量分析.HS-GC检测结果表明,经漆酶处理后木素热塑过程中VOCs挥发量减少35.7%.TGA数据分析显示,热塑温度为190,℃时,漆酶处理后木素中VOCs含量比空白样少0.9%(相对于木素质量).进一步采用气相色谱–质谱联用仪(GC-MS)和凝胶渗透色谱仪(GPC)对漆酶作用原理进行探索,结果显示,漆酶处理后碱木素反应滤液中小分子酚类物质含量减少,而碱木素相对分子质量增大,表明在漆酶处理后,碱木素中的小分子酚类物质发生聚合或与木素大分子接聚,导致碱木素热塑过程中VOCs的挥发量减少.  相似文献   

5.
基于染料木素对高锰酸钾氧化鲁米诺产生的化学发光的增强作用建立了一种测定染料木素的新方法.在优化的实验条件下,测定染料木素的线性范围为:4.0×10^-2~4.0μg/mL,检出限(3d)为8.0×10^-3g/mL,对浓度为0.50μg/mL的染料木素进行11次平行测定,其相对标准偏差(RSD)为1.2%.将本法用于槐角药丸中染料木素含量的测定,结果令人满意.  相似文献   

6.
碱木素冻胶是一种具有热稳定性且易于进入地层深部的高温堵剂,首先合成了碱木素冻胶的交联剂——水溶性酚醛树脂,优化了其合成反应条件,然后评价了碱木素高温冻胶的性能.研究结果表明:水溶性酚醛树脂的最佳合成条件为催化剂NaOH质量分数9%,甲醛与苯酚摩尔比1.8,反应温度85℃,自缩聚反应时间30 min.脱水后的水溶性酚醛树脂中羟甲基质量分数为83.54%,游离醛质量分数为0.35%,黏度为2 950 mPa.s,可在25℃下保存1个月,贮存稳定性好.在酚醛树脂质量分数为3.5%、碱木素质量分数为10%、体系pH值为9.75、高温200℃条件下碱木素冻胶的成胶时间为1.5 h,冻胶强度为0.092 MPa.成胶时间短,冻胶强度高,热稳定性好,具有较好的蒸汽调驱性能和应用前景.  相似文献   

7.
蔗渣碱木素液化制备酚类化合物   总被引:2,自引:0,他引:2  
为了提高蔗渣碱木素的利用价值,以硅酸铝为催化剂催化碱木素的液化过程来制备酚类化合物.对硅酸铝用量、加热时间、加热温度、溶剂体积与溶质质量比等工艺条件进行了优化,确定了最优条件为:硅酸铝用量为绝干碱木素质量的4%,加热时间1h,加热温度270℃,溶剂(丙三醇)体积与溶质(蔗渣碱木素)质量比为6mL/g,此条件下酚类化合物...  相似文献   

8.
瑞香狼毒总木脂素的体外抗肿瘤活性   总被引:1,自引:0,他引:1  
研究了瑞香狼毒总木脂素的体外抗肿瘤作用.用MTT比色分析法、集落形成法对瑞香狼毒总木脂素的体外抗肿瘤活性进行研究,并与长春新碱的活性进行了比较.瑞香狼毒总木脂素成分对肿瘤细胞株SGC-7901,HEP-7402和HL-60的增殖及克隆形成具有较强的抑制作用,其体外抗肿瘤活性高于或接近于长春新碱,证明瑞香狼毒总木脂素成分具有较强的体外抗肿瘤作用.  相似文献   

9.
设计了一种适合于白腐菌处理碱木素废水的流化床生物反应器,采用2种运行方式,分批运行3个循环,碱木素脱色率为50%~80%,COD去除率达50%以上,连续运行55 d,碱木素脱色率达60%,COD去除率达84%.  相似文献   

10.
熔喷非织造白细胞滤材胺碱同浴法改性及涂层的研究   总被引:3,自引:0,他引:3  
选择了白细胞过滤用材料,并对胺碱同溶法改性及改性后涂层丝素进行了实验和分析研究,材料经过改性后亲水性得到了改善。  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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