Influences of Carboxyl Methyl Cellulose on Performances of Mortar

Carboxyl methyl cellulose （CMC） was mixed into mortar to improve the waterretention performance of mortar, the quality of floated coat of aerated concrete became better. The consistency and compression strength of mortar with CMC were studied. The water absorption was studied with the method of filter paper. The micro mechanism was researched with X-ray diffraction and scanning electron microscopy（SEM）. The experimental results show the water-holding performance of mortar with CMC is largely improved and it is better when the mixed amount is about 1.5%; the compression strength had a descending trend with the increase of CMC; CMC reacted with calcium hydroxide（CH） into the deposition of calcium carboxyl methyl cellulose.     

NMMO法纺制纤维素/羧化壳聚糖中空纤维膜的透析性能

研究了纤维素及纤维素/羧化壳聚糖中空纤维膜的超滤速率、筛分系数、溶质透过性等透析性能,发现随着纤维素浓度的增加,纤维素中空纤维膜的透水速率下降,其筛分性能越来越好;随着羧化壳聚糖含量的增加,纤维素/羧化壳聚糖中空纤维膜的透水速率下降,筛分性能则是当羧化壳聚糖质量分数为30%时为最好,溶质的透过性都是随着相对分子质量的增加而不断下降的.     

石墨/聚乙烯醇复合纳米纤维的制备及性能表征

应用静电纺丝技术制备石墨/聚乙烯醇(PVA)纳米纤维,并将该复合纤维收集成无纺布薄膜;采用扫描电子显微镜(SEM)观察了复合纤维的微观形貌和结构,利用宽频质谱仪测试了纤维的导电性,利用万能强力机测试了不同纳米石墨含量纤维薄膜的拉伸力学性能,并利用X射线衍射仪(XRD)和热重分析仪(TG)测试了复合纤维的物相及热力学行为.结果表明:在聚乙烯醇质量分数为8%、石墨质量分数为4%时,所制备的纳米纤维膜导电性最高,且力学性能最好,与纯PVA相比,电导率和断裂强度分别提高1个数量级和127.33%;XRD测试结果表明,纳米石墨成功附着在PVA中;TG结果表明,石墨/PVA复合纤维初始分解温度相对于纯PVA变化不大,当样品质量保持率为40%时,4%石墨/PVA复合纤维较纯PVA相比,其分解温度提高了35℃.     

Fracture characterization and permeability prediction by pore scale variables extracted from X-ray CT images of porous geomaterials

Pore scale variables(e.g., porosity, grain size) are important indexes to predict the hydraulic properties of porous geomaterials.X-ray images from ten types of intact sandstones and another type of sandstone samples subjected to triaxial compression are used to investigate the permeability and fracture characteristics. A novel double threshold segmentation algorithm is proposed to segment cracks, pores and grains, and pore scale variables are defined and extracted from these X-ray CT images to study the geometric characteristics of microstructures of porous geomaterials. Moreover, novel relations among these pore scale variables for permeability prediction are established, and the evolution process of cracks is investigated. The results indicate that the porescale permeability is prominently improved by cracks. In addition, excellent agreements are found between the measured and the estimated pore scale variables and permeability. The established correlations can be employed to effectively identify the hydraulic properties of porous geomaterials.     

天然聚合物电子纺纳米纤维的研究

对天然聚合物蚕丝、甲壳素、壳聚糖、明胶、蜘蛛丝、纤维素的电子纺制备纳米纤维的工艺条件及纤维结构进行综述。     

表面羧基可控的单分散P（St-co-AA）亚微球的制备与表征

用无皂乳液聚合法制备了具有不同表面羧基含量的单分散聚（苯乙烯-共-丙烯酸）亚微球,通过扫描电镜和透射电镜测试发现,制得的聚合物微球粒径均一,具有良好的单分散性.结果表明：通过改变聚合过程丙烯酸用量,可以在一定范围内调控共聚物微球的直径;经红外光谱和X射线光电子能谱分析发现,得到的聚合物亚微球表面存在大量羧基;通过X射线光电子能谱可计算出聚合物微球的表面羧基含量,并且该值可以通过在聚合过程中改变丙烯酸用量进行调控.     

鲍鱼性腺多糖的体内抗氧化活性

采用酶水解结合乙醇醇沉的方法从皱纹盘鲍性腺中提取多糖(CAGP),并研究其体内抗氧化活性.研究发现,对于正常小鼠,200 mg/kg的CAGP可有效提高其肝组织中CAT活力及T-AOC能力(P<0.01),降低血液与肝脏MDA浓度(P<0.01);CAGP还可显著降低脑组织MAO活力(P<0.01).对于四氧嘧啶致氧化...     

利用玉米秸秆制备羧甲基纤维素

以玉米秸秆为原料,预处理后原料中纤维素质量分数由39%提高至81%,探讨了物料配比、醚化与碱化反应温度及时间等因素对产品取代度和黏度影响。实验结果表明,最佳反应条件为m(纤维素)∶m(NaOH)∶m(ClCH2COOH)=1∶1∶1,以异丙醇为溶剂,采用二次加碱法的工艺,两次加碱的质量比为2∶1,碱化温度30℃、时间60 min,醚化温度65℃、时间120 min。按最佳条件反应制得的产品取代度可达1.34,25℃下2%水溶液黏度可达690 mPa.s,并通过红外谱图验证了产品的结构。     

几种提取苔藓植物总RNA方法的比较

将3种RNA提取方法加以比较,以期获得提取不同生境毛尖紫萼藓（Grimmia pilifera P．Beauv）总RNA的最适方法。经比较,改进后的SDS法更适合于毛尖紫萼藓总RNA的提取。此方法简单快捷,所得RNA完整性好,纯度高,试验稳定性好,可用于RT-PCR、基因克隆等进一步分子生物学研究。     

2，2′-联吡啶胺及其钯配合物[PdCl2（2-PY）2NH]的结构表征

2,2'-联吡啶胺(1)的结构经单晶X-射线衍射测定,化合物1的结晶是以正交空间群Pccn,其晶胞参数为a=12.3184(10)A,b=18.404 2(15)A,c=7.755 1(7)A和Z=8,化合物1通过一个对称中心形成氢键二聚体.1的钯配合物[PdCl2(2-py)2NH](2)是以单斜空间群P21/n结晶,其晶胞参数为a=10.251 0(6)A,b=9.509 4(6)A,c=12.269 6(7)A;β=97.865 0(1).;和Z=4,化合物2的结构含有-个微扭曲四平面构型的钯中心键合2,2'-联吡啶胺的两个氮原子和两个氯原子,平均Pd-N和Pd-Cl的键长分别是2.022(2)and2.3140(7)A.     

鲍鱼性腺多糖抗血栓及抗疲劳活性的研究

采用大鼠腹主动脉插管放血、体外试管法测定鲍鱼性腺多糖对大鼠血凝块的溶解作用;采用小鼠负重游泳的方法来检测鲍鱼性腺多糖的抗疲劳效果,并对受试小鼠的负重游泳时间、体内糖原、血红蛋白、乳酸及尿素氮含量及乳酸脱氢酶活性等生化指标进行测定.结果表明,鲍鱼性腺多糖(CAGP)具有一定的体外溶栓作用,50和200 μg/mL CAG...     

鲍鱼性腺多糖抗血栓及抗疲劳活性的研究

采用大鼠腹主动脉插管放血、体外试管法测定鲍鱼性腺多糖对大鼠血凝块的溶解作用;采用小鼠负重游泳的方法来检测鲍鱼性腺多糖的抗疲劳效果,并对受试小鼠的负重游泳时间、体内糖原、血红蛋白、乳酸及尿素氮含量及乳酸脱氢酶活性等生化指标进行测定。结果表明,鲍鱼性腺多糖(CAGP)具有一定的体外溶栓作用,50和200μg/mL CAGP的溶栓率分别为62.95%和67.70%;CAGP还具有明显的抗疲劳作用,剂量为200 mg/kg时,能显著延长小鼠负重游泳时间,降低血清中乳酸含量,提高组织糖原及血红蛋白含量和乳酸脱氢酶的活力。     

三（4—氯苯甲酸）纤维素酯的合成及其作为色谱固定相的性能研究

采用催化合成法合成了三（4－氯苯甲酸）纤维素酯;并负载于Gas Chrom Q载体上,用不同类型的探针分子表征其作为气相色谱固定相时的吸附性能,在其固定相上成功地分离了正构醇（C1－C6）。     

Human plasma protein binding of water soluble flavonoids extracted from citrus peels

The human plasma protein binding of water soluble flavonoids in the peels of five spices of citrus fruits was studied by ultrafiltration combined with HPLC.The flavonoids were extracted separately by hot and cold water,and higher total flavonoid contents were detected in the former extracts than the latter ones.All the extracts show significant scavenging abilities to both ABTS and DPPH free radicals,which indicates the health benefits of the water extracts of citrus fruits peels.For DPPH radical,the IC50values of hot extract follow as Navel orange（NO）≈Mandarin orange（MO） Lemon（LE） Lo tangerine（LO） Pomelo（PO）,while the rank is NO POLE≈MOLO for ABTS radical.The HPLC results reveal that the kinds and contents of the flavonoids detected in the extracts are different among the species.MO extract has the most neohesperidin dihydrochalcone of 118.76 μmol/L and quercetrin of 211.81 μmol/L of which are much more than the rest extracts.Pomelo extract has the most plentiful flavonoids of naringin with a concentration of 303.28 μmol/L.The high contents of myricetrin and dihydromyricetin which both are potent free radical scavengers may explain the highest free radical scavenging activity of the NO extract.The plasma binding rates decrease with the increasing concentrations of flavonoids,and the flavonoids having plenty hydroxyl groups on both A ring and B ring of the molecular skeleton have relative higher plasma binding rates.In addition,the plasma binding rates of flavonoids with saturated C3-C4 bond decrease significantly with the increasing concentrations.     

用超滤膜法浓缩剩余污泥中蛋白提取液的实验研究

采用超滤膜法浓缩剩余污泥中的蛋白提取液,并对浓缩过程中的膜污染展开分析,在此基础上,确定了污染膜适宜的清洗工艺．研究证明,采用超滤膜法浓缩剩余污泥中的蛋白质提取液是可行的．在室温条件下,操作压力为0．10～0．18MPa时,压力的升高有利于膜通量的增加,但也会增加膜污染的速率;浓缩过程中适当的清洗,不仅可以提高工作效率,还有利于膜通量的恢复;采用清水、碱性清洗剂（0．3％的NaOH和0．1％的NaCl0混合液）、酸性清洗剂（0．1％的盐酸溶液）,以动静态混合的方式清洗后,膜通量恢复率（WFR）可达到90％以上．     

酸法提取豆渣微晶纤维素条件的优化

研究利用豆渣提取微晶纤维素及条件优化,并采用响应面试验法研究酸解时间、温度及盐酸的质量分数等因素对微晶纤维素得率的影响．结果表明,3因素间的相互作用对微晶纤维素得率影响显著,回归方程解得其最佳工艺条件：酸解温度88℃、酸解时间61min、盐酸质量分数为6．3％,微晶纤维素得率为69．4％．     

PVP/(NH_4)_2Ce(NO_3)_6复合纳米纤维的制备与表征

用静电纺丝技术成功制备了纺丝液中铈浓度为0.1mol/L的有机-无机复合纳米纤维PVP/(NH4)2Ce(NO3)6,并优化了制备工艺。实验结果表明,复合纳米纤维随着铈含量的增大单位长度上的电压值升高,推进设备的推进速度降低;静电纺丝液中加入一定浓度的乙酸,将溶胶凝胶体系的pH控制在1.5～2.5可以明显提高纺丝液的可纺性。复合纤维的平均直径随着铈浓度的提高而增大:铈浓度为0.005mol/L时纤维平均直径为366nm,铈浓度为0.1mol/L时纤维平均直径为415nm;XRD结果表明复合纤维中铈盐为非结晶态。紫外可见分光光度仪检测结果显示,PVP/(NH4)2Ce(NO3)6静电纺丝制得的纳米纤维薄膜具有较好的可见光透过性与较强的紫外光吸收性能。     

玉米秸秆纤维素乙醇残渣木素碱溶/酸析分级与表征

采用常温、大液比氢氧化钠抽提玉米秸秆纤维素乙醇炼制残渣中木素,以盐酸为沉淀剂,通过逐级酸析分离木素的方法,在pH(10、8、6、4、2)酸析条件下进行木素分级制备。采用用离子色谱、凝胶色谱、红外光谱和热重分析手段对木素样品进行分析表征。结果表明,碱溶/酸析沉淀制备木素中含有碳水化合物,随着酸析pH的降低,木素分离级分中的碳水化合物含量增加,木素纯度降低,木素的平均分子量随酸析pH的降低呈现逐渐降低的趋势,分散系数在酸析pH为6时的达到最低值1.67。在低pH下分级沉淀制备的木素热稳定性低于高pH时分级制备的木素。红外光谱显示,木素各级分结构的官能团基本相同,含有紫丁香基、愈疮木基和对羟基苯基3种结构单元。     

Ultralow frequency wave characteristics extracted from particle data: Application of IGSO observations

Interaction between ultralow frequency (ULF) waves and charged particles plays an important role in the acceleration of particles in the Van Allen radiation belts. The strong wave-particle interaction predicts an energy-dependent observational signature of particle flux variations during different stages of the ULF wave evolution. In this paper, we find that the energetic particle data newly available from an IGSO spacecraft are quite consistent with theoretical predictions, which enables the application of a best-fit procedure to quantitatively extract key parameters of the ULF waves from the particle data. The general agreement between observations and the best-fit results validates the scenario of wave-particle drift resonance within the entire ULF life span, and provides a new technique to understand the ULF wave characteristics in the absence of electromagnetic field data. We also examine the minor differences between observations and the best-fit results, and propose that the differences may result from a longitudinal dependence of the ULF wave power to be considered in a future study.     

反胶束水合萃取藻蓝蛋白研究

反胶束水合萃取技术是将反胶束萃取和水合物生成耦合在一起形成的一项新型、有发展潜力 的分离技术, 可应用于生物物质的活性控制及提取.实验中构建了C TA B/正辛烷-正戊醇反胶束 体系, 通过研究此体系中水合物生成对其内的藻蓝蛋白的萃取作用及纯化效果, 获得反胶束水合萃 取藻蓝蛋白的动力学规律以及温度、压力、CTA B 浓度和初始含水量W0 等对反胶束水合萃取藻蓝 蛋白的影响规律, 为进一步开展水合物法生物质活性控制及反胶束水合萃取技术的研究提供依据.