羧甲基化甜玉米芯多糖的制备

以甜玉米芯为原料,通过细胞破壁的方式将多糖分子从细胞壁或者细胞质中释放,溶解出的多糖经过脱蛋白、脱色、乙醇沉淀等后续处理步骤得粗多糖.在此基础上,将分子修饰技术应用到甜玉米芯多糖研究中,通过羧甲基化进一步对其进行分子修饰和改性.且分别以氢氧化钠溶液浓度、一氯乙酸用量以及反应温度为单因素条件进行羧甲基化修饰,在单因素实验基础上,通过正交试验进一步确定了最适修饰反应条件为,氢氧化钠溶液浓度4.0 mol/L,一氯乙酸用量2.360 g,反应温度45℃.在此条件下得到羧甲基化多糖取代度为0.051 6.     

响应面法优化薤白多糖的羧甲基化修饰工艺及抗氧化活性研究

采用氯乙酸法对醇沉法得到的薤白多糖(PAM)和柱层析纯化的3种分级薤白多糖进行羧甲基化修饰,以氯乙酸浓度、反应时间和反应温度为自变量,修饰产物的羧甲基取代度(DS)为响应值,应用响应面设计法确定羧甲基化修饰的最佳条件,用H2O2/Fe2+体系法和邻苯三酚自氧化法测定修饰产物的抗氧化活性.结果表明:薤白多糖氯乙酸法修饰的最佳条件为氯乙酸浓度1.3 mol/L、反应温度63℃、反应时间3.2 h.此条件下羧甲基取代度为0.882.羧甲基化修饰能提高薤白多糖的体外抗氧化活性.     

茯苓液体培养法中羧甲基茯苓多糖(CMP)的提取、纯化及鉴定

对茯苓菌株HD06-10 进行液体发酵培养,采用醇沉法从其发酵液中提取羧甲基茯苓多糖(CMP).用DEAE-32 纤维素和SephadesG-200 对 CMP 进行柱层析分离提纯,得到主要组分PG.通过紫外光谱和红外光谱对组分PG进行纯度鉴定,结果表明:PG为多糖纯品,未检测出核酸、蛋白质等杂质,仅由羧甲基葡萄糖组成. PG 是β构型的葡聚糖,糖环为吡喃型,糖苷键的连接方式为β (1→3)及β (1→6),分子量大约为4.2×104Da.     

化学修饰β-环糊精接枝壳聚糖及其对水溶液中酚的吸附

对β-环糊精进行羧甲基化、酰氯化,再通过酰胺化反应使之接枝到壳聚糖分子结构上,合成一种新型的化学修饰β-环糊精接枝壳聚糖。研究了其对水溶液中苯酚、对壬基苯酚和间苯二酚的吸附性能,考察温度、pH值、吸附时间、酚溶液初始浓度等因素对其性能的影响。实验结果表明:β-环糊精接枝壳聚糖吸附性能优于壳聚糖本身的吸附性能;对酚的最佳吸附条件是:温度为30℃,pH=2．65,吸附时间为6 h,酚的初始质量浓度为120 mg／L。     

茯苓菌丝体多糖硫酸酯化衍生物的制备及结构分析

目的 :探讨茯苓菌丝体多糖硫酸酯化的适宜条件 ,为进行生物活性的研究奠定基础。方法 :从茯苓菌丝体中得到的一种α ( 1→ 3 ) D 葡聚糖 (ab PCM3 I) ,采用氯磺酸 吡啶作为酯化试剂 ,研究反应温度、时间及反应物的摩尔比对硫酸酯化过程的影响。结果 :得到一系列水溶性的硫酸酯化茯苓菌丝体多糖 (S1-ab-PCM3 -I～S5 -ab -PCM 3 -I) ,经元素分析测定其取代度为 0 .3 9～ 0 .67。用凝胶渗透色谱和光散射联用法 (GPC -LLS)测定硫酸酯化衍生物的分子量为 2 .0× 10 4 ～ 11.3× 10 4 ,仅为原多糖分子量的 4%～ 17%。结论 :硫酸酯化反应打断了α ( 1→ 3 ) D 葡聚糖的分子链     

黄秋葵秸秆多糖的流变学性质研究

文章从黄秋葵秸秆中水提醇沉获得粗多糖,命名为OSPs,测定了多糖溶液的流变学性质,研究了多糖、蔗糖、CaCl_2及NaCl的质量浓度、温度、pH值对OSPs溶液黏度的影响。结果表明,OSPs溶液属于非牛顿型流体,其黏度对温度、pH值的变化比较敏感,而多糖、蔗糖、CaCl_2及NaCl质量浓度的增大均可以不同程度地提高OSPs溶液的黏度。     

枸杞多糖的羧甲基化修饰及抗氧化性能

为了研究枸杞多糖及其羧甲基化衍生物的结构和抗氧化性能,使用微波辅助酶解法提取枸杞多糖并进行羧甲基化修饰。采用高效液相色谱仪(HPLC)、傅里叶变换红外光谱仪(FTIR)和尺寸排阻色谱-多角度激光光散射-示差折光联用仪(SEC-MALLS-RI),对枸杞多糖进行了结构表征,对枸杞多糖及其羧甲基化衍生物的抗氧化性能进行了测定。研究结果表明:枸杞多糖的提取率为4.32%(质量分数),羧甲基化枸杞多糖取代度为0.43。枸杞多糖主要由甘露糖(40.05%,摩尔分数,下同)、葡萄糖醛酸(18.98%)、阿拉伯糖(18.34%)、鼠李糖(15.73%)和葡萄糖(6.90%)组成。枸杞多糖的数均相对分子质量为3.561×10~4,质均相对分子质量为5.059×10~4,多分散系数为1.421,均方根旋转半径为73.0 nm。在相同质量浓度下,羧甲基化枸杞多糖的抗氧化性能高于枸杞多糖。     

怀山药多糖的羧甲基化修饰及保润性能

为了研究山药多糖及其羧甲基化衍生物的结构和保润性能,采用碱提醇沉法从怀山药中提取山药多糖,然后对山药多糖进行羧甲基化修饰。采用傅里叶变换红外光谱仪和尺寸排阻色谱-多角度激光光散射-示差折光(SEC-MALLS-RI)法,对山药多糖羧甲基化衍生物结构进行表征。测定了山药多糖及其衍生物对烟丝的保润性能。研究结果表明:山药多糖的提取率为4.2%(质量分数),羧甲基化山药多糖的取代度为0.37。山药多糖的质均相对分子质量为6.6×10~4。低相对湿度条件下平衡水分48 h后,添加了5%羧甲基化山药多糖比添加了5%山药多糖的烟丝含水率降幅低了14.83%。羧甲基化山药多糖添加到卷烟中可以柔和烟气,提高抽吸舒适度,并降低刺激性。     

微波法制备白芨多糖磷酸酯

以磷酸二氢钠和磷酸氢二钠混合磷酸盐为磷酰化试剂,尿素为催化剂,微波辅助制备白芨多糖磷酸酯,试图寻找一种方便有效的多糖磷酸酯制备方法.考察了反应温度、微波辐射时间、磷酸盐总量和溶液pH值对反应的影响.得到最佳反应条件为:反应温度50°C,pH值为5,辐射时间3min,磷酸盐用量50%,所得产物中磷取代度为1.57%.微波制备方法的反应温度低、时间短、反应物用量小、产物的取代度高,是一种高效的白芨多糖磷酸酯合成方法.     

复合酶法提取红托竹荪多糖的工艺研究

采用复合酶法提取红托竹荪中的水溶性多糖,通过单因素试验和正交试验研究酶浓度、酶解时间、酶解温度以及酶解pH值对多糖得率的影响.确定复合酶法提取红托竹荪水溶性多糖的最佳条件为:酶浓度为1.5%,酶解时间120 min,酶解温度50℃,酶解pH值为4.5,此条件下的红托竹荪多糖得率为7.98%.     

Markedness and its Interpretation in Language Use

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Features of Women's language

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

Design and analysis of generic LBS application developing platform

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

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.