调控酶解底物初始pH制备低聚木糖

研究在木聚糖酶定向酶解纯木聚糖及木聚糖碱抽提液制备功能性低聚木糖时,酸和缓冲溶液调控底物的初始ｐＨ对低聚木糖的影响。结果表明,木聚糖酶在ｐＨ５．０左右的活力最高;酸调控纯木聚糖底物的低聚木糖得率低于缓冲溶液调控的低聚木糖得率,但两者相关不大;而当底物为木聚糖碱抽提液是,由于木素的存在,两种调控方式的低聚木糖得率相差较大,酶解液出现浑浊状态;酸调控纯木聚糖,木聚糖碱抽提液时,低聚木糖得率最高的初始ｐ     

里氏木霉诱导合成木聚糖酶的调控

提出了两种不同用途的木聚糖酶的诱导合成方法。以里氏木霉为产酶菌,经适当处理后的玉米芯可诱导产生含纤维素酶（３．４ＩＵ／ｍＬ）的高活力木聚糖酶（５４．４ＩＵ／ｍＬ）。以混有少量纤维素的粗木聚糖作碳源,通过分批补料及对培养条件的限制性控制里氏木霉可选择性合成木聚糖酶;选择性合成程度与碳源浓度有关,当碳源浓度为１０ｇ／Ｌ时木聚糖酶和纤维素酶活力分别为３５．５ＩＵ／ｍＬ、０．２Ｕ／ｍＬ,两种酶活的比值达１７７．５。     

添加纤维二糖,淀粉水解液对纤维素酶制备的影响

里氏木霉（ＴｒｉｃｈｄｅｒｍａｒｅｓｅｉＲｕｔＣ３０）以经蒸汽爆破预处理的玉米秆为底物制备纤维素酶,产酶ｐＨ值维持在５．０左右,底物浓度为３．７５％（玉米秆,干基）时,产酶３天,滤纸酶活力和纤维二糖酶活力达１．７６ＩＵ／ｍＬ和０．３８ＩＵ／ｍＬ,纤维二糖酶活力高,酶水解得率达８０．２％;在试验培养基中添加纤维二糖对纤维素酶的合成具有抑制作用,培养基中添加纤维二糖浓度在０．２５～１．５０ｇ／Ｌ时,滤纸酶活力和纤维二糖酶活力同时下降３０％～４０％;淀粉水解液对纤维毒酶合成的影响是由葡萄糖的抑制和复合糖的诱导共同作用的结果,在用本研究培养基制备纤维酶过程中添加淀粉水解液,从经济角度来说是不适宜的。     

克鲁维酵母y－85菊粉酶水解菊粉的研究及其中试

克鲁维酵母（Ｋｌｕｖｅｒｏｍｙｃｅｓｓｐ．）Ｙ－８５在菊粉提取液培养基中生长产菊粉酶，其细胞和胞外的菊粉酶活力分别约占菊粉酶总活力的７６％和２４％．试验中以酶发酵液作酶液．该酶的Ｓ／Ｉ值为１５．２．酶液在５０，５５和６０℃下保温１ｈ，活力分别残留１００％，９６％和６５％；在８℃下放置７ｄ，１４ｄ，酶活力分别残留９８％和９６％．在ｐＨ３．６～７．０内，酶活性十分稳定．５ｍｍｏｌＬ－半胱氨酸和Ｆｅ＋２分别可使酶活力提高１０．４％和４１．２％．ｙ－８５菊粉酶水解菊粉的适宜条件是：底物为总糖浓度１０％～１５％菊粉提取液，ｐＨ５．０，温度为５５℃，酶用量为底物每克糖加酶８００ｕ（以蔗糖为底物测酶活力）或２６．３ｕ（以菊糖为底物测酶活力）、搅拌酶解６ｈ．在上述条件上，底物降解率最高可达９８．５％．酶解液中，果糖占总还原糖量的８５％．用１１００Ｌ罐进行酶解中试，５批试验，底物降解率平均达９４．２％．     

木聚糖降解菌的筛选和木聚糖酶性质的研究

筛选两株生长快、产木聚糖酶活力高的菌种；黑曲霉（Ａｓｐｅｒｇｉｌｌｕｓｎｉｇｅｒ，ＡＮ０１）、链霉菌（Ｓｔｒｅｐｔｏｍｙｃｅｓｓｐ．Ｓｔｒ７Ｂ），酶活力分别达１２８ｍｇ／Ｌ·ｍｉｎ和１７６ｍｇ／Ｌ·ｍｉｎ；酶反应最适温度分别为６０℃与５０℃；最适ｐＨ值为５．０和６．０，并分别在ｐＨ２．２～５．０，５．８～６．４酶活性稳定；在６０℃条件下保温１．５ｈ，酶活力分别剩余２０．５％，８８．５％，其中ＡＮ０１株原酶液在９０℃保温１０ｍｉｎ，活力仍剩余１４．５％．Ｃｕ２＋对酶活表现出极强抑制，Ｆｅ２＋，Ｍｇ２＋，Ｃａ２＋等离子则有促进作用；用纸层析法探讨了不同培养时间各种产物产生的情况．     

绿色木霉固态发酵产纤维素酶条件及酶性质的研究

对绿色木霉 Ｔｒｉｃｈｏｄｅｒｍａ　ｖｉｒｉｄｅ９４０５固态发酵产纤维素酶的条件及酶的性质进行了研究。结果表明,最适产酶条件为：秸秆粉与麸皮的比 ７：３;玉米秸秆粉培养基含水量２５０％;花生皮粉培养基含水量１５０％;ｐＨ４．０～４．５;温度３０℃;周期７２ｈ。在玉米秸秆粉固体培养基上,所产纤维素酶ＣＭＣ活力为１３８６ｕ／ｇ,ＦＰＡ活力为２１７ｕ／ｇ,棉花糖化力为３２５ｕ／ｇ。必作用的最适条件为ｐＨ４． ５～５． ０,温度 ５０℃;在 ４５℃以下, ｐＨ３． ５～６． ０之间比较稳定,室温放置半年,酶活保存率在９０％以上。     

生淀粉糖化菌NL—3的发酵条件

以黑曲霉（Ａｓｐｅｒｇｉｌｕｓｎｉｇｅｒ）５２３原生质体为对象,经激光、紫外线和亚硝基胍复合诱变,选育出高产生淀粉糖化酶突变株黑曲霉ＮＬ３,其生淀粉酶活力为１５６Ｕ／ｍｌ．产酶最适培养条件为：起始ｐＨ４５,３０℃,９６ｈ产酶量达最高．Ｋ＋,Ｍｇ２＋对ＮＬ３产生淀粉糖化酶有促进作用;Ｚｎ２＋对产酶有抑制作用．酶的最适作用条件为：以玉米淀粉为底物的最适温度５０℃,最适ｐＨ４５;以甘薯淀粉、马铃薯淀粉为底物时最适温度６０℃,最适ｐＨ４０～４５．酶在６０℃保温１５ｍｉｎ,玉米淀粉为底物时酶剩余活力为８０％;甘薯淀粉、马铃薯淀粉为底物时酶剩余活力为９８％．     

碳源对丝孢酵母(Trichosporon cutaneum ST_(851))生长和β-木聚糖酶诱导形成的影响

以单糖、双糖和多糖等８种有机化合物为碳源，培养丝孢酵母ＳＴ８５１，结果发现该菌株在上述各种碳源中均生长良好，但只有在木糖和木聚糖碳源中培养时，才呈现β－木聚糖酶活性；该菌株所产生的β－木聚糖酶是诱导酶，木糖和木聚糖是良好的诱导物；麸皮和半纤维素可大幅度提高酶活力．在液体或固态培养中，酶活力可分别达到１４．４ＩＵ／ｍｌ和７３．６ＩＵ／ｇ曲．５－氟尿嘧啶和放线菌酮均对该酵母所产的β－木聚糖酶有强列抑制作用     

碳源对丝孢酵母（Trichosporon cuataneum ST851）生长…

以单糖，双糖和多糖等８种有机化合物为碳源，培养丝孢酵母ＳＴ８５１，结果发现该菌株在上述各种碳源中的均生长良好，但只有在木糖和木聚糖碳源中培养时，才呈现β－木聚糖活性，该菌株所产生的β－木聚糖酶是诱导酶，木糖和木聚糖是良好的诱导物，麸皮和半纤维素可大幅主提高酶活力，在液体或固态培养中，酶活力可分别达到１４．４ＩＵ／ｍｌ和７３．６ＩＵ／ｇ曲，５－氟尿嘧啶和放线菌酮均对该酵母所产的β－木聚糖酶有强列抑抽     

调控pH值提高木聚糖酶活力的研究

通过控制产酶过程ｐＨ 值能有效提高里氏木霉木聚糖酶活力。结果表明,当控制产酶ｐＨ 为４ ．０ 时,有利于提高木聚糖酶活力,且此ｐＨ 对提高β－ 木糖苷酶活力的影响更大。ｐＨ 调控时间不宜过长,一般应以控制１ ～２ ｄ 后让其自由发展为宜。     

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.     

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。     

A computer generator for randomly layered structures

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

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.     

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.