离子注入对苹果酒酵母菌的诱变研究

以野生型苹果酒酵母菌为出发菌株 ,利用离子注入对其进行诱变 .结果表明 ,对苹果酒酵母菌的最佳离子注入剂量为 8× 10 15/cm2 N+ ,此时致死率为 70 4 % 用此剂量诱变后的一些菌株菌落特征和形态发生了变化 .对菌株进行发酵试验比较 ,获得一株酒精产率较高的菌株 ,发酵至第十天时 ,酒精产率最高 ,可达到9 0 % (φ酒精) ,比出发菌株高出 10 7%     

N~ 离子束注入庆大霉素产生菌诱变效应研究

用 30kV ,剂量 1 .0× 1 0 1 5ions/cm2 ～ 5.0× 1 0 1 6ions/cm2 的N 离子注入庆大霉素产生菌成熟孢子后 ,作出菌种的存活率曲线 ,为典型的“马鞍型”剂量 -效应曲线 .围绕存活率曲线的峰值区域选取最佳注入剂量对菌种进行诱变育种 ,经筛选得到了高产抗突变菌种 ,摇瓶发酵表明其产抗能力可提高 2 7.39% ,成果显著 .     

氮离子注入选育耐酸性α-淀粉酶产生菌诱变效应的研究

利用低能(30keV)氮离子注入中温中性α-淀粉酶产生菌枯草芽孢杆菌BF7658,研究对其产耐酸性α-淀粉酶的诱变效应.结果表明,BF7658菌株存活率曲线是典型的"马鞍型"剂量-效应曲线,在"马鞍型"区域对应注入剂量50×1014～100×1014 ions/cm2下具有较高的突变率.通过诱变筛选到一株最适作用pH为5.0,较出发菌株的最适作用pH偏低一个单位的突变株,编号TUST743.该突变株产酸性α-淀粉酶的酶活为343U/mL.该酶在pH4.5和4.0条件下的相对酶活为61%和38%,说明此突变株所产酸性α-淀粉酶对低pH有较好的耐受性.经连续传代实验,表明该菌株遗传性质稳定.     

克拉维酸高产菌的选育

在克拉维酸高产菌的选育过程中,应用解除终产物结构类似物作为选择压力,能有效地除去低效价菌株,提高高产菌株的检出率,较传统筛选法优越.试验表明,以带棒链霉菌Strep tomycesclavuligerusCCRC11518(效价为382.4×10-6g/mL)为出发菌,经紫外线诱变,筛选到一株抗20×10-3g/mL的舒巴坦钠突变株my51,my51菌株产克拉维酸的效价达到834.7×10-6g/mL,比出发菌提高了1.18倍.该菌株连续传代7代,克拉维酸的效价保持稳定.     

高能电子诱变选育雷帕霉素产生菌

利用高能电子束对雷帕霉素产生菌进行诱变处理。照射时间分别选用10s、20s、30s,在诱变株中筛选高产突变株。最终获得一株高产菌株NP09-62#,其效价比出发菌株提高了33.3%,且遗传性能稳定。     

利用抗药性选育盐霉素高产菌株

采用紫外线诱变和紫外线复合氯化锂处理盐霉素生产菌株,利用含棕榈油的筛选平板,结合选育脂肪酶活力高的菌株,成功获得产量提高并适应棕榈油发酵的高产菌株Ae-4.棕榈油完全替代豆油摇瓶113 h发酵的产量是豆油发酵的88.7%(出发株为69.6%).进一步通过选育抗药性突变株获得了抗链霉素的高产突变株E4Lt-1(摇瓶发酵产量提高57.4%)和抗利福霉素的高产突变株Rift-1-2(摇瓶发酵产量提高44.9%).     

γ-亚麻酸产生菌的低能离子束诱变选育

为了得到γ-亚麻酸(GLA)高产菌株,以深黄被孢霉As3.3410为出发菌株,利用氮离子(N+)注入诱变,并采用马来酰肼抗性筛选和红四氮唑(TTC)法相结合对突变株进行筛选。试验结果表明:当能量为10 ke V时,最佳氮离子诱变剂量为1.56×1015cm-2;当马来酰肼的添加量为40 mg/L时,出发菌株的抑制率为100%;TTC法酶活测定的最佳条件为:温度35℃、p H为8.4、TTC浓度为8 g/L、反应时间为1 h,以此作为摇瓶初筛的条件。经过反复诱变筛选获得一株遗传稳定的高产突变株F312,其γ-亚麻酸产量为1 236 mg/L,比出发菌株(480 mg/L)提高了157.5%。     

利福霉素产生菌高产菌株的选育

利福霉素产生菌经离子注入诱变处理,利用利福霉素浓度梯度平板和高浓度葡萄糖平板,筛选到的高产菌株再反复进行离子注入诱变、筛选和纯化,最终得到6株菌株,产量较同期对照A606分别高出的比例如下A606-3-1, 58.7%; A606-3-2, 51.0%; A606-3-3, 43.4%; A606-3-4, 41.7%; A606-3-5, 39.3%; A606-3-6, 39.3%.     

不同离子束辅助沉积生物玻璃陶瓷膜的结构和溶解特性

用能量 60keV、辅助注量为 2× 10 16 和 7× 10 15ions/cm2 的N+和Ar+离子束 ,分别将生物玻璃陶瓷 (BGC)辅助沉积于钛合金表面 .通过XRD ,FTIR ,XPS和EDAX对沉积膜进行表征发现 ,膜均呈非晶或无明显的结晶度 ,沉积膜中均出现C和O的污染 ,还引入了CO2 - 3 根基团 .N+离子束辅助沉积膜的Ca/P比低于BGC原材料 ,而Ar+离子束辅助沉积膜的Ca/P比高于BGC原材料 .在Hanks溶液中 ,N+离子辅助沉积膜的抗溶解特性略优于Ar+离子辅助沉积膜 ,二者均优于Ti合金 .作者对实验中观察到的上述现象进行了一定的讨论     

葡甘聚糖酶高产菌株Bacillus subtilis的超剂量诱变育种

超剂量诱变育种就是加大诱变剂处理剂量,提高菌株突变幅度,从而获得较好的诱变效果.以葡甘聚糖酶产生菌Bacillus subtilis MY-1为初始菌株,先用紫外线、硫酸二乙酯进行单因子诱变,再用超剂量复合诱变,经过透明圈法和摇瓶筛选,得到了一株高产葡甘聚糖酶的突变菌株,命名为Bacillus subtilis UDMY-25,连续传代培养5次,发酵酶活稳定在5 387.2U/mL以上,较原初始菌株提高了44.8%,该菌株产酶能力处于同领域较高水平,具有较好的开发潜力和市场应用价值.     

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.     

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.     

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.     

A computer generator for randomly layered structures

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

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.