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1.
研究不同温度和水分胁迫对番茄种子萌发速率的影响,温度、NaCl和PEG6000预处理对番茄种子萌发和幼苗生长的交叉耐性诱导.在15℃、25℃和30℃中,50%萌发需要的时间分别是186h、43h和48h;50%萌发需要的热时间(thermal  相似文献   

2.
化学聚集电融合法在新型酵母构建中的应用   总被引:1,自引:1,他引:1  
在细胞融俣过程中化学聚集电融合法,即用PEG作为聚合剂与电融合法连用,取得明显的效果。其条件是:电压11kV;脉冲宽度5μ脉冲个数3;脉冲时间59s;温度4℃,PEG浓度35%;自理时间30min;处理温度30℃及pH6.从细胞体系、DNA含量,淀粉糖化能力及区区糖发酵能力等方面说明,所获得的新型酵母是两亲本的融合株。  相似文献   

3.
通过试管倒置法考察曲克芦丁对温敏水凝胶温敏性的影响。选用相变温度为25℃的PLGA—PEG—PLGA为载体,曲克芦丁为模型药物,物理混合法制备凝胶浓度为20%(质量分数)含药凝胶,采用无膜溶出模型研究其在体外不同温度下(40℃和30℃)的释药行为。结果显示:曲克芦丁的加入对温敏水凝胶的温敏性影响不大;通过改变PLGA—PEG—PLGA温敏水凝胶的温度可以改变其释药速度。因此可以得出结论:PLGA—PEG—PLGA水凝胶可作为药物脉冲式释放的载体,通过控制温度可控制其对药物的释放。  相似文献   

4.
利用1-丁基-3-甲基咪唑六氟磷酸盐离子液体和PEG20M为涂层材料,制备了复合PEG20M固相微萃取探头,与气相色谱联用测定了水中邻氯苯酚和4-硝基甲苯,并对萃取温度、萃取时间、盐浓度、溶液p H值等萃取条件,解吸温度和解吸时间进行了优化,结果表明:当水样中氯化钠浓度为0.40 g/m L,p H=5时,于30℃萃取30 min,萃取效果最好;140℃下3 min可完成解吸.与未加离子液体的PEG20M固相微萃取涂层相比,该涂层改善了检测的检出限和重现性,但因离子液体粘度较大等,涂层制备的重现性有待进一步提高.  相似文献   

5.
温度对野生大豆种子萌发的影响   总被引:4,自引:0,他引:4  
为探讨野生大豆(Glycine soja )种子萌发与温度的关系,将浓硫酸浸泡处理和砂磨处理过的种子置温度5、10、15、20、25、30、35℃恒温及25/15℃(昼/夜)变温条件下进行发芽试验,测定各温度下种子发芽率、发芽势及发芽指数.试验结果表明,野生大豆种子的适宜萌发温度为15-30℃,浓硫酸浸泡最佳处理时间为40min.  相似文献   

6.
碳酸钙和硼酸铝晶须的表面处理研究   总被引:1,自引:1,他引:0  
采用硬脂酸钠为处理剂对碳酸钙晶须和硼酸铝晶须进行了表面处理,通过测定活化指数、红外谱图及偏光显微观察对晶须的处理效果进行了表征,研究了处理剂的用量、处理温度和处理时间等工艺因素对表面处理的影响。结果表明:硬脂酸钠对两种晶须的处理效果均较好,活化指数分别可达到96.5%和97.3%。其中,碳酸钙晶须的最佳处理条件:处理剂用量为45%,处理时间为50 min,处理温度为40℃;硼酸铝晶须的最佳处理条件:处理剂用量为30%,处理时间为40 min,处理温度为40℃。  相似文献   

7.
以铁皮石斛愈伤组织为材料,采用PEG-6000模拟干旱胁迫处理铁皮石斛愈伤组织,检测愈伤组织可溶性蛋白含量及SOD、POD和APX活性的变化动态。结果表明,不同浓度PEG胁迫下,铁皮石斛愈伤组织可溶性蛋白均高于对照;各浓度PEG胁迫1d后,SOD活性均高于对照,当PEG浓度为30%时,胁迫2d、3d后却低于对照;POD活性随着PEG浓度的增强先上升后下降,在25%PEG胁迫下达到峰值;当PEG浓度为30%时,APX活性随着时间的延长而降低,当PEG浓度低于30%时,APX活性呈上升趋势。铁皮石斛愈伤组织可通过可溶性蛋白含量的增加和保护酶的变化来适应一定程度的干旱胁迫。  相似文献   

8.
采用生物-化学联合处理方法,研究棉杆皮脱胶工艺.通过正交实验,确定了果胶酶脱胶处理的最佳工艺为果胶酶浓度12%(o.w.f),温度40℃,时间30h,pH值4.4,浴比1:30;化学脱胶处理的最佳工艺为NaOH质量浓度8 g/L,H2O2质量浓度7g/L,温度100℃,时间45min,浴比1:50.  相似文献   

9.
本文对天然沸石的改性进行了研究.实验结果表明:用4kmol/m~3盐酸处理后的沸石比铵盐处理的沸石的吸附能力强.沸石改性的最佳条件是:酸处理时间为5.5~6小时;水浴温度为60℃左右;活化温度为40℃;活化时间为3.5~4小时;矿样粒径为2~5mm.  相似文献   

10.
采用真空烧结-热等静压处理工艺制备碳氮化钛基金属陶瓷,考察不同热等静压处理温度和时间对材料力学性能及结构的影响.结果表明:热等静压处理可有效消除材料内部孔洞,细化组织;合理的处理温度和时间为1 550℃,30 min;与真空烧结相比,材料的抗弯强度,硬度和致密度均分别提高了22.9%,1.0%和1.2%.  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.
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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   

19.
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.  相似文献   

20.
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   

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