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1.
将来自PCR法合成的绵羊β-乳球蛋白基因(BLG)5’端898bp上游区和人单核细胞表面分化抗原基因(hCD14)成熟肽1245bp片段构建的BLG-hCD14融合基因纯化后,注入小鼠受精卵原核。实验共注射受精卵1149枚,经体外培养发育到2-细胞期的胚胎计968枚,发育率为84.2%。从发育的胚胎中选择634枚移植到46只假孕受体。其中14只妊娠产仔,妊娠率30.4%。妊娠受体共移植胚移207枚  相似文献   

2.
研究了用手性助剂冰片与5-羟基-2(5H)-呋喃酮(1)缩醛化制得液体差向异体体混合物5「(1S)-内型-冰片氧基」02(5H)-呋喃酮(4(R)+4(S))(n(R)):n(4(S))=50.50),以该混合物为底物与硫酚(醇)进行不对称Michael加成,得到了7非对映异构体混合物,其中1对固体产物(6d(R)+6d(S))经分步结晶分离得6d(S).d.e.大于98%。此研究为由液体差异异构  相似文献   

3.
用胶原酶消化分离小牛肾上腺髓质嗜铬细胞,10-4mol/L乙酰胆碱(Ach)促进细胞儿茶酚胺的分泌,其作用具有Ca2+依赖性,回归方程r=-3.290+5.275x,相关系数R=0.9910>>α0.01=0.7980.高K+(65mmol/L)使膜去极化,也促进细胞儿茶酚胺的分泌,在一定范围内与Ca2+浓度呈正相关,回归方程y=1.376+5.337x,相关系数R=0.9856>>α0.01=0.7981.磷酸川芎嗪(TMP)浓度为10-4~10-7mol/L时,能抑制Ach促进的分泌作用,10-3~10-7mol/L时能抑制高K+促进的分泌作用.  相似文献   

4.
静电场对小鼠体外受精胚胎质量的影响   总被引:1,自引:0,他引:1  
利用静电场处理体外受精(IVF)小鼠原核期胚胎,并在体外进行发育培养,在此过程中通过观察IVF胚胎的发育速度及冷冻-解冻后囊胚孵化率,探讨了静电场对小鼠IVF胚胎质量的影响,实验结果显示,授精处理后84h,处理组的囊邳经(46.5%)显高于对照组(25.5%),并且到108h时,处理组的囊胚孵化率(94.4%) 于对照组(60.0%),表明静电场处理与对照组无差异,然后囊胚孵化率却高于组18.4  相似文献   

5.
研究了在聚乙烯醇(PVA)存在下,钯与钨酸钠和丁基罗丹明B(BRB)反应形成的有色离子缔合物用于痕量钯的光度法测定.最佳条件为:[H2SO4]=1.2mol·L-1,[WO2-4]=9.1×10-5mol·L-1,[BRB]=3.0×10-5mol·L-1.缔合物的最大吸收位于575nm处,表观摩尔吸光系数ε=7.98×107L·mol-1·cm-1.钯量在0~10ng/25ml范围内服从比尔定律.体系至少稳定140h,检测限(3σ)0.048μg·L-1(n=10),对0.40μg·L-1Pd(Ⅱ)测定的相对标准偏差为3.39%(n=11).缔合物的摩尔比为Pd∶BRB=1∶4.考察了50多种共存离子的影响.本法已用于炭基和铝基钯催化剂中微量钯的测定,结果满意  相似文献   

6.
复合型纳滤膜的制备及表征   总被引:12,自引:0,他引:12  
在聚砜基膜上用界面聚合法制备了两种复合型纳滤膜PA01和PA02。在0.3MPa下,PA01膜对MgSO4溶液和FeCl3溶液的脱直 96.0%和78.0%,水通量分别为8.5(L.m^-2.h^-1)和7.9(L.m^-2.h^-1);PA02膜对MgSO4ipwkiyw (2.0g.L^-1)和CaCl溶液(0.5g.L^-1)的脱盐率分别为98.0%和88.8%,水通量分别为1.0(L。m^  相似文献   

7.
基于盐酸羟胺在弱酸性介质中被KIO4 氧化产生H2 O2 , H2 O2 与Luminol 发生化学发光反应,设计了流动注射—化学发光测定盐酸羟胺的方法. 线性范围为0-03 ~1-0μg/mL; 检出限为6-7ng/mL; RSD 为3-6 % . 测定含盐酸羟胺试样, 回收率为95 % ~98 % .  相似文献   

8.
在甲苯溶剂中用“一锅反应法”,以47.6%~92.0%的收率合成了14个通式为[RO(2-CH3SC6H4O)P(O)NHR1]新的磷酰胺酯化合物,用元素分析、IR和NMR进行了表征,生物试验发现4个目标化合物[4a:R=Me,R1=H;4b:R=Me,R1=nPr,4g:R=Me,R1=iBu;4h:R=Et,R1=H]在0.025%的浓度下杀蚜虫的死亡率为90.7%~98.9%.  相似文献   

9.
克鲁维酵母y-85菊粉酶水解菊粉的研究及其中试   总被引:1,自引:0,他引:1  
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%.  相似文献   

10.
铕与4—烷基酰代吡唑啉酮配合物的合成,表征与荧光性能   总被引:5,自引:0,他引:5  
合成了一系列铕与含有不同4-酰代基的1-苯基-3甲基-吡唑啉酮-5的三元梧全物Eu(L)3.2H2O「L=1-苯基-3-甲基-4-乙酰基吡唑啉酮-5(HPMAP),1-苯基-3-甲基-4-丙酰基吡唑啉酮-5-(HPMPP),1-苯基-3-甲在-4-异丁酰基吡唑啉酮-5(HPMIBP),1-苯基-3-甲基-4-特戊酰基吡唑啉酮-5HPMPVP),1-苯基-3-甲基-4-苯甲酰基吡唑啉酮-5(HPMB  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.
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   

13.
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   

14.
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   

15.
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   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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