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1.
乙酰水杨酸合成方法改进   总被引:3,自引:0,他引:3  
首次用路易斯酸作为催化剂, 以水杨酸和乙酸酐为原料合成乙酰水杨酸.当水杨酸用量为 2.0g,乙酸酐用量为 5.0mL,NiSO4用量为0.4g时,反应体系维持80℃反应30min,乙酰水杨酸收率可达85.2%.  相似文献   

2.
红假单胞菌Rhodopseudomonas rutila自养固定CO2特性研究   总被引:1,自引:0,他引:1  
采用分批培养,初始气相CO2体积分数为10%,血色红假单胞菌Rhodopseudomonas rutila固定CO2的最佳培养条件是:NH4Cl 0.5 g*L-1, K2HPO4*3H2O 5 g*L-1, MgSO4*7H2O 0.2 g*L-1,生长因子10 mL*L-1 , 微量元素 10 mL* L-1 ,pH 8.5,转速100~150 r/min,不添加NaCl.在此条件下培养5 d,CO2固定率能够达到56%.培养24 h后,其固定CO2主要是通过卡尔文循环,该循环关键酶1,5-二磷酸核酮糖羧化酶(Rubisco)的活性不断提高,在菌体生长到对数中期时达到最大.  相似文献   

3.
王壹龙 《甘肃科技》2014,(13):12-16
重点用5%壬基酚-二氯乙烷标准溶液确定了乙酸酐-吡啶乙酰化法测定壬基酚含量的样品称样量、酰化时间、水解时间,从而确定了最佳实验条件:乙酸酐用量0.50mL时,样品称样量不大于0.2g(相当于壬基酚质量),酰化时间不少于3h,水解时间不少于30min,在最佳实验条件下,该方法回收率98.86%~99.05%,相对标准偏差RSD≤0.03%。  相似文献   

4.
石英矿物纯化的研究   总被引:3,自引:0,他引:3  
研究了高温 HCl(g)法和 HCl、HF酸浸法对去除石英矿物中杂质元素的作用效果 ,以及高温 HCl(g)法反应时间同杂质含量的关系 ,结果表明 ,高温 HCl(g)法作用强度明显大于 HCl酸浸法 ,并且当反应时间达到 90分钟时 ,高温 HCl(g)法对杂质的作用趋向极限。实验还表明 ,不论是高温 HCl(g)法还是 HCl酸浸法 ,对 Al、B元素的作用均表现出低化学活性 ,说明 Al、B是石英矿物中最难去除的杂质  相似文献   

5.
采用了自制的新型非水溶性聚乙烯醇(PVA)衍生物作为吸附剂,对水中Fe3+进行吸附除去,并用0.2 mol*L-1 HCl将其洗脱,既可回收Fe3+,又使此高聚物吸附能力获得了再生.结果表明,实验条件最佳pH为3.27~3.92;吸附时吸附剂最佳用量为1.188 5 g;吸附时间为75 min;回收实验中,当吸附剂质量达1.482 3 g时,吸附Fe3+回收效果最佳达到98 %.此高聚物在吸附及再生能力方面均取得了较为满意的结果.  相似文献   

6.
石英矿物纯化的研究   总被引:4,自引:0,他引:4  
研究了高温HCl(g)法和HCl,HF酸浸法对去除石英矿物中杂质元素的作用效果,以及高温HCl(g)法反应时间同杂质含量的关系。结果表明,高温HCl(g)法作用强度明显大于HCl酸浸法,并且当反应时间达到90分钟时,高温HCl(g)法对杂质的作用趋向极限。实验还表明,不论是高温HCl(g)法还是HCl酸浸法,对Al,B元素的作用均表现出低化学活性,说明Al,B是石英矿物中最难去除的杂质。  相似文献   

7.
火焰原子吸收光谱法测定水样中铜离子   总被引:2,自引:1,他引:1  
研究了流动注射氧化碳纳米管在线固相吸附预富集火焰原子吸收光度法测定水溶液中痕量铜。对实验条件进行了优化。在pH6.0时,吸附预富集60s的条件下样品流速为3.2mL·min-1,然后用流速为2.8mL·min-1的1.0mol·L-1的HCl洗脱,直接送入FAAS进行检测,得到铜的吸收信号的增感因子为17,检出限(3σ)为0.78μg·L-1,对5μg·L-1的Cu标准溶液11次平行测定,精密度(RSD)为3.8%。此法已成功应用于水样的分析。  相似文献   

8.
设计了一种用于流通体系电解池,将恒电流电解法与流动注射技术相结合,在线定量产生不稳定化学发光试剂Mn(III),使其浓度和反应进度得以在线控制,并基于Mn(III)能够氧化利血平产生化学发光,建立了电生Mn(III)化学发光法测定利血平的新方法,其线性范围为1.0*10^-7-1.0*10^-4g/mL,相对标准偏差为2.3%(c=5.0*10^-6g/mL,n=11),该方法可用于针剂中利血平含量的测定。  相似文献   

9.
改性粉煤灰处理造纸废水的研究   总被引:16,自引:1,他引:16  
用HCl、H2SO4等试剂对粉煤灰进行改性,制得粉煤灰吸附混凝剂,研究了改性粉煤灰对造纸废水处理的一般规律·结果表明,以φ(HCl)∶φ(H2SO4)=1∶3的混合液为改性剂改性的粉煤灰对造纸废水具有良好的吸附混凝性能,在废水COD浓度为800~1500mg/L,改性粉煤灰用量为25g/100mL,粉煤灰的粒径范围为74~83μm,pH为9~12的实验条件下,COD、BOD、悬浮物、色度的去除率分别可达81 5%、80 7%、99 1%、94%·  相似文献   

10.
采用化学法和酶法相结合的合成策略,合成具有高生物活性肽RGD.先采用DCC合成GD二肽(HCl*Gly-Asp(oBzl)2),然后利用胰蛋白酶(trypsin)催化合成 RGD三肽(Z-Arg-Gly Asp(oBzl)2).实验结果表明,其中GD二肽在反应10 h,两底物G与D的摩尔比为1.5∶1时,得率为77.7%;RGD三肽在微水-1,4-丁二醇反应体系中得率为41.9%.  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 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   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
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   

16.
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   

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.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

19.
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   

20.
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