查询词典 acid-base

From the influnce of pH change in water on the copolymerization, the copolymerization mechanism was provided. The copolymerization mechanism is that there is hydrogen bond, which can enhance the copolymerization, between acrylic acid and crotonaldehyde at low pH and there is"Charge Transfer Complex", which gives the more crotonaldehyde in P (acrylic acid-crotonaldehyde), between acrylic acid and crotonaldehyde at high pH.

根据共聚合反应介质pH值变化对丙烯酸-丁烯醛共聚合反应的影响，提出了丙烯酸-丁烯醛共聚合反应机理，即在低pH值时，丙烯酸、丁烯醛之间可形成氢键，从而使共聚合体系具有较高的聚合反应速率和转化率；在较高pH值时，丙烯酸、丁烯醛之间则有电荷转移络合物形成，从而使共聚物中含有更多的丁烯醛链段。

Acid--aldehyde polymer tanning agent P (acrylic acid-crotonaldehyde was copolymerizaed from acrylic acid and crotonaldehyde in water and its structure was characterized by IR,〓C-NMR and DSC.

以丙烯酸、丁烯醛为共聚单体，采用水溶液共聚法，合成了含醛、酸基团高分子鞣剂----丙烯酸-丁烯醛共聚物，并利用IR光谱、〓C-NMR及DSC对其结构进行了确认和表征。

The overall activation energies of crotonic acid, undecylenic acid and oleic acid systems are 118, 122 and 134 kJ/mol, respectively.

反式丁烯酸、10-十一烯酸、油酸接枝ABS树脂的反应活化能分别为：118、122、134kJ／mol。

A DFT study of cyanic acid and isocyanic acid in the isomerization;2. The reaction path of isocyanic acid with carbon-hydrogen radicals CH, CH 2 and CH 3 have been investigated by using UMP2 method at 6-311g level.

在UMP2 / 6 311计算水平上，计算并讨论了碳氢自由基和异氰酸发生氢转移反应位能面上驻点的结构和分子结构变化，并依据UMP2的优化构型，进一步采用UQCISD方法对反应途径上的驻点进行了单点能量计算。

In some range,the addition of chitosan and titriable acidity after deacidification appears linear correlation,1 g chitosan can absorb 0.41 g titriable acidity, but chitosan only can absorb citric acid and malic acid, and it has no effect on quinic acid.

在一定范围内，壳聚糖的加入量与降酸后酒液的滴定酸呈线性关系，1 g壳聚糖可以降低0.41 g／L的滴定酸，但壳聚糖只能吸附主要有机酸中的柠檬酸和苹果酸，对奎尼酸无作用。

There are several D-amino acid itself is toxic to plants even in the relative low concentration of D-amino acids because many plants lack the normal channels of D-amino acid oxidation deamidation, Therefore, we can use D-amino acid lyase having the toxicity to plant as a safe selectable marker.

对植物来说，很多组织缺乏正常的途径对D-氨基酸进行氧化脱氨基作用，由于这种消化系统的不同导致的结果是，有几种D-氨基酸本身对植物是有毒性的，即使在D-氨基酸相对浓度较低的情况下。

Using microorganism fermentation cultivation technique, with escherichia coli strains of ASP - 311 for fermentation, with rich fumaric acid as the substrate to ferment produce l-aspartic acid, Study the result of activated carbon, and the temperature, the use of bleaching time and discoloring pH value of various conditions, aspartic acid decoloring effect, and finally: the concentration of carbon, decoloring temperature of 1.0% 60 degrees, the bleaching time for 0.5 h, pH for 6, in this condition, the result is the absorbency of decolour 3.2%, to achieve the best effect.

本文利用微生物发酵培养技术，以大肠杆菌ASP-311为发酵菌株，以富马酸为底物来发酵生产天冬氨酸；研究了发酵液中活性炭的使用量、脱色的温度、脱色的时间以及pH值等各种条件对L-天冬氨酸脱色效果的影响，最终得出：活性炭的浓度为1.0%，脱色温度为60℃，脱色时间为0.5h，pH为6，在此条件下，发酵液的吸光度为3.2%，此时的脱色效果达到最佳。

To investigate Vitamin C and lycopene contents in different parts of watermelons fruit, 7 triploid seedless watermelon cultivars, including 6 red and 1 yellow flesh, were sampled to determine their total ascorbic acid, ascorbic acid, dehydroascorbic acid and lycopene contents. TAA, AA, DHAA and lycopene contents of 3 uncut red flesh seedless watermelon cultivars were measured after storage at room temperature for 2 months.

为了研究西瓜不同部位维生素C、番茄红素含量，对6个红瓤和1个黄瓤无籽西瓜品种果实不同部位总维生素C、还原型维生素C、氧化型维生素C和番茄红素含量进行测定，并检测红瓤无籽西瓜整瓜贮藏2个月后各成分损失率。

This desaturase, when expressed in Escherichia coli, desaturated stearic acid to yield oleic acid, but did not desaturate other fatty acids in E. coli. These results indicate that PvFadA is specific to stearic acid.

通过将PvfadA基因在大肠杆菌表达系统中成功表达，PvFadA可以特异性地将C18：0脂肪酸转变成C18：1脂肪酸。

The chemistry behavior research of wollastonite indicated that the silicon-potassium fertilizer has a chemical active in organic acid.The factors affecting manurial effect of silicon-potassium fertilizer are not only soil pH and desilicification,but also content and type of organ in the soil.Wollastonite chemistry behavior indicates that silicic acid can be dissolved out from silicon-potassium fertilizer in chlorhydric acid solution if pH of solution is not smaller than 2. The drop of apparent density,increase of DBP sorptive rate and specific surface for leavings indicate that hydrated silicon oxide is polyporous,and those mineralogic feature presignify that silicon-potassium fertilizer has a role of conservation of both Moisture and Fertility and improving soil structure.After active ingredient releasing,silicon-potassium fertilizer leaves half the substance (non-active ingredient)in soil.

熟料单矿物在酸溶液中的化学行为研究表明，硅钾肥矿物在有机弱酸中的化学活性较好，影响硅钾肥肥效发挥的因素是土壤pH值和土壤的去硅化程度，还有土壤有机质的含量与种类；硅灰石在盐酸溶液中化学行为表明，在反应体系pH不小于2的情况下，硅钾肥矿物大量溶出硅酸根组分；溶解残余物表观密度降低、DBP吸着率和比表面积增加表明水合二氧化硅是以多孔形式存在，为硅钾肥具有保水保肥、改良土壤结构的提供了矿物学依据。

Fancy gold-plated dangling earrings with facetted White Opal crystals.

花式镀金悬垂耳环与facetted白欧泊水晶。

This essay chooses the study aim from biology teachers in middle school in Shi Jiazhuang which tells us that most of the middle school biology teachers in Shi Jiazhuang have the"burnout", lower successfulness, individualize.

本文选取石家庄市初中生物教师作为研究对象，运用问卷调查的方法对石家庄市初中生物教师职业倦怠的现状进行调查，调查结果发现，石家庄市初中生物教师这一群体普遍存在职业倦怠，情感枯竭程度偏高，成就感偏低，去个性化程度最为严重。