乳酸

The D,L-lactide was prepared from D,L-lactic acid with the stannous octoate as the catalyst and the factors affecting the preparation were discussed.

以乳酸为单体，在催化剂存在下乳酸先缩聚后解聚制备了D，L-丙交酯。

The capacity of repairing bone defect of biodegradable PLA and the efficacy of PLA as a carrier for bone morphogenetic protein are determined with detecting the osteogenetic process.

18只日本大耳白兔，随机分组，在双侧下颌骨体部形成 12 m m× 6 mm的缺损，分别植入聚乳酸-人骨形成蛋白- 2复合物(PL A- rh BMP- 2 )、单纯聚乳酸，于 2、4、8、12周分批处死。

Star-shaped polyL-lactic acid(SPLLA was synthesized using L-lactic acid and pentaerythritol as starting material by means of polycondensation .

以L-乳酸和季戊四醇为原料，采用缩聚法合成了星形结构的聚L-乳酸。

M treatment materials, and also tartaric acid and no maleic acid detected in G. v treatment materials. Inoculation also increased the content of organic acid secretion (increased by 19.80～56.87 mg/kg) of trifoliate root, and the application of AlPO4 greatly increased organic acid content (increased by 20.06～21.84 mg/kg); uninoculated plant root secreted a bit of organic acid; Mycorrhizal poncirus trifoliata seedlings excreted malic acid (42.87%), citric acid (39.22%) and oxalic acid (12.06%).

接种AM真菌的根系分泌的有机酸种类与对照有所不同，未接种处理枳分泌的有机酸有草酸、苹果酸、乳酸、乙酸、顺丁烯二酸和柠檬酸等6种，而接种G.m的则检测到草酸、酒石酸、苹果酸、乳酸、乙酸、柠檬酸、丁二酸等7种，G.v处理的检测到酒石酸，接种处理均未检测到顺丁烯二酸；接种丛枝菌根真菌增加了枳根系分泌有机酸的量比未接种处理增加19.80～56.87 mg/kg，且施用AlPO4后有机酸含量显著增加(增加20.06～21.84 mg/kg；未接种植株根系仅分泌少量有机酸；接种植株根系分泌的有机酸以苹果酸(42.87%)、柠檬酸(39.22%)和草酸(12.06%)为主。

4Mm harvested in preculture, is the best. In this form, Rhizopus oryzae R1021 produced most L-lactic acid (76. 62g/L), the pellet size in production medium in flask and fermentor are 1. 9mm and 2. 6mm, respectively, and its L-lactic acid productivity reached or exceeded that of the immobilized cell with polyurethane foam. The produced L-lactic acid and the yield of L-lactic acid based on the total glucose and the productivity are above 74g/L and 74% and 2. 69g/L h, respectively, in 7 batches repetitive fermentation in fermentor, and the size of pellets remain 2. 6mm～3. 4mm.

摇瓶种子培养获得的菌球直径为1.4mm时，这种大小的菌球产酸最高，为76.62g/L；研究表明以直径1.4mm的菌球为种子，在摇瓶发酵和发酵罐发酵中菌球大小分别为1.9mm和2.6mm；这种菌球的产酸水平最高，可以达到甚至超过聚氨酯泡沫载体固定化细胞发酵乳酸的水平；在反复7批次发酵罐发酵过程中，菌球的大小始终保持在2.6mm～3.4mm之间，L-乳酸产量、得率和生产能力分别保持在74g/L、74％和2.69g/L h以上。

The method comprises heating up the lactic acid solution to gasify at 150-200 degree C, mixing the obtained mixed vapour of lactic acid and water with the carrier gas, entering into gas-solid catalytic reactor to get the reaction product gas by the action of a modified Y zeolite molecular sieve catalytic agent and dewatering after heating up the mixed gas to 200-450 degree C, obtaining the propenoic acid solution through gas-liquid dissociation after cooling the reaction product gas, obtaining coarse propenoic acid products form the propenoic acid solution by gas stripping, azeotropic distillation, extraction and rectification in turns.

其特征在于将乳酸水溶液加热至150～200℃气化得到的乳酸-水混合蒸气与载气混合，将混合后的气体继续加热到200～450℃后进入气-固相催化反应器中经改性Y沸石分子筛催化剂作用脱水得反应产物气体，反应产物气体冷却后经气液分离得到丙烯酸溶液，丙烯酸溶液再依次经过气提、共沸蒸馏或萃取、精馏得到粗丙烯酸产品。

Moreover,the average rate can rise and the hardness will reach the maximum along with the increasing concentration of propionic acid.The concentration ratio of ...

可见，乳酸与丙酸的体系中不同的镍磷摩尔浓度比及乳酸与丙酸摩尔浓度比对镀层的性质有很大影响。

Refreshing agent contained 0.25% chitosan, 1% sodium lactate, 1% lactic acid and 250 mgkg^(-1) Nisin and MAP were used to determine microbial flora counts, psychrophilic bacteria counts, TBARS, carbonyl content and a* value of chilled meat to evaluate the effect of refreshing agent and MAP on chilled meat.

将复合保鲜剂（0.25%壳聚糖＋1%乳酸钠＋1%乳酸＋250mgkg^(-1) Nisin）与气调包装共同使用，测定冷却肉的细菌总数、嗜冷菌数、TBARS值（硫代巴比妥酸值，Thiobarbituric Acid-reacitive Substances）、羰基含量以及红度值，来综合评价保鲜剂与气调包装复合后对冷却肉的影响。

Hydrothermal reactions makes water a Bronsted base-acid and act as an effective catalyst and the metal ions represent Lewis base character. The conversion process occurs in a very complex network of parallel, consecutive and equilibrium reactions, and the last step being the catalyzed Cannizzaro-type reaction of pyruvaldehyde to lactic acid.

nsted酸碱并具有一定的催化作用，金属离子在水热催化降解丙酮醛生成乳酸中表现出Lewis碱的特性，能与丙酮醛生成金属复合物，最终生成乳酸，此反应过程符合Cannizzaro反应特性。

And the PLA/Chitosan/ACP barriers with additional 2 wt% chitosan still maintain 56.58 % antibacterial ability after eightieth day. The different composition of PLA/Chitosan/ACP composites was prepared by water washing solidification from NMP/water/lactic acid consolvent. After storing at room temperature for 48 hours and taking it out to obtain a shapable composites. To investigate the influence of ratio of composition with the shapable property of composites, it was analyzed by Rheometer, TGA, AFM, XRD. The result of the different APC content had different effect both water content and yield stress of composite materials. The yield stress decreased with ACP content while increases. It was derived that ions, released from ACP interact with amide groups of chitosan to form water-absorbing ionic clusters through chelating or electrostatic attraction.

另外，以聚乳酸/几丁聚醣作为基材并添加不同比例的非晶型磷酸钙，经过水洗固化后可得白色片状沉淀物，於室温下静置48小时后，复合材之体积呈现膨胀且具有可塑形之特性，以热重分析仪与流变仪分析样品之含水率与屈伏应力，结果显示不同ACP含量对复合材含水率与屈伏应力具有消长变化，而PLA/Chitosan/ACP之可塑程度与其所吸收之水份多寡有关，推测可能机制为ACP磷酸钙盐解离后之金属离子与几丁聚醣之胺基透过螯合作用或静电吸引之交互作用，形成具吸水性之离子团簇分散於疏水性之聚乳酸基材中。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。