氨苄青霉素三水酸水解工艺的研究

目的 :获得氨苄青霉素三水酸水解反应需要控制的最佳 pH值 .方法 :测定两种温度下不同pH值时的氨苄青霉素三水酸的溶解度 ,作出溶解度 - pH值的关系曲线 ,并回归分析得到溶解度 - pH值的回归方程 ,经计算推测出氨苄青霉素三水酸的溶解度最大时的 pH值 .结果 :pH值为 1 .0时 ,氨苄青霉素三水酸的溶解度最大 .结论 :水解反应控制pH值为 1 .0时 ,水解反应完全 ,无结晶析出 。

基于六水铝酸三钙的双电层调控从铝酸钠溶液中短流程脱除有机物

从铝酸钠溶液中经济地脱除有机物是长期以来的研究重点。基于叶滤环节将六水铝酸三钙(TCA)作为助滤剂的工艺,提出一种短流程同时滤除杂质颗粒和吸附脱除有机物的新方法。在浓缩铝酸钠溶液中制备结晶度低、TCA含量高、表面能高、晶格畸变大的超细TCA样品。同时,TCA样品在碱性溶液中的Zeta电位线性依赖于TCA含量,揭示二元混合物Zeta电位的可加性。描述在碱性溶液中TCA二元混合物双电层的演化规律。此外,超细TCA样品对长烷基链及高相对分子质量有机物具有较高的吸附容量,对腐殖酸钠的吸附容量可达69.69mg/g(以有机碳计),而高温溶出过程会显著降低TCA的吸附容量。

六水铝酸三钙(C_3AH_6)与CO_2反应的研究

为了阐述C3AH6与CO2反应的机理,应用X线衍射和pH酸度分析等方法,对C3AH6与CO2反应的影响因素、反应过程及其产物进行研究;结合C3AH6和CO2在水体系中反应时溶液pH的变化规律,提出C3AH6与CO2在水中的反应机理。研究结果表明:在空气和乙醇介质中,C3AH6与CO2的反应十分缓慢;但以水作为反应介质时,C3AH6与CO2的反应显著加快,其产物为CaCO3,Al(OH)3和H2O,且随着反应温度和CO2体积分数的增加以及反应时间的延长,反应率增加;在温度为75℃,CO2体积分数为100%的条件下反应80 min,反应率可达到97.76%;C3AH6与CO2在反应初期主要取决于C3AH6的水化作用,而在反应后期主要取决于H2CO3的电离作用;在水介质中,通入CO2回收C3AH6中的氧化铝是可行的。

水泥矿物体系诱导期的水化进程及机理的研究进展

硅酸三钙(C_(3)S)体系及铝酸三钙-二水石膏(C_(3)A-CSH_(2))体系作为主要的硅酸盐水泥矿物相,对水泥新拌阶段及后续性能发展阶段有尤为重要的影响。而水泥在诱导期内的水化进程很大程度上决定了其后续性能的发展。鉴于此,本文回顾了水泥水化的热力学原理,重点综述了目前关于水泥水化诱导期开始及结束时作为主要矿物体系的C_(3)S体系和C_(3)A-CSH_(2)体系的水化进程及机理的研究进展,以及不同矿物体系诱导期的成因。但限于目前的研究手段,对于水泥水化诱导期内各种矿物体系的相互作用和相互影响仍未完全厘清,还需要进一步的探索。

对阿洛西林酸工艺的研究

阿洛西林是一种杀菌效果极强的广普抗生素,对绿脓杆菌、变形杆菌等效果十分明显。近年来,诸多文献偏向于对阿洛西林的药理药效的研究,对它的生产工艺研究较少,作者通过对传统阿洛西林酸工艺的优化操作,实现了成本低、收率高、易于工厂化生产的目的。

叶滤机滤渣中氧化铝高温溶出研究及工业应用

工业合成的六水铝酸三钙(TCA)及叶滤机滤饼(由TCA及赤泥组成)中的主要成分是氧化铝和氧化钙。在配料时,TCA或叶滤机滤饼中的CaO量占总CaO需求量的比例(μ)不超过45%时,3CaO·Al_(2)O_(3)·6H_(2)O分解产生的氧化钙促进矿石中氧化铝的溶出。但当μ过大时,氧化铝溶出率降低,以一水硬铝石的物相存在于赤泥中,且氧化钙的利用率较低,以氢氧化钙的物相存在。在工业生产中,将叶滤机滤饼回收后,送至高温溶出系统,在充分利用氧化钙的同时,实现氧化铝的回收,减少赤泥的外排量。

关于特戊酰氯检测方法的探索

对特戊酰氯开展了色级和澄清度 2个项目的检测 ,明确了检测标准 :色级为小于 15 #标准的铂 -钴色级 ;澄清度为小于 0 .5 #标准浊度液 .结果表明 ,这 2个检测项目适用于生产 .

Thermodynamics study on leaching process of gibbsitic bauxite by hydrochloric acid

For the low-grade gibbsitic bauxite,the leaching rate of alumina is very low during the Bayer process.The acid leaching method is attracting more attention,and the hydrochloric acid leaching was developed rapidly.The mineral composition and chemical composition were investigated by X-ray diffraction analysis and semi-quantitative analysis.The thermodynamics of leaching process was analyzed.The results show that the major minerals in the bauxite are gibbsite,secondly goethite and quartz,anatase and so on.The acid leaching reactions of the bauxite would be thermodynamically easy and completed.Under the conditions that ore granularity is less than-55 μm,the L/S ratio is 100：7,and the leaching temperature is 373-383 K,the leaching time is 120 min and the concentration of HCl is 10%,both the leaching rates of Al and Fe are over 95%.The main composition of leaching slag is SiO2 which is easy for comprehensive utilization.

Thermodynamic model for equilibrium solubility of gibbsite in concentrated NaOH solutions

The thermodynamic properties of the most important NaOH-NaAI（OH）4-H20 system in Bayer process for alumina production were investigated. A theoretical model for calculating the equilibrium constant of gibbsite dissolved in sodium hydroxide solution was proposed. New Pitzer model parameters and mixing parameters for the system NaOH-NaAI（OH）4-H20 were yielded and tested in the temperature range of 298.15-373.15 K. The results show that the proposed model for calculating the equilibrium constant of gibbsite dissolution is applicable and accurate. The obtained Pitzer model parameters of β（0）（NaAl（OH）4）、β（1）（NaAl（OH）4）和CΦ（NaAl（OH）4）,Al（OH）4 for NaAI（OH）4, the binary mixing parameter of θ（OH-Al（OH）4-） with OH-, and the ternary mixing parameter of ψ（Na＋OH-Al（OH）4-） for AI（OH）4- with OH- and Na＋ are temperature-dependent. The prediction of the equilibrium solubility of gibbsite dissolved in sodium hydroxide solution was feasible in the temperature range of 298.15-373.15 K.

Crystallization of gibbsite from synthetic chromate leaching solution in sub-molten salt process

For the clean and economical production of chromium compounds, it is crucial to remove aluminates from chromate alkali solutions and utilize aluminum-containing compounds. In this work, carbonization was used to remove aluminates from a synthetic chromate leaching solution containing a high K2O/Al2O3 mole ratio. The influence of reaction temperature, carbonization time, flow rate of carbon dioxide, and seed ratio on the precipitation of Al was investigated. The optimal output was obtained under the following experimental conditions： a reaction temperature of 50 °C, a carbonization time of 100 min, a carbon dioxide flow rate of 0.1 L/min, and a seed ratio of 1.0. Gibbsite was obtained following carbonization. The structure and morphology of the gibbsite were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and laser particle size analyzer. The particle size distribution and morphology of the gibbsite were significantly influenced by the experimental conditions. The gibbsite had a mean particle size （d50） of 16.72μm. The thermal decomposition of the gibbsite was analyzed by XRD and the decomposition path was determined. The obtained coarseα-Al2O3 precipitate, which contains 0.08% Cr2O3 and 0.10% K2O, was suitable for subsequent utilization.

合成阿洛西林的工艺优选

目的:研究和优化阿洛西林的合成工艺。方法:通过氨苄三水酸和1-氯甲酰基-2-咪唑烷酮进行缩合反应得到阿洛西林。实验研究了反应物摩尔配比、反应温度、溶液pH值等对阿洛西林收率的影响,得出了优化工艺条件。结果:收率达91.8%,产品经高压液相分析,纯度达92.0%。结论:在此优化条件下制备的阿洛西林收率高,质量好,易于实现工业化。

Chylous ascites secondary to hyperlipidemic pancreatitis with normal serum amylase and lipase

A 54-year old man with a family history of hyperlipidemia was admitted with a 12 h history of severe generalized abdominal pain associated with nausea, vomiting and abdominal distension. Examination of the abdomen revealed tenderness in the periumblical area with shifting dullness. Serum pancreatic amylase was 29 IU/L and lipase 44 IU/L, triglyceride 36.28 mmol/L. Ultrasound showed ascites. CT of the abdomen with contrast showed inflammatory changes surrounding the pancreas consistent with acute pancreatitis. Ultrasound (US) guided abdomen paracentesis yielded a milky fluid with high triglyceride content consistent with chylous ascites. The patient was kept fasting and intravenous fluid hydration was provided. Meperidine was administered for pain relief. On the following days the patient’s condition improved and he was gradually restarted on a low-fat diet, and fat lowering agent (gemfibrozil) was begun, 600 mg twice a day. On d 14, abdomen US was repeated and showed fluid free peritoneal cavity. The patient was discharged after 18 d of hospitalization with 600 mg gemfibrozil twice a day. At the time of discharge, the fasting triglyceride was 4.2 mmol/L. After four weeks the patient was seen in the clinic, he was well.

Extraction of germanium(IV) from acid leaching solution with mixtures of P204 and TBP

Solvent extraction experiments were conducted from acidic solutions containing germanium（IV） and other metal ions, such as Ga3＋, Fe3＋, Zn2＋ and Fe2＋ in hydrometallurgical process of zinc. The purpose of this work was to enhance the efficiency of the extraction and stripping processes and the selectivity of germanium and other metals, while making the method as simple as possible. Germanium was recovered from sulfuric acid, using di-（2-ethylhexyl） phosphoric acid （P2O4） as an extractant, tributyl phosphate （TBP） as modifier diluted in sulfonate kerosene and stripped by NaOH aqueous solution. Extraction studies were carried out under different acid concentrations and solvent concentrations, and optimized conditions were determined. The numbers of stages required for extraction and stripping of metal ions were determined from the McCabe-Thiele plot. The results show that the extracting and stripping efficiencies are 94.3% and 100%, respectively, through two-stage extraction and two-stage strip. Moreover, the synergistic effect of TBP on the system P2O4/kerosense/Ge4＋ is revealed with respect to the extraction of germanium.

Effect of CaCO_3 on hydration characteristics of C_3A

Hydration products and morphology characteristics of C3A （tricalcium aluminate）-CaCO3-H2O system were studied by means of XRD, DSC, FTIR spectrum analysis and SEM. The results indicate that, the new phases, i.e., C3A·0.5CaCO3·0.5Ca（OH）2·11.5H2O and C3A·CaCO3·11H2O are found in this system due to the activity of CaC03; the formation of C4AH13 and C2AH8 is prohibited and the generation of C3AH6 is delayed in the early hydration process. C3A·0.5CaCO3·0.5Ca（OH）2.11.5HEO is not stable and will be totally transferred within 24 h; C3A·CaCO3.11H2O exists stably once formation, and its flake-like crystalline phases in the early hydration transform to long rod shape, and to finally fine-needle at 28 d.

Effects of Salinity Fluctuation Frequency on the Osmolarity,Na^+-K^+-ATPase Activity and HSP70 Expression in Juvenile Chinese Shrimp,Fenneropenaeus chinensis

Experiments were conducted to examine the effects of salinity fluctuation frequency on the osmolarity, Na^＋-K^＋-ATPase activity and HSP70 of Chinese shrimp Fenneropenaeus chinensis ruth initial wet body weight of 1.460g±0.091 g. The salinity in the control group （DO） was 28 throughout the experiment, whereas treatments D2, D4, D6 and D8 were subjected to different salinity fluctuation frequencies of 2, 4, 6 and 8d, respectively. The salinity in treatments D2, D4, D6 and D8 was kept at 28 for 2, 4, 6 and 8d, respectively, decreased abruptly to salinity 24, lasted for another 2 d, and then was raised to its initial value 28. This was a complete salinity fluctuation cycle that afterwards repeated itself. After 32 days, the osmolarity in treatments D2, D4, D6 and D8 was significantly lower than that in treatment DO （P〈0.05）. There were significant differences in both muscle and eyestalks HSP70 expression among groups. The HSP70 expressions in muscle and eyestalks in group D4 were 61.4% and 57.0% higher, respectively, than that in the control group DO （P〈0.05）. There were, however, no significant differences in gill or hepatopancreas Na^＋-K^＋-ATPase activity between the treatments and the control.

Hydrothermal Synthesis and Crystal Structure of Trioxomolybdate: NaH_3OMo_3O_(10)

The hydrothermal reaction of Na2MoO4?2H2O, SmCl3 in acidified H2O/CH3CN solution gives rise to the title compound as colorless needle crystals, which was characterized by elemental analysis, IR and X-ray single-crystal diffraction techniques. Crystallographic data: Orthorhombic, Pnma, H3Mo3NaO11, Mr = 489.83, a = 8.411（2）, b = 7.566（2）, c = 14.359（3） ?, V = 913.8（3） ? 3, Z = 4, Dc = 3.560 g·cm-3, ( = 4.148 mm-1, F（000） = 912, the final R = 0.0649 and wR = 0.1569 for 1885 observed reflections with I ≥ 2σ（I）. The title compound consists of infinite chains built up by distorted {MoO6} octahedra via edge sharing, which are further connected into a three-dimensional framework by sodium ions and protoned water molecules.

Physiological levels of ATP negatively regulate proteasome function

Intracellular protein degradation by the ubiquitin-proteasome system is ATP dependent, and the optimal ATP concentration to activate proteasome function in vitro is -100 μM. IntraceUular ATP levels are generally in the low millimolar range, but ATP at a level within this range was shown to inhibit proteasome peptidase activities in vitro. Here, we report new evidence that supports a hypothesis that intracellular ATP at the physiological levels bidirectionally regulates 26S proteasome proteolytic function in the cell. First, we confirmed that ATP exerted bidirectional regulation on the 26S proteasome in vitro, with the optimal ATP concentration （between 50 and 100μM） stimulating proteasome chymotrypsin-like activities. Second, we found that manipulating intracellular ATP levels also led to bidirectional changes in the levels of proteasome-specific protein substrates in cultured cells. Finally, measures to increase intracellular ATP enhanced, while decreasing intraceHular ATP attenuated the ability of proteasome inhibition to induce cell death. These data strongly suggest that endogenous ATP within the physiological concentration range can exert a negative impact on proteasome activities, allowing the cell to rapidly upregulate proteasome activity on ATP reduction under stress conditions.

Dissolving behavior of ammonium paratungstate in(NH_4)_2CO_3-NH_3?H_2O-H_2O system

The effects of temperature, ammonia concentration and ammonium carbonate concentration on the dissolving behavior of ammonium paratungstate were studied in（NH4）2CO3-NH3？H2O-H2O system. The results show that rising temperature, prolonging duration, increasing ammonia concentration and decreasing ammonium carbonate concentration favor dissolving of ammonium paratungstate at temperature below 90 ℃, while the WO3 concentration decreases after a certain time at temperature above 100 ℃. Furthermore, the undissolved tungsten exists in the form of either APT·4 H2O below 90 ℃ or pyrochlore-type tungsten trioxide above 100℃. In dissolving process, the ammonium paratungstate dissolves into paratungstate ions followed by partially converting to tungstate ion, resulting in the coexistence of the both ions. This study may provide a new idea to exploit a novel technique for manufacturing ammonium paratungstate and pyrochlore-type tungsten trioxide.

Intensifying gibbsite precipitation from sodium aluminate solution by adding a mixed seed

Gibbsite precipitation from sodium aluminate solution was intensified by adding mixed industrial and self-prepared active seeds,and its mechanism was researched preliminarily.The interfacial properties of seed/aluminate solution were determined for separate industrial and active seed.Contact angles of seed/aluminate solution and the specific surface area of seeds were respectively measured by sessile drop and BET method,and the morphology and particle size of precipitates were recorded by SEM and laser diffraction.The results show that,compared with the industrial seed,the active seed has a better wettability,lower interfacial tension,and larger specific surface area,being conducive to enhancing gibbsite precipitation from sodium aluminate solution.SEM analysis of the precipitates indicates that the embedment and accumulation/agglomeration of extremely fine particles on the surface of coarse industrial seed can effectively control the content of fine particles in the precipitation product.With extra 3.1–4.6 g/L active seed,the gibbsite precipitation ratio was increased by 3.23%–3.92%.Moreover,the mass percentage of particles<45μm in precipitation product has even a slight decrease compared with that for the traditional precipitation product or of the industrial seed itself.The result presented is favorable to developing an intensified gibbsite precipitation process for commercial alumina manufacture.

Liquid-Liquid Equilibria of the Water-Ethanol-Dimethyl Succinate Ternary System

Liquid-liquid equilibrium (LLE) data for the ternary systemwater-ethanol-dimethyl succinate have been determined experimentallyat temperatures ranging from 298.15 to 318.15 K at 5 K intervals.Complete phase diagrams were obtained by determining solubility andthe tie-line data. Tie-line compositions were correlated byOthmer-Tobias method. The universal quasichemical functional groupactivity coefficient (UNIFAC) and modified UNIFAC methods were usedto predict the phase equilibrium in the system using the interactionparameters deter- Mined from experimental data between groups CH_3,CH_2, OH, CH_3 COO and H_2O.