Wetting front migration model of ion-adsorption rare earth during the multi-hole unsaturated liquid injection

In the process of ion-adsorption rare earth ore leaching,the migration characteristics of the wetting front in multi-hole injection holes and the influence of wetting front intersection effect on the migration distance of wetting fronts are still unclear.Besides,wetting front migration distance and leaching time are usually required to optimize the leaching process.In this study,wetting front migration tests of ionadsorption rare earth ores during the multi-hole fluid injection(the spacing between injection holes was 10 cm,12 cm and 14 cm)and single-hole fluid injection were completed under the constant water head height.At the pre-intersection stage,the wetting front migration laws of ion-adsorption rare earth ores during the multi-hole fluid injection and single-hole fluid injection were identical.At the postintersection stage,the intersection accelerated the wetting front migration.By using the Darcy’s law,the intersection effect of wetting fronts during the multi-hole liquid injection was transformed into the water head height directly above the intersection.Finally,based on the Green-Ampt model,a wetting front migration model of ion-adsorption rare earth ores during the multi-hole unsaturated liquid injection was established.Error analysis results showed that the proposed model can accurately simulate the infiltration process under experimental conditions.The research results enrich the infiltration law and theory of ion-adsorption rare earth ores during the multi-hole liquid injection,and this study provides a scientific basis for optimizing the liquid injection well pattern parameters of ion-adsorption rare earth in situ leaching in the future.

FLOW DYNAMICS OF GAS-SOLID FLUIDIZED BEDS WITH EVAPORATIVE LIQUID INJECTION

The electrical capacitance tomography （ECT） with neural network multi-criteria image reconstruction technique （NN-MOIRT） is developed for real time imaging of a gas-solid fluidized bed using FCC particles with evaporative liquid injection. Some aspects of the fundamental characteristics of the gas-solid flow with evaporative liquid injection including real time and time averaged cross-sectional solids concentration distributions, the cross-sectional solids concentration fluctuations and the quasi-3D flow structures are studied. A two-region model and a direct image calculation are proposed to describe the dynamic behavior in both the bubble/void phase and the emulsion phase based on the tomographic images. Comparisons are made between the fundamental behaviors of the gas-solid flows with and without evaporative liquid injection for various gas velocities ranging from bubbling to turbulent fluidization regimes. Significant differences are observed in the behavior of the gas-solid flow with the evaporative liquid injection compared to the fluidized bed without liquid injection.

Experimental analysis of volatile liquid injection into a fluidized bed

Experiments were conducted on a lab-scale fluidized bed to study the distribution of liquid ethanol injected into fluidized catalyst particles. Electrical capacitance measurements were used to study the liquid distribution inside the bed, and a new method was developed to determine the liquid content inside fluidized beds of fluid catalytic cracking particles. The results shed light on the complex liquid injection region and reveal the strong effect of superficial gas velocity on liquid distribution inside the fluidized bed, which is also affected by the imbibition of liquid inside particle pores. Particle internal porosity was found to play a major role when the changing mass of liquid in the bed was monitored. The results also showed that the duration of liquid injection affected liquid-solid contact inside the bed and that liouid-solid mixin~ was not homogeneous durin~ the limited liouid injection time.

Three-dimensional simulation of liquid injection,film formation and transport,in fluidized beds

Liquid injection, and film formation and transport in dense-phase gas-solids fluidized beds are numerically simulated in three dimensions using a collisional exchange model that is based on the mechanism that collisions cause transfer of liquid mass, momentum, and energy between particles. In the model, each of the particles is represented by a solid core and a liquid film surrounding the core. The model is incorporated in the framework of the commercial code Barracuda developed by CPFD Software. The commercial software is an advanced CFD-based computational tool where the particles are treated as discrete entities, calculated by the MP-PIC method, and tracked using the Lagrangian method. Details of the collisional liquid transfer model have been previously presented in O＇Rourke, Zhao, and Snider （2009）; this paper presents new capabilities and proof-testing of the collision model and a new method to better quantify the penetration length. Example calculations of a fluidized bed without liquid injection show the expected effect of collisions on the reduction of granular temperature （fluctuational kinetic energy） of the bed. When applied to liquid injection into a dense-phase fluidized bed under different conditions, the model predicts liquid penetration lengths comparable to the experiments. In addition, the simulation reveals for the first time the dynamic mixing of the liquid droplets with the bed particles and the transient distribution of the droplets inside the bed.

Fingerprint analysis of placenta polypeptide injection by high performance liquid chromatography

Objective: To develop the representative fingerprint for the quality control of placenta polypeptide injection. Methods: The chromatographic separation was performed using a Phenomenex Gemini C18 column (250 mm 4.6 mm, 5 mm) maintained at 30 1C. 0.1% aqueous trifiuoroacetic acid (Solvent A) and acetonitrile contained 0.1% TFA (Solvent B) were used as mobile phase with a gradient elution. Detection wavelength was 280 nm with the sample injection volume of 50 mL; the fiow rate was 1.0 mL/min. The fingerprints of different samples were investigated by similarity analysis. Results: Nine peaks were identified as the characteristic common peaks. The similarities of the fingerprints of the 10 batches of samples were above 0.992. Conclusion: This method showed high precision and good repeatability, and provided the basis for the improvement of the quality control of placenta polypeptide injection.

Study on the Flow Injection Micro-Column Pre-Separation System Coupled With High Performance Liquid Chromatography for the Determination of Ecdysterone in Traditional Chinese Medicine

A flow injection (FI) micro-column system coupled with high performance liquid chromatography (HPLC) was proposed for the pre-separation and determination of active organic component (ecdysterone) in traditional Chinese medicine, Loulu. The factors influencing separation performance were investigated and optimized. Under the optimal conditions, the contents of ecdysterone in Loulu were determined by HPLC system using MeOH-H_2O (40: 60,V/V) as the mobile phase at a flow rate of 1. 0 mL/min. The calibration curve was linear in the range of 0. 5~ 100 mg/L of ecdysterone concentrations. The detection limit of the analyte was 0. 11mol/L(3) with a precision of 0. 38% RSD (n=7 f c= 10. 0 mg/L). The average recovery of the method was 98. 7%. The proposed method has been applied to determine ecdysterone in practical samples, and the determined values by both external standard method and standard addition method were in good agreement. Compared to the traditional solid extraction method, the system proposed has the advantages of simple procedure, good reproducibility, minimum volume requirement, reduction of matrix interference and low contamination risk.

A High-Performance Liquid Chromatography Method for the Simultaneous Determination of Five Index Components in Danhong Injection

The purpose of this study was to establish a high-performance liquid chromatography (HPLC) method for the simultaneous determination of sodium danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B, and 4-coumaric acid in Danhong injection. The chromatographic method employed was as follows: the column was a Welch Ultimate XB-C18 column (250 mm × 4.6 mm, 10 μm), the mobile phase was a gradient elution of 0.4% formic acid aqueous solution (A) and acetonitrile (B), the detection wavelengths were 280 nm for sodium danshensu, protocatechuic aldehyde, and salvianolic acid B and 326 nm for 4-coumaric acid and rosmarinic acid, the sample volume was 10 μL, the flow rate was 1.0 mL/min, and the column temperature was 35°C. This method can realize the separation and determination of sodium danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B, and 4-coumaric acid within 50 minutes. The linear relationships of the five peak areas and their concentrations are good (R2> 0.9997). The precision RSD values are all less than 1.0%. The reproducibility RSD values are all less than 1.3%. The stability RSD values are all less than 2.2%. The recovery values ranged from 92.4% to 99.4%. This method is simple, accurate, and reproducible. It can be used for the determination of sodium danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B, and 4-coumaric acid in Danhong injection.

Flow Injection Analysis of Hydrazine in the Aqueous Streams of Purex Process by Liquid Chromatography System Coupled with UV-Visible Detector

Present study describes the development of a rapid, sensitive and selective flow injection analysis of hydrazine in the aqueous streams of purex process by liquid chromatography system coupled with UV-Visible detector. The method is based on the formation of yellow coloured azine complex by reaction of hydrazine with para-dimethy laminobenzaldehyde (pDMAB). The formed yellow coloured complex is stable in acidic medium and has a maximum absorption at 460 nm. The presence of uranium in hydrazine solution is not interfering in the analysis. Under optimum condition, the absorption intensity linearly increased with the concentration of hydrazine in the range from 0.05-10 mg?L–1 with a correlation coefficient of R2=0.9999 (n=7). The experimental detection limit is 0.05mgL–1. The sampling frequency is 15 samples h–1 and the relative standard deviation was 2.1% for 0.05 mg?L–1. This method is suitable for automatic and continuous analysis and successfully applied to determine the concentration of hydrazine in the aqueous stream of nuclear fuel reprocessing.

Evaluation of Response Surface Methodology in Dispersive Liquid-Liquid Microextraction for Lead Determination Using Ionic Liquids

This paper describes a dispersive liquid–liquid microextraction (DLLME) procedure using room temperature ionic liquids (RTILs) coupled with flame atomic absorption spectrometry detection with microsample intro-duction system capable of quantifying trace amounts of lead. In the proposed approach, ammonium pyr-rolidine dithiocarbamate (APDC) was used as a chelating agent and 1-hexyl-3-methylimmidazolium bis (trifluormethylsulfonyl)imid as an extraction solvent was dissolved in acetone as the disperser solvent. The binary solution was then rapidly injected by a syringe into the water sample containing Pb2+ complex. Some factors influencing the extraction efficiency of Pb2+ and its subsequent determination, including extraction and dispersive solvent type, pH of sample solution, concentration of the chelating agent and salt effect were inspected by a full factorial design to identify important parameters and their interactions. Next, a central composite design was applied to obtain the optimum points of the important parameters. Under the optimum conditions, the limit of detection (LOD) was 0.2 μg/L. The relative standard deviation (R.S.D) was 1.4% for 5 μg/L of Pb2+ (n = 7). The relative recovery of lead in seawater, blood, tomato and black tea samples was measured.

Riboflavin concentration in corneal stroma after intracameral injection

AIM: To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo.METHODS: The right eyes of 30 New Zealand white rabbits were divided into three groups. Different concentrations riboflavin-balanced salt solutions(BSS)were injected into the anterior chamber(10 with 0.5%, 10 with 1%, and 10 with 2%). Eight corneal buttons of 8.5mm in diameter from each group were dissected at 30 min after injection and the riboflavin concentrations in the corneal stroma were determined using high-performance liquid chromatography(HPLC) after removing the epithelium and endothelium. The other two rabbits in every group were observed for 24 h and sacrificed. As a comparison, the riboflavin concentrations from 16 corneal stromal samples were determined using HPLC after instillation of 0.1% riboflavin-BSS solution for30 min on the corneal surface(8 without epithelium and 8with intact epithelium).RESULTS: The mean riboflavin concentrations were11.19, 18.97, 25.08, 20.18, and 1.13 μg/g for 0.5%, 1%, 2%,de-epithelialzed samples, and the transepithelial groups,respectively. The color change of the corneal stroma and the HPLC results showed that enrichment with riboflavin similar to classical de-epithelialized corneal collagen crosslinking(CXL) could be achieved by intracameral 1%riboflavin-BSS solution after 30min; the effect appeared to be continuous for at least 30 min.CONCLUSION: Riboflavin can effectively penetrate the corneal stroma through the endothelium after an intracameral injection in vivo, so it could be an enhancing method that could improve the corneal riboflavin concentration in transepithelial CXL.

The ocular toxicity and pharmacokinetics of simvastatin following intravitreal injection in mice

AIM：To investigate the retinal toxicity and pharmacokinetics of simvastatin intravitreally injected into mice.METHODS：Forty-eight 6-8-week-old C57BL/6J mice were used in this study.Simvastatin was intravitreally injected into the right eye of each mouse;the left eye was injected with vehicle and was used as a control.Bilateral dark-adapted electroretinography（ERG）was performed 1 and 7d following injection.Histology was examined using a combination of light,fluorescence and electron microscopy.Highperformance liquid chromatography（HPLC）was used to determine the decay in the retinal simvastatin concentration.RESULTS：ERG revealed no significant changes in the simvastatin-injected eyes compared to control.Histologic studies showed normal retinal morphology in eyes injected with simvastatin up to a final vitreal concentration of 200μmol/L.No significant changes in the number of photoreceptors,bipolar cells or ganglion cells were found.The retinal simvastatin concentration decayed exponentially,with a half-life of 1.92-2.41h.CONCLUSION：Intravitreal injection of up to 200μmol/L simvastatin produced no signs of adverse effects in the mouse retina.Simvastatin reaches the retina shortly after intravitreal injectionand has a short half-life.

AGM隔板的装配压力对阀控式铅酸蓄电池性能的影响

研究了AGM隔板的注液量、注液种类、纤维直径、增强隔板以及初始压力等因素对装配压力的影响。实验证明,注液量为饱和吸液量的90%,装配压力控制在60 kPa左右,可以明显改善阀控式铅酸蓄电池的循环寿命。

高效液相色谱法测定室温下硝酸甘油注射液的存贮期限

目的高效液相色谱法测定硝酸甘油注射液在室温下的含量变化,预测硝酸甘油注射液在室温下的存贮期限。方法(1)HPLC法测定硝酸甘油注射液的含量。采用色谱柱(Kromasil C18),以甲醇:水(59:41)为流动相,流速1.0 ml·min^(-1),检测波长215 nm,柱温30℃;(2)采用加速试验和长期留样试验对硝酸甘油注射液的稳定性进行研究,经典恒温试验预测其在室温下的有效期。结果硝酸甘油注射液检测浓度在10μg·ml^(-1)-600μg·ml^(-1)范围内与峰面积呈良好的线性关系(R=0.9999),日内精密度、日间精密度、稳定性试验、重复性实验RSD均小于2%,含量测定平均值在99.99μg·ml^(-1)(标准值100μg·ml^(-1)),加样回收率RSD为1.67%。经典恒温试验测得硝酸甘油的含量变化符合一级反应规律,在25℃,硝酸甘油注射液的速率变化常数K_(25)=7.1395×10^(-4),有效贮存期限为147 d;在30℃时,K_(30)=9.4175×10^(-4),有效贮存期限为111 d。长期留样观察实验可以验证该实验的可靠性。结论高效液相色谱法检测方法简单、快速、精密度高,重复性好。硝酸甘油注射液在室温(25℃)下的存储期限约5个月,可以为临床管理抢救车药品提供参考依据。

人工胶体液和晶体液感染性休克液体复苏对比研究

目的回顾性对比分析人工胶体液和晶体液在容量反应性感染性休克患者液体复苏的疗效及不良反应。方法选取2013年1月至2020年6月于我院ICU住院138例脓毒症伴感染性休克患者。分为羟乙基淀粉氯化钠扩容(A)组和复方氯化钠注射液扩容(B)组。比较两组治疗72小时后,电解质、肌酐、活化部分凝血酶时间(APTT)、凝血酶原时间(PT)、动脉血气分析、PICCO血流动力学监测心脏指数(CI)、心搏指数(SVI)、血管外肺水(EVLW)、肺血管通透性指数(PVPI)、全心舒张末容积指数(GEDI)、中心静脉压(CVP)、水肿情况。结果A组GEDI较B组增加,A组肌酐、乳酸、EVLW、PVPI、水肿较B组少,剩余碱较B组更高,电解质、APTT、PT、CI、SVI、CVP两组没有显著差异。结论感染性休克患者液体复苏,使用羟乙基淀粉氯化钠扩容较晶体液显著改善循环血容量,减少毛细血管渗漏、血管外肺水,减少水肿发生及肾损害,更能显著改善代酸和降低乳酸水平,不增加对凝血功能、电解质及心功能影响。

Numerical Study on the Effects of Contraction Ratio in a Two-Phase Flow Injection Nozzle

The Euler-Euler numerical method was used to investigate the effects of contraction ratio on twophase flow mixing with mass transfer in the flow injection nozzle. The geometric shape of the nozzle was modified to improve carbonation efficiency. A gas inlet hole was created to increase the flow mixing of CO2 with water. A nozzle throat was also introduced to increase the gas dissolution by increasing flow rates. Various contraction ratios of nozzle throat, inlet gas and liquid velocities, and gas bubble sizes were employed to determine their effects on gas hold-up, gas concentration, and mass transfer coefficient. Results revealed that the flow injection nozzle with high contraction ratios improved carbonation because of high gas hold-up. Gas concentration was directly related to contraction ratio and gas flow velocities. Carbonation reduced when high liquid velocities and large gas bubbles were employed because of inefficient flow mixing. This study indicated that flow injection nozzle with large contraction ratios were suitable for carbonation because of their ability to increase gas hold-up, gas concentration, and mass transfer coefficient.

高效凝胶色谱联用质谱法快速鉴定盐酸头孢吡肟中的聚合物

目的:采用高效凝胶色谱法联用质谱法推断注射用盐酸头孢吡肟中聚合物的结构。方法:采用TSK gel G2000SWxl高效分子排阻色谱柱,以5 mM甲酸铵溶液-乙腈(95∶5)为流动相,流速为0.8 mL·min^(-1),检测波长为254 nm,柱温为25℃。在正离子模式下获取各聚合物杂质的质谱数据,结合头孢类抗生素聚合物的质谱裂解规律、降解反应原理,解析相关聚合物的结构。结果:推断出4种聚合物的化学结构,其中2个是头孢吡肟二聚体杂质,另外2个是三聚体杂质,其中三聚体杂质为首次报道。结论:采用高效凝胶色谱法联用质谱技术,可快速推断出注射用盐酸头孢吡肟中的聚合物的化学结构,可为其他头孢菌素聚合物的分离、鉴定及产品质量提高提供参考。

A Study on Release Property through Self Coating in LSR Injection Process

This study explores the molding processes by using the Multi-component-injection molding (MCM) method, in which monolithic products are molded by attaching mixed liquid-silicone-rubbers (LSRs) to polybutylene terephthalate (PBT) that has the characteristic of self-binding while burning due to Pt catalysts. It is seen that this method increases the binding force between LSR and PBT. The surfaces coated with Polytetrafluoroethylene (PTFE), Cr, Ni, etc. have excellent peeling with plastic and such surfaces are compared with those treated with hot forging die and micro blasting without coating. When peeling tests are performed at the specified polymerization temperature and molding time after LSR molding on these surfaces of hot working die molds without coating, these surfaces show excellent peeling of molds and LSR products. In particular, they show better peeling after micro blasting than surfaces with Cr and Ni coating as well as surfaces without coating, and the peeling strength also decreases. The results of contact angle and XPS analysis indicate that the LSR binding force is enhanced as an effect of catalysts, though it is not found by SEM. According to the XPS analysis, the structures of the surfaces are close to methyl and vinyl materials that are produced while LSR molding.

气相色谱法测定异戊烷中微量CO、CO_(2)的研究

利用高压液体进样阀-气相色谱仪,结合镍转化炉,建立了一种测定异戊烷中微量CO和CO_(2)含量的分析方法,考察了方法的精密度、回收率以及最低检测限,并对实际异戊烷样品中CO、CO_(2)的含量进行分析。定量分析结果表明,标样组分的回收率为98.0%,重复3次测定的相对标准偏差小于3%。CO、CO_(2)的最低检测限分别为0.13μL L和0.26μL L,该方法完全可以满足全密度聚乙烯工艺对异戊烷中微量CO、CO_(2)的质量监控要求。

采用非共沸制冷剂的双喷气增焓两级压缩热泵循环研究

提出一种采用非共沸制冷剂的双喷气增焓两级压缩热泵循环(DVIC),该循环在普通喷气增焓循环(VIC)的基础上采用分液冷凝技术,并增加一组闪蒸器,减少系统不可逆损失,改善热力性能。采用R290/R1336mzz(Z)非共沸制冷剂,对DVIC进行研究,并与VIC进行比较。结果表明:在设定工况下,DVIC比VIC拥有更优的循环性能,系统COP和(火用)效率分别提高5.82%和8.41%,压缩机功耗降低6.39%;在较低蒸发温度或较高冷凝温度的运行工况下,DVIC性能的改善效果更加明显。