闪速吹炼炉内颗粒在不同操作参数下的分布与演化规律

通过开展工业试验揭示闪速吹炼炉内颗粒质量和粒径的分布与演化规律,同时研究不同配风参数对颗粒分布的影响。结果表明,颗粒在反应塔内的下落过程中,其平均粒径增长通常为2~3倍,且聚并后的大颗粒主要分布在料锥中部和外部;而导致该现象出现的原因是较高的湍流强度和颗粒分布密度、以及天然气燃烧的位置使该位置处颗粒升温熔融、并发生碰撞和聚并。另外,提高分散风与工艺风动量比能使物料颗粒在反应塔内的分布更加均匀,更有利于冰铜的氧化反应。相较于调整工艺风参数,改变分散风能更有效地提高颗粒的空间分布范围。

富氧侧吹氧化炉内两相流动的实验和数值模拟

以某富氧侧吹炉为原型,根据相似原理建立其水模型,并分析喷枪内气体流速、喷枪浸没深度以及喷枪倾斜角度对气液两相流动的影响。同时,利用不同湍流模型开展对水模型的数值模拟,通过与实验对比寻找最合适的湍流模型。实验结果表明:气流速度对液体内部流动情况影响较大,而喷枪浸没深度对气流在液体内部的贯穿深度以及液面波动高度影响相对较小。同时,当喷枪向下倾角为15°时,气流在液体内部的贯穿深度以及液面波动高度均有所减小。从数值模拟结果可以发现,使用realizable k-ε湍流模型所得仿真结果在气体贯穿深度、液面波动幅度以及气泡形状上与实验最为接近。

铜闪速炉内颗粒受热过程的数学建模与数值优化

为了研究闪速炉冶炼颗粒着火延迟问题,建立反应塔内颗粒受热过程的数学模型,并进行计算。结果表明,在塔高0.6 m范围内,辐射换热对于颗粒的加热过程影响较大,而在反应塔0.6 m以下区域,对流换热占主导作用。鉴于强化对流换热过程对提高颗粒加热速度进而提高着火高度更有效,因此,建议采用高速热氧射流技术代替闪速炉内的天然气,使得颗粒周围的气相产生横向扰动,从而提高气−粒两相间的滑移速度和对流换热系数。同时,开展高速热氧射流和常规天然气燃烧工况下的数值模拟。结果表明,采用高速热氧射流技术能够提高颗粒的升温速度,进而使颗粒更快着火,特别是在塔径R=0.3~0.6 m范围内。这说明,在相同的操作条件下,采用高速热氧射流技术可以进一步提升熔炼效率。

Preparation of Artificial Antigen and Egg Yolk-derived Immunoglobulin(IgY) of Citrinin for Enzyme-Linked Immunosorbent Assay

Objective To prepare artificial antigens and anti-citrinin egg yolk-derived immunoglobulin （IgY） to build an enzyme-linked immunosorbent assay （ELISA） for citrinin （CTN）. Methods CTN was conjugated with bovine serum albumin （BSA）, ovalbumin （OVA） with formaldehyde condensation method to prepare artificial antigens and identified by ultraviolet （UV） spectrometry and Infrared （IR） spectrometry. Artificial antigens for CTN and anti-CTN IgY were purified with polyethylene glycol two-step precipitation method and identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）. ELISA with IgY was established. Cross-reactivity of IgY with various structural similarities to CTN and possible co-occurrence with CTN in agricultural commodities were studied. Results UV and IR absorption spectra suggested that CTN was correlated with the carrier protein of BSA or OVA. SDS-PAGE patterns showed that the anti-CTN IgY was almost pure with a molecular weight of approximate 100 KD. The indirect competitive ELISA showed that the detection limit of CTN was 10 ng·mL^-1, with a good linearity ranging 20-640 ng·mL^-1. Conclusion Artificial antigens of CTN can be successfully synthesized. The established ELISA can be used to determine CTN- contaminated samples.

Liquid chromatography coupled with time-of-flight and ion trap mass spectrometry for qualitative analysis of herbal medicines

With the expansion of herbal medicine （HM） market, the issue on how to apply up-to- date analytical tools on qualitative analysis of HMs to assure their quality, safety and efficacy has been arousing great attention. Due to its inherent characteristics of accurate mass measurements and multiple stages analysis, the integrated strategy of liquid chromatography （LC） coupled with time-of-flight mass spectrometry （TOF-MS） and ion trap mass spectrometry （IT-MS） is well-suited to be performed as qualitative analysis tool in this field. The purpose of this review is to provide an overview on the potential of this integrated strategy, including the review of general features of LC-IT-MS and LC-TOF-MS, the advantages of their combination, the common procedures for structure elucidation, the potential of LC-hybrid-IT-TOF/MS and also the summary and discussion of the applications of the integrated strategy for HM qualitative analysis （2006-2011）. The advantages and future developments of LC coupled with IT and TOF-MS are highlighted.

Downregulation of EphB2 by RNA interference attenuates glial/fibrotic scar formation and promotes axon growth

The rapid formation of a glial/fibrotic scar is one of the main factors hampering axon growth after spinal cord injury. The bidirectional Eph B2/ephrin-B2 signaling of the fibroblast-astrocyte contact-dependent interaction is a trigger for glial/fibrotic scar formation. In the present study, a new in vitro model was produced by coculture of fibroblasts and astrocytes wounded by scratching to mimic glial/fibrotic scar-like structures using an improved slide system. After treatment with RNAi to downregulate Eph B2, changes in glial/fibrotic scar formation and the growth of VSC4.1 motoneuron axons were examined. Following RNAi treatment, fibroblasts and astrocytes dispersed without forming a glial/fibrotic scar-like structure. Furthermore, the expression levels of neurocan, NG2 and collagen I in the coculture were reduced, and the growth of VSC4.1 motoneuron axons was enhanced. These findings suggest that suppression of Eph B2 expression by RNAi attenuates the formation of a glial/fibrotic scar and promotes axon growth. This study was approved by the Laboratory Animal Ethics Committee of Jiangsu Province, China(approval No. 2019-0506-002) on May 6, 2019.

Comparative analysis of essential oils found in Rhizomes Curcumae and Radix Curcumae by gas chromatography-mass spectrometry

A comparison of the volatile compounds in Rhizomes Curcumae （Ezhu） and Radix Curcumae （Yujin） was undertaken using gas chromatography mass spectrometi-y （GC-MS）. Ultrasonic extraction and GC-MS methods were developed for the simultaneous determination of five sesquiterpenes, namely, α-pinene, β-elemene, curcumol, germacrone and curdione, in Ezhu and Yunjin. Good linearity （r〉0.999） and high inter-day precision were observed over the investigated concentration ranges. The validated method was successfully used for the simultaneous determination of five sesquiterpenes in Ezhu and Yujin. The quantitative method can be effectively used to evaluate and monitor the quality of Chinese curcuma in clinical use.

UPLC-Q-TOF/MS based metabolomic profiling of serum and urine of hyperlipidemic rats induced by high fat diet

Hyperlipidemia is considered to be a high lipid level in blood,can induce metabolic disorders and dysfunctions of the body,and results in some severe complications.Therefore,hunting for some metabolite markers and clarifying the metabolic pathways in vivo will be an important strategy in the treatment and prevention of hyperlipidemia.In this study,a rat model of hyperlipidemia was constructed according to histopathological data and biochemical parameters,and the metabolites of serum and urine were analyzed by UPLC-Q-TOF/MS.Combining pattern recognition and statistical analysis.19 candidate biomarkers were screened and identified.These changed metabolites indicated that during the development and progression of hyperlipidemia,energy metabolism,lipid metabolism,amino acid metabolism and nucleotide metabolism were mainly disturbed,which are reported to be closely related to diabetes,cardiovascular diseases,etc.This study demonstrated that a UPLC-Q-TOF/MS based metabolomic approach is useful to profile the alternation of endogenous metabolites of hyperlipidemia.

Comparative Proteomic Analysis of B. henselae Houston and B. henselae Marseille by Two-dimensional Gel Electrophoresis

To compare the protein difference between B. henselae Houston and B. henselae Marseille by two-dimensional gel electrophoresis. Method Protein samples were prepared by vorterx, ultrasonic treatment, and centrifugation. Protein concentrations were determined by Bradford method. Protein difference was compared by the first IEF and the second SDS-polyacrylamide gel electrophoresis. Results Protein concentrations in samples of Bartonella henselae Houston and Bartonella henselae Marseille were 2.117 μg/μL and 2.200 μg/μL respectively. Sample protein of 40 μg for IPG strips loading was perfect. The results of 2-DE in pH 4 to 7 IPG strips showed that the total protein spots of Bartonella henselae Houston and Bartonella henselae Marseille were 375 and 379 respectively, 95% of the spots were the same between the two strains of Bartonella henselae. Conclusion The procedure of 2-DE may prove successful for the proteomic analysis of Bartonella henselae. Bartonella henselae Houston and Bartonella henselae Marseille are different genotypes.

Two-thiols-regulated fabrication of plasmonic nanoparticles with co-enhanced Raman scattering and circular dichroism responses

Plasmonicnanoparticles(PNPs)with stable nanogaps are important to achieve strong,uniform and quantitative gap-enhanced Raman scattering(GERS)signals.Chiral PNPs with plasmonic circular dichroism(PCD)responses have been discovered to be suitable for applications in enantiomeric recognition,cancer therapy and activation of immune system.Herein,two-thiolsmodulated growth was demonstrated to result in the acquisition of PNPs with synergistically enhanced GERS and PCD signals.4-Aminothiophenol(4-ATP)and cysteine(Cys)played the role of Raman reporter and chiral stimulus,respectively.At a fixed 4-ATP concentration,the GERS signal of PNPs was significantly enhanced with the increase of the concentration of Cys.Simultaneously,at a fixed concentration of Cys,an increase in PCD response was observed by elevating the concentration of 4-ATP.Both aforementioned molecules acted as morphology controllers,leading to the formation of helical shell.It is suggested that the giant GERS and PCD response were contributed by the‘‘hot spots''within the PNPs and more perfect helical shells.Our research pointed out a novel synthetic guideline to obtain PNPs with multiple functionalities by incorporating multi-ligands into the growth stages.

CFD modeling of gas−liquid flow phenomenon in lead smelting oxygen-enriched side-blown furnace

A validated numerical model was established to simulate gas−liquid flow behaviors in the oxygen-enriched side-blown bath furnace.This model included the slip velocity between phases and the gas thermal expansion effect.Its modeling results were verified with theoretical correlations and experiments,and the nozzle-eroded states in practice were also involved in the analysis.Through comparison,it is confirmed that the thermal expansion effect influences the flow pattern significantly,which may lead to the backward motion of airflow and create a potential risk to production safety.Consequently,the influences of air injection velocity and furnace width on airflow behavior were investigated to provide operating and design guidance.It is found that the thin layer melt,which avoids high-rate oxygen airflow eroding nozzles,shrinks as the injection velocity increases,but safety can be guaranteed when the velocity ranges from 175 to 275 m/s.Moreover,the isoline patterns and heights of thin layers change slightly when the furnace width increases from 2.2 to 2.8 m,indicating that the furnace width shows a limited influence on production safety.

Screening and Validation of Active Ingredients in Sini Decoction by Combination Method of Pharmacophore Modeling and Molecular Docking

Objective To screen the active compounds in Sini Decoction showing the potential to inhibit tumor necrosis factor α（TNFα） to alleviate Doxorubicin（DOX）-induced heart failure. Methods A chemical database of Sini Decoction was constructed from literature research. The generated pharmacophore models based on TNF-α used to screen active ingredients of Sini Decoction in the database by Discovery Studio 2.5. Molecular docking by Autodock 4.2 was adopted to demonstrate the hit compounds＇ affinities with TNFα. Furthermore, DOX-induced heart failure model on H9c2 cell line was constructed and cell viability was detected by CCK-8 to validate the therapeutic effect of potential active compounds. Results The higenamine showed potential cardiovascular protective effect through virtual screening. And the activity was identified in vitro. Conclusion In this study, we found that higenamine may inhibit TNF-ɑ through virtual docking and validated that higenamine may have the potential of treatment for heart failure in the model of doxorubicin-induced myocardial toxicity to H9c2 cells.

Relation between gravitational mass and baryonic mass for non-rotating and rapidly rotating neutron stars

With a selected sample of neutron star(NS)equations of state(EOSs)that are consistent with the current observations and have a range of maximum masses,we investigate the relations between NS gravitational mass Mg and baryonic mass and the relations between the maximum NS mass supported through uniform rotation(Mmax)and that of nonrotating NSs(Mtov).We find that for an EOS-independent quadratic,universal transformation formula(Mb=Mg+A×M^2/g),the best-fit A value is 0.080 for non-rotating NSs,0.064 for maximally rotating NSs,and 0.073 when NSs with arbitrary rotation are considered.The residual error of the transformation is?0.1M⊙ for non-spin or maximum-spin,but is as large as?0.2M⊙ for all spins.For different EOSs,we find that the parameter A for non-rotating NSs is proportional to R^-1/1.4(where R1.4 is NS radius for 1.4M⊙ in units of km).For a particular EOS,if one adopts the best-fit parameters for different spin periods,the residual error of the transformation is smaller,which is of the order of O.O1M⊙ for the quadratic form and less than O.O1M⊙ for the cubic form(Mb=Mg+A1×M^2/g+A2×M^3/g).We also find a very tight and general correlation between the normalized mass gain due to spin △m≡(Mmax-MTOV)MTOV and the spin period normalized to the Keplerian period P,i.e.,log10 △m=(-2.74±0.05)log10 P+log10(0.20±0.01),which is independent of EOS models.These empirical relations are helpful to study NS-NS mergers with a long-lived NS merger product using multi-messenger data.The application of our results to GW170817 is discussed.