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Effects of lanthanum and ethylenediamine tetraacetic a cid
Get PDFUsing nickel-tungsten as active metals and TiO₂-Al₂O₃ as the support, Ni-W/TiO₂-Al₂O₃ catalysts for the hydrodesulfurization of heavy oil were prepared by wetness impregnation. The effects of the modification of lanthanum, ethylenediamine tetraacetic acid (EDTA)and La in cooperation with EDTA on the structure and hydrodesulfurization performance of the catalysts were investigated. The catalysts were characterized by XRD, BET, H₂-TPR and SEM. The results indicated that La and EDTA could weaken the interaction between support and active component, facilitate the reduction of active component, and benefit the formation of Ni-W-S phase. Addition of La or EDTA could increase the surface area and suppress the agglomeration of active metals on surface, forming smaller and highly dispersed active phase particles. The La, EDTA and combined La and EDTA modified catalysts possessed higher HDS activity than Ni-W sample, Ni-W-La-E catalyst had the highest HDS activity, and its thiophene conversion reached 99.7%
Rapid quantitative determination method of four heavy metals in strawberry
Get PDFA rapid quantitative determination method of mercury, arsenic and arsenic, cadmium and chromium in strawberry was established. The sample to be tested was prepared into the solution to be tested, and the content of mercury, arsenic, cadmium and chromium were determined respectively on the machine. The results showed that the correlation coefficient of the standard curves of the four heavy metals was within 0.9961.000, and the detection limit was 0 mercury 0.028 g / kg, arsenic 0.062 g / kg, cadmium 0.14 g / kg, chromium 4.76 g / kg; the recovery was 80.2% 108.3% and 1.58% 26.34%; the test results of the standard samples were within the standard value. The method established in this experiment can determine the four heavy metals of mercury, arsenic, cadmium and chromium, etc. It has good linear correlation, low detection limit, good accuracy, high safety, simple operation, batch processing, and saves reagent consumables and detection time
Research on the Practice of Higher Vocational Mathematics Teaching Based on a Mathematical Experiment Platform
Get PDFFor most vocational colleges, the introduction of mathematics laboratory courses is still in the continuous exploration phase, and the views on mathematics laboratory courses vary from one institution to another. In the two years since the introduction of mathematics experiments, we have adopted a combination of basic mathematical experiments and modeling mathematical experiments to open up students\u27 horizons, stimulate their enthusiasm for learning mathematics, cultivate their awareness and ability to use mathematical methods with the aid of computers to solve practical problems, and foster their innovative spirit
Research on the biophysical properties of circulating tumor cells
Get PDFThis article reviews the biophysical properties of circulating tumor cells (CTCs) and their significance in tumor metastasis and liquid biopsy. CTCs are tumor cells that have shed from solid tumors or metastatic foci and entered the bloodstream, possessing various biological markers. They may be cleared by the immune system, enter a dormant state, or form clusters to facilitate metastasis. The physical properties of CTCs, including cell size, density, rigidity, and dielectric properties, differ from normal blood cells, providing a theoretical basis for separation and detection. The biological characteristics of CTCs include epithelial cell properties, expression of specific surface marker proteins, and the characteristics of epithelial-mesenchymal transition, which are crucial for the aggressiveness and metastatic potential of tumors. The development of CTC detection technologies, such as the Cell Search system, has been clinically applied, but the heterogeneity of tumor cells remains a major challenge in research. The development of composite separation technologies that combine various properties of CTCs is expected to improve the sensitivity, specificity, and efficiency of CTC detection, thereby playing an important role in the personalized treatment and prognostic assessment of tumors
Research on BIM sub-model data of construction engineering based on MVD
Get PDFBIM technology has been widely applied to various stages of construction projects in China. The data required at each stage and scenario of construction projects varies, necessitating the definition of target BIM data according to data needs. When BIM software generates IFC models, different MVD templates can be configured to output BIM sub-models. To study the characteristics of data configuration for different MVDs, this article takes construction projects as an example and designs an analysis experiment for BIM sub-model output based on MVD. It analyzes the differences and characteristics of IFC model data from both the overall project level and the professional component level according to key indicators, with the aim of providing references for construction project personnel to select matching MVDs, ensuring the effectiveness of BIM sub-models, and meeting the needs of business scenario applications
Teaching mathematical concepts based on the principle of "Consistency in Explanation"
Get PDFThis paper explores the importance and methods of achieving "self-consistency" in the teaching of mathematical concepts. It first emphasizes the central role of mathematical concepts in learning mathematics and, through the example of teaching the eccentricity of an ellipse, points out the complexity of understanding mathematical concepts. Then, by exploring the history of "eccentricity," the paper demonstrates the human conventions and historical development behind mathematical concepts, highlighting the need for teachers to delve into the origins and meanings of concepts in their teaching. The paper proposes four strategies to achieve "self-consistency": sorting out the history of mathematical development, finding applications of mathematics in daily life, rebuilding connections between mathematical knowledge, and utilizing perspectives from other disciplines. Finally, the paper argues that "self-consistency" is not only a teaching method but also a teaching philosophy, aimed at helping students gain a deep understanding of mathematical concepts
Coprecipitation preparation of copper -cobalt based catalysts for higher alcohol production
Get PDF A series of K modified coppercobalt based catalysts were prepared using step by step continuous coprecipitation method, and the catalytic performance of the catalysts was investigated. The experimental results showed that the catalyst exhibited the best activity, CO conversion, the yield of C₂+OH in liquid products and the mass fraction of C₂+OH was 65.74%,0.062 g·(mL·h)-I and 18.95%, respectively, under the condition as follows: mass ratio of cobalt to copper 1:1, K₂CO₃ loading mass fraction 1%, pH=7.2 and reaction temperature 310 ℃
The Influence of Polygonatum King ilium on the Activity of Calcium-Regulating Enzymes and Calcium Ion Concentration in SH-SY5Y Cells Damaged by Aβ25-35 In Vitro
Get PDFObjective To explore the effects of Polygonatum King ilium and Earthworm Formula (RPEWM) on the activity of calcium-regulating enzymes and free calcium ion (Ca2+) concentration in SH-SY5Y cells with Aβ damage in vitro. Methods SH-SY5Y cells were induced to differentiate with retinoic acid, then damaged by Aβ to mimic Alzheimer\u27s disease (AD) injury. RPEWM extract was added during the AD injury to protect the cells, and its effects on cell proliferation, apoptosis, and the activity of cellular Ca2+-ATPase､Ca2+-Mg2+- ATPase ,as well as free calcium ion concentration were observed. Results RPEWM extract significantly protected cells from AD injury, resisted apoptosis, and promoted cell proliferation; it increased the activity of intracellular Ca2+-ATPase､Ca2+-Mg2+- ATPase, reduced Ca2+ concentration, and showed a dose-dependent relationship. Conclusion RPEWM has a good protective effect on differentiated SH-SY5Y cells with Aβ25-35damage and has a certain therapeutic effect on AD
Therapeutic effects investigation of physical therapy and pharmacotherapy in the treatment of persistent allergic rhinitis
Get PDFTo investigate the therapeutic effects of physical therapy and pharmacotherapy in the treatment of persistent allergic rhinitis. Methods:192 patients were randomly divided into 3groups, A group 72 cases, B group 70 cases. A and B group were treated with focused ultrasound and radiofrequency ablation respectively under the endoscope and using spraying Mometasone Furoate Nasal Spray for 1month after the operation. Patients of C group use the Mometasone Furoate Nasal Spray and Cetirizine Hydro- chloride Tablets for 1 month. Follow up for 6 months after treatment and evaluate the curative effect with soring method. Results: Total effectiveness was as fllowed:1st months: A group 97.2%, B group 97.1%C group 96.0%;6 months: A group 90.3%, B group 87.1%, C group 64.0%. The curative effect score of three group after the treatment for 1month have no significant difference (P>0.05). Comparing the efficiency of patients in three groups after treatment for 6 months, there was significant difference of stat is tactically significance. The efficiency of A and B group were higher than group C(P<0.05).A group was better than B group with the score of sneezing after the treatment ,the difference was significant(P<0.05).But B group was better than A group with the score of nasal congestion ,the difference was significant(P<0.05).Conclusion: The curative effect of treatment with two physical therapy methods combined with mometasone furoate for persistent allergic rhinitis, the former is better than the latter for sneezing ,but the improvement of nasal congestion is less than the latter. Long-erm therapeutic effect of drug with AR is less than physical therapy in combination with drug. The treatment with focused ultrasound combined with mometasone furoate for persistent AR is worth promoting, especially suitable for medium and severe persistent AR patients
Screening of drugs for Jiu Dan syndrome animal model
Get PDFObjective: To establish an experimental animal model that conforms to the traditional Chinese medicine (TCM) syndrome of Jiu Dan. Methods: Based on the historical discourses of TCM practitioners on the Jiu Dan syndrome, the study deeply analyzed the mechanisms behind the formation of Jiu Dan syndrome. Taking into full consideration the clinical diagnostic basis of the TCM syndrome animal model, which includes symptoms, etiology, treatment, related factors, and objective indicators, a high-fat diet combined with free access to ethanol was used to induce spleen and stomach deficiency in rats, followed by the induction of liver injury using carbon tetrachloride, aminogalactose, and α-naphthylisothiocyanate. By observing the general biological status and biochemical indicators of the rats, the study screened the three chemical modeling drugs, carbon tetrachloride, aminogalactose, and α-naphthylisothiocyanate, to determine the modeling factor combination that could simulate the formation mechanism of the Jiu Dan syndrome, and established an animal model that meets the characteristics of the Jiu Dan syndrome. Conclusion: Ethanol and α- naphthylisothiocyanate were selected as the modeling drugs for the TCM Jiu Dan syndrome animal model