Qualitative analysis of aromatic compounds via 1D TOCSY techniques

The aromatic compounds,including o-xylene,m-xylene,p-xylene,and ethylbenzene,primarily originate from the catalytic reforming of crude oil,and have a wide variety of applications.However,because of similar physical and chemical properties,these compounds are difficult to be identified by gas chromatography(GC)without standard samples.With the development of modern nuclear magnetic resonance(NMR)techniques,NMR has emerged as a powerful and efficient tool for the rapid analysis of complex and crude mixtures without purification.In this study,the parameters of one-dimensional(1D)total correlation spectroscopy(TOCSY)NMR techniques,including 1D selective gradient TOCSY and 1D chemicalshift-selective filtration(CSSF)with TOCSY,were optimized to obtain comprehensive molecular structure information.The results indicate that the overlapped signals in NMR spectra of nonpolar aromatic compounds(including o-xylene,m-xylene,p-xylene and ethylbenzene),polar aromatic compounds(benzyl alcohol,benzaldehyde,benzoic acid),and aromatic compounds with additional conjugated bonds(styrene)can be resolved in 1D TOCSY.More importantly,full molecular structures can be clearly distinguished by setting appropriate mixing time in 1D TOCSY.This approach simplifies the NMR spectra,provides structural information of entire molecules,and can be applied for the analysis of other structural isomers.

Measurement Analysis and Evaluation of Twenty-Five Years of Mathematics Education Research in China:Visual Econometric Analysis Based on CiteSpace Knowledge Mapping(1999-2024)

Since the new century,China’s mathematics curriculum reform in basic education has continued to move forward in attempts and explorations,presenting many new changes,trends,movements,and developments.Sorting out,analyzing,and summarizing the achievements,experiences,problems,and challenges in this journey are conducive to providing insights for the reform and development of the Chinese basic education mathematics curriculum in the new era.This paper analyses the research on mathematics education in China(1999-2024)using the visual measurement of CiteSpace knowledge mapping,hoping to provide directions for the future of mathematics education in China.

Consequences of Insufficient Selectivity in Quantitative and Qualitative Chemical Analysis

A problem in chemical analysis in connection with measurements of a substance normally occurring in a sample, or identification of a substance which should not exist in a sample, is insufficient selectivity. In this article, we analyze this problem and propose remedies. We use a real doping case to illustrate how chemical noise causes a serious selectivity problem, probably causing a false positive outcome.

Teaching Reform and Practice of “Mathematical Analysis” under the New Engineering Education Paradigm

With the advent and promotion of the new engineering education paradigm,university mathematics courses face new challenges and opportunities.As a fundamental course for engineering majors,the reform of“Mathematical Analysis”is particularly crucial.This paper explores the necessity,specific practices,and outcomes of teaching reform in“Mathematical Analysis”within the context of the new engineering education.By reforming teaching content,methods,and assessment approaches,this study aims to enhance students’mathematical literacy and comprehensive abilities to meet the demands of the new engineering education development.

Qualitative and Quantitative Analysis of Alkaloids in Cortex Phellodendri by HPLC-ESI-MS/MS and HPLC-DAD

A combined method of high performance liquid chromatograph-elecrtrospray-ionization mass spectrometer（HPLC-ESI-MS/MS） coupled with a photodiode array detector（HPLC-DAD） and principal component analysis（PCA） was applied to the qualitative and quantitative analyses of alkaloids in Cortex Phellodendri（CP） samples, and to the differentiation of two species of CP, Cortex Phellodendri Chinensis（CPC） and Cortex Phellodendri Amurensis（CPA）. Twenty-two peaks appeared in the HPLC-MS base peak chromatogram of CP detected by the HPLC-ESI-MS/MS analysis, and the alkaloids were identified according to the MSn data, the known MS fragmentation rules and the literature data. Five alkaloids including berberine, palmatine, jatrorrhizine, phellodendrine and magnoflorine were simultaneously determinated by the HPLC-DAD. Berberine was the primary component in all CP samples, and the contents of berberine and palmatine were exploited to be two critical parameters for effective discrimination between the two species of CP. The average content of berberine in CPC（58.75 mg/g） was higher than that in CPA（9.16 mg/g）, while the content of palmatine was less, only 0.25 mg/g in CPC and 4.19 mg/g in CPA. With the use of PCA, samples datasets were separated successfully into two different clusters corresponding to the two species, and berberine, pahnatine, phellodendrine and magnoflorine contribute most to the above mentioned calssifying . The proposed method oroved to be a useful tool in the aualitv control of Chinese herbal medicines.

Signed Directed Graph and Qualitative Trend Analysis Based Fault Diagnosis in Chemical Industry

In the past 30 years,signed directed graph(SDG) ,one of the qualitative simulation technologies,has been widely applied for chemical fault diagnosis.However,SDG based fault diagnosis,as any other qualitative method,has poor diagnostic resolution.In this paper,a new method that combines SDG with qualitative trend analysis(QTA) is presented to improve the resolution.In the method,a bidirectional inference algorithm based on assumption and verification is used to find all the possible fault causes and their corresponding consistent paths in the SDG model.Then an improved QTA algorithm is used to extract and analyze the trends of nodes on the consis-tent paths found in the previous step.New consistency rules based on qualitative trends are used to find the real causes from the candidate causes.The resolution can be improved.This method combines the completeness feature of SDG with the good diagnostic resolution feature of QTA.The implementation of SDG-QTA based fault diagno-sis is done using the integrated SDG modeling,inference and post-processing software platform.Its application is illustrated on an atmospheric distillation tower unit of a simulation platform.The result shows its good applicability and efficiency.

Qualitative and semi-quantitative analysis of health-care pharmaceutical products using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy(LIBS) is a sensitive optical technique that is capable of rapid multi-elemental analysis. The development of this technique for elemental analysis of pharmaceutical products may eventually revolutionize the field of human health. Under normal circumstances, the elemental analysis of pharmaceutical products based on chemical methods is time-consuming and complicated. In this investigation, the principal aim is to develop an LIBS-based methodology for elemental analysis of pharmaceutical products. This LIBS technique was utilized for qualitative as well as quantitative analysis of the elements present in Ca-based tablets. All the elements present in the tablets were detected and their percentage compositions were verified in a single shot, using the proposed instrument. These elements(e.g., Ca, Mg, Fe, Zn, and others) were identified by the wavelengths of their spectral lines, which were verified using the NIST database. The approximate amount of each element was determined based on their observed peaks and the result was in exact agreement with the content specification. The determination of the composition of prescription drug for patients is highly important in numerous circumstances. For example, the exploitation of LIBS may facilitate elemental decomposition of medicines to determine the accuracy of the stated composition information. Moreover, the approach can provide element-specific, meaningful, and accurate information related to pharmaceutical products.

Qualitative Algebra and Graph Theory Methods for Dynamic Trend Analysis of Continuous System

Qualitative algebraic equations are the basis of qualitative simulation,which are used to express the dynamic behavior of steady-state continuous processes.When the values and operation of qualitative variables are redefined,qualitative algebraic equations can be transformed into signed direct graphs,which are frequently used to predict the trend of dynamic changes.However,it is difficult to use traditional qualitative algebra methods based on artificial trial and error to solve a complex problem for dynamic trends.An important aspect of modern qualitative algebra is to model and characterize complex systems with the corresponding computer-aided automatic reasoning.In this study,a qualitative affection equation based on multiple conditions is proposed,which enables the signed di-rect graphs to describe complex systems better and improves the fault diagnosis resolution.The application to an industrial case shows that the method performs well.

Greek Texts and the Rigorization of Analysis:An Inquiry into J.L.Lagrange's Work on the History of Mathematics

This paper offers a study of J.L.Lagrange's research on history of mathematics,aiming to clarify Lagrange's intention in carrying out historical work.To this end,I first document how Lagrange worked with and exerted his influence on other scholars in the translation and diffusion of ancient Greek texts.Second,investigating Lagrange's style in doing and writing history of mathematics,this paper takes a new perspective and elucidates his motivation in these activities.In particular,it focuses on Lagrange's presentation of the history of calculus while he was teaching analysis at the Ecole Polytechnique(1795-1799)so as to clarify the function of history in Lagrange's mathematical works.My thesis is that Lagrange's intention in examining the different methods employed by his predecessors was to find inspiration and useful contents in his search for the proper approach to mathematical problems.I thus argue in this paper that history served as a guide or methodology for Lagrange's mathematics.Meanwhile,through an analysis of his historical writing,this paper points to four epistemological values according to which Lagrange judged various historical methods of differential calculus:generality,simplicity,clarity,and rigor.Lagrange's move to rigorize analysis was connected to his interest in and research of Greek texts;he was attempting to introduce the rigor of the ancient Greeks'demonstration in his works of analysis.

Volatile profile and multivariant analysis of Sanhuang chicken breast in combination with Chinese 5-spice blend and garam masala

Sanhuang chicken is a popular native breed in China and well-known for delicious flavour.Spices could enhance the chicken meat flavour and work well in preservation.Chinese 5-spice blend(CS)and garam masala(GM)are routinely using spices in China and Pakistan,respectively.The flavour profiles of Sanhuang chicken breast(CB)and its blends with CS and GM were obtained by electronic nose(E-nose),solid-phase microextraction gas chromatography-mass spectrometry(SPME GC-MS)and GC-ion mobility spectrometry(GC-IMS).Principal component analysis(PCA)efficiently discriminated the aroma profiles of three chicken formulations.The GC-chromatographs revealed the significant aroma alterations of chicken breast meat after marination with spices.Aldehydes were the major contributors of chicken aroma,while most of the aromatic hydrocarbons were generated by spices.Almost all chicken key-compounds produced by oxidation reaction were either reduced or eliminated by marination,showing the antioxidation capacity of spices leading to meat preservation.GC-IMS is not only a rapid and comprehensive detection method,but also proved to be more sensitive than GC-MS.The substantial role of both traditional spices in enhancing flavour quality of chicken meat,and their exposure as functional ingredients in Chinese and Pakistan cuisines could lead to the cross-cultural meat trade opportunities.

Qualitative and Quantitative Analysis of Linoleic Acid in Polygonati Rhizoma

Objective To explore the major compound in Polygonati Rhizoma(Huang Jing,黄精)for quality control.Methods The major compound was isolated and analyzed by liquid chromatography-mass spectrometry(LC-MS),and subsequently further identified by nuclear magnetic resonance(NMR).Thin layer chromatography(TLC)was optimized based on the previous methods reported in the Chinese Pharmacopeia(2015 edition).Results The major compound was isolated from the natural material and identified as linoleic acid.A high performance liquid chromatography(HPLC)method with robust linearity(R2=0.9997),specificity,precision,stability,repeatability and recovery was developed for linoleic acid determination.TLC chromatogram was improved significantly after optimization for qualitative analysis.Conclusions The optimized TLC method is practical and can be adopted for quality control of Polygonati Rhizoma(Huang Jing,黄精).The levels of linoleic acid vary between species of Polygonati Rhizoma(Huang Jing,黄精),with Polygonatum cyrtonema Hua(Jiang Xing Huang Jing,姜型黄精)showing the highest contents.This study provides valuable information for quality control of Polygonati Rhizoma(Huang Jing,黄精).

Improved Qualitative Trajectory Calculus for Pair-Activity Analysis

Trajectory provides the most robust feature for activity recognition in far-field surveillance videos,in which increasing attentions have been given to the use of qualitative methods with symbolic rather than real-value features.Qualitative trajectory calculus(QTC)showed a good performance in pair-activity from video.However,QTC and similar works are not good at dealing with noise,since they are all considering short-term features.To deal with the problems mentioned above,two types of long-term features,including sub-trajectory feature and point-trajectory feature,are designed.The sub-trajectory feature is a long-term feature in a coarse granularity,while the point-trajectory feature is a long-term feature in a relatively fine granularity.Using the sub-trajectory feature,a couple of trajectories are segmented into sub-trajectories and enveloping boxes are used to substitute the original sub-trajectory for capturing the major attributes.The point-trajectory feature describes the relationship between a single point in one trajectory and all parts of the other trajectory.The experiments on the human activity classification data demonstrated that our proposed methods are better than the original QTC and previous short-term features.

Qualitative and Quantitative Analysis of Five Bioactive Flavonoids in <i>Salix bordensis</i>Turcz. by HPLC-DAD and HPLC-ESI-MS

The qualitative characterization and quantitative analysis of five bioactive flavonoids in Salix bordensis Turcz. were achieved via reversed-phase high-performance liquid chromatography coupled with diode array detection and tandem mass spectrometry, by using an Agilent ZORBAX SB-C18 HPLC column with a gradient elution of 0.3% (v/v) formic acid in water and methanol as the mobile phase. The compounds in the mixture were clearly identified by comparing their HPLC-DAD ultraviolet spectra, retention times, and MS data with those of corresponding reference compounds. All calibration curves showed good linearity (r2 > 0.9998) within the test ranges. The LOD, LOQ, specificity, precision, and accuracy for the method were validated. The results demonstrated that this analytical approach is ideal for the determination of bioactive compounds, such as flavonoids, and that it constructed a basis for the comprehensive evaluation of the quality of Salix bordensis Turcz.

Views on patient safety by operations managers in somatic hospital care: a qualitative analysis

Healthcare outcome is to achieve optimal health for each patient. It is a well-known phenomenon that patients suffer from care injuries. Operations managers have difficulties in seeing that the relationship between safety culture, values and attitudes affects the medical care to the detriment of the patient. The aim was to describe the views on patient safety by operations managers and the establishment of patient safety and safety culture in somatic hospital care. Four open questions were answered by 29 operations managers in somatic hospital care. Data analysis was carried out by deductive qualitative content analysis. Operations managers found production to be the most important goal, and patient safety was linked to this basic mission. Safety work meant to achieve optimal health outcomes for each patient in a continuous development of operations. This was accomplished by pursuing a high level of competence among employees, having a functioning report system and preventing medical errors. Safety culture was mentioned to a smaller extent. The primary target of patient safety work by the operations managers was improving care quality which resulted in fewer complications and shorter care time. A change in emphasis to primary safety work is necessary. To accomplish this increased knowledge of communication, teamwork and clinical decision making are required.

Prediction and sensitivity analysis of the surface quality in Ni60/WC coatings

For laser cladding a large temperature gradient easily weakened the surface quality by generating cracks and irregular coating surfaces,which in turn affected the bearing capacity and corrosion resistance of coatings in the rapid heating and cooling process.The response surface methodology(RSM)was used to predict coating cracks by changing the powder ratio,energy density,and preheating temperature,which obtained the relevant mathematical model.After that,the sensitivity of the crack length to process parameters was analyzed based on the sensitivity analysis method.The effect of Ni60/WC composite powder process parameters on the surface quality was revealed in laser cladding.The crack length first decreased and then increased,and the Smooth decreased with the increased powder ratio.The crack length and Smooth increased with the increased energy density.The crack length decreased and Smooth increased with the increased preheating temperature.Sensitivity analysis showed that the crack length and Smooth were the most sensitive to the powder ratio.Therefore,the process parameters were reasonably selected to control the surface quality.The mathematical model and sensitivity analysis method in the work could improve the surface quality,which provided a theoretical basis for the prediction and control of laser cladding cracks.

Midwives’views and experiences of providing healthy eating advice to pregnant women:a qualitative content analysis of semi-structured interviews

Objective:To explore midwives’views on how they provide healthy eating education to pregnant women after attending a healthy eating education workshop/webinar.Methods:A qualitative descriptive approach was utilized.Semi-structured interviews were conducted to explore the views and experiences of midwives on providing healthy eating education for pregnant women.A purposive sample of six midwives was interviewed face-to-face,and one was conducted by telephone interview.Data were analyzed through qualitative conventional content analysis.Results:Midwives described their views and experiences of factors that impacted their role in providing healthy eating educa-tion.They identified three categories:perceived role of midwi ves,health literacy,and model of care.Conclusions:Knowledge and confidence of midwives improved after attending the workshop/webinar on healthy eating education.Findings suggested that midwives perceived their role as important in providing nutrition education.However,time and resources were highlighted as challenges when providing healthy eating education for pregnant women.The availability of health literacy and model of care were significant factors in enabling midwives to adequately provide this education.Midwives acknowledged a need for further education in areas of vegan diet,cultural food preferences for ethnic minority groups,and regular updates on national healthy eating guidelines.

The Impact of Peer Instruction on Students’ Achievement in Mathematics Analysis

In this research,we investigated the effect of peer instruction method on the first course mathematics education students’academic achievement and the attitudes of students by using peer instruction method.The implementation was carried out seven weeks with 60 participants in an introduction to mathematics analysis lesson in Suleyman Demirel University in Kazakhstan.Two first course groups were randomly assigned to treatment and control groups.The final results were obtained to measure students’academic achievement and questionnaires used to indicate attitudes towards peer instruction.Data were analyzed,using analysis of t-test(p=0.029)with an alpha significance level of 0.05.The results of final questions indicated,peer instruction has a significant positive effect on students’achievement in the introduction to mathematics analysis course and the results of questionnaires demonstrated peer instruction(PI)has a positive impact on peers’understanding by making learning interesting and interactive,and it also creates conducive atmosphere in the class.

Conceptual framework of modern Zangxiang concept: a qualitative content analysis

Background:Some scholars believe modern Zangxiang concept is conceived under the thought of bio-medicine (Western medicine),which differs greatly compared to the ancient one.The view put forward stirs up great argument.Therefore,we attempt to explore whether the modern Zangxiang concept can fully reflect the specific content and structural relationship of ancient one through analyzing the frame structure of modern Zangxiang concept.Methods:The qualitative content analysis was used.The document was selected from Zangxiang Chapter in Fundamental Theory of Traditional Chinese Medicine (7th edition).The textual document was added to QSR International's NVivo qualitative data analysis software.Text was manually coded line by line according to the content described,and new categories were identified which were further divided into initial code,sub-theme,and theme.The relationships among them were explored,and a visual map of the body of knowledge (BoK) in Zangxiang theory was depicted.The similarities and differences between modern and ancient Zangxiang concepts were discussed by interpreting these themes,relationships and the visual map.Results:After analysis,there were 126 initial codes,13 sub-themes,and 4 themes including structure,function,functional outcome and the corresponding external sign.Two principal relationships,generation and mutual promotion,restriction,and inter-dependence in function were obtained.By analyzing four themes and two kinds of principal relationships,we found five different aspects between modern Zangxiang concept and ancient Zangxiang theory.Conclusion:The BoK of the modern Zangxiang concept contains four themes:structure,function,functional outcome,and the corresponding external sign.The principal relationship is referring to generation between structure and function,and between function and its corresponding outcomes.Great differences exist when talking about modern Zangxiang concept which doesn't reflect TCM characteristics and is more inclined to bio-medicine in structure from the perspective of ancient TCM theory.

Bibliometric analysis of qualitative researches in nursing in China from 2013 to 2019

Aims:To analyze the research status and development trend of nursing qualitative research in China from 2013 to 2019.Method:China national knowledge infrastructure(CNKI),Wanfang Data and VIP database were researched to include all related articles which were published from 2013 to 2019 about nursing qualitative research literature.NoteExpress literature management software and Excel were used to organize literature from annual distribution region,organization,core periodical,as well as the research object,research methods,data collection method and sampling method for metrology analysis.Results:2194 articles met the inclusion criteria,the number of articles is increasing year by year.Most of them come from Shanghai,Beijing,zhejiang and other developed areas.The top three institutions were the Huazhong University of Science and Technology,Tongji Medical College,Affiliated Union Hospital,Fudan university and Shanghai jiao tong university.And 835 of them were published in core journals.Research object are mainly divided into patient,nurses,nursing managers,etc.The included literature mainly adopts phenomenological research methods.Interview is the mainly data collection methods,and Colaizzi method is the mainly data analysis methods.Most articles use the method of purpose sampling.Conclusion:The qualitative research is becoming more and more attention by researchers in China.Qualitative research has covered clinical nursing,nursing education,nursing management,nursing psychology and other different nursing field.However,the selection of qualitative research methods,data analysis methods and related reports need to be further improved and standardized.

Analysis and Strategy Research on the Mathematics Learning Situation of the Postgraduate Candidates

This study takes the students who intend to study for graduate students as the research object,and makes a questionnaire survey on the mathematics learning situation and learning platform of the postgraduate candidates.Questionnaires were distributed online and offline,and a total of 326 valid questionnaires were collected.Based on 326 questionnaires,this paper analyzes the current learning situation of mathematics in the postgraduate entrance examination and studies the strategies based on the present situation,which points out the direction for the construction of mathematics learning and communication platform based on the needs of postgraduate entrance examination.