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.

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.

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.

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.

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.

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.

改进PSO训练的BPNN方法的舰船主尺度建模

利用改进粒子群优化算法训练的BP神经网络(BPNN)对以航母为代表的大型舰船主尺度进行了回归分析.对粒子群优化算法(PSO)的学习因子进行了关于迭代进程的自适应调整,并将改进后的PSO算法对BPNN训练过程进行优化.利用新型BPNN对典型航母主尺度(总长、总宽、设计水线长、设计水线宽、吃水与满载排水量)进行数学建模,与基于传统多项式回归的结果进行对比分析.结果表明经改进PSO训练的BPNN具有更高的输出精度且具有良好的分段光滑特性,这对于大型舰船方案论证与总体设计可起到重要的指导性作用.

基于PCA-BPNN方法的中长期电力负荷预测

针对基于反向传播神经网络(Back-Propagation Neural Network,BPNN)的中长期电力负荷预测算法中,预测模型的精度和泛化能力易受输入样本变量影响这一问题,利用主元分析(Principal Component Analysis,PCA)方法能消除变量间相关性的特点,对BPNN的输入空间进行重构,消除重叠信息,提取主导因素,优化了网络结构,提高了预测精度。通过实例验证了该方法的有效性。此方法可以使用电计划部门实时、准确的预测电力负荷,以此最优的配比发电机组,也可减少由于预测不准确带来的电力系统各种故障的发生。

基于Apriori-BPNN分析的继电保护通信电路风险评估研究及应用

为解决"海量数据"和"有限知识"之间的矛盾,提高继电保护通信电路风险评估准确性和算法效率,提升事前预警能力,论文提出一种融合关联规则分析和神经网络的风险评估方法 Apriori-BPNN。该方法首先基于多源异构的数据构建初始指标体系,在此基础上采用改进的Apriori算法确定多种因素与目标的关联度,实现指标筛选;采用BP神经网络算法确定各因素的权重,并加权求得最终的综合风险评估指标。仿真结果表明,Apriori-BPNN既避免了传统层次分析法的不足,又简化了神经网络的结构,提高了继电保护通信电路风险评估准确度和算法效率,使运维人员能及时发现存在的隐患和风险,指导继电保护通信电路的主动预警与智能检修,提高继电保护业务运行的安全性和稳定性。

基于多BPNN敏感性分析的气候变化脆弱性指标赋权方法

为尽量减小气候变化脆弱性评估中对指标权重的人为干扰,通过对某市卫生领域的气候变化脆弱性的评价案例,提出了一种基于多反向传播神经网络(BPNN)敏感性分析的气候变化脆弱性指标赋权方法。结果表明:多组BPNN拟合与泛化能力普遍较好,且每个模型敏感性分析结果具有一致性,总敏感性指数远大于一阶敏感性指数,反映了气候指标巨大潜在影响。所提出的敏感性分析具有较好的稳定性;该方法能够有效识别出气候指标的直接影响及间接影响,可以为指标权值的确定提供参考。

RDWKCPSO-PCA-BPNN的汽车燃油消耗预测

针对不同乘用车综合工况下理论百公里燃油消耗数据,文章提出了一种基于主成分分析(principal component analysis,PCA)和BP神经网络(back propagation neural network,BPNN)的燃油消耗预测模型;通过PCA方法对选取影响理论燃油消耗的24个因素进行压缩,简化模型结构,再利用BPNN算法,构建燃油消耗预测模型;由于神经网络中的权值和阈值对预测模型效果影响较大,采用基于随机动态惯性权重和Kent映射的混沌粒子群算法(RDWKCPSO)优化PCA-BPNN模型中的权值和阈值。对3种标准函数的寻优测试结果表明,RDWKCPSO优化算法更容易跳出局部最优实现全局寻优,提高了模型适应能力及预测精度。

结合ERDAS的基于BPNN遥感图像分类

基于改进BPNN的遥感图像分类,先利用ERDASImagine的Classifier模块对原始遥感图像进行聚类分析并对比,确定分类类别数。后在原始图像上采集各类别的训练样本和测试样本,通过输入训练样本集训练BP神经网络分类器。最后输入整幅遥感图像到训练好的分类器,得到分类图像。试验表明,其精度优于传统统计分类方法。

基于PCA-BPNN对无机氢化物pK_a的QSPR研究

采用Chemoffice10.0中的MOPAC/AM1半经验算法,计算13个无机氢化物的6种量子化学参数:偶极距(μ)、分子电子能(EE)、分子最高占据轨道能(E homo)、分子最低未占据轨道能(E lumo)、分子总能量(TE)和非氢原子的净电荷(q),利用SPSS19.0软件的主成分分析模块和BP神经网络模块对样本数据集进行预处理,将得到的样本数据集输入人工神经网络,构建无机氢化物pK a的主成分-反向传播神经网络(PCABPNN)QSPR模型.结果表明:利用SPSS19.0软件快速实现PCA-BPNN模型取得了非常满意的结果,而且模型的相关系数高,所得结果均优于传统的多元线性回归方法.