Chromatographic fingerprinting and quantitative analysis for the quality evaluation of Xinkeshu tablet

A simple, sensitive and accurate method based on high performance liquid chromato- graphy （HPLC） with diode array detector （DAD） was developed and validated for systematic quality evaluation of one type of traditional Chinese medicine preparations named Xinkeshu （XKS） tablet. In this study, the chromatographic fingerprints of XKS tablet were developed first, 23 peaks were selected as the common peaks to evaluate the similarities among different batches of XKS samples, which were manufactured in a long time span of three years. Additionally, simultaneous quantification of six markers in XKS tablet, including Danshensu, Protocatechuic aldehyde, Puerarin, Daidzin, Salvianolic acid B and Daidzein, was performed. The validation results showed that the developed method was specific, accurate, precise and robust. The preliminary explanation on why a close similarity between fingerprints did not exactly mean similar contents of chemical components in samples was given. The contribution of each chromatographic peak to similarity was also evaluated. The developed method offers an efficient, reliable and practical approach for systematic quality evaluation of XKS tablet.

Spectra selection methods:A novel optimization way for treating dynamic spectra and in-line near infrared modeling

Near infrared(NIR)spectroscopy is now widely used influidized bed granulation.However,there are still some demerits that should be overcome in practice.Valid spectra selection during modeling process is now a hard nut to crack.In this study,a novel NIR sensor and a cosine distance method were introduced to solve this problem in order to make thefluidized process into"visualization".A NIR sensor wasfixed on the side of the expansion chamber to acquire the NIR spectra.Then valid spectra were selected based on a cosine distance method to reduce the influence of dynamic disturbances.Finally,spectral pretreatment and wavelength selection methods were investigated to establish partial least squares(PLS)models to monitor the mois-ture content.The results showed that the root mean square error of prediction(RMSEP)was 0.124%for moisture content model,which was much lower than that without valid spectra selection treatment.All results demonstrated that with the help of valid spectra selection treatment,NIR sensor could be used for real-time determination of critical quality attributes(CQAs)more accurately.It makes the manufacturing easier to understand than the process parameter control.

Chemometric identification of canonical metabolites linking critical process parameters to monoclonal antibody production during bioprocess development

A deeper understanding of the biological events occurring when bioprocess parameters changed will be of great value in improving the monoclonal antibodies (mAbs) production. Design of experiment (DoE) was applied to investigate the effect of process parameters (pH, temperature shift and dissolve oxygen (DO)) on protein titer. The key metabolites connecting the critical process parameters (CPPs) with monoclonal antibody production were identified by different chemometrics tools. Finally, the biological events of marker metabolites relating with titer improvement were concluded. pH and temperature shift were identified as CPPs that affect the target protein titer. A series of metabolites influenced by the altered CPPs and correlated with protein titer were screened by principal component analysis (PCA) and Pearson' correlation test. The marker metabolites and their pathways linking CPPs to target protein titer in different culture phases were summarized. Metabolomics and chemometrics are promising data-driven tools to shine light into the biological black box between the bioprocess parameters and process performance.

Geographical origin discrimination and polysaccharides quantitative analysis of Radia codonopsis with micro near-infrared spectrometer engine

At present,Tradition Chinese Medicine(TCM)industry in China is in the stage from the empirical development to industrial production.Near infrared(NIR)spectroscopy has been widely used in the quality control of TCM's modernization with its characteristics incuding rapidness,nondestruction,simplicity,economy,and so on.In this study,as one type of a portable micro NIR spectrometer,Micro NIR 1700 was used to establish the qualitative models for identification of geographical region and authenticity of Radix codonopsis based on discriminant analysis(DA)method.Both of the DA models had better predictive ability with 100%accuracy.In addition,a method for rapid quantitative analysis of polysaccharide in Radix codonopsis was also developed based on Micro NIR 1700 spectrometer with partial last-squares(PLS)algo-rithm.In the PLS calibration model,the NIR.spectra of samples were pretreated with different preprocessing methods and the spectral region was selected with different variable selection methods as well.The performance of the final PLS model was evaluated according to correlation cofficient of calibration(Rc),correlation coefficient of prediction(Rp),root mean squared error of cross validation(RMSECV),and root mean squared of prediction(RMSEP).The values of Re,Rp,RMSECV,and RMSEP were 0.9775,0.9602,2.496,and 2.734 g/mL,respectively.This work demonstrated that micro infrared spectrometer could be more convenient and rapid for quality control of Radix codonopsis,and the presented models would be a u1seful reference for quality control of other simi lar raw materials of TCM.

Application of near infrared spectroscopy in monitoring the moisture content in freeze-drying process of human coagulation factor VIII

As an important process analysis tool,near infrared spectroscopy(NIRS)has been widely used in process monitoring.In the present work,the feasibility of NIRS for monitoring the moisture content of human coagulation factor VIII(FVIII)in freeze-drying process was investigated.A partial least squares regression(PLS-R)model for moisture content determination was built with 88 samples.Different pre-processing methods were explored,and the best method found was standard normal variate(SNV)transformation combined with 1st derivation with Savitzky–Golay(SG)15 point smoothing.Then,four different variable selection methods,including uninformative variable elimination(UVE),interval partial least squares regression(iPLS),competitive adaptive reweighted sampling(CARS)and manual method,were compared for eliminating irrelevant variables,and iPLS was chosen as the best variable selection method.The correlation coe±cient(R),correlation coe±cient of calibration set(Rcal),correlation coefficient of validation set(Rval),root mean square errors of cross-validation(RMSECV)and root mean square errors of prediction(RMSEP)of PLS model were 0.9284,0.9463,0.8890,0.4986% and 0.4514%,respectively.The results showed that the model for moisture content determination has a wide range,good linearity,accuracy and precision.The developed approach was demonstrated to be a potential for monitoring the moisture content of FVIII in freeze-drying process.

Foreign Grain Security Mechanisms and Implications for China

With constant growth of China's population and increasingly serious situation of farmland protection,the grain security has become a hot issue of China.This study firstly elaborated grain security measures in grain exporters,such as the United States,Australia,and EU,and grain importers such as Japan,South Korea and India.In line with these security measures,it analyzed implementation background of these policies.Finally,combining social and economic development situations and natural resource endowment of China,it revealed the implications of these measures for China and came up with policy recommendations for China's grain security.

Overview of Studies on Grain Security in China

Through overview of relevant literature and on the basis of basically grasping frontier study and development trend,this paper discussed the grain security from industrial structure,farmland protection,grain import,urbanization and industrialization,grain reserve,ecological protection,and grain security pre-warning,in the hope of providing some convenience and reference for future related researches.

pH value monitoring during human albumin purification with near infrared spectroscopy and chemometrics

Human albumin(HA)is a very important blood product which requires strict quality controlstrategy.Acid precipitation is a key step which has a great effect on the quality of final product.Therefore,a new method based on quality by design(QbD)was proposed to investigate thefeasibility of realizing online quality control with the help of near infrared spectroscopy(NIRS)and chemometrics.The pH value is the critical process parameter(CPP)in acid precipitationprocess,which is used as the end-point indicator.Six batches,a total of 74 samples of acidprecipitation process,were simulated in our lab.Four batches were selected randomly as cali-bration set and remaining two batches as validation set.Then,the analysis based on materialinformation and three dfferent variable selection methods,including interval partial least squaresregression(iPLS),competitive adaptive reweighted sampling(CARS)and correlation coeficient(CC)were compared for eliminating irrelevant variables,Fimally,iPLS was used for variablesselection.The quantitative model was built up by partial least squares regression(PLSR).Thevalues of determination coeficients(R^(2)_(C) and R^(2)_(P)),root mean squares error of prediction(RMSEP),root mean squares error of calibration(RMSEC)and root mean squared error of crossvalidation(RMSECV)were 0.969,0.953,0.0496,0.0695 and 0.0826,respectively.The paired t test and repeatability test showed that the model had good prediction ability and stability.The results indicated that PLSR model could give accurate measurement of the pH value.

A useful quantitative model for determination of enantiomeric composition of racemate praziquantel by ultraviolet spectroscopy combined with partial least squares and its application to praziquantel tablets

A simple and novel method has been proposed to determine the enantiomeric composition ofracemate praziquantel(PzQ)by using the analysis of ultraviolet(UV)spectroscopy combinedwith partial least squares(PLS),This method does not rely on the use of expensive carbohydratessuch as cyclodextrins,but on the use of inexpensive sucrose,which is equally effective as car-bohydrate.PZQ has two enantiomers.Through measuring the slight diference in the UV spectralabsorption of PzQ due to different interactions between its two enantiomers and sucrose,theenantiomeric composition was determined by a quantitative model based on PLS analysis.Themodel showed that the correlation coeficients of calibration set and validation set were 0.9971and 0.9972,respectively.The root mean square error of calibration(RMSEC)and the root meansquare error of prediction(RMSEP)were 0.0167 and 0.0129,respectively,Then,the independentdata of PZQ tablets were also used to test how well the quantitative model of PLS predicted theenantiomeric composition,The ratio of S-PZQ in tablet was 0.492,determined by high-perfor-mance liquid chromatography as the reference value,Six solutions of the tablet samples were prepared,and the ratios of S-PZQ in tablet samples in the validation set were predicted by the PLS model.,Theirrelative erors with the reference value were not more than 4%.Therefore,the established model couldbe accurate and employed to predict the enantiomeric compositions of PzQ tablets.

Rapid monitoring the water extraction process of Radix Paeoniae Alba using near infrared spectroscopy

Near infrared(NIR)spectroscopy has been developed into one of the most important process analytical techniques(PAT)in a wide field of applications.The feasibility of NIR spectroscopy with partial least square regression(PLSR)to monitor the concentration of paeoniflorin,albi-florin,gallic acid,and benzoyl paeoniforin during the water extraction process of Radix Paeoniae Alba was demonstrated and verified in this work.NIR spectra were collected in transmission mode and pretreated with smoothing and/or derivative,and then quantitative models were built up using PLSR.Interval partial least squares(iPLS)method was used for the selection of spectral variables.Determination coeficients(R2aI and R2red),root mean squares error of prediction(RMSEP),root mean squares error of calibration(RMSEC),and residual predictive deviation(RPD)were applied to verify the performance of the models,and the corresponding values were 0.9873 and 0.9855,0.0487 mg/mL,0.0545mg/mL and 8.4 for paeoniforin;0.9879,0.9888,0.0303 mg/mL,0.0321 mg/mL and 9.1 for albiflorin;0.9696,0.9644,0.0140 mg/mL,0.0145 mg/mL and 5.1 for gallic acid;0.9794,0.9781,0.00169 mg/mL,0.00171 mg/mL and 6.9 for benzoyl paeoniflorin,respectively.The results turned out that this approach was very efficient and environmentally friendly for the quantitative monitoring of the water extraction process of Radix Paeoniae Alba.

Numerical modeling to investigate slopes and mass flow phenomena

An overview is given about up-to-date techniques for slope stability and deformation analysis as well as mass flow phenomena simulation.The paper concentrates on a few aspects in respect to the use of numerical modeling techniques,especially in relation to the shear strength reduction techniques,discontinuum modeling,probabilistic concepts,the combination of GIS and numerical modeling as well as sophisticated hydro-mechanical coupling with time-dependent material behavior.At present these topics are preferred topics of scientific and technical research.

Anti-seismic research on nuclear engineering siting

Nuclear engineering belongs to significant project;there is higher requirement on sitings.The study has discussed basic factors of selecting sites,anti-seismic research on sitings including the seismic ground motion,probability methods of seismic hazard analysis as well as interaction about structure and foundation,meanwhile provide the reason for nuclear engineering selecting sites.

再成形(Re-Balled)焊球阵列封装的焊球强度评估

近年来,许多国家禁止在电子产品中铅的使用,但是一些特定产品拥有豁免权。拥有豁免权的电子产品生产厂商面临含铅元器件供应缺乏的现状,因此生产厂商开始寻求利用焊球再成形技术把焊球阵列封装中的无铅焊球转变为锡铅焊球。焊球再成形技术曾经被用于元器件的回收再利用,但是关于焊球再成形元器件的可靠性信息十分有限。介绍了利用焊球再成形技术使无铅焊球阵列封装转变为锡铅焊球阵列封装。两种焊球去除方法和两种焊球再贴装方法分别用于实现从无铅焊球到锡铅焊球的转变,用以调查再成形工艺对于封装质量的影响。热时效试验以及焊球强度评估用于检测焊球再成形工艺过程。

Fault diagnosis of HVAC system with imbalanced data using multi-scale convolution composite neural network

Accurate fault diagnosis of heating,ventilation,and air conditioning(HVAC)systems is of significant importance for maintaining normal operation,reducing energy consumption,and minimizing maintenance costs.However,in practical applications,it is challenging to obtain sufficient fault data for HVAC systems,leading to imbalanced data,where the number of fault samples is much smaller than that of normal samples.Moreover,most existing HVAC system fault diagnosis methods heavily rely on balanced training sets to achieve high fault diagnosis accuracy.Therefore,to address this issue,a composite neural network fault diagnosis model is proposed,which combines SMOTETomek,multi-scale one-dimensional convolutional neural networks(M1DCNN),and support vector machine(SVM).This method first utilizes SMOTETomek to augment the minority class samples in the imbalanced dataset,achieving a balanced number of faulty and normal data.Then,it employs the M1DCNN model to extract feature information from the augmented dataset.Finally,it replaces the original Softmax classifier with an SVM classifier for classification,thus enhancing the fault diagnosis accuracy.Using the SMOTETomek-M1DCNN-SVM method,we conducted fault diagnosis validation on both the ASHRAE RP-1043 dataset and experimental dataset with an imbalance ratio of 1:10.The results demonstrate the superiority of this approach,providing a novel and promising solution for intelligent building management,with accuracy and F1 scores of 98.45%and 100%for the RP-1043 dataset and experimental dataset,respectively.

A review of whole-process control of industrial volatile organic compounds in China

Volatile organic compounds(VOCs)play an important role in the formation of ground-level ozone and secondary organic aerosol(SOA),and they have been key issues in current air pollution prevention and control in China.Considerable attention has been paid to industrial activities due to their large and relatively complex VOCs emissions.The present research aims to provide a comprehensive review on whole-process control of industrial VOCs,which mainly includes source reduction,collection enhancement and end-pipe treatments.Lower VOCs materials including water-borne ones are the keys to source substitution in industries related to coating and solvent usage,leak detection and repair(LDAR)should be regarded as an efficient means of source reduction in refining,petrochemical and other chemical industries.Several types of VOCs collection methods such as gas-collecting hoods,airtight partitions and others are discussed,and airtight collection at negative pressure yields the best collection efficiency.Current end-pipe treatments like UV oxidation,low-temperature plasma,activated carbon adsorption,combustion,biodegradation,and adsorption-combustion are discussed in detail.Finally,several recommendations are made for future advanced treatment and policy development in industrial VOCs emission control.

Interspecific competition predicts the potential impact of little fire ant Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae) invasion on resident ants in southern China

The little fire ant Wasmannia auropunctata(Roger)is a major invasive species that seriously threatens the biodiversity of invaded areas.W.auropunctata was first reported in Chinese mainland in 2022 and its impact on native species is still unknown.To evaluate the impact of W.auropunctata invasion on the ant communities in southern China,a series of interspecific competition experiments were conducted in this study.The individual aggression index and group aggression experiments showed the advantage of W.auropunctata in competition with 5 resident ants under equal worker numbers.When encountering Anoplolepis gracilipes,Camponotus nicobarensis,Tetramorium bicarinatum,Polyrhachis dives,and Solenopsis invicta,W.auropunctata gradually gained a competitive advantage with an increase in its number of workers.In the group aggression experiments with equal worker numbers,there was a negative correlation between the body length and mortality rate of resident ants.The results of the foraging behavior experiments showed that W.auropunctata was able to dominate food resources under competition with Carebara diversa,which also displayed weak competition in the group aggression bioassay.In addition,the abilities to recruit workers and retrieve food were inhibited under competition with S.invicta and T.bicarinatum.The results of the nesting behavior experiments showed that in the 24-h bout of space resource competition,W.auropunctata was dominant over C.diversa,S.invicta,and T.bicarinatum.The results of this study show that W.auropunctata has certain advantages in competition for food and space resources over resident ants in southern China,and some resident ant species may be replaced in the future.

A comprehensive classification method for VOC emission sources to tackle air pollution based on VOC species reactivity and emission amounts

In China, volatile organic compound（VOC） control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were based on VOC emission amounts（EA）, but never considered the significant differentiation of VOC species in terms of atmospheric chemical reactivity. This will adversely influence the effect of VOC reduction on air quality improvement. Therefore,this study attempted to develop a comprehensive classification method for typical VOC sources in the Beijing–Tianjin–Hebei region（BTH）, by combining the VOC emission amounts with the chemical reactivities of VOC species. Firstly, we obtained the VOC chemical profiles by measuring 5 key sources in the BTH region and referencing another 10 key sources, and estimated the ozone formation potential（OFP） per ton VOC emission for these sources by using the maximum incremental reactivity（MIR） index as the characteristic of source reactivity（SR）. Then, we applied the data normalization method to respectively convert EA and SR to normalized EA（NEA） and normalized SR（NSR） for various sources in the BTH region.Finally, the control index（CI） was calculated, and these sources were further classified into four grades based on the normalized CI（NCI）. The study results showed that in the BTH region,furniture coating, automobile coating, and road vehicles are characterized by high NCI and need to be given more attention; however, the petro-chemical industry, which was designated as an important control source by air quality managers, has a lower NCI.

Multi-dimension apportionment of clean air “parade blue”phenomenon in Beijing

The mass concentration and major chemical components of fine particulate matter were measured before,during and after Beijing＇s massive parade commemorating 70th anniversary of the Chinese Victory in World War II on September 3,2015.Regional emission inventory,positive matrix factorization（PMF）,observations from space and backward air mass trajectories were jointly applied to identify the major pollution sources and their temporal and spatial variations.The contributions of emissions variations and the meteorological conditions related to the＂parade blue＂phenomenon in Beijing and its surrounding areas were investigated in detail.The main cause of the decreased PM（2.5）mass concentration was attributed to the absolute reduction in emissions of primary air pollutants.The chemical composition of PM（2.5）varied significantly before,during and after the parade.Fugitive dust particles were well controlled,the secondary formation of PM（2.5）was reduced along with the controlled gaseous precursors＇emissions from vehicles and industrial sources during the temporary intensified control period.During the parade period,the SO2and NO2column concentrations in Beijing and the surrounding areas decreased sharply,indicating that the coordinated reduction in primary emissions from the surrounding areas of Beijing played an important role in lowering the ambient concentration of SO2and NO2and accordingly lowered PM（2.5）and improved the regional air quality.A comparison of the temperature,humidity,and wind speed and direction during the same periods in 2014 and 2015 showed that the meteorological conditions positively influenced the achievement of＂parade blue＂.

Physico-chemical characterization and source tracking of black carbon at a suburban site in Beijing

Particles from ambient air and combustion sources including vehicle emission, coal combustion and biomass burning were collected and chemically pretreated with the purpose of obtaining isolated BC（black carbon） samples. TEM（transmission electron microscopy）results indicate that BC from combustion sources shows various patterns, and airborne BC appears spherical and about 50 nm in diameter with a homogeneous surface and turbostratic structure. The BET（Barrett-Emmett-Teller） results suggest that the surface areas of these BC particles fall in the range of 3-23 m2/g, with a total pore volume of 0.03-0.05 cm3/g and a mean pore diameter of 7-53 nm. The nitrogen adsorption-desorption isotherms are indicative of the accumulation mode and uniform pore size. O2-TPO（temperature programmed oxidation）profiles suggest that the airborne BC oxidation could be classified as the oxidation of amorphous carbon, which falls in the range of 406-490℃ with peaks at 418, 423 and 475℃,respectively. Generally, the BC characteristics and source analysis suggest that airborne BC most likely comes from diesel vehicle emission at this site.

A V2I communication-based pipeline model for adaptive urban traffic light scheduling

Adaptive traffic light scheduling based on realtime traffic information processing has proven effective for urban traffic congestion management. However, fine-grained information regarding individual vehicles is difficult to acquire through traditional data collection techniques and its accuracy cannot be guaranteed because of congestion and harsh environments. In this study, we first build a pipeline model based on vehicle-to-infrastructure communication, which is a salient technique in vehicular adhoc networks. This model enables the acquisition of fine-grained and accurate traffic information in real time via message exchange between vehicles and roadside units. We then propose an intelligent traffic light scheduling method (ITLM) based on a “demand assignment” principle by considering the types and turning intentions of vehicles. In the context of this principle, a signal phase with more vehicles will be assigned a longer green time. Furthermore, a green-way traffic light scheduling method (GTLM) is investigated for special vehicles (e.g., ambulances and fire engines) in emergency scenarios. Signal states will be adjusted or maintained by the traffic light control system to keep special vehicles moving along smoothly. Comparative experiments demonstrate that the ITLM reduces average wait time by 34%-78% and average stop frequency by 12%-34% in the context of traffic management. The GTLM reduces travel time by 22%^44% and 30%-55% under two types of traffic conditions and achieves optimal performance in congested scenarios.