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To solve the problem of inaccurate position estimation due to the influence of magnetic saturation in sensorless control of switched reluctance motor (SRM), a new position estimation method is proposed. By analysing the linearity of the inductance curve, the region with better linearity can be found. Then, in this region, the mathematical model between rotor position and inductance can be built to estimate the rotor position by the linear fitting. However, the inductance curve will shift due to the influence of magnetic saturation in the case of heavy load, which makes the estimation error larger. Therefore, this study carries out a linear fitting of this region under different loads and establishes a linear inductance model with variable coefficient. This method can effectively eliminate the influence of saturation inductance on position estimation and have better estimation accuracy. Simulation and experimental results show the effectiveness and correctness of the proposed method.

The stress rupture properties and deformation mechanisms of K4750 alloy at 650 °C, 700 °C, 750 °C and 800 °C were investigated. As the decrease of temperature and stress, the stress rupture life gradually increased. A Larson-Miller Parameter (LMP) method was used for analyzing the stress rupture life under different conditions. The linear fitting formula between stress (σ) and LMP was derived as σ = 3166.455 − 119.969 × LMP and the fitting coefficient was 0.98. After testing, the dislocation configurations of all stress rupture samples were investigated by transmission electron microscopy (TEM). The temperature and stress had a significant impact on the deformation mechanism, thereby affected the stress rupture life of K4750 alloy. As the increasing stress at a given temperature, the deformation mechanism gradually transformed from Orowan looping to stacking fault shearing. Based on experimental results, the threshold stress at 650 °C, 700 °C, 750 °C and 800 °C for the transition of deformation mechanism was estimated to be about 650 MPa, 530 MPa, 430 MPa and 350 MPa, respectively. Below the threshold stress, γ' phase effectively hindered dislocation motion by Orowan looping mechanism, K4750 alloy had a long stress rupture life. Slightly above the threshold stress, Orowan looping combining stacking fault shearing was the dominant mechanism, the stress rupture life decreased. As the further increase of stress, stacking fault shearing acted as the dominant deformation mechanism, the resistance to dislocation motion decreased rapidly, so the stress rupture life reduced significantly.

The influence of the thickness variation of the cell wall on the active heat dissipation of the cellular sandwich was studied by deducing the thermal performance index of the cellular sandwich with variable thickness. The relationship between the relative density and the thermal performance index of the cellular sandwich with different cell structures was analyzed. Then, the maximum thermal performance index and the optimum relative density of the cellular sandwich with different cell structures were obtained. The relationship between the maximum thermal performance index and the optimal relative density and the variable thickness parameter was given by using linear fitting. The influence of the thickness of cell wall thickness on the optimal relative density and maximum thermal performance index of different cell structures was analyzed. It was concluded that the change in cell wall thickness has the slight effect on the hexagon, and the effect on the triangle and square is big.

In this paper, spinyhead croaker (Collichthys lucidus) fat content forecasting model using electronic nose (e-nose) and non-linear stochastic resonance (SR) has been studied. Spinyhead croaker samples are stored at 4 °C temperature. Physical/chemical indexes (firmness, total volatile basic nitrogen (TVB-N), pH, and fat content) are examined to provide quality references for e-nose. E-nose responses are treated by principal component analysis (PCA), bistable SR, and double-layered cascaded serial SR (DCSSR). SR and DCSSR SNR maximal (SNR-Max) values discriminate croakers clearly. Multi-variables regressions (MVR) are conducted between physical/chemical indexes and SR/DCSSR SNR-Max values. MVR results demonstrate that DCSSR feature values have more significant linearity relation with physical/chemical indexes. Spinyhead croaker fat content forecasting model is developed via linear fitting regression on SR SNR-Max values. Validating experimental results demonstrate that the developed model has good accuracy.

Background Three-dimensional (3D) speckle tracking imaging (STI) allows the simultaneous assessment of left ventricular (LV) strain and volume. We aim to explore the value of LV strain–volume loops in predicting response to cardiac resynchronization therapy (CRT). Methods Forty heart failure (HF) patients scheduled for CRT and twenty healthy individuals were enrolled. All subjects received a 3D echocardiography and 3D STI analysis to acquire LV global and segmental principal strain (PS) and volume simultaneously. Values were plotted in a Cartesian system to construct PS–volume loop which was assessed using the two characteristics of the linear fitting curve: the slope and the coefficient of determination (R2-S/D coupling). Results HF patients at baseline showed significantly lower slope and R2-S/D coupling of all PS–volume loops than healthy subjects. As for as comparing Segmental PS–Global volume loop at baseline, Midseptal R2-S/D coupling was lower and Midlateral slope was higher in CRT responders than in non-responders. For each individual, the abnormal segmental heterogeneity of Midseptal slope and R2-S/D coupling were lower than Midlateral was observed only in responders. At follow-up, significant improvements of the Midseptal slope and R2-S/D coupling were observed in responders. Midseptal R2-S/D coupling at baseline was an independent predictor of CRT response and the cut-off value of 0.55 was recommended with sensitivity of 89% and specificity of 77%. Conclusions Analysis of strain–volume loops could provide unique information for predicting response to CRT. Assessment of septal myocardial wasted work at baseline is helpful to improve patient selection for CRT.

We proposed a rapid autofocusing method exploiting holographic polarization microscope, which could determine the refocusing distance without multiple reconstructions and complex network training. The defocus distance of the object is calculated rapidly by identifying the separation distance of the two defocus images of the object and using the linear relation between the defocus distance of the object and the separation distance of the two defocus images of the object. The linear relationship is obtained by numerical propagation and linear fitting. Last, we have demonstrated the effectiveness of the proposed method by reconstructing the in-focus images of flowing cells. We believe that our proposed method could be a powerful tool for dynamic observation and extend the application of holographic polarization microscope.

In this paper, a synthesis algorithm of text classification and image recognition is proposed. This algorithm directly extends the original image recognition method. And its novelty is based on the fusion algorithm of image recognition and text classification as a new mathematical derivation approach, which uses stepwise linear fitting to fuse multiple models. We use the new fitting method, which makes use of the idea of fitting the model with different weights, to expand the training data. The principle of the method is introduced in detail, and the experimental results are given.

The poplar wood industry chain from planted forests takes a strategic position for the creation of a competitive, profitable, and highly technological bioeconomy in the world. Niche sectors such as buildings can find in poplar wood an effective ally to reduce its carbon footprint and ecological backpack. For the poplar wood, it is important to understand the huge significance of the proper silvicultural management of a plantation and to characterize the raw material. In this context, this paper carries out such characterization for the particular case of young plantations of the clone I-214 (Populus × euroamericana (Dode) Guinier), commonly used for its high growth rate. The acoustic non-destructive characterization of poplar wood is carried out from standing trees, logs and sawn timber and then compared with the one obtained through destructive mechanical tests. The study shows that growth parameters are highly affected by the age and moderately affected by stand density, while mechanical properties are strongly affected by the age and less affected by the stand density. The study also shows high values of the linear regression coefficients between the mechanical properties obtained on standing trees, logs, and sawn timber using non-destructive and destructive methods (R2 = 0.7 for all three cases), greater than those obtained for other species. A good linear fitting was obtained between the tree and log velocities (R2 = 0.76) and between the tree and log elastic moduli (R2 = 0.85). Consequently, the evaluation of the mechanical properties employing the optimized acoustic protocol provides a reliable characterization for the poplar wood.

The monitoring value of strain of a concrete bridge is mainly affected by concrete shrinkage and creep, temperature, vehicle loads, etc. Seasonal temperature, daily solar radiation and cold current are the main influencing factors of temperature. Among them, temperature effect of daily solar radiation has a significant impact on the monitoring value of strain. Based on the monitoring data of the concrete bridge in Dongying City, Shandong Province, China, a method to separate the temperature effect of daily solar radiation from the monitoring value of strain of the bridge health monitoring system is obtained. Based on the analysis of the monitoring data of strain and temperature in the concrete girder, a model of the relationship between strain and temperature was established by using the unary linear fitting method. The strain separated from temperature effect of daily solar radiation can provide an effective basis for safety assessment of a concrete bridge.

Countries in the world now are trying best to conserve energy and reduce emissions, at the meantime, efficient actions are taken to tackle with global warming. Emission reduction of main greenhouse gas CO2 can be achieved efficiently via CO2 geological storage, in terms of CO2 saline aquifer storage. The gas–liquid–solid interactions such as interfacial tension determines the injectability, sealing capacity and safety of this scheme. In order to better predict the storage capacity to evaluate the storage safety, this work aims at carrying out the numercial modelling work on the interfacial tension of CO2–water/brine binary system under the reservoir temperatures and pressures condition. A linear relationship between the increase in average interfacial tension and molality was observed and it is a function of the ionic type. Finally, modified empirical correlations based on experimental data in the literature, using only few regression coefficients with a relatively low error for most of the experimental data in the literature, were presented to estimate the CO2–water/brinebinary system interfacial tensions under wide range of temperatures, pressures, and the ionic strength..

Intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging (MRI) can be used to estimate perfusion-related parameters, but these parameters may differ, based on the curve-fitting algorithm used for IVIM. Microvessel density (MVD) and vascular endothelial growth factor (VEGF) status are used as angiogenic factors in breast cancer. We aimed to investigate the relationship between MVD, VEGF, and intravoxel incoherent motion (IVIM)-derived parameters, obtained by 4 curve-fitting algorithms, in patients with invasive breast cancers. This retrospective study investigated IVIM-derived parameters, D (ie, tissue diffusivity), D∗ (ie, pseudodiffusivity), and f (ie, perfusion fraction), of 55 breast cancers, using 10 b values (range, 0–800 s/mm2) and 4 curve-fitting algorithms: algorithm 1, linear fitting of D and f first, followed by D∗; algorithm 2, linear fitting of D and f and nonlinear fitting of D∗; algorithm 3, linear fitting of D and f, linear fitting of D∗, and ignoring D contribution for low b values; and algorithm 4, full nonlinear fitting of D, f, and D∗. We evaluated whole-tumor histograms of D, f, and D∗ for their association with MVD and VEGF. D∗10, D∗25, D∗50, D∗mean, D∗75, D∗90, f10, and f25, derived using algorithm 3, were associated with VEGF expression (P = .043, P = 0.012, P = .019, P = .024, P = .044, P = .041, P = .010, and P = .005, respectively). However, no correlation existed between MVD and IVIM-derived parameters. Perfusion-related IVIM parameters obtained by curve-fitting algorithm 3 may reflect VEGF expression.

Background: Since January 2020, COVID-19 has spread globally to more than 210 countries, and the epidemic lasted for more than 11 months. Scientists have studied many effective prevention and control strategies. Based on real-time big data on COVID-19 pneumonia captured by the Baidu App, our study aimed to analyse the characteristics of the COVID-19 pandemic in 10 epicentre countries. It also aimed to discuss the impact of politics, economy, and humanities on COVID-19 as well as effective strategies of prevention and control the epidemic. Methods: Based on the real-time big data report of the new coronavirus pneumonia epidemic in Baidu APP, collected from January 27 to December 22, 2020. Incidence and death data in the world and China, India, Europe UK, Italy, France, Spain, Russia, America Brazil, the United States, Mexico were collected.1 Excel 2016 was used to build a database and performed linear fitting analysis, R3.6.3 and ggplot2 package was used for descriptive statistical analysis. Current status and trends of morbidity and mortality in the world and epicenter countries were analyze. Findings: To December 22, 2020, in the recent 5 days, the top two incidence cases were America with 1,079,385 cases, and the United Kingdom with 197,037 cases; the bottom two were China with 507 cases, and Mexico 48,416 cases. The top two mortality cases were America with 12,180 cases, and Brazil with 3,500 cases; the bottom two were China 7 Cases, and Spain 664 cases. The top two incidence rates were in America 0.3303%, and the United Kingdom 0.2959%;the bottom two were in China 0.0000%,and India 0.0097%.The top two mortality rates were in Italy 0.0044%, and the United Kingdom 0.0042%;the bottom two were in China 0.0000%,and India 0.0001%.From January 27 to December 22, 2020,The top two cumulative confirmed cases were in America with 18,494,265 cases, and India with 10,094,801 cases; the bottom two were China 95,998 cases, and Mexico 1,325,915 cases. The top two incidence rate were America 5.6597%,and Spain 3.9442%;the bottom two were China 0.0069%, and India 0.7624%.The top two mortality cases were America with 327,171 cases, and Brazil with 187,322 cases; the bottom two were China with 4,773 cases, and Spain with 49,260 cases. The top two mortality rates were Italy 0.1144%,and Spain 0.1062%;the bottom two were China 0.0003%,and India 0.0111%.Compared with the global cumulative incidence rate general trend (κ=0.0141), there are significant differences between America (κ=0.0716), Brazil (κ=0.0579), Spain (κ=0.0547), and China (κ=4E-05). Compared with the global incidence rate in recent trend (κ=0.0283), there are obvious differences between America (κ=0.2962), Italy (κ=0.2171), France (κ=0.1840), and China (κ=1E-05).Compared with the global cumulative mortality general trend (κ=0.0003), there are significant differences between Brazil (κ=0.0016),America and Mexico (κ=0.0015), Spain and the United Kingdom (κ=0.0014), Italy (κ=0.0013), and China (κ=3E-06).Compared with the global incidence rate in recent trend (κ=0.0006), there are significant differences between Italy (κ=0.0048), France (κ=0.0037), America (κ=0.0033), and China (κ=E-07). Interpretation: The lives of people in India, the United States and most of epicenter countries in European and American are suffering from grave damage. The mutation of Coronavirus has made the already serious epidemic worse. The current epidemic situation in the epicenter country and the mutation of Coronavirus also pose a serious threat to the lives of people in the non-epicenter country. It is urgent to construct a new anti-epidemic strategy based on aseptic technology to end the devastation caused by Coronavirus to human beings. Funding Statement: The Key Projects of Research and Development of Hainan Province (No.: ZDYF2020109) Declaration of Interests: We declare no competing interests.

Investigating the effect of common allergens on allergic disease is very important for future human health. In this paper, we firstly propose the models for predicting the relationship between 39 common allergens and the joint level of total IgE and ECP. The joint level of total IgE and ECP is utilized to evaluate the order of severity for allergic disease. In particular, we employ the linear fitting method and deep learning method to obtain the models with high prediction accuracy, respectively. The validity of the proposed models can be verified by testing two other independent data sets from hospital diagnosis record. Additionally, we obtain some useful medical conclusions accordingly.

In this paper, we propose a pseudo-binocular stereo vision and linear fitting to achieve robot navigation. Pseudo-binocular stereo vision is realized by moving the robot body to the left or right with a certain distance. Then, a disparity map is calculated with the semi-global matching algorithm. This method can overcome the interference of complex color and texture for objects that are at the same distance. After edge detection and binarizing of the disparity map, road lines are extracted by the Hough transform algorithm. To extract the road lines from the noisy edges, the least square method for linear fitting is utilized for high-accuracy navigation.

In order to investigate the effect of different loading models on the nonlinear variations in Global Positioning System (GPS) height time series, the characteristics of annual signals (amplitude and phase) of GPS time series, loading series from Deutsche GeoForschungsZentrum, Germany (GFZ) and School and Observatory of Earth Sciences, France (EOST) at 633 global GPS stations are processed and analyzed. The change characteristics of the root mean square (RMS) reduction rate, annual amplitude and phase of GPS time series after environmental loading corrections (ELCs) are then detected. Results show that ELCs have a positive effect on the reduction in the nonlinear deformation contained in most GPS stations around the world. RMS reduction rates are positive at 82.6% stations after GFZ correction and 87.4% after EOST correction, and the average reduction rates of all stations are 10.6% and 15.4%, respectively. As for the environmental loading series from GFZ and EOST, their average annual amplitudes are 2.7 and 3.1 mm, which explains ~40% annual amplitude of GPS height time series (7.2 mm). Further analysis of some specific stations indicates that the annual phase difference between GPS height time series and the environmental loading series is an important reason that affects the reduction rates of the RMS and annual amplitude. The linear relationship between the annual phase difference and the annual amplitude reduction rate is significant. The linear fitting results show that when there is no annual phase difference between GPS and loading series, the reduction rates of the RMS and annual amplitude will increase to the maximum of 15.6% and 41.6% for GFZ, and 22.0% and 46.6% for EOST.

The nonlinear response of O3 to nitrogen oxides (NOx) and volatile organic compounds (VOC) is not conducive to accurately identify the various source contributions and O3-NOx-VOC relationships. An enhanced meta-modeling approach, polynomial functions based response surface modeling coupled with the sectoral linear fitting technique (pf-ERSM-SL), integrating a new differential method (DM), was proposed to break through the limitation. The pf-ERSM-SL with DM was applied for analysis of O3 formation regime and real-time source contributions in July and October 2015 over the Pearl River Delta Region (PRD) of Mainland China. According to evaluations, the pf-ERSM-SL with DM was proven to be effective in source apportionment when the traditional sensitivity analysis was unsuitable for deriving the source contributions in the nonlinear system. After diagnosing the O3-NOx-VOC relationships, O3 formation in most regions of the PRD was identified as a distinctive NOx-limited regime in July; in October, the initial VOC-limited regime was found at small emission reductions (less than 22-44%), but it will transit to NOx-limited when further reductions were implemented. Investigation of the source contributions suggested that NOx emissions were the dominated contributor when turning-off the anthropogenic emissions, occupying 85.41-94.90% and 52.60-75.37% of the peak O3 responses in July and October respectively in the receptor regions of the PRD; NOx emissions from the on-road mobile source (NOx_ORM) in Guangzhou (GZ), Dongguan&Shenzhen (DG&SZ) and Zhongshan (ZS) were identified as the main contributors. Consequently, the reinforced control of NOx_ORM is highly recommended to lower the ambient O3 in the PRD effectively.

Phthalate acid esters (PAEs) are one of the essential plastic additives which may lead to plenty of harmful effects, including reproductive toxicity, teratogenicity, and carcinogenicity. Increasing attention has been paid to the migration of plasticizer. In this article, the disposable plastic lunch boxes were taken as the research object. The result showed that dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP) have been mainly found, whose content was 1.5 mg/kg and 2.4 mg/kg, respectively. The LOD was 2 ng/g, and LOQ was 6.7 ng/g. We further investigated the migration of PAEs into the simulated liquid at different temperature conditions. Then, the linear fitting performing by first‐order kinetic migration model revealed that the lower the polarity of the simulated liquid, the larger the rate constant K 1 and initial release rate V 0. The higher the temperature, the bigger the K 1 and V 0., This study takes disposable plastic lunch boxes as the research object, and determines the types and contents of PAEs, which can provide some data support when considering the safety of lunch boxes. Secondly, polypropylene‐based lunch box was chosen as the migration material. The migration laws of different types of simulants at various temperatures and time points are studied, which lays a foundation for further studying the migration laws of PAEs in food processing and preservation.

Background: End-stage renal disease (ESRD) patients undergoing hemodyalisis therapy (HD) experience blood potassium ([K+]) variations that are reflected on the T-wave (TW) morphology. Methods: We evaluated the performance of different lead space reduction (LSR) methods: principal component analysis (PCA), maximising the TW energy, and two derived versions of periodic component analysis (πCA) named πCA B and πCA T , maximising the QRST or TW beat periodicity. We applied these methods to 12-lead electrocardiogram (ECG) from 24 ESRD-HD patients. Then, we derived three markers of TW morphology changes (d u w , d w and d ^ w,c ), comparing an average TW derived every 30 min with that at the HD end, from the PCA, πCA B and πCA T based leads having the highest TW energy content. Similarities between these three methods were assessed by using Bland-Altman plots and the linear fitting error (∊) evaluated from the 12 th to the 44 th h of ECG recordings after the HD onset. Results: All series of d u w , d w and d ^ w,c values showed good degree of mutual agreement (median bias ≤. 0.5 ms) and a small deviation from linearity in the [K+] increasing stage (median ∊ ≤ 3.3 ms). Conclusions: PCA andπCA can be used interchangeably to track TW changes in ESRD-HD patients, in this type of low noise contamination ECG recordings.

In this article, a new method for the reconstruction of hit-position and hit-time of photons in long scintillator detectors is investigated. This article is motivated by the recent development of the positron emission tomography scanners based on plastic scintillators. The proposed method constitutes a new way of signal processing in multivoltage-technique. It is based on the determination of the degree of similarity between the registered signals and the synchronized model signals stored in a library. The library was established for a set of well-defined hit-positions along the length of the scintillator. The Mahalanobis distance was used as a measure of similarity between the two compared signals. The method was validated on the experimental data measured using two-strips J-PET prototype with dimensions of $5\times 9\times 300$ mm3. The obtained time-of-flight (TOF) and spatial resolutions amount to 325 ps (FWHM) and 25 mm (FWHM), respectively. The TOF resolution was also compared to the results of an analogous study done using the linear fitting method. The best TOF resolution was obtained with this method at four predefined threshold levels which was comparable to the resolution achieved from the Mahalanobis distance at two predefined threshold levels. Although the algorithm of the linear fitting method is much simpler to apply than the Mahalanobis method, the application of the Mahalanobis distance requires a lower number of applied threshold levels and, hence, decreases the costs of electronics used in PET scanner.

La medición y evaluación de la biomasa aérea de árboles juega un papel importante en el manejo de los recursos forestales. Existen muchos modelos alométricos para especies tropicales y subtropicales, pero muy pocos para las zonas semiáridas. Un total de 144 árboles de Prosopis laevigata, de siete rodales naturales localizados en el noreste de méxico, fueron muestreados por un método destructivo con la finalidad de desarrollar ecuaciones para la predicción de la biomasa total. la selección de los individuos cubrió varios intervalos de diámetro basal (5.2 a 41.8 cm) y de altura (1.4 a 9.7 m). Se contrastaron procedimientos de ajuste no-lineal y lineal de la ecuación alométrica y = a·xb + ε, para estimar la biomasa aérea de P. laevigata. Aunque, el procedimiento no-lineal tuvo el mejor ajuste (r2 = 0.95 y p < 0.001) vs el lineal (r2 = 0.84 y p < 0.001), los resultados demuestran que la transformación logarítmica y el uso de un factor de corrección en alometría mejora de forma significativa la predicción de la biomasa. Se concluye que los modelos de regresión obtenidos al usar el diámetro basal pueden ser aplicados para la estimación de biomasa total, en árboles de Prosopis laevigata. Así mismo, el número mínimo de observaciones necesarias para calcular los parámetros a y b, con varianza mínima es de 40 ejemplares.

International audience; This article describes a new measure model to harvest electrical energy from a mechanically excited structure equipped with piezoelectric elements. With the P-43 type cylinder piezoceramic as an object of the research, the output current was theoretically analysed and the output current prediction model was established by multivariate linear fitting method under different frequency, preload and sinusoidal excitation. The excitation experiment was carried out with the excitation frequency of 5–70 Hz, preload of 5–20 MPa and stress amplitude of 0–20 MPa, and the output current parameters were obtained. The experimental results were compared with the theoretical model with the error

The measurement of the infiltration airflow rates can support the calculation of the infiltration cooling load for the better understanding and optimizing the energy consumption of cold stores. However, the large temperature difference and the intense transient features make it difficult and complex to measure the airflow rates accurately. In this paper, a simple and practical method to measure the transient infiltration airflow rates is developed by using the local air velocity linear fitting. The proposed method is validated by the measurement results of the tracer gas decay method. It is concluded that the proposed method shows a good performance on the transient infiltration airflow rates measurement. The measurement errors are between ±10%. To enhance the application of this method, the layout of the measuring points of the air velocities are analyzed. The results show that, along the vertical layout direction, air velocity measuring points around the neutral level (where the cold and the warm air separate, about the middle height of the door) are not preferred when using this method. What’s more, the calculation of the infiltration cooling load by using this measuring method is also discussed.

In this paper, effects of heavy rain on the lateral/directional stability and control performance of a DHC-6 Twin Otter aircraft are determined based on from the numerical simulation data. A two-way momentum coupled Eulerian–Lagrangian approach developed for two-phase flow simulation is adopted to obtain the fundamental aerodynamic coefficients in the rain condition. Then the lateral/directional aerodynamic derivatives of the aircraft in rain are evaluated based on the linear fitting processing and the strip theory. Finally, the lateral/directional stability of the aircraft in rain is obtained and the controllability is analyzed by simulation of the responses to unit step changes in the control surface deflections. The present results indicate that heavy rain can cause penalties in both the aerodynamic and flight mechanical performance of aircraft.

Csium-137 (137Cs) contamination resulted from wastes disposal and incidents holds serious threat to ecosystems and human health. Electro-kinetic remediation (EKR) is a promising technique for the 137Cs remediation while soil pH polarization remains to be the obstacle for improving its performance. In this study, strategies of non-uniform electric intensity (EI) and polarity reversal (PR) have been employed to enhance the EKR. A 2-dimensinal (2D) numerical model was applied to stimulate the transport-reactive processes and predict the possible electro-chemical variations during the remediation. Within 168 h treatment, each strategy could increased the EKR efficiency on 137Cs removal by 5% and larger increase (12%) was observed when combined these two strategies. Good agreements were achieved between the experimental and model results which further verified the feasibility of enhanced EKR on soil 137Cs removal. In addition, a polynomial linear fitting analysis was implemented for the optimization of PR frequency. The 24 h was determined as the optimal PR frequency and 90% of 137Cs (276 mg) in polluted kaolin was eliminated within 415 h by PR-EKR under a non-uniform EI. Moreover, the energy utilization efficiency and cost for such technology was obtained in an acceptable value of 0.96 mg/kWh and $ 829, respectively. The results of the semi-pilot experiments indicated that EKR enhanced with non-uniform EI and PR strategies might be practicable and effective for the decontamination of soil 137Cs in full-scale applications.

Ocean heat content (OHC) plays an important role in ocean carbon uptake (OCU). However, the changes of OHC and OCU are model-dependent and have large bias compared with observations. This makes it difficult to quantify their relationship. Here, we propose a new metric to measure the uncertainty of the relationship between OHC and OCU. The new metric can link the uncertainty with different OCU processes and allow direct comparison of the impact of OHC on the OCU in different simulations. The metric is illustrated in different simulations of the Coupled Model Intercomparison Project phase 5 (CMIP5) in which atmospheric CO2 is increased by 1%/year. Results show that OHC in 0–500 m plays a dominant role in the OCU for the radiatively coupled (RAD) experiment because warming intensifies the carbon loss in the upper ocean. Relatively, OHC in the intermediate waters (500–2000 m) are crucial for the fully coupled and biogeochemically coupled experiment because this layer largely regulates the OCU. For different ocean basins, the intermediate Southern Ocean and deep North Atlantic are more important for the OCU in the RAD simulation. The metric also suggests the importance of global overturning circulation and the Southern Ocean in the OCU.

In this paper, ridgetail white prawn (Exopalaemon carinicauda) K value predicting model by electronic nose (EN) was studied. Human sensory evaluation (HSE), weight loss, color, total viable counts (TVC), GC-MS, and K value were examined to provide quality references for EN detection. EN responses to prawns were recorded and processed by principal component analysis (PCA) and stochastic resonance (SR). Results indicated that prawn K value rapidly increased due to microbiology propagation. The volatile gases emitted by prawns increased with the increase of storage time based on GC-MS results. PCA method could not discriminate the prawns in different qualities, and SR signal-to-noise ratio (SNR) maximum (SNRmax) values successfully discriminated all samples. K value predicting model was developed by linear fitting regression between K values and SNRmaxvalues (R2 = 0.97). The proposed method will promote the applications of EN in aquatic product quality rapid determination.

Objective To determine the effect of very high stimulation frequency (150 and 200 Hz) with wide pulse duration versus 50 Hz with wide pulse duration on stimulated force and fatigue of quadriceps femoris in healthy participants. Methods Thirty-four healthy participants underwent fatigue test using three stimulation frequency conditions (50, 150, and 200 Hz) with pulse duration of 0.9 ms. Normalized force values at the end of each fatigue protocol and curve fitting patterns were compared among stimulated frequencies. Results Very high stimulation frequency (150 and 200 Hz) conditions showed a trend of having more decline in normalized stimulated force during fatigue test compared to a low stimulation frequency at 50 Hz. However, the difference was not statistically significant. Responder group showed the same slope of a linear fitting pattern, implying the same pattern of muscle fatigue among three stimulation frequency conditions (-3.32 in 50 Hz, -2.88 in 150 Hz, and -3.14 in 200 Hz, respectively). Conclusion There were high inter-subject variations in the response to different frequency stimulation conditions. However, very high stimulation frequency generated the same fatigue pattern as the low stimulation frequency in the responder group. Further research is needed to explore the mechanism involved.

In this study, changes in various states of water in apple cubes were assessed using low-field nuclear magnetic resonance (LF-NMR) during microwave vacuum drying. Apple cubes were dried at differen...

The interactions between elements such as Ca, Fe, Si, Na, Mg, Al, and S in a cement sample were analyzed using prompt gamma neutron activation analysis (PGNAA). The actual Ca, Si, and Fe contents in the cement sample and the measured values from the PGNAA were compared in terms of the interactions between the elements using a linear fitting technique, followed by applying a regression analysis correction. The results show that the linearly fitted graphs have more decentralized data points, with relatively larger errors in the measured Ca, Fe, and Si contents (maximum errors are 18.07, 1.68, and 18.47, respectively). However, the interactions between Ca, Fe, Si, Na, Mg, Al, S, and other elements were eliminated after applying the correction. Accordingly, the errors in the measured Ca, Fe, and Si contents were lower (maximum values are 0.97, 0.13, and 0.01, respectively). The correction method helps in improving the measurement accuracy.

A scheme for quantitatively computing the acid dissociation constant, pKa, of hydrated molecules is proposed. It is based on the three-dimensional reference interaction site model self-consistent field (3D-RISM-SCF) theory coupled with the linear fitting correction (LFC) scheme. In LFC/3D-RISM-SCF, pKa values of target molecules are evaluated using the Gibbs energy difference between the protonated and unprotonated states calculated by 3D-RISM-SCF and the parameters fitted by the LFC scheme to the experimental values of training set systems. The pKa values computed by LFC/3D-RISM-SCF show quantitative agreement with the experimental data.

A chairside tool for quantitative analysis of dental caries would improve clinical dental inspections. The wireless caries sensing tool with dental-explorer size has been developed comparing two sensing methods, Raman reading and pH reading for evaluating dental caries. The Raman spectra at 575 cm−1 and 960 cm−1 for in inorganic compounds, as well as 1450 cm−1 and 2940 cm−1 for organic compounds reinforced and supported the pH results. An Iridium/Iridium oxide (Ir/IrOx) pH sensing probe and wireless pH sensor (comprising an ESP8266 ESP-01 wireless module and ADS1115 analog digital converter) has been developed to quantitatively evaluate dental caries. All the operations of the wireless pH sensor were performed with a developed LabVIEW-based real-time data monitoring program. The slope and the linear fitting regression value (R2) of the wireless pH sensor using seven standards were −54.9 mV/pH and 0.999, respectively, showing high accuracy and stability for the pH measurements. The pH on the dental caries surface was measured with the wireless pH sensor, and the pH mapping results in the non-caries and caries areas were 6.9 and 5.7, respectively. The developed wireless pH sensor would be useful to understand the condition of dental caries and support dentists’ inspection to remove only the caries part while keeping the non-caries structure.

This study proposes a realistic model for the bond stress–slip relation between concrete and carbon fiber-reinforced polymer plates under fatigue loading. Double-lap shear experimental tests were implemented to explore the bond stress–slip behavior under fatigue loading. The bond stress–slip relation under fatigue loading was derived as a function of the loading/unloading linear slip, the stiffness of the unloading branch in slip and the number of fatigue cycles. In this model, the stiffness of the unloading branch in slip was derived from the simplest linear fitting of the experimental data based on the bond stress–slip relationship. Numerical analyses using the proposed model compared well overall to the experimental fatigue results.

Antibiotics residues have a potentially threaten to people’s health and has become a hotspot around the world. In this paper, the binding characteristics of the bovine serum albumin (BSA) to Norfloxacin (NFX) were studied by synchronous fluorescence spectroscopy under simulative physiological conditions. The synchronous fluorescence spectra of interaction system was obtained under the different concentration of NFX. The relationship between the fluorescence intensity of NFX-BSA system and the content of NFX was discussed. Results show that NFX can interact with BSA, the endogenous fluorescence of BSA appeared regular quenching with the increasing concentration of NFX. The prediction between the fluorescence intensity of NFX-BSA system and norfloxacin content was eatablished based on the least squares linear fitting. The regression equation was obtained to be y = 67.626-10.071x, The correlation coefficient is 0.9932. the recovery is between 95.59%-103.45%.

A new wiping product prepared by wetlaid/spunlace (wetlace) method possess dispersibility and fully degradability. To obtain the excellent products, the present research first investigates the apparent microstructures, mechanical properties and dispersibility of wood pulp/Danufil wetlaid nonwovens with/without hydroentanglement. The results suggest that fibers are stacked and some of the fiber cohesions occurred on the surface of wetlaid nonwoven. After hydroentanglement, a 3D entanglement skeleton formed by Danufil fibers is found to determine the mechanical and dispersion properties of nonwovens, while wood pulp ensures the dispersion properties and is attributed as the main component of the nonwovens. The breaking extension and tearing strength of nonwovens have been improved significantly and the material with decreasing dispersibility becomes soft. Meanwhile, the dispersion of wetlaid and wetlace nonwovens over time both show linear fitting trend. The increase in content and length-to-diamete...

Mango (M. indica cv. Datainong) fruit quality rapid determination method based on electronic nose (E-nose) was investigated in this research. E-nose responses to mangoes stored at room temperature were examined for 9 days. Meanwhile, physicochemical and microbiological indexes including firmness, weight loss, surface colour, yellowing rate, pH, total soluble solids, polyphenol oxidase activity and total viable counts were measured to provide quality references for E-nose analysis. Principal component analysis (PCA) and stochastic resonance (SR) were utilized for E-nose data analysis. Results indicated that mango fruit quality decreased sharply during storage. PCA just allowed qualitative quality discrimination, while SNR spectrum using eigen values successfully characterized mango quality. Mango quality predictive model was developed by linear fitting SR eigen values. Validation experiment results demonstrated that the forecasting accuracy of the developed model reached 90%.

Operating rules are important in the long-term operation of reservoirs for its capability of coping with inflow uncertainty. The characteristics of inflow vary as a result of climate change and human activities, and using stationary operating rules would lead to inefficient reservoir operation. This study focuses on identifying changing patterns of operating rules under various inflow alteration scenarios. Two simulation methods, the simple adjustment method (SAM) and the stochastic reconstruction method (SRM), are used to generate three inflow alteration scenarios: shifts of mean, coefficient of variation (CV), and seasonality. A deterministic reservoir optimization model is established and then resolved using discrete differential dynamic programming algorithm. Finally, the operating rules under each scenario are derived using the linear fitting method. China's Three Gorges Reservoir is used as a case study. The results show that the SAM and SRM produce similar operating rules, which are sensitive to inflow changes during refill and drawdown periods. It is shown that (1) the increase (decrease) of inflow mean changes the operating rules, resulting in the increase (decrease) of the water releases while the shift of CV has little impact on operating rules; (2) the seasonality changes operating rules in opposite directions during refill and drawdown periods; (3) the changing patterns of operating rules would be superimposed by the superposition of various inflow alteration scenarios whereas the effects might be not obvious. These findings are helpful for adaptive operation of reservoirs under changing environment.

The purpose of this study is to clarify the degree of impregnation resulting from treatment of internal waterlogged wood samples using MRI. On a 1.5T MR scanner, T1 and T2 measurements were performed using inversion recovery and spin-echo sequences, respectively. The samples were cut waterlogged pieces of wood treated with various impregnation techniques which were divided into different concentrations of trehalose (C12H22O11) and polyethylene glycol (PEG; HO-(C2H4O)n-H) solutions. Then these samples underwent impregnation treatment every two weeks. From the results, we found that the slope of the T1-concentration curve using linear fitting showed the value of the internal area for PEG to be higher than the external area; internal, -2.73ms/wt% (R2=0.880); external, -1.50ms/wt% (R2=0.887). Furthermore, the slope of the T1-concentration curve using linear fitting showed the values for trehalose to have almost no difference when comparing the internal and the external areas; internal, -2.79ms/wt% (R2=0.759); external, -3.02ms/wt% (R2=0.795). However, the slope of the T2-concentration curve using linear fitting for PEG showed that there was only a slight change between the internal and the external areas; internal, 0.26ms/wt% (R2=0.642); external, 0.18ms/wt% (R2=0.920). The slope of the T2-concentration curve did not show a change in linear relationship between the internal and the external areas; internal, 0.06ms/wt% (R2=0.175); external, -0.14ms/wt% (R2=0.043). In conclusion, using visualization of relaxation time T1, it is possible to obtain more detail information noninvasively concerning the state of impregnation treatment of internal waterlogged wood.

The influence of mesa edge capacitance on the frequency characteristics of AlGaN/GaN HEMTs with 90 nm gate length was studied in this paper. To extract mesa edge capacitances, a small-signal equivalent circuit model considering mesa edge capacitances was provided. Based on the model, the intrinsic gate capacitances of AlGaN/GaN HEMTs with 2 × 20 μm, 2 × 30 μm, 2 × 40 μm, and 2 × 50 μm gate widths were extracted, respectively. Through linear fitting along gate width for the extracted results and simulations, 8.06 fF/μm2 of mesa edge capacitances at Vgs = −4.5 V and Vds = 8 V in the devices with 2 × 20 μm gate width was obtained, which can be about 33.2% of the total gate capacitance. Mesa edge capacitances results in a significant drop of current-gain cut-off frequency (fT), and the effect is more serious in the shorter gate length devices.

In this study, we report on total gaseous mercury (TGM) field observations made in the rural area of Shanghai, Chongming Island, China, from September 2009 to April 2012. The average TGM was 2.65 ± 1.73 ng m-3 in Chongming Island, which is higher than the TGM background value of the Northern Hemisphere (1.5-1.7 ng m-3); this indicates that to some extent, the Chongming area has been affected by anthropogenic mercury emissions. The observed TGM follows a seasonal pattern; concentrations are highest in winter, followed by autumn, summer, and spring. There is also a clear diurnal variation in TGM. All peak values appear between 7:00 and 9:00 in all four seasons; this appears to be the result of the height change in the atmospheric boundary layer that occurs between day and night. TGM concentrations in Chongming remain high in the westerly wind direction, especially in the southwest direction because of its low frequency, so the greatest source contribution to TGM in Chongming lies to the northwest. Wind speed is also a significant factor affecting TGM, and was negatively correlated with TGM concentrations. TGM is also closely related to carbon monoxide (CO) concentrations, indicating that TGM is impacted by human activities. The slope of the linear fitting of TGM and CO demonstrates that the contribution of noncoal source emissions to TGM in summer is greater than in autumn, mainly because the high temperature and intensive sunlight in summer increase mercury emissions from natural sources. Implications Except for some studies in the coastal areas (e.g., Kang Hwa Island by Kim et al., 2006, An-Myun Island by Kim et al., 2002, and Okinawa by Chan et al., 2008), data specifically for coastal areas are lacking. Monitoring of total gaseous mercury (TGM) in the rural area of Shanghai, Chongming Island, can help us understand mercury distribution.

Convergent-beam electron diffraction (CBED) is one of the most popular techniques to measure crystal thickness. The traditional measurement involves linear fitting of several fringes across the CBED disc, but for a thin crystal with fewer than three fringes the usefulness of this method will be limited. CBED Tools, a free plugin for the DigitalMicrograph software, provides a fast (∼1–2 min) and accurate algorithm to measure the crystal thickness on the basis of the linear fitting method, but it is also capable of determining the crystal thickness when it is very thin and only one fringe or part of the first fringe is recorded. CBED Tools can also be utilized to handle the severely distorted CBED pattern obtained when the zero-order Laue zone Kikuchi lines overlap with the fringes.

Several types of deterioration have developed at earthen sites of the Ming Great Wall in Qinghai Province, including cracks, gullies, collapses, sapping, and scaling off, the first four of which could threaten the wall's stability. The correlations of these types of deterioration with each other and with other factors were explored. The authors selected 16 sampling points from nine typical earthen sites of the wall to investigate its deterioration. Linear fitting of the data on the types of deterioration was conducted to determine their correlations. Then, indoor tests of these samples were systematically performed to clarify the physical, water-related, and mechanical properties of the rammed earth, and meteorological data for each county were collected. Finally, the linear fitting was carried out among the deterioration indices, engineering-related parameters of the rammed earth, and meteorological data to determine the influence of these factors on the development of each type of deterioration. This research illustrates the mechanisms involved in such deterioration and its evolution from a macro perspective.

A device that can measure the amount of paper, display it, and announce it by voice is designed. The hardware part of the device consists of two metal plates, a capacitor voltage detection circuit and a single-chip microcomputer; the software part uses the least square method for linear fitting, which reduces the amount of data required for system self-calibration, and uses statistical principles to reduce linear errors, which improves the accuracy of discriminating the number of sheets of paper.