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Nonradiative recombination in InGaN epilayers grown by metal-organic chemical vapor deposition has been investigated. Time-resolved photoluminescence measurements show that the nonradiative recombination is suppressed with the periodical dilute H2 carrier gas. Space-resolved cathodoluminescence images indicate that clustered V-pits in hillock-like In-rich regions and scattered V-pits primarily contribute to the nonradiative recombination. The number and size of hillock-like In-rich regions as well as the density of scattered V-pits are effectively reduced by the periodical introduction of dilute H2 carrier gas, leading to a significant reduction of the nonradiative recombination. Transmission electron microscopy shows that the basal plane stacking faults, which are considered as the origins of the hillock-like In-rich regions, can be suppressed by the introduction of dilute H2 carrier gas.

Crystal quality improvements of AlN epilayers grown on sapphire substrates has been achieved by using periodically pulsed-trimethylgallium (TMGa) flows (PTFs) in the initial growth stage of high-temperature AlN. The 400-nm-thick AlN layer deposited with this method demonstrated atomically flat surface, and the line widths of x-ray rocking curves were 40 and 245 arcsec for (002) and (105) reflections, respectively. GaN mole fraction was measured to be less than 0.6% in the AlN layer, indicating a surfactant effect of the PTFs. A combination of experimental characterizations and density functional theory calculations unveils that the improvements are ascribed to the supplement of Ga atoms and the enhanced surface migration of Al adatoms by using the PTFs which promotes the transition of growth mode from three-dimension to two-dimension one.

We reported the selective area growth (SAG) of semipolar { 11 2 2 } InGaN/GaN multiple quantum wells (MQWs) laser diodes (LDs) on the patterned GaN/AlN/Si (111) templates. For GaN (0001) on Si (111), the natural cleavage planes of GaN { 1 1 00 } and Si { 11 2 } are aligned. In this work, the templates were patterned with stripe windows oriented along GaN [ 1 1 00 ] direction. Utilizing a two-step SAG method, the semipolar GaN-based laser structures were successfully deposited on the inclined { 11 2 2 } facets of the laser stripes. STEM measurements indicated the upper areas of inclined { 11 2 2 } facets are nearly defect free due to the bending effect of TDs. The cavity facets were produced by cleaving method. Stimulated emission was achieved under optical pumping at room temperature, showing a threshold pump power density of 1.85 MW/cm2, which was attributed to the low defect and small internal field on the upper areas of semipolar { 11 2 2 } facets selectively grown on the Si (111) substrates.

InGaN/GaN multiple quantum wells (MQWs) were selectively grown on patterned GaN/AlN/Si (111) templates with periodic stripe openings separated by large SiO2 covered spacing. In comparison with the conventional epitaxial lateral overgrowth, the migration behaviours of group-III adatoms on the large mask region has a distinct effect on the structural and optical properties of InGaN/GaN MQWs selectively grown on the narrow stripe openings. In order to control them, a wide stripe window nearby the narrow one was adopted to modulate the local growth environments in our experiment. Flat and faceted InGaN/GaN MQWs stripes with trapezoidal cross section composed of basal (0001) plane and two semipolar { 11 2 2 } facets were obtained. The optical properties were investigated by the microscopic photoluminescence (micro-PL) measurement. The difference in emission peak positions observed by scanning the excitation laser across the stripes is related to the surface migration behaviour of the group-III adatoms on the SiO2 masks.

Introduction Leptinʼs role in bone formation has been reported, however, its mechanism of affecting bone metabolism is remaining unclear. In this study, we aimed to test whether leptin has a positive effect on fracture healing through the possible mechanism of increasing vascular endothelial growth factor (VEGF) expression in callus tissue. Methods Standardized femur fractures were created in leptin-deficient ob/ob and wildtype C57BL/6J mice, and recombinant mouse leptin or its vehicle (physiological saline) was administered intraperitoneally during the study. Body weight, radiological, histologic and immunoblotting analyses were performed at different stages of fracture healing. Key findings The results showed that leptin treatment led to lower rate of body weight change in both mice genotypes. Radiological and histological analyses showed that the experimental groups had better fracture healing at 14, 21 and 28 days compared to the control groups. Leptin-treated groups had significantly higher VEGF expression in callus compared with the control groups at 2 and 3 weeks post-fracture except normal mice at 2 weeks, and leptin-deficient mice had higher VEGF levels in calluses than normal mice at the same timepoint. Conclusion Low-dose systemically-administered leptin has a positive effect on promoting fracture healing during the latter stages in a clinically-relevant mouse bone fracture model, and increase callus VEGF levels.

Dependence of carbon doping concentration on the strain-state and properties was studied in detail for the GaN on Si system. Combining the results of XRD and Raman spectra, it is found that compressive stress is introduced into the GaN with a moderate carbon concentration, while it turns into tensile stress when the carbon concentration is higher than a critical point. A possible mechanism is that the carbon tend to replace the N atom in GaN at a relative lower carbon concentration because of the relatively smaller formation energy, while it turned to replace the Ga atom after the carbon concentration is higher than a critical level. Those results are also confirmed by the photoluminescence spectrum.

The crystalline quality of AlN epitaxial layers on sapphire substrates was improved by introducing trimethylgallium (TMGa) pulse flow into the growth of AlN nucleation layers. It was found that the density of both screw- and edge-type threading dislocations could be significantly reduced by introducing the TMGa pulse flow. With increasing TMGa pulse flow times, the lateral correlation length (i.e. the grain size) increases and the strain in the AlN epilayers changes from tensile state to compressive state. Unstrained AlN with the least dislocations and a smooth surface was obtained by introducing 2-times TMGa pulse flow. The crystalline improvement is attributed to enhanced lateral growth and improved crystalline orientation by the TMGa pulse flow.

Objective: A novel processing analytical framework of Chinese Material Medica (CMM) includes breeding process analysis, planting process analysis, producing process analysis and manufacture process analysis. In order to study this framework, we used quality control of honeysuckle flower (Lonicerae japonicae Flos) including diploid and tetraploid Lonicera japonica, and wild honeysuckle flower (Lonicerae Flos) including Lonicerae hypoglauca, Lonicerae confusa, Lonicerae fulvotomentosa and Lonicerae macranthoides as an example. Methods: A total of 360 samples were analyzed from three variables including species, growing areas, and optimization of processing methods. For quantitative analysis, chlorogenic acid (CA), isochlorogenic acid A (3, 5-DCA), and isochlorogenic acid C (4, 5-DCA) were measured with high performance liquid chromatography (HPLC). Results: The three organic acids contents are higher in wild honeysuckle flower than honeysuckle flower; L. japonica (tetraploid) is higher than L. japonica (diploid). Modern processing methods (kill-enzyme torrefaction and fixing machine drying) are popular in growing areas and are superior to traditional methods (sun and shade drying). Conclusions: Novel process analysis concepts in processing analytical technology (PAT) enriched the Chinese Material Medica contents. Keywords: Honeysuckle flower, Wild honeysuckle flower, Processing analytical technology, Quality control, Processing method

A novel methodology is proposed to determine the error propagation of partial least-square (PLS) for parameters optimization in near-infrared (NIR) modeling. The parameters include spectral pretreatment, latent variables and variable selection. In this paper, an open source dataset (corn) and a complicated dataset (Gardenia) were used to establish PLS models under different modeling parameters. And error propagation of modeling parameters for water quantity in corn and geniposide quantity in Gardenia were presented by both type І and type II error. For example, when variable importance in the projection (VIP), interval partial least square (iPLS) and backward interval partial least square (BiPLS) variable selection algorithms were used for geniposide in Gardenia, compared with synergy interval partial least squares (SiPLS), the error weight varied from 5% to 65%, 55% and 15%. The results demonstrated how and what extent the different modeling parameters affect error propagation of PLS for parameters optimization in NIR modeling. The larger the error weight, the worse the model. Finally, our trials finished a powerful process in developing robust PLS models for corn and Gardenia under the optimal modeling parameters. Furthermore, it could provide a significant guidance for the selection of modeling parameters of other multivariate calibration models.

There are still huge challenges from clinical real-world data to accurate targets and critical quality attributes (CQAs) for effective treatment of allergic rhinitis (AR). Here, we present a novel integrated strategy that biosensors and intelligent algorithms were used to angle AR targets and CQAs from clinical real world. Firstly, bagging and boosting partial least squares discrimination analysis (PLS-DA) and Monte-Carlo sampling were proposed to screen accurate AR targets. Macrophage migration inhibitory factor (MIF) and Interleukin-1beta (IL-1β) potential targets were obtained based on large-scale analysis of one thousand proteins and in-depth precise screening of seventy proteins. Furthermore, high electron mobility transistor (HEMT) biosensors were fabricated and successfully modified by MIF and IL-1β potential targets with a low detection concentration as 1 pM and quantitative range from 1 pM to 10 nM. Surprisingly, through MIF/IL-1β biosensors, we angled 5-O-methylvisammioside, amygdalin, and cimicifugoside three CQAs. The strong interaction was discovered among three CQAs and MIF/IL-1β biosensors with almost all KD up to 10−11 M. Finally, interaction among three CQAs and MIF/IL-1β biosensors were evaluated by in vitro and vivo experiments. In this paper, two critical potential targets and three effective CQAs for AR treatment were discovered and validated by biosensor and advanced algorithms. It provides a superior integrated idea for angling critical targets and CQAs from clinical real-world data by biosensors and informatics.

Thiazolium salts are structurally analogous to the most common imidazolium-based ionic liquids (ILs), and are supposed to be a new class of ILs. However, there are up to now only a few reports and absence of systematic study on thiazolium ILs. In this work, several thiazolium-based ILs were prepared, characterized and comparatively studied. Most of the thiazolium ILs are liquid at room temperature, with melting points below 43.0 °C. Good thermal stability was observed for thiazolium ILs, resulting in thermal decomposition temperatures up to 264 ∼ 358 °C. In comparison with the conventional imidazolium ILs, thiazolium ILs exhibit moderate density, refractive index and surface tension, which all generally decrease with temperature. According to the temperature-dependent viscosity and conductivity, thiazolium ILs follow fractional Walden’s rule, indicating strong ion-ion coupling. Besides, thiazolium ILs display relatively narrow electrochemical window (3.1 ∼ 4.0 V).

The cutoff frequency of Schottky barrier diode (SBD) depends on its junction capacitance and series resistance. The two-dimensional electron gas (2DEG) at AlGaN/GaN interface has high carrier mobility and carrier concentration. However, AlGaN/GaN heterostructure SBD usually shows a high series resistance because of the thin 2DEG channel. In this work, multiple AlGaN/GaN heterojunctions are vertically stacked for forming multiple parallel 2DEG channels to reduce the series resistance. Multi-channel AlGaN/GaN-based air-bridge structure planar SBDs with a half through-hole are demonstrated. The series resistance of quintuple-channel SBD is only 39.5% of the single-channel SBD's. Moreover, a low capacitance is obtained by the Schottky electrode with a half through-hole structure. The low series resistance and the low capacitance contribute to a 16 GHz cutoff frequency in millimeter-wave band.

Combining the p-NiO gate electrode and the stack barrier structure with unintentionally doped GaN insertion layer (serves as etching termination layer) is promising for achieving normally-off GaN power device. The band alignment and band offsets at the interface of NiO and GaN insertion layer play a crucial role in determining the performance of GaN device. In this letter, the p-NiO thin film/unintentionally doped GaN heterojunction was fabricated through a simple thermal oxidation method. The p-NiO thin film presents face-centered cubic crystalline structure with a band gap of approximately 3.69 eV. The interfacial band alignment of the heterojunction is characterized by X-ray photoelectron spectroscopy. Based on core-level binding energies and valence band maximum values, the valence and the conduction band offsets were determined to be 1.16 eV and 1.45 eV, respectively. The NiO/GaN heterojunction is concluded to be type-II staggered band configuration.

p-type NiO films were prepared at different oxidizing temperatures in O 2 ambient for normally-off AlGaN/GaN HFETs application. The crystalline structure, electrical properties and band gap of NiO films are dependent upon temperatures. Compared with the conventional Ni-gated HFETs, NiO-gated HFETs present positively shifted threshold voltage and smaller gate leakage current, while the drain current density shows slightly degradation. Combining the recess structure and NiO gate, normally-off GaN HFETs was achieved with a threshold voltage of approximately 0.5 V. The band diagram of the NiO/AlGaN/GaN structure demonstrates that the p-type conductivity and large conduction band offset between NiO and GaN cause the lift-up potential, which result in 2DEG depletion and positive threshold voltage shift.

The movement of molten metal at the wire end in submerged arc welding (SAW) was filmed by a high-speed video camera through a preset tunnel, the welding electric signal was acquired simultaneously. A physical modeling experiment was carried out to simulate the metal transfer in SAW. Welding electric signal shows that the stability of welding process is higher at medium current, but it could not reflect the metal transfer behavior completely. Combining high-speed videos for welding and physical modeling experiment, it is suggested that there might be three metal transfer modes with the increase of welding current, which in turn are: repelled globular transfer without short-circuit, flux-wall guided transfer without short-circuit and flux-wall guided transfer with short-circuit. Analysis result suggests that the arc would always burn even when short-circuit is ongoing in high-current SAW, which is quite different from the short-circuit in gas metal arc welding (GMAW).

The electric properties of Pt Schottky contacts on semipolar r-plane and polar c-plane of GaN micro truncated-pyramid are compared. The Schottky diodes of the inclined r-plane sample illustrate a relatively inferior rectified performance than that of the top c-plane GaN in term of the lower Schottky barrier heights, larger ideality factor and reverse leakage current. By depositing Pt metal on the dislocation-free area of the top of GaN micro pyramid, the Schottky performance of r-plane GaN can be slightly improved, but still shows much larger reverse leakage current than that of c-plane GaN. It is found that polarization-related surface states and incorporation of donor impurities, rather than dislocation, should mainly contribute to this remarkable electric discrepancy of the planes.

In this study, convolutional neural networks (CNN) strategy combined with mid-infrared (MIR) spectra is applied for sugar adulteration identification in honey. In order to acquire the variations from different classes as well as obtain a better interpretation of the model, a visualization of the CNN algorithm is employed for honey adulteration determination. All kernels are co-acted to explore subtle features by learning different weights and biases. The amplified or attenuated signals transformed by the kernels yield positive or negative effects to the model. Furthermore, the visualized features are implemented for spectroscopy interpretation. The overall results demonstrate that CNN is a promising method with improved accuracy over least squares support vector machines (LS-SVM) and partial least squares discriminant analysis (PLS-DA) especially for the market-obtained samples. Besides, this study supports the theoretical and practical foundation for CNN on the aspects of feature selection, visualization and model interpretation.

This study is about the rice syrup adulteration determination in different botanical origin honey in the food product. Due to time-consuming and large risk of misdiagnosis, it is essential to establish a general model for adulteration detection regardless of the original category of honey. In this paper, infrared (IR) spectra combined with four supervised pattern recognition methods were employed to establish the general model for rice syrup adulteration detection in acacia, linden and jujube honey samples simultaneously. Moreover, Monte-Carlo sampling technology was executed to evaluate the models via the average accuracy, sensitivity and specificity. The first derivative-least squares support vector machines (Der-LS-SVM) gave an outstanding performance with higher accuracy (97.09%), higher sensitivity (96.64%), higher specificity (97.58%) and lower standard deviations after fifty trials. In addition, this study makes further efforts to control the quality of the honey product in the market on rice syrup adulteration.

The quality of safflower (Carthamus tinctorius L.) in the market is uneven due to the problems of dyeing and adulteration of safflower, and there is no perfect standard for the classification of quality grade of safflower at present. In this study, computer vision (CV) and near-infrared (NIR) were combined to realize the rapid and nondestructive analysis of safflower. First, the partial least squares discrimination analysis (PLS-DA) model was used to qualitatively identify the dyed safflower from 150 samples. Then the partial least squares (PLS) model was used for quantitative analysis of the hydroxy safflower yellow pigment A (HSYA) and water extract of undyed safflower. Herein, the discrimination rate of PLS-DA model reached 100%, and the residual predictive deviation (RPD) values of the PLS models for HSYA and water extract were 2.5046 and 5.6195, respectively. It indicated that the rapid analysis method combining CV and NIR was reliable, and its results can provide important reference for the formulation of safflower quality classification standards in the market.

Real-time process quality control of ramulus cinnamomi (cassia twig) is still a challenge in pharmaceutical industry. Rapid critical quality attribute (CQA) determination of ramulus cinnamomi is essential for quality control. Microscale thermophoresis (MST) was used to investigate the CQA of ramulus cinnamomi by the interaction with biomacromolecule. There was a good affinity between cinnamaldehyde and human serum albumin (HSA) with Ka as 2.1722 × 103 mol/L. It was an excellent combination of similarity to ibuprofen with same binding force as discovered as hydrogen bond and van der Waals force. Furthermore, regarding cinnamaldehyde as CQA, on-line near-infrared was used to monitor pilot extraction process of ramulus cinnamomi combined with high performance liquid chromatography (HPLC). Quantitative model was established with Rpre2 as 0.9798 and RMSECV as 0.0993, suggesting the NIR model was so robust and accurate for pilot process quality control. This method provided a perfect guideline for rapid CQA determination and real-time process quality control of Chinese materia medica (CMM) based on a vital CQA.

Laser-induced breakdown spectroscopy (LIBS) was used to assess the cinnabar and realgar blending of An-Gong-Niu-Huang Wan (AGNH) in a pilot-scale experiment, including the blending end-point. The blending variability of two mineral medicines, cinnabar and realgar, were measured by signal relative intensity changing rate (RICR) and moving window standard deviation (MWSD) based on LIBS. Meanwhile, relative concentration changing rate (RCCR) was obtained based on the reference method involving inductively coupled plasma optical emission spectrometry (ICP-OES). The LIBS result was consistent with ICP-OES at blending end-point determinations of both mineral medicines. Unlike the ICP-OES method, LIBS does not have an elaborate digestion procedure. LIBS is a promising and rapid technique to understand the blending process of Chinese Materia Medica (CMM) containing cinnabar and realgar. These results demonstrate the potential of LIBS in monitoring CMM pharmaceutical production.

We demonstrated the fabrication of GaN nanowire (NW) by selective etching of the GaN micro truncated-pyramid (μ-TP) in KOH solution. The GaN μ-TP, which consists of a (0 0 0 1) Ga-polar top surface and six {1 1 ¯ 0 1} N-polar sidewalls, were grown on the patterned AlN/Si template in metal organic chemical vapor deposition (MOCVD) system. KOH solution can selectively etch the N-polar sidewalls while leave the Ga-polar top surface intact. Hexagonal-prism-structured GaN NW with (0 0 0 1) top surface and {1 1 ¯ 0 0} sidewalls was obtained after adequate chemical etching. It was found that the three-dimensional geometry of the GaN NW is determined by the diameter of the (0 0 0 1) top surface and the height of the GaN μ-TP. And the chemical etching mechanism of GaN μ-TP towards GaN NW in hydroxide solution was explained.

One simple-structure dye and two bulky dyes have been designed for exploring a new co-sensitization system utilizing synergy between simple-structure and bulky organic dyes. This small-sized dye molecule can fill up the space defects between bulky dyes, and its strong absorption band from 350 to 500 nm can complement the absorption valleys of the bulky dyes. Additionally, the dye loading of titanium dioxide surface was investigated by Thermogravimetric analysis, which confirms that the molar loading of co-sensitized device has significantly increased. These results exhibit that the simple molecule can be used not only as a co-adsorbent to inhibit charge recombination and π-π aggregation between the bulky dyes but also as a co-sensitizer to improve light-harvesting ability.

Display Omitted Surface morphologies were roughened without the use of masks.Surface morphologies were optimized by varying Cl2 concentration.Surface morphologies were optimized by adjusting RF bias power.Light output of surface-roughened LEDs was enhanced by 43.2%. In the present paper, the surface of GaN-based light-emitting diodes (LEDs) was roughened by inductively coupled plasma reactive ion etching (ICP-RIE) system. Without the utilization of etching mask, the roughened surface morphologies were optimized by varying Cl2 concentration in Cl2/BCl3/N2 mixing gas and adjusting RF bias power parameters of the ICP system. There was no obvious degradation of electrical properties of surface-roughened LEDs after the ICP dry etching process. Furthermore, the light output power of surface-roughened LEDs was enhanced by 43.2%, compared with conventional LEDs.

To deal with heterogeneous classification problem efficiently, each heterogeneous object was represented by a set of measurements obtained on different part of it, and the heterogeneous classification problem was reformulated in the framework of multi-instance learning (MIL). Based on a variant of count-based MIL assumption, a maximum count least squares support vector machine (maxc-LS-SVM) learning algorithm was developed. The algorithm was tested on a set of toy datasets. It was found that maxc-LS-SVM inherits all the sound characters of both LS-SVM and MIL framework. A comparison study between the proposed approach and the other two MIL approaches (i.e., mi-SVM and MI-SVM) was performed on a real wolfberry fruit spectral dataset. The results demonstrate that by formulating the heterogeneous classification problem as a MIL one, the heterogeneous classification problem can be solved by the proposed maxc-LS-SVM algorithm effectively.

Objective Rapid discrimination of three classes of safflowers, dyed safflower, adulterated safflower, and pure safflower using computer vision and image processing algorithms. Methods A low cost computer vision system (CVS) was designed to measure the color of safflowers in the RGB (red, green, blue), L∗a∗b∗, and HSV (hue, saturation, vale) color spaces. The color moments in these three color spaces were extracted from the acquired images as color features of safflower. In addition, five kinds of pigments that are commonly used to dye safflowers were identified by high-performance liquid chromatography as a reference. Pattern recognition methods were investigated for rapid discrimination, including an unsupervised principal component analysis (PCA) algorithm and a supervised partial least squares discriminant analysis (PLS-DA) algorithm. Results The mean error ( e ¯ ) between color values measured with the colorimeter and calculated with the CVS was 2.4%, with a high correlation coefficient (r) of 0.9905. This result indicated that the established CVS was reliable for color estimation of safflowers. The PLS-DA model, which had a total accuracy of 91.89%, outperformed the PCA model in classifying pure, adulterated, and dyed safflowers. Conclusion The color objectification is a promising tool for rapid identification of dyed and adulterated safflowers.

We report the effect of periodic Si-delta-doping on the yellow luminescence (YL) and stress evolution in n-GaN epilayers. Photoluminescence measurements indicated that the YL component could be effectively suppressed with increasing dopant flow rate or decreasing period length. X-ray diffraction, transmission electron microscopy and secondary ion mass spectroscopy measurements revealed that the variations of dislocation density and carbon concentration are not the responsible mechanisms for the of YL emissions. The reduction of Ga vacancy related defects seems to be the probable reason for the YL suppression by Si-delta-doping. Moreover, Raman spectroscopy showed no obvious stress variation among these samples with different equivalent electron concentration. These observed features are entirely different from those reported for uniformly Si-doped GaN.

The arrays of edge threading dislocations (TD) have been observed in highly dislocated GaN film grown on Al 2 O 3 (0001) substrate. There are three kinds of arrays including straight-row, partial-circle and full-circle arrays. A theoretical model derived from the thermodynamics of grains evolution during the GaN recrystallization was used to explain the appearance of these arrays and the statistical distribution of edge TDs. Both the theoretical and experimental results show a Weibull distribution of edge TDs. It is concluded that in crystalline GaN epitaxial films, the edge TD arrays originate from grain coalescence after the recrystallization.

We investigated the influences of periodic Si δ-doping on the characteristics of n-GaN grown on Si (111) substrate by metal organic chemical vapor deposition (MOCVD). By using periodic δ-doping, the tensile stress in GaN film induced by Si-doping was reduced to 0.057 GPa/10 18 cm −3 electrons, which was 56% smaller than that in uniformly doped GaN. Moreover, superior electrical properties were achieved in periodic δ-doped GaN films without cracks by varying the Si doping level. X-ray diffraction measurements show similar 002 and 102 full widths at half maximum (FWHMs) for periodic δ-doped GaN and uniformly doped GaN with the same Si doping amount, implying equivalent crystalline qualities of GaN:Si through the two doping methods. A narrower FWHM of the near band edge emission of GaN was obtained in the photoluminescence spectrum with periodic δ-doping, indicating enhanced optical properties.

Extraction process plays an important role in the pretreatment of Flos Lonicerae Japonicae for Qingkailing oral liquid and is also one of the most popular preparation processes of traditional Chinese medicine (TCM). In order to monitor the content of API in the extraction solution, a PLS model was developed based on NIR spectroscopy. However, due to the raw materials’ natural variability introduced into the extraction process of TCM or variations in spectral measurement conditions, it was unable to foresee the changes in the spectral response for new source batches, which could render a calibration model invalid. The development of a reliable multivariate calibration model for each new source batch is usually time-consuming and costly. In this work, a new calibration model transfer strategy which combined direct orthogonal signal correction with slope and bias correction (DOSC-SBC) was proposed and applied to maintain the predictive abilities of the original calibration model for new source batches. Performance of this model transfer strategy has been validated by two new individual batches which raw materials were from different sources, and the predictive relative errors of the samples from the above new batches decreased from 15.67% and 19.82% to 8.35% and 6.80% respectively after using DOSC-SBC strategy, demonstrating the good performance of the proposed model transfer strategy.

This paper presents a new strategy, target-oriented overall process optimization (TOPO), which can be used to assure the consistent quality in herbal medicine products. The methodology of TOPO includes four parts, target definition, data pretreatment, process modeling and overall process optimization. The Bayesian approach is integrated into the optimization step. The mechanism of TOPO involves optimizing multiple units of the production system step by step, giving each unit optimal operating conditions consistent with the quality target. The effects of TOPO were assessed using the descriptive statistics of the Bayesian posterior predictive distribution and the final target achievement. The probability trajectory was adjusted to monitor and optimize the production process. The proposed TOPO strategy was successfully applied to a seven-unit manufacturing process used to produce Lonicerae Japonicae extract. Results demonstrated that TOPO could keep the production process in line with the predefined target and reduce the variability of the final products.

In the present paper, compositionally graded AlGaN buffer layer was employed to compensate the tensile stress and improve the crystalline quality of GaN grown on silicon substrate. During the growth of the graded buffer layer, the flow rate of trimethylaluminum (TMAl) was gradually decreased according to a series of functions, while the flow rate of trimethylgalliumm (TMGa) was increased with the same linear function. Therefore, these graded AlGaN layers showed different distributions of Al, which was confirmed by the high-resolution X-ray diffraction (HR-XRD) and the secondary ion mass spectroscopy (SIMS). A linear compositionally graded AlGaN layer was obtained by using the convex parabolic TMAl flow rate, which leads to a large compressive stress in GaN layer due to a linearly gradual change of lattice parameters and thermal expansion coefficient (TEC) from AlN seeding layer to GaN layer. Using the linear compositionally graded buffer layer, a 3-μm-thick crack-free GaN film with a low dislocation density was grown on silicon substrate. The dislocation evolution associated with stress was investigated by the cross-sectional micro-Raman scattering and transmission electron microscopy (TEM).

Two nonfluorescent and colorless chemodosimeters featuring benzothiazoline moiety were developed for chromo-fluorogenic detection of HOCl.

The use of near infrared spectroscopy was investigated as a process analytical technology to monitor the amino acids concentration profile during hydrolysis process of Cornu Bubali. A protocol was followed, including outlier selection using relationship plot of residuals versus the leverage level, calibration models using interval partial least squares and synergy interval partial least squares (SiPLS). A strategy of four robust root mean square error of predictions (RMSEP) values have been developed to assess calibration models by means of the desirability index. Furthermore, multivariate quantification limits (MQL) values of the optimum model were determined using two types of error. The SiPLS(3) models for L-proline, L-tyrosine, L-valine, L-phenylalanine and L-lysine provided excellent accuracies with RMSEP values of 0.0915 mg/mL, 0.1605 mg/mL, 0.0515 mg/mL, 0.0586 mg/mL and 0.0613 mg/mL, respectively. The MQL ranged from 90 ppm to 810 ppm, which confirmed that these models can be suitable for most applications.

Our previous work had proved that accuracy profile theory could be employed as a means of validating one PLS model in Chinese material medica system. In this paper, accuracy profile theory is proposed as a powerful decision tool to demonstrate the prediction performance of multi-model at each concentration level rather than all concentration levels. Partial least square (PLS), interval partial least square (iPLS), backward interval partial least square (BiPLS) and moving window partial least square (MWPLS) were selected to construct visible and near-infrared (vis/NIR) spectroscopy models. Chemometric indicators, i.e., determination coefficient (R(2)), root-mean-square error of prediction (RMSEP) and ratio of performance to inter-quartile (RPIQ), were used to select the optimum model. However, the results clarified that these commonly used indicators could not clearly demonstrate different PLS models' ability because these indicators depend on all concentration levels to assess the multi-model. Therefore, "total error concept" (accuracy profile theory) was introduced to assess the ability of multi-model at each concentration level. Analytical methodology parameters, i.e., linearity, relative bias, uncertainty, repeatability, intermediate precision, lower limit of quantification (LLOQ) and risk, were calculated by accuracy profile theory. Final results showed that model selection strategy which was based on model assessment at every concentration level was more sensitive than the one based on all concentration levels. The analytical procedures involved in this work ensure that model selection strategy using total error concept is coherent.

This study demonstrated a novel application of near-infrared chemical imaging (NIR-CI) for monitoring the blending process of Yinhuang powder. An experiment design was created including eight intermediates. The blending process was executed at different rotation velocities and ended at various time points. Baicalin (BAI) of Yinhuang powder could be spatially determined by the method of basic analysis of correlation between analytes (BACRA). However, starch (STA) and Lonicera japonica extract (LJE) could not be identified by the BACRA method due to high correlation coefficients of each other. Subsequently, characteristic wavenumbers were used to generate a RBG image, which indicated the distribution of the BAI (red), LJE (green) and STA (black). Furthermore, the homogeneity of BAI distribution in a ternary system during the blending process was measured by histogram analysis and moving block macropixel relative standard deviation (MBMRSTDEV). In the histogram analysis, the standard deviation decreased from 0.171 to 0.032 with increased blending time, which indicated that the Yinhuang powder gradually became homogeneous. However, other statistical parameters such as kurtosis and skewness were difficult to be used in understanding the blending process of Yinhuang powder. MBMRSTDEV was introduced as a suitable approach to evaluate the homogeneity. The result indicated that the blending process of the powder experienced different blending stages. The MBMRSTDEV parameter could provide an advantage in visualizing the trend of blending process. These results highlighted a promising technology to extract critical process information and provided essential process knowledge of the blending process of Yinhuang powder.

N-(rhodamine B)-deoxylactam-5-amino-1-pentanol (dRB-APOH) was designed and prepared as the chromo-fluorogenic sensor for detection of a nerve agent simulant via analyte triggered tandem phosphorylation and opening of the intramolecular deoxylactam. The successful detection of diethyl chlorophosphate suggests the utility of rhodamine-deoxylactams as the chromo-fluorogenic signal reporting platform for design of sensors targeting reactive chemical species via various chemistries.

The present study focuses on the interpretation of the relationship between absorption characteristics and quantitative contribution in each near-infrared (NIR) frequency range. NIR spectra were measured for citric acid in each mixture solvent of water and ethanol. Accuracy profile theory was successfully utilized to validate the performance of partial least squares (PLS) models in each frequency range. It was found that saturated absorption characteristic (i.e. intensity) occurred in combination region (CR) and proportion of first combination-overtone (FCOT) region. The result of chemometric indicators, i.e. correlation coefficient (r), the root mean square errors of calibration and prediction (RMSEC and RMSEP), revealed the importance of second combination-overtone (SCOT) region in the calibration model performance. Simultaneously, it demonstrated that PLS model in FCOT or CR region could provide the lowest RMSEC and RMSEP, only when FCOT or CR region has rich transmission information. According to validation methodology parameters, i.e. relative bias, repeatability, intermediate precision, risk, lower limits of quantification (LLOQ), these results also indicated that FCOT or CR region was preferred as variables selection region, but if saturated absorption FCOT or CR region occurred, SCOT region was a better choice. In addition, the validated results testified that absorption intensities of solvent seriously interfered with model performance, especially for FCOT or CR region. Therefore, this revelation work provided a guideline for variables selection in each NIR frequency range.

This study demonstrated that near-infrared chemical imaging (NIR-CI) was a promising technology for visualizing the spatial distribution and homogeneity of Compound Liquorice Tablets. The starch distribution (indirectly, plant extraction) could be spatially determined using basic analysis of correlation between analytes (BACRA) method. The correlation coefficients between starch spectrum and spectrum of each sample were greater than 0.95. Depending on the accurate determination of starch distribution, a method to determine homogeneous distribution was proposed by histogram graph. The result demonstrated that starch distribution in sample 3 was relatively heterogeneous according to four statistical parameters. Furthermore, the agglomerates domain in each tablet was detected using score image layers of principal component analysis (PCA) method. Finally, a novel method named Standard Deviation of Macropixel Texture (SDMT) was introduced to detect agglomerates and heterogeneity based on binary image. Every binary image was divided into different sizes length of macropixel and the number of zero values in each macropixel was counted to calculate standard deviation. Additionally, a curve fitting graph was plotted on the relationship between standard deviation and the size length of macropixel. The result demonstrated the inter-tablet heterogeneity of both starch and total compounds distribution, simultaneously, the similarity of starch distribution and the inconsistency of total compounds distribution among intra-tablet were signified according to the value of slope and intercept parameters in the curve.

A facile and scalable process is established to prepare titanium dioxide/carbon (TiO 2 /C) composite nanotubes possessing a large specific surface area and an enhanced conductivity, with which H-titanate nanotubes are used as a precursor and glucose as a shape-stabilizing agent to retain the tubular morphology of the precursor during heat treatment. The effects of glucose dosage and calcination temperature on the microstructure and electrochemical properties of as-prepared TiO 2 /C composite nanotubes are investigated. The results show that TiO 2 /C composite nanotubes exhibit markedly improved electrochemical properties as compared with pristine TiO 2 sample. The incorporation of carbon helps to retain the tubular morphology of the precursor and improves the electrochemical properties of the target products. In general, the microstructure and electrochemical properties of as-prepared TiO 2 /C composite nanotubes are closely dependent on the dosage of carbon and calcination temperature as well. The electrode made of TiO 2 /C composite nanotubes calcinated at 400 °C, with a carbon content of 5%, possesses good high-rate capability (110 mAh g −1 at 20 C ) as well as excellent cycle life and capacity, showing promising application as an anode material for lithium-ion batteries.

A new approach to the massive production of TiC whiskers with high purity and low cost was presented. It is a modified carbothermal reduction method (MCTR) characterized by argon stream flowing vertically and passing through the interior of the mixture of raw materials. It is found for the first time that there is an optimum flow of the upward flowing argon stream, at which large quantity of high quality TiC can be obtained. This paper described the new method, analyzed the mechanism and conditions for the formation of high purity TiC whiskers on a large scale, and compared MCTR with the traditional carbothermal reduction method (TCTR). Based on the analysis and comparison, it is concluded that in order to produce high quality transition metal carbides, nitrides and carbonitrides with low cost TCTR must be replaced by MCTR.

The influence of growth pressure on the properties of p-GaN grown by metal-organic chemical vapor deposition method was investigated. The p-GaN layers were grown at low temperature under growth pressures ranging from 100 to 400 mbar. We find that higher growth pressure leads to lower Mg incorporation in the p-GaN layer and results in high resistivity of p-GaN grown at 400 mbar. By optimizing the Cp2Mg/TMGa ratio, however, low sheet resistivity can be achieved for p-GaN grown at 100–300 mbar. The p-GaN grown at 300 mbar using optimal Cp2Mg/TMGa ratio of 1.3% shows the highest hole concentration of 5.0×10 17 cm −3 and the consequent minimum sheet resistivity of 2.6×10 4 Ω/sq. The superior electrical properties are ascribed to the reduction of compensation effect for the layer grown under the high growth pressure.