Moisture self-regulating ionic skins with ultra-long ambient stability for self-healing energy and sensing systems

Dehydration has been a key limiting factor for the operation of conductive hydrogels in practical application. Here, we report self-healable ionic skins that can self-regulate their internal moisture level by capturing extenral moistures via hygroscopic ion-coordinated polymer backbones through antipolyelectrolyte effect. Results show the ionic skin can maintain its mechanical and electrical functions over 16 months in the ambient environment with high stretchability (fracture stretch ∼2216 %) and conductivity (23.5 mS/cm). The moisture self-regulating capability is further demonstrated by repeated exposures to harsh environments such as 200°C heating, freezing, and vacuum drying with recovered conductivity and stretchability. Their reversible ionic and hydrogen bonds also enable self-healing feature as a sample with the fully cut-through damage can restore its conductivity after 24 h at 40 % relative humidity. Utilizing the ionic skin as a building block, self-healing flexible piezoelecret sensors have been constructed to monitor physiological signals. Together with a facile transfer-printing process, a self-powered sensing system with a self-healable supercapacitor and humidity sensor has been successfully demonstrated. These results illustrate broad-ranging possibilities for the ionic skins in applications such as energy storage, wearable sensors, and human-machine interfaces

Serological Thymidine Kinase 1 is a Biomarker for Early Detection of Tumours—A Health Screening Study on 35,365 People, Using a Sensitive Chemiluminescent Dot Blot Assay

Serological thymidine kinase 1 (STK1) is a reliable proliferation marker for prognosis, monitoring tumour therapy, and relapse. Here we investigated the use of STK1 in health screening for early detection of pre-malignant and malignant diseases. The investigation was based on 35,365 participants in four independent health screening studies in China between 2005–2011. All participants were clinically examined. The concentration of STK1 was determined by a sensitive chemiluminescent dot blot ECL assay. The ROCvalue of the STK1 assay was 0.96. At a cut-off STK1 value of 2.0 pM, the likelihood (+) value was 236.5, and the sensitivity and the specificity were 0.78 and 0.99, respectively. The relative number of city-dwelling people with elevated STK1 values (≥2.0 pM) was 0.8% (198/26,484), while the corresponding value for the group of oil-field workers was 5.8% (514/8,355). The latter group expressed significantly higher frequency of refractory anaemia, fatty liver, and obesity, compared to the city dwellers, but no cases of breast hyperplasia or prostate hyperplasia. Furthermore, people working in oil drilling/oil transportation showed higher STK1 values and higher frequency of pre-malignancies and benign diseases than people working in the oil-field administration. In the STK1 elevated group of the city-dwelling people, a statistically significantly higher number of people were found to have malignancies, pre-malignancies of all types, moderate/severe type of hyperplasia of breast or prostate, or refractory anaemia, or to be at high risk for hepatitis B, compared to people with normal STK1 values (<2.0 pM). No malignancies were found in the normal STK1 group. In the elevated STK1 group 85.4% showed diseases linked to a higher risk for pre-/early cancerous progression, compared to 52.4% of those with normal STK1 values. Among participants with elevated STK1 values, 8.8% developed new malignancies or progress in their pre-malignancies within 5 to 72 months, compared to 0.2% among people with normal STK1 values. People who showed elevated STK1 values were at about three to five times higher risk to develop malignancies compared to a calculated risk based on a cancer incidence rate of 0.2–0.3%. We conclude that serological TK1 protein concentration is a reliable marker for risk assessment of pre/early cancerous progression

Omnichannel Retail Strategy Considering Cost-Sharing and Consumer Heterogeneity under Different Power Structures

This paper explores two Omnichannel retail models consisted of one online platform and one brick-and-mortar store under different power structures considering cost-sharing mechanisms. In retail supply chain dominated by the online platform and brick-and-mortar store, respectively, under a “Buy online and pick up in store” strategy, the influences of the cost-sharing ratio and the proportion of traditional consumers on pricing and service decisions, the demands of various groups of consumers, and the performance of the retail system have been examined. In addition, the results of decision-making and profitabilities of retailers under different power structures have also been considered. The key findings show that the optimal price and service level first increase and then decrease with the cost-sharing ratio in a retail system dominated by the online platform. In contrast, the price and service level increase with the cost-sharing ratio only when the proportion of traditional consumers is relatively large in a retail system dominated by brick-and-mortar store. The symmetry demand increases as the scale of traditional consumers shrinks when the cost-sharing ratio is relatively large in a retail system dominated by the online system. At the same time, it only increases when the cost-sharing ratio is in the range of 5/8,5/6 in a retail system dominated by the brick-and-mortar store. No matter what the power structure is, the profit of the retail system always first increases and then decreases with the proportion of traditional consumers. Additionally, when the cost-sharing ratio and the proportion of traditional consumers are relatively small, the total demand in the retail system dominated by the online platform is higher than that in the retail system dominated by the brick-and-mortar store. The total profit is larger in the online platform-dominated retail system than that in the brick-and-mortar store-dominated retail system when the cost-sharing ratio is relatively high. However, when the cost-sharing ratio is relatively low, the profitability of the brick-and-mortar store-dominated retail system is stronger

Omnichannel Retail Strategy Considering Cost-Sharing and Consumer Heterogeneity under Different Power Structures

This paper explores two Omnichannel retail models consisted of one online platform and one brick-and-mortar store under different power structures considering cost-sharing mechanisms. In retail supply chain dominated by the online platform and brick-and-mortar store, respectively, under a &ldquo;Buy online and pick up in store&rdquo; strategy, the influences of the cost-sharing ratio and the proportion of traditional consumers on pricing and service decisions, the demands of various groups of consumers, and the performance of the retail system have been examined. In addition, the results of decision-making and profitabilities of retailers under different power structures have also been considered. The key findings show that the optimal price and service level first increase and then decrease with the cost-sharing ratio in a retail system dominated by the online platform. In contrast, the price and service level increase with the cost-sharing ratio only when the proportion of traditional consumers is relatively large in a retail system dominated by brick-and-mortar store. The symmetry demand increases as the scale of traditional consumers shrinks when the cost-sharing ratio is relatively large in a retail system dominated by the online system. At the same time, it only increases when the cost-sharing ratio is in the range of 5/8,5/6 in a retail system dominated by the brick-and-mortar store. No matter what the power structure is, the profit of the retail system always first increases and then decreases with the proportion of traditional consumers. Additionally, when the cost-sharing ratio and the proportion of traditional consumers are relatively small, the total demand in the retail system dominated by the online platform is higher than that in the retail system dominated by the brick-and-mortar store. The total profit is larger in the online platform-dominated retail system than that in the brick-and-mortar store-dominated retail system when the cost-sharing ratio is relatively high. However, when the cost-sharing ratio is relatively low, the profitability of the brick-and-mortar store-dominated retail system is stronger

OPTIMAL DESIGN OF HORN FOR SMALL HOLE EXTRUSION MACHINING WITH ULTRASONIC VIBRATION

In order to design a horn for small hole extrusion machining with ultrasonic vibration,an optimization method of composite horn was proposed. Three surrogate models,Polynomial Response Surface,Kriging and Support Vector Regression,were employed to predict the performance parameters of the horn according to its dimension parameters. The accuracy of the surrogate models were compared. Based on genetic algorithm and the model with the higher accuracy,the optimization of the composite horn was investigated. The simulation results confirm the validity of the optimization method. The experimental results show that the horn meets the requirements of use and the machining effect is ideal

Quantitative Detection of Pesticides Based on SERS and Gold Colloid

International audienceThe detection of pesticide residued in fruit is an important concern for consumers. Surface enhanced Raman spectroscopy (SERS) coupled with gold colloid was applied to analyze two kinds of pesticides (phosmet, chlorpyrifos) which were mainly used on the navel orange. The concentration of the phosmet samples of range from 3 to 33 mg/L and chlorpyrifos samples of range from 4 to 34 mg/L. Using Partial least squares (PLS) regression and the different preprocessing method for the spectral data analyses, and different pretreatment methods such as the Savitzky-Golay were compared. The optimal model of phosmet pesticide and chlorpyrifos pesticide were set up. The prediction correlation coefficient (R) and the root mean square error of prediction (RMSEP) of phosmet pesticide were 0.924 and 4.293 mg/L; The R and RMSEP of chlorpyrifos pesticide were 0.715 and 6.646 mg/L. It indicated that SERS technology is a effective method in the field of pesticide residue detection in fruit

Analysis of Load-Sharing Behavior of the Multistage Planetary Gear Train Used in Wind Generators: Effects of Random Wind Load

Load-sharing behavior is very important for power-split gearing systems. Taking the multistage planetary gear train transmission of an Million Watt (MW) wind generator as the investigation object, and based on the gear transmission system of a wind generator in a complex and changing load environment, a random wind model of a wind farm is built by using the two-parameter Weibull distribution. According to the realistic working region of the wind generator, the random wind speed is changed into time-varying input speed of the wind generator gear box. Considering the internal excitation, such as mesh stiffness, mesh damping of gear pairs and the meshing error, a dynamic model for a multistage planetary gear transmission system is built by using the lumped parameter method. The load-sharing coefficients are obtained for each planet gear pair in the same meshing period of the transmission system that is under the interaction of time-varying input speed and internal excitation. It is shown that the degree of load-sharing coefficient fluctuation for each planet gear pair of the first- and second-stage planetary gear train is significantly affected by time-varying input speed. The research results can lay a theoretical foundation for optimization and reliability of planetary gear transmission systems of wind generators

Determination of Lead (Pb) Content in Vetiver Grass Roots by Raman Spectroscopy

International audienceIn order to provide references for heavy metals diagnosis of Vetiver grass, Raman spectroscopy technology was employed, the partial least squares (PLS) quantitative analysis model of heavy metal lead of Vetiver grass root was established, different processing methods were used to optimize the Raman spectra of Vetiver grass roots, Successive projection algorithm (SPA) was applied to screen the bands of Raman spectrum and enhance the model’s accuracy. The best Raman spectroscopy quantitative analysis model of lead content in Vetiver grass root were set up, 20 unknown samples were used to test the quality of optimized model. The prediction correlation coefficient and the root mean square error were 0.607 and 0.040 g/kg, respectively

Study on Qualitative Impact Damage of Loquats Using Hyperspectral Technology Coupled with Texture Features

Bruising is one of the main problems in the post-harvest grading and processing of ‘Zaozhong 6’ loquats, reducing the economic value of loquats, and even food quality and safety problems are caused by it. Therefore, one of the main tasks in the post-harvest processing of loquats is to detect whether loquats are bruised, as well as the degree of bruising of loquats, to reduce the loss by proper treatment. An appropriate dimensionality reduction method can be used to reduce the redundancy of variables and improve the detection speed. The multispectral analysis method (MAM) has the advantage of accurate, rapid, and nondestructive detection, which was proposed to identify the different bruising degrees of loquats in this study. Firstly, the visible and near-infrared region (Vis–NIR, 400–1000 nm), the visible region (Vis, 400–780 nm), and the near-infrared region (NIR, 781–1000 nm) were analyzed using principal component analysis (PCA) to obtain the spectral regions and PC vectors, which could be used to effectively distinguish bruised loquats from normal loquats. Then, based on the selected second PC (PC2) score images, a morphological segmentation method (MSM) was proposed to distinguish bruised loquats from normal loquats. Furthermore, the weight coefficients of corresponding wavelength points of different degrees of bruising of loquats were analyzed, and the local extreme points and both sides of the interval were selected as the characteristic wavelength points for multi-spectral image processing. A gray level co-occurrence matrix (GLCM) was used to extract texture features and gray information from two-band ratio images K782/999. Finally, the MAM was proposed to detect the degree of bruising of loquats, which included the spectral data of three characteristic wavelength points in the NIR region coupled with texture features of the two-band ratio images, and the classification accuracy was 91.3%. This study shows that the MAM can be used as an effective dimensionality reduction method. The method not only improves the effect of prediction but also simplifies the process of prediction and ensures the accuracy of classification. The MSM can be used for rapid detection of normal and bruised fruits, and the MAM can be used to classify the degree of bruising of bruised fruits. Consequently, the processed methods are effective and can be used for the rapid and nondestructive detection of the degree of bruising of fruit