The efficient extraction of targets from complex surfaces is vital for technological applications ranging from environmental pollutant monitoring to analysis of explosive traces and pesticide ...residues. In our present study, we proposed a proof-of-concept surface enhance Raman scattering (SERS) active substrate serving directly to the rapid extraction and detection of target molecules. The novel substrate was constructed by decorating the commercial tape with colloidal gold nanoparticles (Au NPs), which simultaneously provides SERS activity and “sticky” of adhesive. The utility of SERS tape was demonstrated by directly extracting pesticide residues in fruits and vegetables via a simple and viable “paste and peel off” approach. The obtained strong and easily distinguishable SERS signals allow us to detect various pesticide residues such as parathion-methyl, thiram, and chlorpyrifos in the real samples with complex surfaces including green vegetable, cucumber, orange, and apple.
Module parallel connection for three-phase VSC can increase the system level effectively. However, the circulating currents problem will occur. The circulating currents will distort the three-phase ...currents, increase the power loss and decrease the system efficiency. A novel deadbeat circuiting currents control method is proposed in this paper. Based on the analysis of the average model of parallel system, a circuiting currents deadbeat controller is designed while presenting the design method. The control strategy is realized by adjusting the voltage zero vector of space-vector pulse-width modulation in each paralleled module. No additional hardware is needed through the method. Fast dynamic response can be achieved and the performance of circulating currents is better compared with conventional PI controller. This method can be applied to common dc-link double parallel three-phase voltage converters with communication line. The validity of proposed theory was verified by simulation and experimental results. It is shown that the parallel converters can operate with different line inductor or different line currents by using this novel control strategy.
Altruistic caste, including worker and soldier (derived from worker), plays a critical role in the ecological success of social insects. The proportion of soldiers, soldier sex ratios, and the number ...of workers vary significantly between species, and also within species, depending on colony developmental stage and environmental factors. However, it is unknown whether there are sex-linked effects from parents on controlling the caste fate or not. Here, we compared soldier sex ratios, soldier proportions, and population size among a four mating types of
Reticulitermes amamianus
(Ra) and
R
.
speratus
(Rs) (male × female, mRa × fRa, mRa × fRs, mRs × fRa, mRs × fRs) and demonstrate that the soldier sex ratio and worker population size of hybrid colonies skew to colonies of king’s species, while the soldier proportion skew to queen’s species. The survival rate of offspring resulting from interspecies hybridization was significantly higher for mRa × fRs than for mRs × fRa. The results of this study demonstrate the asymmetric influence of kings and queens on caste determination and colony growth, which can contribute to our better understanding of parental influence on the colony dynamics of social insects.
•The Natural Circulation Mechanism Experimental System (NCMES) has been constructed.•The experiment on the thermal hydraulic investigation of multiple-loops coupled natural circulation has been ...performed.•A comprehensive analysis of experimental and calculated results has been carried out.•The self-adaptive characteristic of natural circulation has been discussed.
The passive safety design is advantageous because it simplifies the system and brings higher safety features. Passive residual heat removal system (PRHRS) is one of the most important passive safety systems, which is designed to cool down the reactor during accidental conditions. For floating nuclear power platforms, seawater could be utilized as the final heat sink of PRHRS through multiple-loops coupled natural circulation.
To study the operating characteristics and thermal hydraulic behavior of multiple-loops coupled natural circulation system, the Natural Circulation Mechanism Experimental System (NCMES) has been constructed. The station blackout accident (SBO) scenario is simulated in NCMES, which leads to the stopping of circulation pump and operation of PRHRS. Based on the experimental data, an analysis was carried out using the thermal hydraulic system code RELAP5, aiming to validate applicability and accuracy, as well as predict the operating characteristics of the experiment facility. The comprehensive analysis of experimental and calculated results shows that when it comes to the SBO scenario, the releasing residual heat and sensible heat of fluid can be removed to seawater through triple-loops coupled natural circulation; the calculated results fit the experimental data quite well and the RELAP5 code is applicable to predict operating characteristics of multiple-loops coupled natural circulation and PRHRS. As a result of self-adaptive characteristic of natural circulation, with the heating power decreasing, the response rate of natural circulation flow rate and fluid temperature is slow.
The use of common dc-link parallel three-phase PWM converters without isolating transformers will cause zero-sequence circulating current problem. Previous works have proven that the circulating ...current is mainly affected by zero vectors employed in each PWM cycle. This paper proposes a novel method to suppress the circulating current. Detailed analysis is presented on the causes of zero-sequence circulating current based on a derived average model. A zero vectors feed-forward control strategy in combination with traditional PI control method is proposed to reject disturbances in zero-axis current system. In addition, a dual current sampling and dual PWM duty ratio update (DSDU) scheme is used to expand the bandwidth of zero-axis current loop. As a result, better circulating current suppression performance can be achieved in different filter inductance and converter output currents condition. Compared with the PI control method, the converters operated in parallel can be switched on and switched off separately with small current impact. Experimental results confirm the performance and effectiveness of the proposed method.
Health monitoring devices are integral parts of smart health in the era of smart connected communities. In recent years, remote heart monitoring systems are developed to harness advanced machine ...learning methods to identify heart disorders by processing electrocardiogram (ECG) signals. However, current technologies suffer from two important drawbacks: i) the lack of prediction capacity to predict heart abnormalities ahead of time, and ii) failure in capturing inter-patient variability. In this paper, we propose a novel two-step predictive framework for ECG signal processing, where a global classifier recognizes severe abnormalities (red alarms) by comparing the signal against a universal reference model. The seemingly normal signal samples undergo a subsequent deviation analysis and yellow alarms are called by identifying mild and yet informative signal morphology distortions comparing to the learned patient-specific baseline that can be indicative of upcoming heart conditions. To facilitate an accurate deviation analysis, a controlled nonlinear transformation with optimized parameters is proposed to increase the symmetry of signals for different abnormality classes in the feature space. The proposed method achieves a classification accuracy of 96.6% and provides a unique feature of predictive analysis by generating precaution warning messages about the elevated risk of heart abnormalities to take preventive actions according to physician orders. In particular, the chance of observing a severe problem (in terms of a red alarm) is raised by about 5% to 10% after observing a yellow alarm of the same type. The main goal of this technology is providing quality healthcare for elderly and high-risk heart-patients, however, the developed methodology is general and applicable to other biomedical signals such as EEG, Pleth, and PPG.
Besides aroma and taste, the color of dry tea leaves, tea infusion, and infused tea leaves is also an important index for tea quality. Shading can significantly increase the chlorophyll content of ...tea leaves, leading to enhanced tea leaf coloration. However, the underlying regulatory mechanism remains unclear. In this study, we revealed that the expressions of chlorophyll synthesis genes were significantly induced by shading, specially, the gene encoding protochlorophyllide oxidoreductase (
). Indoor control experiment showed that decreased light intensity could significantly induce the expression of
, and thus cause the increase of chlorophyll content. Subsequently, we explored the light signaling pathway transcription factors regulating chlorophyll synthesis, including CsPIFs and CsHY5. Through expression level and subcellular localization analysis, we found that CsPIF3-2, CsPIF7-1, and CsHY5 may be candidate transcriptional regulators. Transcriptional activation experiments proved that CsHY5 inhibits
transcription. In summary, we concluded that shading might promote the expression of
by inhibiting the expression of
, leading to high accumulation of chlorophyll in tea leaves. The results of this study provide insights into the mechanism regulating the improvements to tea plant quality caused by shading.
The occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs) in a city of Central China were determined in the settled dust and its extracted water phase from different land use types ...and bus stops in Nanchang City. The physicochemical properties of its water extracted dissolved organic matter (WEOM) were characterized to investigate the effect of fluorescence organic matter on the dust-water partitioning coefficients (Kd) using three-dimensional excitation-emission matrix fluorescence spectroscopy combined parallel factor analysis. Results showed that the range of ∑PAHs in settled dust and the extracted water phase was 0.05–15.92 μg·g−1 and 2–211 ng·L−1, respectively. These PAHs mostly came from the combustion of biomass. The risk assessment showed that PAHs in dust had no obvious health risk (less than the magnitude of 10−6). Additionally, the high molecular weight (HMW) PAHs and the low molecular weight (LMW) PAHs were preferentially adsorbed by dust and the dissolved portion, respectively. It was confirmed by the relatively high logKd values of 4.23 for the HMW-PAHs. Pearson correlation analysis suggested that the higher concentration of dissolved organic carbon and humic-like substance were in favor of PAHs in dust released into waters. This study can provide information on pollution control when considering the impact of fluorescent organic matter on the fate and transport of PAHs.
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•Partitioning behavior of PAHs between dust and WEOM was investigated.•Higher concentrations of ∑PAHs in both dust and WEOM were from the traffic roads.•LMW-PAHs preferred to dissolve in waters due to their higher solubility.•HMW-PAHs were predominantly existed in dust having a higher logKd value.•Humic-like substance was in favor of PAHs in dust released into waters.
Giant reed (Arundo donax) is widely distributed across the globe and is considered an important energy crop. This study presents the first comprehensive analysis of the chloroplast genome of giant ...reed, revealing detailed characteristics of this species’ chloroplast genome. The chloroplast genome has a total length of 137,153 bp, containing 84 protein-coding genes, 38 tRNA genes, and 8 rRNA genes, with a GC content of 39%. Functional analysis indicates that a total of 45 photosynthesis-related genes and 78 self-replication-related genes were identified, which may be closely associated with its adaptability and growth characteristics. Phylogenetic analysis confirmed that Arundo donax cv. Lvzhou No.1 belongs to the Arundionideae clade and occupies a distinct evolutionary position compared to other Arundo species. The findings of this study not only enhance our understanding of the giant reed genome but also provide valuable genetic resources for its application in biotechnology, bioenergy crop development, and ecological restoration.
Abstract
Artificial neural networks (ANN) which include deep learning neural networks (DNN) have problems such as the local minimal problem of Back propagation neural network (BPNN), the unstable ...problem of Radial basis function neural network (RBFNN) and the limited maximum precision problem of Convolutional neural network (CNN). Performance (training speed, precision, etc.) of BPNN, RBFNN and CNN are expected to be improved. Main works are as follows: Firstly, based on existing BPNN and RBFNN, Wavelet neural network (WNN) is implemented in order to get better performance for further improving CNN. WNN adopts the network structure of BPNN in order to get faster training speed. WNN adopts the wavelet function as an activation function, whose form is similar to the radial basis function of RBFNN, in order to solve the local minimum problem. Secondly, WNN-based Convolutional wavelet neural network (CWNN) method is proposed, in which the fully connected layers (FCL) of CNN is replaced by WNN. Thirdly, comparative simulations based on MNIST and CIFAR-10 datasets among the discussed methods of BPNN, RBFNN, CNN and CWNN are implemented and analyzed. Fourthly, the wavelet-based Convolutional Neural Network (WCNN) is proposed, where the wavelet transformation is adopted as the activation function in Convolutional Pool Neural Network (CPNN) of CNN. Fifthly, simulations based on CWNN are implemented and analyzed on the MNIST dataset. Effects are as follows: Firstly, WNN can solve the problems of BPNN and RBFNN and have better performance. Secondly, the proposed CWNN can reduce the mean square error and the error rate of CNN, which means CWNN has better maximum precision than CNN. Thirdly, the proposed WCNN can reduce the mean square error and the error rate of CWNN, which means WCNN has better maximum precision than CWNN.
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