This paper focuses on yaw stability control of in-wheel-motored electric vehicle (EV), and a model predictive controller is designed based on holistic control structure via active front steering and ...motor torque distribution. By designing a suitable reference model, the controller stabilizes a vehicle along the desired states while rejecting skid and fulfilling its physical constraints, so this is described as a constrained tracking problem. To solve this, the holistic control scheme is built to simplify the hierarchical structure of the controller and directly optimize the control inputs of system. Based on holistic control structure and MPC method, an objective function with constraints is designed over a receding horizon to meet the control requirements. Finally, the proposed nonlinear model predictive controller is evaluated on eight degrees of freedom (8DOF) EV model offline simulation platform. Simulation results of different road maneuver on slippery surfaces show the benefits of the control methodology used.
In order to save energy and improve the driving distance of electric vehicle, a regenerative braking control strategy based on fuzzy control for the electric vehicle with four in-wheel motors is ...proposed in this paper. Firstly, the braking force is distributed between front axis and rear axis to ensure the safety and stability of the vehicle. Secondly, the braking force is distributed between hydraulic braking and the motor braking. The required braking force can be obtained from the braking force calculation module, and the proportion of regenerative braking force can be obtained from the fuzzy controller. Finally, the mamdani fuzzy controller is established under the Matlab/Simulink environment and embedded into the vehicle model which established on AMESim software. The effectiveness of the proposed control strategy is verified by the simulation.
The objective of this study was to select the elements in tea leaves correlated with provenance soils, and further build a robust discriminant model of tea according to the geographical origin. Fresh ...tea leaves along with corresponding topsoil and subsoil samples were collected from three different tea producing regions in China. The concentrations of 20 elements were determined in tea leaf and soil samples. Analysis of variance, Pearson correlation analysis and linear discriminant analysis were used to analyze the obtained data. The results indicated that elemental fingerprinting profiles were different for tea leaves and provenance soils from different regions. The accumulation of some elements in tea leaves was closely correlated with their concentrations in soils. And this study revealed that Na, Mg, Ca, Ni, Rb, Sr and Pb were good descriptors to build discriminant models related to geology for tracing tea.
•Tea leaves and soils from different regions had their own elemental profiles.•The elements in tea closely correlated with provenance soil were selected.•Na, Mg, Ca, Ni, Rb, Sr and Pb were good tracers for tea authenticity.•A robust discriminant model of tea according to geographical origin was built.
DNA detection with high sensitivity and specificity has tremendous potential as molecular diagnostic agents. Graphene and graphene-based nanomaterials, such as graphene nanopore, graphene nanoribbon, ...graphene oxide, and reduced graphene oxide, graphene-nanoparticle composites, were demonstrated to have unique properties, which have attracted increasing interest towards the application of DNA detection with improved performance. This article comprehensively reviews the most recent trends in DNA detection based on graphene and graphene-related nanomaterials. Based on the current understanding, this review attempts to identify the future directions in which the field is likely to thrive, and stimulate more significant research in this subject.
Development in additive manufacturing is exceptionally rapid than the expected forecast so far and it has traced out new dimensions in engineering applications. 3D printing technology becomes more ...glamorous when Skylar Tibbits incorporated the concept of “Time” as a fourth dimension by encapsulating smart materials in current additive manufacturing technique. Materials having an explicit response to external stimuli over a certain time span are designated as smart materials and additive manufacturing of such time-dependent, programmable, and intelligent materials is termed as 4D printing. In 4D printing, primary 3D printed configuration switched exclusively into a transformed shape when exposed to an external stimuli, e.g. heat, light, water, chemical, electric current, magnetic field or pH. Perhaps, additive manufacturing technology seems to be superseded exclusively by this modern technology in forthcoming years, and much effort is demanding from every discipline to actualize this technology. A task-oriented entire landscape of 4D printing followed by a comprehensive smart material perspective is presented in this review. Graphical abstract set forth a route to the complete process comprehension. Moreover, other components of 4D technology like customary techniques, computational challenges, reversibility and current stature of 4D printing are probed through recent experimental and theoretical literature. Finally, potential applications of 4D printing are summarised with promising research directions and outlook.
Graphic Abstract
4D printing: A future insight in additive manufacturing
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•A novel online neuraminidase-immobilized capillary microreactor was developed.•Short-end injection procedure was introduced to greatly shorten the analytical time.•Dual wavelength detection was ...employed to eliminate the interference of inhibitors.•Kinetics constant of neuraminidase was studied by CE.•Eighteen natural products were screened for their inhibitory potency.
A simple and effective neuraminidase-immobilized capillary microreactor was fabricated by glutaraldehyde cross-linking technology for screening the neuraminidase inhibitors from traditional Chinese medicines. The substrate and product were separated by CE in short-end injection mode within 2min. Dual-wavelength ultraviolet detection was employed to eliminate the interference from the screened compounds. The parameters relating to the separation efficiency and the activity of immobilized neuraminidase were systematically evaluated. The activity of the immobilized neuraminidase remained 90% after 30 days storage at 4°C. The immobilized NA microreactor could be continuously used for more than 200 runs. The Michaelis–Menten constant of neuraminidase was determined by the microreactor as 136.6±10.8μM. In addition, six in eighteen natural products were found as potent inhibitors and the inhibition potentials were ranked in the following order: bavachinin>bavachin>baicalein>baicalin>chrysin and vitexin. The half-maximal inhibitory concentrations were 59.52±4.12, 65.28±1.07, 44.79±1.21 and 31.62±2.04 for baicalein, baicalin, bavachin and bavachinin, respectively. The results demonstrated that the neuraminidase-immobilized capillary microreactor was a very effective tool for screening neuraminidase inhibitors from traditional Chinese medicines.
Limited data are available for clinical characteristics of patients with coronavirus disease 2019 (COVID-19) outside Wuhan. This study aimed to describe the clinical characteristics of COVID-19 and ...identify the risk factors for severe illness of COVID-19 in Jiangsu province, China. Clinical data of hospitalized COVID-19 patients were retrospectively collected in 8 hospitals from 8 cities of Jiangsu province, China. Clinical findings of COVID-19 patients were described and risk factors for severe illness of COVID-19 were analyzed. By Feb 10, 2020, 202 hospitalized patients with COVID-19 were enrolled. The median age of patients was 44.0 years (interquartile range, 33.0-54.0). 55 (27.2%) patients had comorbidities. At the onset of illness, the common symptoms were fever (156 77.2%) and cough (120 59.4%). 66 (32.7%) patients had lymphopenia. 193 (95.5%) patients had abnormal radiological findings. 11 (5.4%) patients were admitted to the intensive care unit and none of the patients died. 23 (11.4%) patients had severe illness. Severe illness of COVID-19 was independently associated with body mass index (BMI) ≥ 28 kg/m2 (odds ratio OR, 9.219; 95% confidence interval CI, 2.731 to 31.126; P<0.001) and a known history of type 2 diabetes (OR, 4.326; 95% CI, 1.059 to 17.668; P = 0.041). In this case series in Jiangsu Province, COVID-19 patients had less severe symptoms and had better outcomes than the initial COVID-19 patients in Wuhan. The BMI ≥ 28 kg/m2 and a known history of type 2 diabetes were independent risk factors of severe illness in patients with COVID-19.
We reported the clinical characteristics of a case series of 10 patients with coronavirus disease 2019 (COVID‐19) aged from 1 year to 18 years. Seven patients had contact with confirmed COVID‐19 ...family members before onset. Fever (4 40.0%) and cough (3 30.0%) were the most common symptoms. No patient showed leucopenia and lymphopenia on admission. Pneumonia was observed in chest CT images in 5 (50.0%) patients. Five (50.0%) patients received antiviral treatment. No patient had severe complications or developed a severe illness in our study. Our study indicated that COVID‐19 children present less severe symptoms and have better outcomes.
A ligand‐controlled regiodivergent and enantioselective copper‐catalyzed intermolecular hydroallylation of alkynes with allylic phosphates and hydrosilanes has been achieved for the first time. The ...chiral bidentate sulfonate‐containing N‐heterocyclic carbene ligated CuCl complex leads to enantioenriched SN2′‐type products, whereas the use of the IMesCuCl catalyst affords SN2‐type products. Thus a range of chiral branched and achiral linear 1,4‐dienes could be facilely synthesized from readily available alkynes in a regiodivergent manner.
Under control: A ligand‐controlled regiodivergent and enantioselective copper‐catalyzed intermolecular hydroallylation of alkynes with allylic phosphates and hydrosilanes has been achieved. Chiral branched or achiral linear dienes can be obtained by proper choice of the ancillary N‐heterocyclic carbene ligand.
► Wheat could be classified based on geographical origins by NIR with chemometrics. ► Harvest year affected NIR spectra of wheat from the same origin. ► NIR prediction of origins was slightly better ...with kernel than whole wheat flour. ► DPLS were better than LDA for wheat geographical origin determination.
The feasibility of using near infrared reflectance (NIR) spectroscopy combined with chemometrics was investigated to discriminate wheat geographical origins. A total of 240 wheat samples from two growing years from four major wheat producing regions in China were analyzed. After spectral data pre-treatment to wheat kernel and whole wheat flour, linear discriminant analysis (LDA) based on principal component scores and discriminant partial least squares analysis (DPLS) were applied to classify origins of samples excluding water spectrum. The results showed that there were significant differences among wheat NIR spectra from different regions. Wheat could be classified based on geographical origins with chemometrics. DPLS were better than LDA for wheat origin determination. In conclusion, NIRS combined with chemometrics is a promising method for identifying wheat according to geographical origin, but the effectiveness should be verified further.
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