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Polymer dielectrics for energy storage applications usually endure high electric field strength. Adjustment of the composition and structure of the dielectric bulk phase to enhance the dielectric breakdown strength has been widely studied. However, the effect of electrode–dielectric interface on the breakdown strength has received little attention, which greatly hinders further development in this field. In this work, an all-organic double-layer dielectric film consisting of poly(vinylidene fluoride) (PVDF) as the matrix and polymethyl methacrylate (PMMA) as the organic nano-interlayer was prepared. By adjusting the electrode–dielectric interface, remarkably improved electric breakdown strength (767.05 MV m−1) and discharged energy density (19.08 J cm−3) were realized concurrently without sacrificing the charge–discharge efficiency. The experimental results and computational simulations reveal that the surface morphology of dielectrics has a great effect on the electric field distribution at the electrode–dielectric interface, and further affects the leakage current and breakdown strength of the dielectric. The PMMA nano-interlayer modifies the surface defects and increases the Young's modulus at the electrode–dielectric interface, leading to the improvement of insulation performance. These findings offer a new perspective to understand the impact of the electrode–dielectric interface on the polymer dielectric breakdown strength. This work provides a novel paradigm for fabricating polymer dielectrics with high breakdown strength for energy storage.

Polymer-based dielectrics have received intensive interest from academic community in the field of high-power energy storage owing to their superior flexibility and fast charge-discharge ability. Recently, how to suppress the loss of polymer-based dielectrics has been increasingly recognized as a critical point to attain a high charge-discharge efficiency in the film capacitors. Some achievements are made in analyzing the source of loss and suppressing loss via Edison's trial and error method. In this review, the significance of suppressing loss in polymer-based dielectrics is firstly emphasized. Then, different sources of loss are discussed carefully and an in-depth analysis of the related measurements is presented. Next, recent research results in suppressing loss are summarized and discussed in detail according to different strategies. Finally, the challenges and opportunities in the loss suppression research for the rational design of high-efficiency polymer-based dielectrics are proposed.

Dielectric elastomer actuators (DEAs) with large electrically-actuated strain can build light-weight and flexible non-magnetic motors. However, dielectric elastomers commonly used in the field of soft actuation suffer from high stiffness, low strength, and high driving field, severely limiting the DEA’s actuating performance. Here we design a new polyacrylate dielectric elastomer with optimized crosslinking network by rationally employing the difunctional macromolecular crosslinking agent. The proposed elastomer simultaneously possesses desirable modulus (~0.073 MPa), high toughness (elongation ~2400%), low mechanical loss (tan δm = 0.21@1 Hz, 20 °C), and satisfactory dielectric properties (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\varepsilon }_{{{{{{\rm{r}}}}}}}$$\end{document}εr = 5.75, tan δe = 0.0019 @1 kHz), and accordingly, large actuation strain (118% @ 70 MV m−1), high energy density (0.24 MJ m−3 @ 70 MV m−1), and rapid response (bandwidth above 100 Hz). Compared with VHBTM 4910, the non-magnetic motor made of our elastomer presents 15 times higher rotation speed. These findings offer a strategy to fabricate high-performance dielectric elastomers for soft actuators., Dielectric elastomer actuators (DEAs) with large electrically actuated strain can be used in non-magnetic motors, but high stiffness, poor strength and slow response currently limit the application of DEAs. Here, the authors optimize the crosslinking network in a polyacrylate elastomer to enable a DEA with high toughness and actuation strain and use the polyacrylate to build a motor which can be driven under low electric field.

This work reports the low-loss polyacrylate dielectric elastomer with outstanding actuation performance by employing a molecular engineering route. It is found that the difunctional macromolecular crosslinking agent we choose can not only effectively tune the dimensions of elastomer meshes and avoid uneven distribution of crosslinking points in elastomer matrix, accordingly eliminating the stress concentration and delaying the failure of elastomer, but also as “soft segments” and alleviate the strong dipole-dipole interaction between adjacent side groups of polyacrylate, which makes the dielectric elastomer with low elastic modulus and low mechanical loss. Simultaneously, a certain amount of uncrosslinked chains will remain in the free volume space of elastomer network, which would increase the dielectric constant of as-synthesized elastomers owing to their strong orientation ability. Therefore, the improvements in mechanical and dielectric properties of elastomer will contribute to the amelioration of actuation performance. We also design a home-made non-magnetic motor apparatus to verify the optimized actuation performance. This finding represents the first molecular engineering approach to improve the intrinsic actuation performance of dielectric elastomers, which are key materials of choice for flexible dielectric elastomer actuators.

Ceramic spheres and fibers co-filled nanocomposite has shown great potential in the field of high energy density dielectrics. In this work, finite element simulation was adopted to investigate the dielectric property of the nanocomposite with ceramic spheres and fibers co-filled configuration. A three-dimensional model with random distribution of fillers was built to study the effect of filler parameters on the dielectric performance of nanocomposites. The effect of the co-filled particles with different shape and distribution on the dielectric properties of composites has been systematically studied. The aspect ratio of fiber is found to have great effect on the dielectric performance of the composites. The size of sphere fillers affects their distribution in composites, which leads to the variation of the composite permittivity.

Dielectric elastomers (DEs) are kinds of advanced functional materials, attracting more attention due to that they can used to fabricate ingenious devices. In this work, a series of advanced DEs based on the copolymer of polyurethane (PU) and acrylate, were chemically prepared through the condensation polymerization between p (BA-HEA), the n-butyl acrylate (BA) and hydroxyethyl acrylate (HEA) copolymer and diphenyl methane diisocyanate (MDI), named as p (BA-HEA)@MDI. The absence of urethane group was confirmed by infrared spectroscopy measurements. And the DEs show a decreased elastic modulus and an improved elongation at break with the decreasing content of MDI. For the absence of strong polar urethane group, the dielectric permittivity of new DEs still keeps at a relatively high value. And the p (BA-HEA)@MDI-3 shows the highest electromechanical sensitivity and the foreseeable highest actuation strain (14.4%) at a relatively low electric field (15.2 kV/mm) without any pre-strains, which is almost 2 times of that of VHB 4910 (acrylic adhesive tape, 3 M Corporation). The present work provides a new strategy to design high performance dielectric elastomers.

Most dielectric elastomers (DEs) need high operating electric field (>100 kV/mm) and the essential pre-strains to achieve satisfied actuation, which limits their widespread application. In this work, we prepare a series of high performance DEs using the common acrylate monomers through a versatile method. By adjusting the component of polymers, the advanced DE possess a high actuation coefficient β (51.54 MPa−1) and shows a high actuated strain of 52.08% at a low electric field of 21.57 kV/mm without pre-strain. It is also found that the actuated strain of the c-p (BA-GMA)-3 is almost 4.2 times higher than that of VHB 4910. Furthermore, the advanced DE material is used to fabricate into a bend actuator, which can bend a angel of 180° and show a good electromechanical response. The present work opens a new strategy for designing advanced dielectric elastomers displaying high actuated strain without pre-strain at very low electric field.

Background Ethylene-responsive factors (ERFs) play important roles in plant growth and development and the response to adverse environmental factors, including abiotic and biotic stresses. Results In the present study, we identified 160 soybean ERF genes distributed across 20 chromosomes that could be clustered into eight groups based on phylogenetic relationships. A highly ABA-responsive ERF gene, GmERF75, belonging to Group VII was further characterized. Subcellular localization analysis showed that the GmERF75 protein is localized in the nucleus, and qRT-PCR results showed that GmERF75 is responsive to multiple abiotic stresses and exogenous hormones. GmERF75-overexpressing Arabidopsis lines showed higher chlorophyll content compared to WT and mutants under osmotic stress. Two independent Arabidopsis mutations of AtERF71, a gene homologous to GmERF75, displayed shorter hypocotyls, and overexpression of GmERF75 in these mutants could rescue the short hypocotyl phenotypes. Overexpressing GmERF75 in soybean hairy roots improved root growth under exogenous ABA and salt stress. Conclusions These results suggested that GmERF75 is an important plant transcription factor that plays a critical role in enhancing osmotic tolerance in both Arabidopsis and soybean.

Abscisic acid (ABA) mediates various abiotic stress responses, and ethylene responsive factors (ERFs) play vital role in resisting stresses, but the interaction of these molecular mechanisms remains elusive. In this study, we identified an ABA-induced soybean ERF gene GmERF135 that was highly up-regulated by ethylene (ET), drought, salt, and low temperature treatments. Subcellular localization assay showed that the GmERF135 protein was targeted to the nucleus. Promoter cis-acting elements analysis suggested that numerous potential stress responsive cis-elements were distributed in the promoter region of GmERF135, including ABA-, light-, ET-, gibberellin (GA)-, and methyl jasmonate (MeJA)-responsive elements. Overexpression of GmERF135 in Arabidopsis enhanced tolerance to drought and salt conditions. In addition, GmERF135 promoted the growth of transgenic hairy roots under salt and exogenous ABA conditions. These results suggest that soybean GmERF135 may participate in both ABA and ET signaling pathways to regulate the responses to multiple stresses.

Leucobryum juniperoideum (Brid.) Mull.Hal., a common moss in eastern China, grows in three typical habitats in the Tianmu Mountain National Nature Reserve, Zhejiang, China. This study aims to reveal the role of soil nitrogen and phosphorus in the distribution of Leucobryum juniperoideum by investigating soil conditions in the Tianmu Mountain National Nature Reserve. Epigeic populations of this bryophyte were found only in areas with a Moso bamboo forest, while the epixylous populations always occurred in areas with Chinese fir forest and Chinese cedar forest, and the epilithic populations occurred in all three habitat types. Analyses showed that nitrogen (N) and phosphorus (P) concentrations in the soils of Chinese fir forests and Chinese cedar forests were remarkably higher than those of Moso bamboo forests. In the laboratory, experiments showed that the growth of L. juniperoideum was remarkably reduced by N additions of 0.1 mol/L over a period of six months, while growth was increased by P additions of up to 0.1 mol/L over six months. In addition, physiological responses to N indicated that the mosses were sensitive to N additions, but not to additions of P. Also, high concentrations of N (200 mg/L) can significantly reduce the germination rates and can delay the development of early germination stages and stable germination stages for 2 to 4 days. Phosphorus additions did not affect the germination rate, but did cause delays in the development of germination stages. The combination of N and P caused remarkable declines in the germination rate and delayed the germinating time. Taken together, our results demonstrate that soil N is the primary determinant in limiting the distribution of L. juniperoideum populations.

Multilayer structural design (including sandwich structure) has received wide attention due to its complementary advantages of different layers in the field of high energy density dielectric materials. Although multilayer polymer composites with improved breakdown strength and energy density have been prepared in some studies, the key mechanism is not clear. In this work, different kinds of multilayer films consisting of various pure polymer [polyimide, poly(vinylidene fluoride) (PVDF), and polypropylene (PP)] layers were prepared to investigate the underlying mechanism of improved performances by multilayer structural design. Experimental results indicated that the relative position of the multilayer film and electrode had an effect on the result of breakdown strength. Meanwhile, when the layer with high relative permittivity (high-k layer) came in contact with the negative electrode, the thinner the high-k layer was, the more remarkable the enhancement of the multilayer materials breakdown strength was. Finally, a double-layer film of PP and PVDF with a Weibull breakdown strength of 649.31 MV/m, which was 60.83 MV/m higher than that of the commercial PP film, was prepared. The simulation result showed that the coating high-k layer could effectively restrain the local electric field distortion around the defect. This study reveals an effective way to improve the breakdown strength of films, which is of great significance for the improvement of capacitor performance and enhancement of energy storage.

Based on the flammability requirements of toy and textile product in Entry-Exit Inspection, design and development the automation tester of flammability combined with PLC control technology, high-performance and fine-segmentation driver as well as step-in motor. It demonstrated the tester machinery design, work principle, control system and programming of software. It is pointed out the tester can settle for testing requirement of International standard toy safety, and also settle for testing requirement of International standard textile safety.

Recent advances in the electrospinning technique offer significant opportunities for improved fiber reinforced polymer composites of interest for capacitor applications. Classical effective medium approximation may fail to reach exact solutions due to the intricately inhomogeneous distribution of the depolarizing field in fibers with arbitrary orientation degrees. In this work, a three-dimensional finite element method (FEM) model has been developed to in-depth study the effects of fiber alignment on the dielectric response in fiber/polymer composites. A quantitative relationship between the effective permittivity of composites and the alignment degree of fiber has been initially established. Furthermore, we define a parameter of the effective angle which has the equivalent contribution on the effective permittivity with the actually distributed multiple alignment angles of fibers in practical composite materials. The calculation results with FEM show good agreement with the experiment measurements delivered recently.

The RNA-guided Cas9 nuclease from microbial clustered regularly interspaced short palindromic repeats (CRISPR) adaptive immune system has been used to facilitate efficient genome engineering in eukaryotic cells. The specific targeted genome is recognized and cut by gRNA-directed CRISPR/Cas9 complex, specifically by the endonuclease Cas9. The targeted gene locus could be repaired either by homology-directed repair or nonhomologous end joining, thus achieving a desired editing outcome. Viruses infect cells through specific receptors, and then the viral genome is transcribed, replicated and translated to complete its life cycle. As a result, some DNA virus and retrovirus genomes are integrated into the cellular genome. Gene therapy is a new trend to treat viral infected diseases. Given its designable sequence-specific editing of the targeted genome, CRISPR/Cas9 has tremendous potential in treating persistent and latent viral infections. In this review, we summarize the mechanism and progresses of CRISPR/Cas9, and also highlight its therapeutic application in infectious diseases.

This paper proposes a novel voltage control method for single-phase shunt active power filter (SAPF) using the space vector pulse-width modulation (SVPWM). The method provides compensation for harmonics and reactive power and has an excellent dynamic performance. A detailed analysis is presented for the principle of single-phase SVPWM. The APF's current reference is obtained by subtracting the measured load current from the supply current reference. MATLAB simulation result shows that the compensation effect of this kind of APF is very well in the case of load changes, and it can achieve flexible compensation. The validity of this APF processing system to compensate current harmonics and reactive power is substantiated by simulation and experimental results.

To investigate effect of clinical pathway management on pediatric pneumonia.Data were colleted from children hospitalizated with bronchial pneumonia, bronchiolitis, mycoplasma pneumonia in Center of Respiratory Disorders in Children's Hospital of Chongqing Medical University from January 2011 to December 2012. According to implement of clinical pathway management, all patients were divided into pathway management group (n = 405) and non-pathway management group (n = 503). Length of stay, costs of hospitalization, clinical effect and use of antibiotics were compared in these two groups.In pathway management group, average length of stay of children with bronchial pneumonia and bronchiolitis was (6.1 ± 1.6) d and (6.2 ± 1.5) d respectively. While in non-pathway management group, length of stay was (7.2 ± 1.9) d and (7.3 ± 1.5) d (P = 0.000). There was no significant difference in length of stay between these two groups of children with mycoplasma pneumonia [ (6.9 ± 1.8) d vs.(7.7 ± 2.5) d] (P = 0.198). Costs of auxiliary tests in pathway management group was slightly higher than that in non-pathway management group. While other costs in pathway management group were significantly lower than those in non-pathway management group. Total costs of hospitalization of patients with these three diseases in pathway management group and non-pathway management group were ¥(4609 ± 1225) vs ¥ (5629 ± 1813) , ¥ (5006 ± 1250) vs. ¥ (5686 ± 1337), ¥ (4946 ± 1259) vs. ¥ (6488 ± 3032) respectively. There was a significant difference (P0.05). Percentages of antibiotics use in two groups were 70.9% vs.99.4%, 45.7% vs.93.4% and 96.2% vs.100.0%. Antibiotics related indicators such as mean number of day of use, ratio of combination and grade of antibiotics were significantly higher in pathway management group compared to non-pathway management group (P0.01). There was no significant difference in other indicators like clinical effect and unscheduled readmission in 30 days between two groups (P0.05).Clinical pathway management can regulate medical behaviors through reduction of medical costs, avoidance of excessive laboratory tests and therapy, and regulation of antibiotic use.

To investigate the mixed infection and analyze risk factors in children with severe adenovirus pneumonia.A retrospective analysis was performed on the clinical data of 756 children with adenovirus pneumonia between June 2009 and June 2011. Pathogens and risk factors were studied in 216 severe cases.Of the 216 severe cases, 138 (63.9%) were aged from 6 months to 2 years, and 161 (74.5%) developed the disease in the winter and spring; 177 (81.9%) were affected by 1-4 pathogens besides adenovirus, including 74 cases (34.3%) infected with one pathogen as an addition. A total of 334 pathogen strains were identified from the respiratory secretions and sera of the 216 cases. Of them, 163 (48.8%) were bacterial strains, dominated by Gram-negative bacteria (124 strains), 108 (32.3%) were viral strains, and 40 (12.0%) were fungal strains. Multivariate logistic regression analysis indicated that congenital heart disease, congenital airway abnormalities, nutritional anemia, recurrent pulmonary infection, and surgical history were the independent risk factors for severe adenovirus pneumonia in children, with odds ratios of 3.3, 11.1, 7.2, 14.3 and 12.9 respectively (P0.05).Severe adenovirus pneumonia is mostly seen in children aged from 6 months to 2 years and occurs frequently in the winter and spring. Many cases are also infected with other pathogens, most commonly Gram-negative bacteria. Congenital heart disease, congenital airway abnormalities, nutritional anemia, recurrent pulmonary infection and surgical history are the independent risk factors for severe adenovirus pneumonia in children.

Oxidative stress caused by accumulation of reactive oxygen species (ROS) is capable of damaging effects on numerous cellular components. Glutathione peroxidases (GPXs, EC 1.11.1.9) are key enzymes of the antioxidant network in plants. In this study, W69 and W106, two putative GPX genes, were obtained by de novo transcriptome sequencing of salt-treated wheat (Triticum aestivum) seedlings. The purified His-tag fusion proteins of W69 and W106 reduced H2O2 and t-butyl hydroperoxide (t-BHP) using glutathione (GSH) or thioredoxin (Trx) as an electron donor in vitro, showing their peroxidase activity toward H2O2 and toxic organic hydroperoxide. GFP fluorescence assays revealed that W69 and W106 are localized in chloroplasts. Quantitative real-time PCR (Q-RT-PCR) analysis showed that two GPXs were differentially responsive to salt, drought, H2O2, or ABA. Isolation of the W69 and W106 promoters revealed some cis-acting elements responding to abiotic stresses. Overexpression of W69 and W106 conferred strong tolerance to salt, H2O2, and ABA treatment in Arabidopsis. Moreover, the expression levels of key regulator genes (SOS1, RbohD and ABI1/ABI2) involved in salt, H2O2 and ABA signaling were altered in the transgenic plants. These findings suggest that W69 and W106 not only act as scavengers of H2O2 in controlling abiotic stress responses, but also play important roles in salt and ABA signaling.

In this paper, we discuss the seedling planting mechanism which is applied in transplantation of baccy, corn?beet, eggplant, tomato, cotton Conclusions Etc. A mathematic model of the seedling transplanting mechanism is established and the model is calculated&simulated with MATLAB. By means of this model, the analysis for the movement of the mechanism became Intuitive and visible. And this model could also provide bases for choosing the rational parameters of transplanting mechanism and enhancing its transplanting performance. According to the agronomy requirement of seedlings transplantation, we optimally design the key component that is suitable for the seedling transplanting mechanism, analyze and study the universal law of the mechanical planting and find the main factors that affect the transplanting performance.