Soil salinization and a degraded ecological environment are challenging agricultural productivity and food security. Rice (
), the staple food of much of the world's population, is categorized as a ...salt-susceptible crop. Improving the salt tolerance of rice would increase the potential of saline-alkali land and ensure food security. Salt tolerance is a complex quantitative trait. Biotechnological efforts to improve the salt tolerance of rice hinge on a detailed understanding of the molecular mechanisms underlying salt stress tolerance. In this review, we summarize progress in the breeding of salt-tolerant rice and in the mapping and cloning of genes and quantitative trait loci (QTLs) associated with salt tolerance in rice. Furthermore, we describe biotechnological tools that can be used to cultivate salt-tolerant rice, providing a reference for efforts aimed at rapidly and precisely cultivating salt-tolerance rice varieties.
Mosaic, Rust, Brown spot, and Alternaria leaf spot are the four common types of apple leaf diseases. Early diagnosis and accurate identification of apple leaf diseases can control the spread of ...infection and ensure the healthy development of the apple industry. The existing research uses complex image preprocessing and cannot guarantee high recognition rates for apple leaf diseases. This paper proposes an accurate identifying approach for apple leaf diseases based on deep convolutional neural networks. It includes generating sufficient pathological images and designing a novel architecture of a deep convolutional neural network based on AlexNet to detect apple leaf diseases. Using a dataset of 13,689 images of diseased apple leaves, the proposed deep convolutional neural network model is trained to identify the four common apple leaf diseases. Under the hold-out test set, the experimental results show that the proposed disease identification approach based on the convolutional neural network achieves an overall accuracy of 97.62%, the model parameters are reduced by 51,206,928 compared with those in the standard AlexNet model, and the accuracy of the proposed model with generated pathological images obtains an improvement of 10.83%. This research indicates that the proposed deep learning model provides a better solution in disease control for apple leaf diseases with high accuracy and a faster convergence rate, and that the image generation technique proposed in this paper can enhance the robustness of the convolutional neural network model.
This paper deals with the attraction–repulsion chemotaxis system {ut=Δu−χ∇⋅(u∇v)+ξ∇⋅(u∇w),x∈Ω,t>0,0=Δv+αu−βv,x∈Ω,t>0,0=Δw+γu−δw,x∈Ω,t>0, under homogeneous Neumann boundary conditions in a smooth ...bounded domain in R2. We study the finite-time blowup of nonradial solutions in the parameter values χα−ξγ>0 and β≠δ.
Despite the significant progresses made in all-polymer solar cells (all-PSCs) recently, the relatively low short-circuit current density (J sc) and large energy loss are still quite difficult to ...overcome for further development. To address these challenges, we developed a new class of narrow-bandgap polymer acceptors incorporating a benzotriazole (BTz)-core fused-ring segment, named the PZT series. Compared to the commonly used benzothiadiazole (BT)-containing polymer PYT, the less electron-deficient BTz renders PZT derivatives with significantly red-shifted optical absorption and up-shifted energy levels, leading to simultaneously improved J sc and open-circuit voltage in the resultant all-PSCs. More importantly, a regioregular PZT (PZT-γ) has been developed to achieve higher regiospecificity for avoiding the formation of isomers during polymerization. Benefiting from the more extended absorption, better backbone ordering, and more optimal blend morphology with donor component, PZT-γ-based all-PSCs exhibit a record-high power conversion efficiency of 15.8% with a greatly enhanced J sc of 24.7 mA/cm2 and a low energy loss of 0.51 eV.
Ternary organic solar cells are promising alternatives to the binary counterpart due to their potential in achieving high performance. Although a growing number of ternary organic solar cells are ...recently reported, less effort is devoted to morphology control. Here, ternary organic solar cells are fabricated using a wide‐bandgap polymer PBT1‐C as the donor, a crystalline fused‐ring electron acceptor ITIC‐2Cl, and an amorphous fullerene derivative indene‐C60 bisadduct (ICBA) as the acceptor. It is found that ICBA can disturb π–π interactions of the crystalline ITIC‐2Cl molecules in ternary blends and then help to form more uniform morphology. As a result, incorporation of 20% ICBA in the PBT1‐C:ITIC‐2Cl blend enables efficient charge dissociation, negligible bimolecular recombination, and balanced charge carrier mobilities. An impressive power conversion efficiency (PCE) of 13.4%, with a high fill factor (FF) of 76.8%, is eventually achieved, which represents one of the highest PCEs reported so far for organic solar cells. The results manifest that the adoption of amorphous fullerene acceptor is an effective approach to optimizing the ternary blend morphology and thereby increases the solar cell performance.
Ternary organic solar cells based on a wide‐bandgap polymer donor (PBT1‐C), a fullerene derivative indene‐C60 bisadduct (ICBA), and a crystalline fused‐ring electron acceptor (ITIC‐2Cl) yield an impressive efficiency of 13.4%, and a high fill factor of 76.8%, indicating that the use of an amorphous fullerene acceptor is an effective way to optimize the ternary blend morphology.
No design rules have yet been established for producing solid electrolytes with a lithium-ion conductivity high enough to replace liquid electrolytes and expand the performance and battery ...configuration limits of current lithium ion batteries. Taking advantage of the properties of high-entropy materials, we have designed a highly ion-conductive solid electrolyte by increasing the compositional complexity of a known lithium superionic conductor to eliminate ion migration barriers while maintaining the structural framework for superionic conduction. The synthesized phase with a compositional complexity showed an improved ion conductivity. We showed that the highly conductive solid electrolyte enables charge and discharge of a thick lithium-ion battery cathode at room temperature and thus has potential to change conventional battery configurations.
Brazing, as a common method of bonding ceramic and metal, has been applied in microelectronics, aerospace, machinery and other domains extensively. The residual thermal stress in the brazed joint has ...direct effects on the mechanical properties of the joint, so how to control the generation of residual thermal stress has become the vital point. In this paper, the methods of reducing residual thermal stress in the brazing process in recent years are reviewed. The generation and effects of residual thermal stress in the brazed joint are introduced. Besides, the methods of detecting residual thermal stress are discussed, and different methods of reducing residual thermal stress in brazed joints are also analyzed. Finally, the future development directions of reducing residual thermal stress in the brazed joint are proposed.
Purpose
The purpose of this study was to conduct a systematic review to assess the effect of exercise on the quality of life among people with breast cancer.
Methods
We conducted a systematic review ...using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Cochrane Library, PubMed, EMBASE, Web of Science, CINAHL, and four Chinese databases were searched for studies published until January 2018. The review included all randomized controlled trials that evaluated the effect of exercise on quality of life compared with that of usual care for people with breast cancer. Two reviewers independently assessed the quality of all the included studies using the
Cochrane Handbook for Systematic Reviews of Interventions
.
Results
In total, 36 studies (3914 participants) met the inclusion criteria. We divided the exercise into three modes: aerobic, resistance, and a combination of aerobic and resistance. All three modes of exercise intervention showed a significant effect on quality of life between groups.
Conclusions
Exercise is a safe and effective method of improving the quality of life in patients with breast cancer. In particular, combined training was associated with a significant improvement in quality of life. In future research, more high-quality, multicenter trials evaluating the effect of exercise in breast cancer patients are needed.
Many environmental pollutants inherently exist in their anionic forms and are therefore highly mobile in natural water systems. Cationic framework materials that can capture those pollutants are ...highly desirable but scarcely reported. Here we present a mesoporous cationic thorium-based MOF (SCU-8) containing channels with a large inner diameter of 2.2 nm and possessing a high surface area of 1360 m
g
. The anion-exchange properties of SCU-8 were explored with many anions including small oxo anions like ReO
and Cr
O
as well as anionic organic dyes like methyl blue and the persistent organic pollutant, perfluorooctane sulfonate (PFOS). Both fast uptake kinetics and great sorption selectivity toward PFOS are observed. The underlying sorption mechanism was probed using quantum mechanical and molecular dynamics simulations. These computational results reveal that PFOS anions are immobilized in SCU-8 by driving forces including electrostatic interactions, hydrogen bonds, hydrophobic interactions, and van der Waals interactions at different adsorption stages.
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