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Purpose: To clarify the effects of rice straw returning on the yield and quality of common buckwheat. Methods: Common buckwheat cultivar Fengtian 1 was used across two years and treated with no rice straw returning combined with no compound fertilizer (CK), no rice straw returning combined with normal fertilizer (NSNF), full rice straw returning with 20% (FSRF20%), 40%, (FSRF40%) and 80% (FSRF80%) reduction in compound fertilizer application, and full rice straw returning with no compound fertilizer (FSNF). Results: Compared with the CK treatment, the FSRF20% treatment increased the accumulation and transport rate of non-structural carbohydrate in leaves at full bloom and grain filling stages and the enzyme activity of rhizosphere soil. With decreased compound fertilizer application rate, the grain weight per plant, 100-grain weight, and yield initially increased and then decreased, reaching the maximum at FSRF20% treatment. Compared with that of the CK treatment, the NSNF, FSRF20%, FSRF40%, FSRF80%, and FSNF treatment increased the yield by 172.54%, 181.02%, 104.49%, 69.30%, and 22.33%, respectively. The proportion of essential amino acids was about half that of total amino acids of common buckwheat. The flavonoid and starch content in grains of FSRF40% treatment were the highest. The protein, total amino acids, and essential amino acids content in grains of CK treatment were the highest. Conclusions: For the sustainable development of farmland and improve the economic benefits of cultivating common buckwheat, 20% reduction in compound fertilizer can be considered when the total amount of rice straw was returned to the field.

Purpose: To address the problem of poor soil conditions and low straw return measures in Southwestern China, straw decomposition liquid was used to simulate the effects of straw return on common buckwheat seed germination and growth in the field. Methods: The high-yielding common buckwheat variety “Fengtian 1” was used as test material to study the effect of different rice straw decomposition liquid treatments (0, 6.25, 12.50, 25.00, 50.00, 100.00 mg mL− 1) on seed germination, root morphology and activity, antioxidant enzyme activity, and nutrient uptake and utilization of common buckwheat. Results: The germination rate, germination potential, and germination index of common buckwheat seed with low concentration of rice straw decomposition liquid treatment were not significant difference from those of the control. The root activity, root surface area, and the root volume of seedlings increased significantly with the increase in treatment concentration, at the 12.50 mg mL− 1concentration treatment with the best effect. As the concentration of rice straw decomposition liquid increased further, the seed germination indicators, seedling root indicators, and antioxidant activities significantly decreased. Meanwhile, the decomposition liquid ammonium nitrogen, available phosphorus, available potassium content and plant total nitrogen, total phosphorus, total potassium content, biomass (dry weight underground), root-to-shoot ratio, main stem length were increased with increasing the decomposition liquid concentration. Conclusions: The appropriate concentration of rice straw decomposition liquid will not inhibit the common buckwheat seed germination, while it can promote seedling growth and improve the efficiency of nutrient absorption. There was a better effect at 12.50 mg mL− 1concentration treatment.

Poor grain filling and light grain test weight limit the grain yield potential of crops. The quality of grain filling is closely related to the grains on the position of the plant. This study assesses the positive effect of apical dominance removal treatment (ADR) on poor grain filling and the yield formation of common buckwheat (Fagopyrum esculentumMoench). Common buckwheat cultivar “Fengtian 1” was used to study the effects of ADR on grain filling, starch synthesis enzyme activities, endogenous hormone content, root morphology and physiology, and yield. Compared to no apical dominance removal (CK), the grain filling rate, abscisic acid (ABA), and indo‐3‐acetic acid (IAA) content of grains of the ADR treatment were increased by 54.9%, 26.2%, and 24.5%, respectively. The ADR treatment had better root growth and stronger antioxidant enzyme activity than the CK treatment. The grains per plant, grain weight per plant, and yield in the ADR treatment were 1.17, 1.34, and 1.12 times higher than the CK treatment, respectively. The findings indicate high starch synthesis activity, and high ABA and IAA contents accounted for the increased grain weight and filling rate of buckwheat grains in the ADR treatment. This research demonstrates potential for improved management in buckwheat production to increase the yield and improve the grain quality. Apical dominance removal (ADR) treatment can form high yield plant type of buckwheat.ADR treatment can also promote the grain filling.High abscisic acid and indo‐3‐acetic acid contents can increase the grain weight.

•Graphene oxide increased the antioxidant capacity and osmotic adjustment substance content.•Graphene oxide coordinated the dynamic balance of endogenous IAA and ABA contents.•Graphene oxide had concentration dependence in improving tolerance to continuous cropping.

MVOH/rGO cathode with dual defect of Mg2+pre-intercalation defect (P-Mgd) and surface oxygen defect (Od) is prepared.The dual defect of Odand P-Mgdin MVOH/rGO lamellar structure effectively enhances Mg2+migration kinetics, structural stability, and electronic conductivity.The Mg foil//MVOH/rGO full cell achieves an ultralong lifespan of 850 cycles at 0.1 A g−1and powers an orange light-emitting diode.

The yield of Tartary buckwheat (Fagopyrum tataricumGaertn) is significantly affected by continuous cropping. This study aimed to clarify the effects of continuous cropping on the growth and yield formation of Tartary buckwheat. Tartary buckwheat cultivar Jinqiao was used as the experimental material to study the effects of different continuous cropping years on the rhizosphere soil, root morphology and physiology, senescence, and yield of Tartary buckwheat. Available nutrients, number of actinomycetes, soil enzyme activities, and contents of total chlorophyll and soluble protein in the leaves of Tartary buckwheat continuously decreased with an increase in continuous cropping years. However, the pH and number of fungi showed a continuous increasing trend. The number of bacteria in rhizosphere soil, root morphological indexes and root activity, and oxidase activity of the leaves initially increased and then decreased. Compared with that of the control, the yield of Tartary buckwheat significantly reduced by 6.36, 24.85, 78.62, and 83.10% with 1, 2, 3, and 4 yr of continuous cropping, respectively. Therefore, continuous cropping reduces the yield of Tartary buckwheat by destroying the microenvironment system of rhizosphere soil, inhibiting the growth and development of the root and shoot systems, and accelerating senescence. Continuous cropping destroyed the rhizosphere soil microenvironment system.Continuous cropping inhibited the growth of the root system and aboveground parts.Continuous cropping accelerated the senescence of Tartary buckwheat.Short‐term continuous cropping could promote the growth of Tartary buckwheat.

LEDs are an essential component in visible light communication systems and need to be modulated for data transmission at the same time of lighting. The modulation speed of LEDs is limited by the remaining carriers that remain in the depletion capacitance when the LEDs turn off. This paper designs a high-speed LED driver that can remove remaining carriers, which shortens the falling time of modulation pulse, and thus improves the modulation speed. The driver is fabricated using three discrete FETs and some resistors and capacitors on a board. One FET is used to control the lighting and extinguishing of a LED and the other two FETs are used to remove remaining carriers. The performance of the driver is demonstrated by driving a blue LED and a near ultraviolet LED respectively. In experiments, the FETs on the board are triggered by a square-wave signal with the frequency of 1 MHz and the optical signals emitted from the LEDs are detected by a photoelectric detector. The experimental results show that this design decreased the falling time from 66 down to 32 ns for the blue LED as well as from 40 down to 26 ns for the near ultraviolet LED, which demonstrates the improvement of the LED modulation speed.

Vitrimers undergoing dynamic bond exchange enable reprocessing and recycle of thermosets. However, vitrimers are susceptible to creep, leading to their poor dimensional stability, which limits their applications. Here, a facile method via integration of metal complexes was utilized to address this issue, and cross-linked polyimine was selected as an example of vitrimer. Three different metal complexes were introduced into a polyimine vitrimer via a one-pot preparation involving the formation of metal complexes and cross-linking of polyimine. The addition of 0.5 mol % Cu2+relative to imine bond reduced creep degree from 30% to 20% at 60 °C, and the creep resistance was enhanced with increasing Cu2+content. Loading 5 mol % Cu2+increased the initial creep temperature from 60 to about 100 °C and raised the Arrhenius activation energy (Ea) for stress relaxation from 52.3 to 67.7 kJ mol–1. The ability of different metal complexes to suppress creep followed the order of Fe3+> Cu2+> Mg2+, and the initial creep temperature reached around 120 °C for vitrimer with 5 mol % of Fe3+. Meanwhile, the polyimine–metal complex vitrimers still exhibited excellent reprocessing recyclability. Moreover, the introduction of coordination structures enhanced the thermal and mechanical properties, solvent, and acid resistance. Thus, metal coordination is an efficient approach to achieve high-temperature creep resistance, excellent thermal and mechanical properties, and chemical stability for vitrimers based on the Schiff base.

Recycling thermosets have become extremely important due to their ecological and economic benefits. The development of thermosets that undergo reversible polymerization provides a solution to the end-life disposal issue of thermosetting materials. However, the synthesis and recycling of the current chemically recyclable thermosets are harsh, complex, and energy-intensive, and their stability is often low. Here, we designed asymmetric acetal-containing thermosets (PRCs) from general phenolic resin and 1,4-cyclohexanedimethanol divinyl ether through one-step “click” cross-linking without using catalysts and solvents and without releasing small-molecule byproducts. PRCs exhibited conspicuous stress relaxation via a dissociative mechanism, corresponding to the superior malleability and reprocess recyclability. Importantly, PRCs presented excellent creep resistance even at 100 °C. In addition, PRCs could be readily and highly efficiently recovered to original phenolic resin via hydrolysis under specific mild acidic conditions but possessed high chemical stability under neutral conditions and even weak acidic conditions or acidic conditions in the absence of organic solvents with outstanding wettability and swellability toward the samples. Thermosets with different properties could be easily achieved via regulating raw materials. This work provides a promising dynamic covalent motif and a practical method to produce readily dual-recyclable (reprocess recyclable and chemically recyclable) thermosets with superior performance and stability.

Under the influence of deep high ground stress and strong mining, stress of surrounding rock of gob-side entry increases. The original roadway filling without coal pillar excavation is proposed to cope with the difficult problem of surrounding rock control in deep roadway. In the technology, filling body and surrounding rock form a variety of combined structures, and these structures stability is closely related to roadway control. In this paper, theoretical analysis and mechanical test are used to analyze the strength characteristics of single lithology and bearing capacity deterioration characteristics of multi-lithology combination. The results show that the long-term strength of filling body is greatly affected by water-cement ratio, and the water-cement ratio of 2:1 has characteristics of high long-term residual strength and small residual strain. When analyzing the strength of the contact surface of the combined body, the D-P criterion is closer to test results than M-C. The strength of combinations is determined by the minimum value of the strength of the contact surface between filling body and other lithology and the strength of the non-standard sample of each lithology. And stress-strain curves of the combined body are elastic-plastic, and all belong to the shear tension composite failure. The UCS of combinations of two lithologies decreases with the increase of the volume ratio of filling body. When volume ratio of filling body is constant, the UCS of the three and four lithologic combinations increases with the increase of volume ratio of sandy mudstone to mudstone. The test results play a theoretical and reference role for the application of original roadway filling without coal pillar excavation in different geological conditions.

Third-party libraries are a key building block in software development as they allow developers to reuse common functionalities instead of reinventing the wheel. However, third-party libraries and client projects are developed and continuously evolving in an asynchronous way. As a result, outdated third-party libraries might be commonly used in client projects, while developers are unaware of the potential risk (e.g., security bugs) in usages. Outdated third-party libraries might be updated in client projects in a delayed way, while developers are less aware of the potential risk (e.g., API incompatibilities) in updates. Developers of third-party libraries may be unaware of how their third-party libraries are used or updated in client projects. Therefore, a quantitativeand holisticstudy on usages, updates and risks of third-party libraries in open-source projects can provide concrete evidence on these problems, and practical insights to improve the ecosystem sustainably. In this paper, we make the first contribution towards such a study in the Java ecosystem. First, using 806 open-source projects and 13,565 third-party libraries, we conduct a library usage analysis(e.g., usage intensity and usage outdatedness), followed by a library update analysis(e.g., update intensity and update delay). The two analyses aim to quantify usage and update practices from the two holistic perspectives of open-source projects and third-party libraries. Then, we carry out a library risk analysis(e.g., usage risk and update risk) on 806 open-source projects and 544 security bugs. This analysis aims to quantify the potential risk of using and updating outdated third-party libraries with respect to security bugs. Our findings suggest practical implications to developers and researchers on problems and potential solutions in maintaining third-party libraries (e.g., smart alerting and automated updating of outdated third-party libraries). To demonstrate the usefulness of our findings, we propose a security bug-driven alerting system, named LibSecurify, for assisting developers to make confident decisions by quantifying risks and effort when updating outdated third-party libraries. 33 open-source projects have confirmed the presence of security bugs after receiving our alerts, and 24 of those 33 have updated their third-party libraries. We have released our dataset to foster valuable applications and improve the Java third-party library ecosystem.

Lithium-ion battery (SE60AHA type)is the main power of mine trolleybus. It studies the characteristics of main parameters such as capacity, charging and discharging time and cycle life with temperature, which can effectively ensure safety. This paper designs charging and discharging experiments under different temperature conditions and conducts OCV-SOC curve analysis. The results show that under the charging conditions of different temperature, there is no significant change in the relative capacity of charging, but the lower the temperature is, the shorter the constant-current charging time is and the longer the constant-voltage time is. Under the discharging condition of different temperature, the change of relative discharging capacity is obvious, the voltage drops faster when the temperature is lower than 0degC, and it keeps the same voltage variation when the temperature is higher than 0degC, while the discharging time reduces with decreased temperature. Further more, according to the variation of charging and discharging voltage with different temperature, it analyze the health status and optimal working environment of mine-type lithium-ion battery adopting the characteristics of charging and discharging efficiency. The research results provide a basis of the using and maintenance of large-capacity lithium-ion battery stack in special environments of the coal mining.