Stabilising cobalt sulphide nanocapsules with nitrogen-doped carbon for high-performance sodium-ion storage

Abstract: Conversion-type anode materials with a high charge storage capability generally suffer from large volume expansion, poor electron conductivity, and sluggish metal ion transport kinetics. The electrode material described in this paper, namely cobalt sulphide nanoparticles encapsulated in carbon cages (CoS@NC), can circumvent these problems. This electrode material exhibited a reversible sodium-ion storage capacity of 705\ua0mAh\ua0g at 100\ua0mA\ua0g with an extraordinary rate capability and good cycling stability. Mechanistic study using the in situ transmission electron microscope technique revealed that the volumetric expansion of the CoS nanoparticles is buffered by the carbon cages, enabling a stable electrode–electrolyte interface. In addition, the carbon shell with high-content doped nitrogen significantly enhances the electron conductivity of the CoS@NC electrode material and provides doping-induced active sites to accommodate sodium ions. By integrating the CoS@NC as negative electrode with a cellulose-derived porous hard carbon/graphene oxide composite as positive electrode and 1\ua0M NaPF in diglyme as the electrolyte, the sodium-ion capacitor full cell can achieve energy densities of 101.4 and 45.8\ua0Wh\ua0kg at power densities of 200 and 10,000\ua0W\ua0kg, respectively

Effects of Long-Term Fertilization Management Practices on Soil Microbial Carbon and Microbial Biomass in Paddy Soil at Various Stages of Rice Growth

ABSTRACT Soil microbial biomass plays a significant role in soils, and it is often used as an early indicator of change in soil quality. Soil microbial biomass is affected by different fertilization management practices. Therefore, the impact of different long-term fertilization management practices on the soil organic carbon (SOC) content, soil microbial biomass carbon (SMBC), and soil microbial biomass nitrogen (SMBN), as well as the soil microbial quotient (SMQ) in the tilled layer (0.00-0.20 m) were studied in the present paper, together with grain yield, in a double-cropping rice (Oryza sativa L.) system. The experiment in NingXiang county of Hunan Province, China, begin in 1986, and the experiment included five fertilization treatments: without fertilizer input (CK), mineral fertilizer alone (MF), rice straw residues and mineral fertilizer (RF), 30 % organic matter and 70% mineral fertilizer (LOM), and 60% organic matter and 40 % mineral fertilizer (HOM). The results showed that there is no significant difference in effect on SOC, SMBC, and SMBN contents and on the SMQ in the paddy field with MF treatment compared with the CK treatment at the main growth stages of early and late rice. The SOC, SMBC, SMBN contents, and the SMQ in the paddy field were highest in the LOM and HOM treatments, followed by the RF treatment, at the main growth stages of early and late rice. The results indicated that grain yields of early and late rice with the LOM, HOM, and RF treatments were higher than the yields under the MF and CK treatments. As a result, combined application of organic matter or rice straw residues with mineral fertilizer is a practice available for increasing SOC and microbial biomass contents in double-cropping rice paddy soils

Effects of Different Long-Term Fertilizer Management Systems on Soil Microbial Biomass Turnover in a Double-Cropping Rice Field in Southern China

Soil microbial biomass content is usually regarded as an early indicator of changes in soil quality and soil fertility in paddy fields. Soil microbial biomass turnover is mainly influenced by the application of different fertilizer management systems. However, there is still a need to further investigate the effects of different long-term fertilizer management systems on soil microbial biomass turnover in paddy fields under the double-cropping rice (Oryza sativa L.) system. Therefore, the effects of different long-term (36 years) fertilizer practices on soil microbial biomass carbon (SMBC) and soil microbial biomass nitrogen (SMBN) contents, and the flux turnover rates of SMBC and SMBN at the 0–10 cm and 10–20 cm layers in a double-cropping rice field in southern China were investigated in the present paper. The field experiment included four different fertilizer treatments: MF, RF, OM, and CK. The results showed that SMBC and SMBN contents at the 0–10 cm and 10–20 cm soil layers with RF and OM treatments were increased compared with the MF and CK treatments. Compared with the CK treatment, SMBC contents at the 0–10 cm and 10–20 cm soil layers with RF and OM treatments increased by 35.72% and 50.28%, and 32.29% and 42.77%, respectively. SMBN contents at the 0–10 cm and 10–20 cm soil layers with RF and OM treatments increased by 15.52% and 22.70%, and 16.32% and 21.49%, respectively. The fluxes of SMBC and SMBN at the 0–10 cm and 10–20 cm soil layers with RF and OM treatments were significantly higher than those of the CK treatment. This result indicated that the flux turnover rates of SMBC and SMBN at the 0–10 cm and 10–20 cm soil layers with the MF, RF, and OM treatments were significantly higher than those of the CK treatment. Compared with the CK treatment, the flux turnover rates of SMBC and SMBN at the 0–10 cm and 10–20 cm soil layers with OM treatment increased by 46.10% and 48.59%, and 73.39% and 116.67%, respectively. SMBC and SMBN contents, and the flux turnover rates of SMBC and SMBN at the 0–10 cm layer were higher than those of the 10–20 cm layer under the same fertilizer treatment condition. Early rice and later rice yields with RF and OM treatments were significantly higher than those of the MF and CK treatments. As a result, the combined application of crop residue and organic manure with inorganic fertilizer management is a beneficial practice for increasing soil nutrients and rice yield under the double-cropping rice system in southern Chin

Mesoporous niobium pentoxide/carbon composite electrodes for sodium-ion capacitors

Sodium-ion capacitors with unique characteristics such as higher energy density than electrical double-layer capacitors, higher power density than rechargeable batteries, and abundant sodium resources represent current research trend in developing large-scale electrical energy storage technology. One of the key challenges presently facing the development of this technology is the imbalanced kinetics between the sluggish Faradaic sodium insertion in the anode and the fast capacitive ion adsorption on the cathode. Here we demonstrate the sol-gel synthesis of a novel, high-rate, stable composite anode material for sodium-ion capacitors (NICs). The composite consisted of NbO nanoparticles embedded in a carbon matrix (denoted by m-NbO/C). Sodium-ion capacitors employing the m-NbO/C anode and a commercial activated carbon as the cathode showed an admirable performance, delivering high energy densities in a wide range of power densities (73 Wh kg@250 W kg-1 and 16.8 Wh kg@20 kW kg). These favourable cell characteristics are attributed to the properties of the m-NbO/C anode: the mesoporous structure that facilitates electron and ion transport, the presence of the niobium carbide interlayer between the NbO nanoparticles and the surrounding graphitic carbon that additionally improves the electron conductivity, and the predominant capacitive charge storage mechanism

MTA1 promotes the invasion and migration of non-small cell lung cancer cells by downregulating miR-125b

BACKGROUND: The metastasis-associated gene 1 (MTA1) has been identified as one critical regulator of tumor metastasis. Previously, we identified miR-125b as a downregualted miRNA in non-small cell lung cancer (NSCLC) cell line upon MTA1 depletion. However, the role of miR-125b and MTA1 in the regulation of NSCLC metastasis remains unclear. METHODS: Stable MTA1 knockdown NSCLC cell lines 95D and SPC-A-1 were established by transfection with MTA1 shRNA. The effects of MTA1 depletion on the expression of miR-125b and cell migration and invasion were examined by real-time PCR, wound healing and matrigel invasion assay. RESULTS: MTA1 knockdown led to the upregulation of miR-125b level in NSCLC cells. Furthermore, MTA1 knockdown reduced while miR-125b inhibitor enhanced cell migration and invasion of NSCLC cells. Notably, miR-125b inhibitor antagonized MTA1 siRNA induced inhibition of cell migration and invasion. CONCLUSION: MTA1 and miR-125b have antagonistic effects on the migration and invasion of NSCLC cells. The newly identified MTA1-miR-125b axis will help further elucidate the molecular mechanism of NSCLC progression and suggest that ectopic expression of miR-125b is a potentially new therapeutic regimen against NSCLC metastasis