2,5‐Furandicarboxylic acid was obtained from the electrooxidation of 5‐hydroxymethylfurfural (HMF) with non‐noble metal‐based catalysts. Moreover, combining the biomass oxidation with the hydrogen ...evolution reaction (HER) increased the energy conversion efficiency of an electrolyzer and also generated value‐added products at both electrodes. Here, the reaction pathway on the surface of a carbon‐coupled nickel nitride nanosheet (Ni3N@C) electrode was evaluated by surface‐selective vibrational spectroscopy using sum frequency generation (SFG) during the electrochemical oxidation. The Ni3N@C electrode shows catalytic activities for HMF oxidation and the HER. As the first in situ SFG study on transition‐metal nitride for the electrooxidation upgrade of HMF, this work not only demonstrates that the reaction pathway of electrochemical oxidation but also provides an opportunity for nonprecious metal nitrides to simultaneously upgrade biomass and produce H2 under ambient conditions.
To sum up: A carbon‐coupled nickel nitride nanosheet was employed as an efficient electrocatalyst for 5‐hydroxymethylfurfural (HMF) oxidation. In situ sum frequency generation (SFG) spectroscopy was used to explore the HMF electrooxidation process, and confirmed that the oxidation pathway proceeds via 5‐hydroxymethyl‐2‐furancarboxylic acid (HMFCA).
Oxygen evolution reaction is a critical reaction for renewable energy technologies. Conventionally, metal phosphides or metal sulfides are active for HER, their OER activity is relatively poor. ...Herein, we have precisely prepared quaternary (NiFe)PS3 nanosheets as ultra-effective OER catalysts via a one-step sulfurization and phosphorization method with NiFe prussian blue analogues as precursors. The systematic results demonstrate that the coexistence of PBA, P and S sources is the keypoint for the nanosheet structure. The (NiFe)PS3 nanosheets show very good OER activity with a super-low overpotential (223 mV) to reach 10 mA cm-2. However, from the energy diagrams, we find that the basal plane of (NiFe)PS3 is almost inert to OER due to the prohibitively high theoretical overpotential of 1.50 V, derives from the weak binding of OH* and OOH* intermediates, and only unsaturated Fe and Ni atoms locate on the (010) plane of (NiFe)PS3 are active for OER. The further ex-situ characterizations demonstrate that the in-situ electrochemically formed oxohydroxide layer on the nanosheets contributes significantly to the OER actvity. This work not only provides a simple method to synthesize quaternary bimetallic phosphosulphide nanosheets, but also provides a deep understanding on the origin of the high activity of (NiFe)PS3 nanosheets.
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•(NiFe)PS3 nanosheets were prepared from NiFe PBA under mild conditions.•(NiFe)PS3 are highly active for driving oxygen evolution reaction.•In-situ formed oxohydroxide layer contribute significantly to the OER actvity.
This work presents a design of sandwich MoO3/C hybrid nanostructure via calcination of the dodecylamine‐intercalated layered α‐MoO3, leading to the in situ production of the interlayered graphene ...layer. The sample with a high degree of graphitization of graphene layer and more interlayered void region exhibits the most outstanding energy storage performance. The obtained material is capable of delivering a high specific capacitance of 331 F g−1 at a current density of 1 A g−1 and retained 71% capacitance at 10 A g−1. In addition, nearly no discharge capacity decay between 1000 and 10 000 continuous charge–discharge cycles is observed at a high current density of 10 A g−1, indicating an excellent specific capacitance retention ability. The exceptional rate capability endows the electrode with a high energy density of 41.2 W h kg−1 and a high power density of 12.0 kW kg−1 simultaneously. The excellent performance is attributed to the sandwich hybrid nanostructure of MoO3/C with broad ion diffusion pathway, low charge‐transfer resistance, and robust structure at high current density for long‐time cycling. The present work provides an insight into the fabrication of novel electrode materials with both enhanced rate capability and cyclability for potential use in supercapacitor and other energy storage devices.
A sandwich MoO3/C hybrid nanostructure assembled by α‐MoO3 and graphene layers at a molecular level provides more accessible active sites and bicontinuous pathways for quick transfer of charges inside the interlayers, as well as an excellent structure stability in the charge/discharge process. The electrode material has a high rate discharge capability accompanying with a long cycle life.
•The double cropping system (DCS) is expanding benefited from the climate warming.•We studied whether the precipitation meet crop water demand in potential DCS region.•The highest probability of ...water deficit was found in winter crop growing season.•The probability of sufficient precipitation for DCS in study area is less than 20%.•The yield of DCS is projected to increase 11.6%–86.2% under different irrigations.
Multiple cropping systems have been widely used in China as smart strategies to address climate change to ensure that increasing food demand is met. In the context of climate warming, the climate-based boundaries of multiple cropping systems are moving northward, and the potential crop yield is projected to increase due to continuous cropping that will be possible with increased light and heat resources. However, increasing demands for crop water have further aggravated the severity of water shortages in Northern China. In this study, we determine the impacts of climate change on the double cropping system (DCS) in Northern China using the annual accumulated temperature above 0 °C. The northern climate-based boundaries of the DCS have moved significantly northward and westward in Liaoning, Hebei, Gansu, Shaanxi and Shanxi Provinces. At the same time, the annual crop water requirement has increased by 198–403 mm in the planting areas sensitive to climate change areas where the cropping system can potentially be transformed from a single cropping system (SCS) to a DCS. The highest probability of water deficit exceedance was found during the winter wheat growing season. In addition, the difference in crop yields between the two planting patterns was analyzed using the Agricultural Production Systems Simulator (APSIM) model. The annual output per arable land unit in the potential DCS region, which benefited from the increase in winter crops, increased by 11.6–86.2% under different irrigation scenarios. The increase in crop production is related to irrigation. In the water-saving irrigation scenarios of Irrigation-Wheat (180 mm for winter wheat critical growth periods) and Irrigation-Wheat & Maize (180 mm for winter wheat critical growth periods and 50 mm for maize sowing), the annual output reached approximately 74–80% of the potential high yield in the Full Irrigation scenario. Our research provides suggestions for adjusting planting patterns under climate change. In the future, it will be necessary to develop multiple cropping practices that include innovative water-saving techniques and breeding technologies.
2,5‐Furandicarboxylic acid was obtained from the electrooxidation of 5‐hydroxymethylfurfural (HMF) with non‐noble metal‐based catalysts. Moreover, combining the biomass oxidation with the hydrogen ...evolution reaction (HER) increased the energy conversion efficiency of an electrolyzer and also generated value‐added products at both electrodes. Here, the reaction pathway on the surface of a carbon‐coupled nickel nitride nanosheet (Ni3N@C) electrode was evaluated by surface‐selective vibrational spectroscopy using sum frequency generation (SFG) during the electrochemical oxidation. The Ni3N@C electrode shows catalytic activities for HMF oxidation and the HER. As the first in situ SFG study on transition‐metal nitride for the electrooxidation upgrade of HMF, this work not only demonstrates that the reaction pathway of electrochemical oxidation but also provides an opportunity for nonprecious metal nitrides to simultaneously upgrade biomass and produce H2 under ambient conditions.
Eine kohlenstoffgekoppelte Nickelnitrid‐Nanoschicht wurde als effizienter Elektrokatalysator für die Oxidation von 5‐Hydroxymethylfurfural (HMF) eingesetzt. Mittels In‐situ‐SFG‐Spektroskopie wurde der Oxidationsprozess untersucht und bestätigt, dass die Reaktion über 5‐Hydroxymethyl‐2‐furancarbonsäure (HMFCA) verläuft.
To investigate the expression level and analyze the clinical significance of NT5C2, which is an nucleoside analogues metabolism related gene, in children with acute leukemia (AL).
Real-time PCR and ...immunohistochemistry were presented to detect the level of NT5C2 mRNA and its protein product cN- Ⅱ in bone marrow samples of 63 patients initially diagnosed with AL, 15 patients who achieved complete remission, 7 patients who relapsed and 16 non- hematologic malignancie controls. The expression of NT5C2 mRNA in different groups of AL and its relevance with clinical indicators were analyzed.
①The expression of NT5C2 mRNA in newly diagnosed B-ALL, TALL, AML and controls were 1.16 (0.89-2.25, 0.96 (0.74-1.25, 1.66 (0.84-3.15) and 0.88 (0.61-1.21), respectively. NT5C2 mRNA expression in AML (P<0.01) and B-ALL (P<0.05) cases were higher than that in controls; NT5C2 mRNA expression in T- ALL and in controls showed no significant difference (P>0.05). Changes of NT5C2 mRNA level were observed between preliminary diagnosis
Metal phosphates are considered as advanced electrocatalysts for oxygen evolution reaction in metal-air batteries and water splitting devices. However, it is of huge challenge to expose more active ...sites due to the typical amorphous feature. Besides, proper defect engineering is promising to enhance the performance of electrocatalysts. Herein, we have successfully prepared disordered CoFePi nanosheets with rich vacancies from layered double hydroxide by a solution plasma method. The plasma can etch the interlayer anions to realize the physical exfoliation of layered double hydroxides. Meanwhile, the as-physically-exfoliated layered double hydroxides nanosheets are in-situ chemically-conversed to disordered CoFePi nanosheets by the NaH2PO4. The X-ray adsorption spectra results suggest the abundance of vacancies in the products. Cobalt tends to adjust the local structural rearrangement and to sustain the structure in the presence of a great deal of oxygen and metal vacancies. Under this adjustment, the crystal field is expected to be influenced in CoFePi. The oxygen and metal vacancies may be extensively present in MO6 octahedra layers, giving rise to a relative structure disorder and more unbonded speciec within the layers which provides more active sites in CoFePi. As a result, the disordered CoFePi nanosheets with rich vacancies could catalyse OER effectively.
•Disordered CoFePi nanosheets with rich vacancies were prepared by a solution plasma.•The plasma etch the interlayer anions to realize the exfoliation of hydroxides.•The plasma conversed hydroxides to disordered CoFePi nanosheets.•Disordered CoFePi nanosheets with rich vacancies could catalyse OER effectively.
In China, grape is one of the top five fruit crops for both bearing acreage and production. Recently, national grape production has been stalling because of an increase in drought events. In order to ...combat the adverse effects of drought on grape production, it is imperative to understand the historical drought trend and frequency during the growing season. In this study, we focused on agricultural drought during the four growth periods of grape: bud break-flowering, flowering-veraison, veraison-berry maturation, and berry maturation-leaf fall. Based on the weather data from 429 meteorological stations, we computed the Crop Water Deficit Index (
CWDI
) in the five main grape-growing regions of China: Northeast China, North China, Northwest China, Southwest China, and Southeast China. Then, we evaluated the
CWDI
-based drought distribution and trend in the study regions, as well as the frequency of different degrees of drought. The results showed that exceptional drought was occurring frequently in Xinjiang Uyghur Autonomous Region, northern Gansu province, and northern Ningxia Hui Autonomous Region. Among the four study growth periods of grape, exceptional drought was the most expansive during bud break-flowering. What’s more, exceptional drought coverage during bud break-flowering in the study regions was increasing from 1981 to 2016. Analysis of butterfly structure showed that the occurrence of drought was continuous and persistent in northern China. Our study results could serve as guideposts to highlight Chinese grape production industry’s vulnerability to agricultural drought against the background of climate change.
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