资源类型

期刊论文 448

会议视频 3

年份

2024 44

2023 63

2022 72

2021 44

2020 34

2019 15

2018 25

2017 27

2016 21

2015 19

2014 10

2013 6

2012 10

2011 8

2010 6

2009 8

2008 11

2007 14

2005 1

2002 1

展开 ︾

关键词

光催化 2

安全 2

5% 法 1

CAE 1

CO2 加氢 1

CP);符号间干扰(inter symbol interference, ISI);载波间干扰(inter carrier interference 1

Cu(In 1

GPU;密度峰值;聚类;并行计算 1

Ga)Se2 1

ICI);最大似然估计(maximum likelihood estimation 1

K 助剂 1

Key technology 1

K波段;高效率;宽带;氮化镓(GaN);功率放大器 1

MLE) 1

Mn 助剂 1

MnAl 1

N3C空位 1

Nd-Fe-B磨削油泥 1

OFDM);快速傅立叶变换(Fast Fourier transform, FFT);循环前缀(cyclic prefix 1

展开 ︾

检索范围:

排序: 展示方式:

Approaches to achieve high grain yield and high resource use efficiency in rice

Jianchang YANG

《农业科学与工程前沿(英文)》 2015年 第2卷 第2期   页码 115-123 doi: 10.15302/J-FASE-2015055

摘要: This article discusses approaches to simultaneously increase grain yield and resource use efficiency in rice. Breeding nitrogen efficient cultivars without sacrificing rice yield potential, improving grain fill in later-flowering inferior spikelets and enhancing harvest index are three important approaches to achieving the dual goal of high grain yield and high resource use efficiency. Deeper root distribution and higher leaf photosynthetic N use efficiency at lower N rates could be used as selection criteria to develop N-efficient cultivars. Enhancing sink activity through increasing sugar-spikelet ratio at the heading time and enhancing the conversion efficiency from sucrose to starch though increasing the ratio of abscisic acid to ethylene in grains during grain fill could effectively improve grain fill in inferior spikelets. Several practices, such as post-anthesis controlled soil drying, an alternate wetting and moderate soil drying regime during the whole growing season, and non-flooded straw mulching cultivation, could substantially increase grain yield and water use efficiency, mainly via enhanced remobilization of stored carbon from vegetative tissues to grains and improved harvest index. Further research is needed to understand synergistic interaction between water and N on crop and soil and the mechanism underlying high resource use efficiency in high-yielding rice.

关键词: rice     nitrogen-efficient cultivar     grain fill     harvest index     nitrogen use efficiency     water use efficiency    

Cobalt-nitrogen co-doped porous carbon sphere as highly efficient catalyst for liquid-phase cyclohexane

《化学科学与工程前沿(英文)》 2024年 第18卷 第3期 doi: 10.1007/s11705-024-2395-3

摘要: The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol (KA oil) is a challenging issue in the chemical industry. At present the industrial conversion of cyclohexane to cyclohexanone and cyclohexanol is normally controlled at less than 5% selectivity. Thus, the development of highly active and stable catalysts for the aerobic oxidation of cyclohexane is necessary to overcome this low-efficiency process. Therefore, we have developed a cobalt-nitrogen co-doped porous sphere catalyst, Co-NC-x (x is the Zn/Co molar ratio, where x = 0, 0.5, 1, 2, and 4) by pyrolyzing resorcinol-formaldehyde resin microspheres. It achieved 88.28% cyclohexanone and cyclohexanol selectivity and a cyclohexane conversion of 8.88% under Co-NC-2. The results showed that the introduction of zinc effectively alleviated the aggregation of Co nanoparticles and optimized the structural properties of the material. In addition, Co0 and pyridinic-N are proposed to be the possible active species, and their proportion efficiently increased in the presence of Zn2+ species. In this study, we developed a novel strategy to design highly active catalysts for cyclohexane oxidation.

关键词: KA oil production     cyclohexane selective oxidation     cobalt-nitrogen co-doped porous carbon spheres     metal-organic framework    

Ultrafine Fe-modulated Ni nanoparticles embedded within nitrogen-doped carbon from Zr-MOFs-confined conversionfor efficient oxygen evolution reaction

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1114-1124 doi: 10.1007/s11705-021-2087-1

摘要: Improvement of the low-cost transition metal electrocatalyst used in sluggish oxygen evolution reaction is a significant but challenging problem. In this study, ultrafine Fe-modulated Ni nanoparticles embedded in a porous Ni-doped carbon matrix were produced by the pyrolysis of zirconium metal-organic-frameworks, in which 2,2′-bipyridine-5,5′-dicarboxylate operating as a ligand can coordinate with Ni2+ and Fe3+. This strategy allows formation of Fe-modulated Ni nanoparticles with a uniform dimension of about 2 nm which can be ascribed to the spatial blocking effect of ZrO2. This unique catalyst displays an efficient oxygen evolution reaction electrocatalytic activity with a low overpotential of 372 mV at 10 mA·cm–2 and a small Tafel slope of 84.4 mV·dec–1 in alkaline media. More importantly, it shows superior durability and structural stability after 43 h in a chronoamperometry test. Meanwhile, it shows excellent cycling stability during 4000 cyclic voltammetry cycles. This research offers a new insight into the construction of uniform nanoscale transition metals and their alloys as highly efficient and durable electrocatalysts.

关键词: metal-organic framework     pyrolysis     ultrafine     Fe-modulated Ni nanoparticles     oxygen evolution reaction    

Efficient removal of Cr(VI) and Pb(II) from aqueous solution by magnetic nitrogen-doped carbon

Wanyue Liu, Xiaoqin Liu, Jinming Chang, Feng Jiang, Shishi Pang, Hejun Gao, Yunwen Liao, Sheng Yu

《化学科学与工程前沿(英文)》 2021年 第15卷 第5期   页码 1185-1196 doi: 10.1007/s11705-020-2032-8

摘要: The magnetic nitrogen-doped carbon (MNC) was prepared from polypyrrole by a simple high temperature calcination process in this paper. The structure and properties of MNC were analyzed by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, Brunner Emmet Teller, vibrating sample magnetometer, and X-ray photoelectron spectroscopy. The capacity of MNC to adsorb Cr(VI) and Pb(II) was evaluated. The effects of the initial pH, dosage, concentration and temperature on the adsorption capacity of MNC were measured. MNC had a large specific surface area and a special porous structure. Its nitrogen and carbon sources were rich, and the ratio of carbon to nitrogen was fixed. The maximum Cr(VI)-adsorption capacity and maximum Pb(II) adsorption capacity of MNC could reach 456.63 and 507.13 mg∙g at 318 K, respectively. The pseudo-second-order model was used to describe the adsorption kinetics of MNC, and the Freundlich model was employed to discuss its isotherms. The adsorption process was affected by the electrostatic force, the reducing reaction, pores and chelation. The results of this study suggest that MNC is a material with superior performance, and is very easily regenerated, reused, and separated in the adsorption process.

关键词: magnetic     nitrogen-doped carbon     adsorption     Cr(VI)     Pb(II)    

Efficient photodegradation of phenol assisted by persulfate under visible light irradiation via a nitrogen-doped

Yan Cui, Zequan Zeng, Jianfeng Zheng, Zhanggen Huang, Jieyang Yang

《化学科学与工程前沿(英文)》 2021年 第15卷 第5期   页码 1125-1133 doi: 10.1007/s11705-020-2012-z

摘要: To realize the utilization of visible light and improve the photocatalytic efficiency of organic pollutant degradation in wastewater, a nitrogen-doped titanium-carbon composite (N-TiO /AC) prepared by sol-gel methods was applied in the photodegradation of phenol assisted by persulfate under visible light irradiation (named N-TiO /AC/PS/VIS). The results show that a synergistic effect exists between visible-light photocatalysis and persulfate activation. Compared with TiO /PS/VIS, the phenol degradation rate was found to be observably improved by 65% in the N-TiO /AC/PS/VIS system. This significant increase in degradation rate was mainly attributed to the following two factors: 1) The N and C doping can change the crystal structure of TiO , which extends the TiO absorption wavelength range to the visible light region. 2) As an electron acceptor, PS can not only prevent electrons and holes from recombining with each other but can also generate strong oxidizing radicals such as ∙SO and ∙OH to accelerate the reaction dynamics. The process of phenol degradation was found to be consistent with the Langmuir pseudo-first-order kinetic model with an apparent rate constant of 1.73 min . The N-TiO /AC/PS/VIS process was proven to be a facile method for pollutant degradation with high pH adaptability, excellent visible-light utilization and good application prospects.

关键词: N-TiO2/AC     visible light     photocatalysis     persulfate activation     phenol    

Efficient CO

Yanxia Wang, Xiude Hu, Tuo Guo, Jian Hao, Chongdian Si, Qingjie Guo

《化学科学与工程前沿(英文)》 2021年 第15卷 第3期   页码 493-504 doi: 10.1007/s11705-020-1967-0

摘要: In this work, nitrogen-doped porous carbons (NACs) were fabricated as an adsorbent by urea modification and KOH activation. The CO adsorption mechanism for the NACs was then explored. The NACs are found to present a large specific surface area (1920.72–3078.99 m ·g ) and high micropore percentage (61.60%–76.23%). Under a pressure of 1 bar, sample NAC-650-650 shows the highest CO adsorption capacity up to 5.96 and 3.92 mmol·g at 0 and 25 °C, respectively. In addition, the CO /N selectivity of NAC-650-650 is 79.93, much higher than the value of 49.77 obtained for the nonnitrogen-doped carbon AC-650-650. The CO adsorption capacity of the NAC-650-650 sample maintains over 97% after ten cycles. Analysis of the results show that the CO capacity of the NACs has a linear correlation ( = 0.9633) with the cumulative pore volume for a pore size less than 1.02 nm. The presence of nitrogen and oxygen enhances the CO /N selectivity, and pyrrole-N and hydroxy groups contribute more to the CO adsorption. Fourier transform infrared spectra analysis indicates that CO is adsorbed onto the NACs as a gas. Furthermore, the physical adsorption mechanism is confirmed by adsorption kinetic models and the isosteric heat, and it is found to be controlled by CO diffusion. The CO adsorption kinetics for NACs at room temperature and in pure CO is in accordance with the pseudo-first-order model and Avramís fractional-order kinetic model.

关键词: porous carbon     CO2 adsorption     nitrogen-doped     adsorption mechanism     kinetics    

Efficient production of D-1,2,4-butanetriol from D-xylose by engineered

Shewei Hu, Qian Gao, Xin Wang, Jianming Yang, Nana Xu, Kequan Chen, Sheng Xu, Pingkai Ouyang

《化学科学与工程前沿(英文)》 2018年 第12卷 第4期   页码 772-779 doi: 10.1007/s11705-018-1731-x

摘要: We have developed a whole-cell bioconversion system for the production of D-1,2,4-butanetriol (BT) from renewable biomass. A plasmid pETduet- T7- T7- was constructed and transformed to BL21(DE3) to obtain the whole cells of BL21- capable of bioconversion D-xylose to BT. Then, the factors including carbon sources, nitrogen sources, metal ions, and culture conditions (pH, temperature, IPTG) were identified, and their effects on the whole-cell activity for BT production were investigated. To obtain the highest whole-cell activity, the optimal cultivation parameters are: 15 g·L yeast extract, 5 g·L sucrose, 3g·L KH PO , 5 g·L NaCl, 3g·L NH Cl, 0.25 g·L MgSO ?7H O and 1 mL·L the mixture of trace elements. With the optimized whole cells of BL21- , 60 g·L of xylose was converted to 28g·L BT with a molar yield of 66 %, which is higher than those reported in the biotechnological system.

关键词: D-1     2     4-butanetriol     whole-cell bioconversion     carbon source     nitrogen sources     metal ions     culture conditions    

SUSTAINABLE NITROGEN MANAGEMENT FOR VEGETABLE PRODUCTION IN CHINA

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 373-385 doi: 10.15302/J-FASE-2022455

摘要:

● Sustainable nitrogen management strategies for Chinese vegetable production are summarized.

关键词: enhanced-efficiency nitrogen fertilizer     integrated knowledge and products strategy     nitrogen rate     reactive nitrogen loss     vegetable     yield    

EFFECTS OF SUBSTITUTION OF MINERAL NITROGEN WITH ORGANIC AMENDMENTS ON NITROGEN LOSS FROM SLOPING CROPLAND

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 396-406 doi: 10.15302/J-FASE-2022456

摘要:

● Interflow acts as the dominant pathway for N loss loadings.

关键词: improved fertilization regime     interflow     nitrogen forms     nitrogen leaching     purple soil     sloping cropland    

SOIL NITROGEN CYCLING AND ENVIRONMENTAL IMPACTS IN THE SUBTROPICAL HILLY REGION OF CHINA: EVIDENCE FROM

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 407-424 doi: 10.15302/J-FASE-2022448

摘要:

● Soil nitrogen fluxes and influencing factors were reviewed in the subtropical hilly regions.

关键词: nitrogen cycling     soil nitrogen     nitrogen deposition     greenhouse gases emission     non-point source pollution     nitrogen use efficiency    

SUSTAINABLE NITROGEN MANAGEMENT IN AUSTRALIAN AGROECOSYSTEMS: CHALLENGES AND OPPORTUNITIES

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 366-372 doi: 10.15302/J-FASE-2022447

摘要:

● There is huge potential for improvement of nitrogen management in Australia.

关键词: Australian agroecosystems     reactive nitrogen     sustainable development    

IMPROVING NITROGEN SAFETY IN CHINA: NITROGEN FLOWS, POLLUTION AND CONTROL

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 465-474 doi: 10.15302/J-FASE-2022454

摘要:

● It is necessary to address the N flows and their impacts on environment in China for sustainable N management.

关键词: barriers     future management     ammonia emissions     nitrogen input     water N pollution    

Nitrogen distribution in the products from the hydrothermal liquefaction of sp. and sp.

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 985-995 doi: 10.1007/s11705-021-2126-y

摘要: The high contents of nitrogen-containing organic compounds in biocrude obtained from hydrothermal liquefaction of microalgae are one of the most concerned issues on the applications and environment. In the project, Chlorella sp. and Spirulina sp. were selected as raw materials to investigate the influence of different reaction conditions (i.e., reaction temperature, residence time, solid loading rate) on the distribution of nitrogen in the oil phase and aqueous phase. Three main forms of nitrogen-containing organic compounds including nitrogen-heterocyclic compounds, amide, and amine were detected in biocrudes. The contents of nitrogen-heterocyclic compounds decreased with temperature while amide kept increasing. The effect of residence time on the components of nitrogen-containing organic compounds was similar with that of temperature. However, the influence of solid loading rate was insignificant. Moreover, it was also found that the differences of amino acids in the protein components in the two microalgae might affect the nitrogen distribution in products. For example, nitrogen in basic amino acids of Spirulina sp. preferred to go into the aqueous phase comparing with the nitrogen in neutral amino acids of Chlorella sp. In summary, a brief reaction map was proposed to describe the nitrogen pathway during microalgae hydrothermal liquefaction.

关键词: microalgae     hydrothermal liquefaction     biocrude     nitrogen distribution    

PROGRESS ON IMPROVING AGRICULTURAL NITROGEN USE EFFICIENCY: UK-CHINA VIRTUAL JOINT CENTERS ON NITROGEN

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 475-489 doi: 10.15302/J-FASE-2022459

摘要:

● Virtual joint centers on N agronomy were established between UK and China.

关键词: CINAg     N-CIRCLE     nitrogen use efficiency     reactive nitrogen     sustainable production    

Recent advances and challenges of nitrogen/nitrate electro catalytic reduction to ammonia synthesis

《能源前沿(英文)》 2024年 第18卷 第2期   页码 128-140 doi: 10.1007/s11708-023-0908-2

摘要: The Haber-Bosch process is the most widely used synthetic ammonia technology at present. Since its invention, it has provided an important guarantee for global food security. However, the traditional Haber-Bosch ammonia synthesis process consumes a lot of energy and causes serious environmental pollution. Under the serious pressure of energy and environment, a green, clean, and sustainable ammonia synthesis route is urgently needed. Electrochemical synthesis of ammonia is a green and mild new method for preparing ammonia, which can directly convert nitrogen or nitrate into ammonia using electricity driven by solar, wind, or water energy, without greenhouse gas and toxic gas emissions. Herein, the basic mechanism of the nitrogen reduction reaction (NRR) to ammonia and nitrate reduction reaction (NO3 RR) to ammonia were discussed. The representative approaches and major technologies, such as lithium mediated electrolysis and solid oxide electrolysis cell (SOEC) electrolysis for NRR, high activity catalyst and advanced electrochemical device fabrication for NO3 RR and electrochemical ammonia synthesis were summarized. Based on the above discussion and analysis, the main challenges and development directions for electrochemical ammonia synthesis were further proposed.

关键词: electrochemical ammonia synthesis     nitrogen     nitrate     nitrogen reduction reaction (NRR) to ammonia     nitrate reduction reaction (NO–3 RR)    

标题 作者 时间 类型 操作

Approaches to achieve high grain yield and high resource use efficiency in rice

Jianchang YANG

期刊论文

Cobalt-nitrogen co-doped porous carbon sphere as highly efficient catalyst for liquid-phase cyclohexane

期刊论文

Ultrafine Fe-modulated Ni nanoparticles embedded within nitrogen-doped carbon from Zr-MOFs-confined conversionfor efficient oxygen evolution reaction

期刊论文

Efficient removal of Cr(VI) and Pb(II) from aqueous solution by magnetic nitrogen-doped carbon

Wanyue Liu, Xiaoqin Liu, Jinming Chang, Feng Jiang, Shishi Pang, Hejun Gao, Yunwen Liao, Sheng Yu

期刊论文

Efficient photodegradation of phenol assisted by persulfate under visible light irradiation via a nitrogen-doped

Yan Cui, Zequan Zeng, Jianfeng Zheng, Zhanggen Huang, Jieyang Yang

期刊论文

Efficient CO

Yanxia Wang, Xiude Hu, Tuo Guo, Jian Hao, Chongdian Si, Qingjie Guo

期刊论文

Efficient production of D-1,2,4-butanetriol from D-xylose by engineered

Shewei Hu, Qian Gao, Xin Wang, Jianming Yang, Nana Xu, Kequan Chen, Sheng Xu, Pingkai Ouyang

期刊论文

SUSTAINABLE NITROGEN MANAGEMENT FOR VEGETABLE PRODUCTION IN CHINA

期刊论文

EFFECTS OF SUBSTITUTION OF MINERAL NITROGEN WITH ORGANIC AMENDMENTS ON NITROGEN LOSS FROM SLOPING CROPLAND

期刊论文

SOIL NITROGEN CYCLING AND ENVIRONMENTAL IMPACTS IN THE SUBTROPICAL HILLY REGION OF CHINA: EVIDENCE FROM

期刊论文

SUSTAINABLE NITROGEN MANAGEMENT IN AUSTRALIAN AGROECOSYSTEMS: CHALLENGES AND OPPORTUNITIES

期刊论文

IMPROVING NITROGEN SAFETY IN CHINA: NITROGEN FLOWS, POLLUTION AND CONTROL

期刊论文

Nitrogen distribution in the products from the hydrothermal liquefaction of sp. and sp.

期刊论文

PROGRESS ON IMPROVING AGRICULTURAL NITROGEN USE EFFICIENCY: UK-CHINA VIRTUAL JOINT CENTERS ON NITROGEN

期刊论文

Recent advances and challenges of nitrogen/nitrate electro catalytic reduction to ammonia synthesis

期刊论文