Residential sector is one of the energy-consuming districts of countries that causes CO_(2)emission in large extent.In this regard,this sector must be considered in energy policy making related to the reduction of emi...Residential sector is one of the energy-consuming districts of countries that causes CO_(2)emission in large extent.In this regard,this sector must be considered in energy policy making related to the reduction of emission of CO_(2)and other greenhouse gases.In the present work,CO_(2)emission related to the residential sector of three countries,including Indonesia,Thailand,and Vietnam in Southeast Asia,are discussed and modeled by employing Group Method of Data Handling(GMDH)and Multilayer Perceptron(MLP)neural networks as powerful intelligent methods.Prior to modeling,data related to the energy consumption of these countries are represented,discussed,and analyzed.Subsequently,to propose a model,electricity,natural gas,coal,and oil products consumptions are applied as inputs,and CO_(2)emission is considered as the model’s output.The obtained R^(2) values for the generated models based on MLP and GMDH are 0.9987 and 0.9985,respectively.Furthermore,values of the Average Absolute Relative Deviation(AARD)of the regressions using the mentioned techniques are around 4.56%and 5.53%,respectively.These values reveal significant exactness of the models proposed in this article;however,making use of MLP with the optimal architecture would lead to higher accuracy.展开更多
The catalytic conversion of CO_(2) to fuels or chemicals is considered to be an effective pathway to mitigate the greenhouse effect. To develop new types of efficient and durable catalysts, it is critical to identify ...The catalytic conversion of CO_(2) to fuels or chemicals is considered to be an effective pathway to mitigate the greenhouse effect. To develop new types of efficient and durable catalysts, it is critical to identify the catalytic active sites, surface intermediates, and reaction mechanisms to reveal the relationship between the active sites and catalytic performance. However, the structure of a heterogeneous catalyst usually dynamically changes during reaction, bringing a great challenge for the identification of catalytic active sites and reaction pathways. Therefore, in-situ/operando techniques have been employed to real-time monitor the dynamic evolution of the structure of active sites under actual reaction conditions to precisely build the structure–function relationship. Here, we review the recent progress in the application of various in-situ/operando techniques in identifying active sites for catalytic conversion of CO_(2) over heterogeneous catalysts. We systematically summarize the applications of various optical and X-ray spectroscopy techniques, including Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS), in identifying active sites and determining reaction mechanisms of the CO_(2) thermochemical conversion with hydrogen and light alkanes over heterogeneous catalysts. Finally, we discuss challenges and opportunities for the development of in-situ characterization in the future to further enlarge the capability of these powerful techniques.展开更多
Spring wheat (Triticum aestivum L. cv. Dingxi No. 8654) was treated with twoconcentrations of atmospheric CO_2 (350 and 700 μmol mol^(-1)), two levels of soil moisture(well-watered and drought) and five rates of nitr...Spring wheat (Triticum aestivum L. cv. Dingxi No. 8654) was treated with twoconcentrations of atmospheric CO_2 (350 and 700 μmol mol^(-1)), two levels of soil moisture(well-watered and drought) and five rates of nitrogen fertilizer (0, 50, 100, 150, and 200 mgkg^(-1) soil) to study the atmospheric CO_2 concentration effect on dry matter accumulation and Nuptake of spring wheat. The effects of CO_2 enrichment on the shoot and total mass depended largelyon soil nitrogen level, and the shoot and total mass increased significantly in the moderate to highN treatments but did not increase significantly in the low N treatment. Enriched CO_2 concentrationdid not increase more shoot and total mass in the drought treatment than in the well-wateredtreatment. Thus, elevated CO_2 did not ameliorate the depressive effects of drought and nitrogenstress. In addition, root mass decreased slightly and root/shoot ratio decreased significantly dueto CO_2 enrichment in no N treatment under well-watered condition. Enriched CO_2 decreased shoot Ncontent and shoot and total N uptake; but it reduced root N content and uptake slightly. Shootcritical N concentration was lower for spring wheat grown at 700 μmol mol^(-1) CO_2 than at 350μmol mol^(-1) CO_2 in both well-watered and drought treatments. The critical N concentrations were16 and 19 g kg^(-1) for the well-watered treatment and drought treatment at elevated CO_2 and 21 and26 g kg^(-1) at ambient CO_2, respectively. The reductions in the movement of nutrients to theplant roots through mass flow due to the enhancement in WUE (water use efficiency) and the increasein N use efficiency at elevated CO_2 could elucidate the reduction of shoot and root Nconcentrations.展开更多
The biomass and ratio of root-shoot of Pinus sylvestfthermis seedlings at Co, concentration of 700 μL L-1 and 50 μL-1L-1 were measured using open-top chambers (OTCs) in Changbai Mountain during Jun. to oct. in 1999....The biomass and ratio of root-shoot of Pinus sylvestfthermis seedlings at Co, concentration of 700 μL L-1 and 50 μL-1L-1 were measured using open-top chambers (OTCs) in Changbai Mountain during Jun. to oct. in 1999. The results showed that doubling CO2 concentration was benefit tb seedling growth of the species (500 μL- L1 was better than 700 μLL’ L-1 ) and the biomass production was increased in both aboveground and underground parts of seedlings. Carbon trans formation to roots was evident as rising of CO2 concentration.展开更多
At a rice wheat rotational free air CO 2 enrichment(FACE) platform, the effect of elevated atmospheric CO 2 on soil nematode communities in a farmland ecosystem was studied. Wheat plots were exposed to elevated atmosp...At a rice wheat rotational free air CO 2 enrichment(FACE) platform, the effect of elevated atmospheric CO 2 on soil nematode communities in a farmland ecosystem was studied. Wheat plots were exposed to elevated atmospheric CO 2(ambient 370 μl/L + 200 μl/L). 32 families and 40 genera of nematode were observed in soil suspensions during the study period. Under FACE treatment, the numbers of total nematodes, bacterivores and fungivores exhibited an increasing trend. Because of the seasonal variation of soil temperature and moisture, the effect of elevated atmospheric CO 2 on soil nematodes was only observed under favorable conditions. The response of nematode communities to elevated atmospheric CO 2 may indicate the change of soil food web.展开更多
The increase of atmospheric carbon dioxide（CO_2） concentration adversely affect several quality traits of rice grains, but the biochemical mechanism remains unclear. The objectives of this study were to determine ho...The increase of atmospheric carbon dioxide（CO_2） concentration adversely affect several quality traits of rice grains, but the biochemical mechanism remains unclear. The objectives of this study were to determine how changes in the source-sink relationship affected rice quality. Source-sink manipulation was achieved by free-air CO_2 enrichment from tillering to maturity and partial removal of spikelet at anthesis using a japonica rice cultivar Wuyunjing 23. Enrichment with CO_2 decreased the head rice percentage and protein concentration of milled rice, but increased the grain chalkiness. In contrast, spikelet removal resulted in a dramatic increase in the head rice percentage and protein concentration, and much less grain chalkiness. Neither CO_2 enrichment nor spikelet removal affected the starch content, but the distribution of starch granule size showed distinct treatment effects. O n average, spikelet removal decreased the percentage of starch granules of diameter 〉10 and 5–10 μm by 23.6 and 5.6%, respectively, and increased those with a diameter of 2–5 and 〈2 μm by 4.6 and 3.3%, respectively. In contrast, CO_2 elevation showed an opposite response： increasing the proportion of large starch granules（〉5 μm） and decreasing that of 〈5 μm. The starch pasting properties were affected by spikelet removal much more than by CO_2 elevation. These results indicated that the protein concentration and starch granule size played a role in chalkiness formation under these experimental conditions.展开更多
基金This work was funded by the Ministry of Higher Education Malaysia under the Fundamental Research Grant Scheme No.FRGS/1/2020/TK0/UNIMAS/03/4.
文摘Residential sector is one of the energy-consuming districts of countries that causes CO_(2)emission in large extent.In this regard,this sector must be considered in energy policy making related to the reduction of emission of CO_(2)and other greenhouse gases.In the present work,CO_(2)emission related to the residential sector of three countries,including Indonesia,Thailand,and Vietnam in Southeast Asia,are discussed and modeled by employing Group Method of Data Handling(GMDH)and Multilayer Perceptron(MLP)neural networks as powerful intelligent methods.Prior to modeling,data related to the energy consumption of these countries are represented,discussed,and analyzed.Subsequently,to propose a model,electricity,natural gas,coal,and oil products consumptions are applied as inputs,and CO_(2)emission is considered as the model’s output.The obtained R^(2) values for the generated models based on MLP and GMDH are 0.9987 and 0.9985,respectively.Furthermore,values of the Average Absolute Relative Deviation(AARD)of the regressions using the mentioned techniques are around 4.56%and 5.53%,respectively.These values reveal significant exactness of the models proposed in this article;however,making use of MLP with the optimal architecture would lead to higher accuracy.
基金Authors acknowledge the financial support from the National Natural Science Foundation of China(NSFC)under Grant No.21978148 and 21808120.
文摘The catalytic conversion of CO_(2) to fuels or chemicals is considered to be an effective pathway to mitigate the greenhouse effect. To develop new types of efficient and durable catalysts, it is critical to identify the catalytic active sites, surface intermediates, and reaction mechanisms to reveal the relationship between the active sites and catalytic performance. However, the structure of a heterogeneous catalyst usually dynamically changes during reaction, bringing a great challenge for the identification of catalytic active sites and reaction pathways. Therefore, in-situ/operando techniques have been employed to real-time monitor the dynamic evolution of the structure of active sites under actual reaction conditions to precisely build the structure–function relationship. Here, we review the recent progress in the application of various in-situ/operando techniques in identifying active sites for catalytic conversion of CO_(2) over heterogeneous catalysts. We systematically summarize the applications of various optical and X-ray spectroscopy techniques, including Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS), in identifying active sites and determining reaction mechanisms of the CO_(2) thermochemical conversion with hydrogen and light alkanes over heterogeneous catalysts. Finally, we discuss challenges and opportunities for the development of in-situ characterization in the future to further enlarge the capability of these powerful techniques.
基金the National Key Basic Research Support Foundation(NKBRSF)of China(No.G1999011708) the Guangxi University Science funds,China(No.1701).
文摘Spring wheat (Triticum aestivum L. cv. Dingxi No. 8654) was treated with twoconcentrations of atmospheric CO_2 (350 and 700 μmol mol^(-1)), two levels of soil moisture(well-watered and drought) and five rates of nitrogen fertilizer (0, 50, 100, 150, and 200 mgkg^(-1) soil) to study the atmospheric CO_2 concentration effect on dry matter accumulation and Nuptake of spring wheat. The effects of CO_2 enrichment on the shoot and total mass depended largelyon soil nitrogen level, and the shoot and total mass increased significantly in the moderate to highN treatments but did not increase significantly in the low N treatment. Enriched CO_2 concentrationdid not increase more shoot and total mass in the drought treatment than in the well-wateredtreatment. Thus, elevated CO_2 did not ameliorate the depressive effects of drought and nitrogenstress. In addition, root mass decreased slightly and root/shoot ratio decreased significantly dueto CO_2 enrichment in no N treatment under well-watered condition. Enriched CO_2 decreased shoot Ncontent and shoot and total N uptake; but it reduced root N content and uptake slightly. Shootcritical N concentration was lower for spring wheat grown at 700 μmol mol^(-1) CO_2 than at 350μmol mol^(-1) CO_2 in both well-watered and drought treatments. The critical N concentrations were16 and 19 g kg^(-1) for the well-watered treatment and drought treatment at elevated CO_2 and 21 and26 g kg^(-1) at ambient CO_2, respectively. The reductions in the movement of nutrients to theplant roots through mass flow due to the enhancement in WUE (water use efficiency) and the increasein N use efficiency at elevated CO_2 could elucidate the reduction of shoot and root Nconcentrations.
文摘The biomass and ratio of root-shoot of Pinus sylvestfthermis seedlings at Co, concentration of 700 μL L-1 and 50 μL-1L-1 were measured using open-top chambers (OTCs) in Changbai Mountain during Jun. to oct. in 1999. The results showed that doubling CO2 concentration was benefit tb seedling growth of the species (500 μL- L1 was better than 700 μLL’ L-1 ) and the biomass production was increased in both aboveground and underground parts of seedlings. Carbon trans formation to roots was evident as rising of CO2 concentration.
文摘At a rice wheat rotational free air CO 2 enrichment(FACE) platform, the effect of elevated atmospheric CO 2 on soil nematode communities in a farmland ecosystem was studied. Wheat plots were exposed to elevated atmospheric CO 2(ambient 370 μl/L + 200 μl/L). 32 families and 40 genera of nematode were observed in soil suspensions during the study period. Under FACE treatment, the numbers of total nematodes, bacterivores and fungivores exhibited an increasing trend. Because of the seasonal variation of soil temperature and moisture, the effect of elevated atmospheric CO 2 on soil nematodes was only observed under favorable conditions. The response of nematode communities to elevated atmospheric CO 2 may indicate the change of soil food web.
基金funded jointly by the National Natural Science Foundation of China(31171460,31371563,31571597,31471437,31261140364)the Major Fundamental Research Program of Natural Science Foundation of Jiangsu Higher Education Institutions,China(11KJA210003)+2 种基金the Jiangsu Planned Projects for Postdoctoral Research Funds,China(1501077C)the China Postdoctoral Science Foundation(2015M581870)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘The increase of atmospheric carbon dioxide（CO_2） concentration adversely affect several quality traits of rice grains, but the biochemical mechanism remains unclear. The objectives of this study were to determine how changes in the source-sink relationship affected rice quality. Source-sink manipulation was achieved by free-air CO_2 enrichment from tillering to maturity and partial removal of spikelet at anthesis using a japonica rice cultivar Wuyunjing 23. Enrichment with CO_2 decreased the head rice percentage and protein concentration of milled rice, but increased the grain chalkiness. In contrast, spikelet removal resulted in a dramatic increase in the head rice percentage and protein concentration, and much less grain chalkiness. Neither CO_2 enrichment nor spikelet removal affected the starch content, but the distribution of starch granule size showed distinct treatment effects. O n average, spikelet removal decreased the percentage of starch granules of diameter 〉10 and 5–10 μm by 23.6 and 5.6%, respectively, and increased those with a diameter of 2–5 and 〈2 μm by 4.6 and 3.3%, respectively. In contrast, CO_2 elevation showed an opposite response： increasing the proportion of large starch granules（〉5 μm） and decreasing that of 〈5 μm. The starch pasting properties were affected by spikelet removal much more than by CO_2 elevation. These results indicated that the protein concentration and starch granule size played a role in chalkiness formation under these experimental conditions.
