Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research ob...Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research object(data excluding Hong Kong,Macao and Taiwan) and used the carbon emission coefficient method to quantitatively measure the food carbon emissions from 1987–2020,then analyzed the carbon emission effects under the evolution of dietary structure.The results showed that during the study period,the Chinese dietary structure gradually changed to a high-carbon consumption pattern.The dietary structure of urban residents developed to a balanced one,while that of rural residents developed to a high-quality one.During the study period,the per capita food carbon emissions and total food consumption of Chinese showed an increasing trend.The per capita food carbon emissions of residents in urban and rural showed an overall upward trend.The total food carbon emissions in urban increased significantly,while that in rural increased first and then decreased.The influence of beef and mutton on carbon emissions is the highest in dietary structure.Compared with the balanced dietary pattern,the food carbon emissions of Chinese residents had not yet reached the peak,but were evolving to a high-carbon consumption pattern.展开更多
The potential (E)-dependent vibrational behavior of a saturated CO adlayer on Au-core Pd-shell nanoparticle film electrodes was investigated over a wide potential range, in acidic, neutral, and basic solutions, usin...The potential (E)-dependent vibrational behavior of a saturated CO adlayer on Au-core Pd-shell nanoparticle film electrodes was investigated over a wide potential range, in acidic, neutral, and basic solutions, using in situ surface-enhanced Raman spectroscopy (SERS). Over the whole of the examined potential region (-1.5 to 0.55 V vs. NHE), the peak frequencies of both the C-OM and the Pd-COM band (here, M denotes the multiply-bonded configuration) displayed three distinct linear regions: dvc oM/dE decreased from -185-207 (from -1.5 to -1.2 V) to -83-84 cm-1/V (-1.2 to -0.15 V), and then to 43 cm-1/V (-0.2 to 0.55 V); on the other hand, dvpd coM/dE changed from -10 to -8 cm I/V (from -1.5 to -1.2 V) to ^-31 to -30 cm-1/V (-1.2 to -0.15 V), and then to -15 cm-1/V (-0.2 to 0.55 V). The simultaneously recorded cyclic voltammograms revealed that at E 〈 -1.2 V, a hydro- gen evolution reaction (HER) occurred. With the help of periodic density functional theory calcula- tions using two different (2 × 2)-3CO slab models with Pd(111), the unusually high dvc-oM/dE and the small dVPd-CoM/dE in the HER region were explained as being due to the conversion of COad from bridge to hollow sites, which was induced by the co-adsorbed hydrogen atoms formed from dissociated water at negative potentials.展开更多
Employing decoupling index and industrial structure characteristic bias index methods, this study analyzed the spatial-temporal characteristics of industrial structure transformations and their resulting carbon emissi...Employing decoupling index and industrial structure characteristic bias index methods, this study analyzed the spatial-temporal characteristics of industrial structure transformations and their resulting carbon emissions in the Xuzhou Metropolitan Area from 2000 to 2014, with a focus on their relationships and driving factors. Our research indicates that carbon emission intensity from industrial structures in the Xuzhou Metropolitan Area at first showed an increasing trend, which then decreased. Furthermore, the relationship between emissions and industrial economic growth has been trending toward absolute decoupling. From the perspective of the center-periphery, the Xuzhou Metropolitan Area formed a concentric pattern, where both progress towards low emissions and the level of technological advancement gradually diminished from the center to the periphery. In terms of variation across provinces, the ISCB index in the eastern Henan has decreased the slowest, followed by the southern Shandong and the northern Anhui, with the northern Jiangsu ranking last. During this period, resource-and labor-intensive industries were the primary growth industries in the northern Anhui and the eastern Henan, while labor-intensive industries dominated the southern Shandong and capital-intensive industries dominated the northern Jiangsu. In terms of city types, the spatial pattern for industrial structure indicates that recession resource-based cities had higher carbon emission intensities than mature resource-based cities, followed by non-resource-based cities and regenerative resource-based cities. Generally, the industrial structure in the Xuzhou Metropolitan Area has transformed from being resource-intensive to capital-intensive, and has been trending toward technology-intensive as resource availability has been exploited to exhaustion and then been regenerated. Industrial structure has been the leading factor causing heterogeneity of carbon emission intensities between metropolitan cities. Therefore, the key to optimizing the industrial structure and layout of metropolitan areas is to promote industrial structure transformation and improve the system controlling collaborative industrial development between cities.展开更多
Hydrocarbon expulsion occurs only when pore fluid pressure due to hydrocarbon generation in source rock exceeds the force against migration in the adjacent carrier beds.Taking the Middle-Upper Ordovician carbonate sou...Hydrocarbon expulsion occurs only when pore fluid pressure due to hydrocarbon generation in source rock exceeds the force against migration in the adjacent carrier beds.Taking the Middle-Upper Ordovician carbonate source rock of Tarim Basin in China as an example,this paper proposes a method that identifies effective carbonate source rock based on the principles of mass balance.Data from the Well YW2 indicate that the Middle Ordovician Yijianfang Formation contains effective carbonate source rocks with low present-day TOC.Geological and geochemical analysis suggests that the hydrocarbons in the carbonate interval are likely self-generated and retained.Regular steranes from GC-MS analysis of oil extracts in this interval display similar features to those of the crude oil samples in Tabei area,indicating that the crude oil probably was migrated from the effective source rocks.By applying to other wells in the basin,the identified effective carbonate source rocks and non-source rock carbonates can be effectively identified and consistent with the actual exploration results,validating the method.Considering the contribution from the identified effective source rocks with low present-day TOC(TOC_(pd))is considered,the long-standing puzzle between the proved 3 P oil reserves and estimated resources in the basin can be reasonably explained.展开更多
The hydraulic concrete durability under the alternation of freeze-thaw and carbonation has been systematically investigated in this work, where both the micro part and the microscopic characteristics of concrete inter...The hydraulic concrete durability under the alternation of freeze-thaw and carbonation has been systematically investigated in this work, where both the micro part and the microscopic characteristics of concrete interface were analyzed based on computed tomography(CT) test and scanning electron microscopy(SEM). Average CT numbers of each section, declined at water-cement ratio of 0.35, increased at 0.45, and changed a little at 0.55. The specimen in the absence of fly ash exhibited less types of hydration products and the surface was observed to be a needle-like ettringite, with a relatively dense overall structure. However, with the increase of fly ash content, pores and micro-cracks of specimen structure increased. Hexagonal flake calcium hydroxide, present in the specimen after the first carbonation, was negligible in the test pieces of the first freezethaw where the main hydration products were ettringite and calcium silicate gel. Regular hexagonal plates of calcium hydroxide exhibited in the interior of the specimen in which charring first occurred but calcium hydroxide rarely existed in the interior of the specimen in which freeze-thaw first occurred.展开更多
The effect of C content (0.014-0.39 wt pct) on the paramagnetic-antiferromagnetic transition and γ→ε martensitic transformation of Fe-24Mn alloys has been investigated by the resistivity, dilation, tensile properti...The effect of C content (0.014-0.39 wt pct) on the paramagnetic-antiferromagnetic transition and γ→ε martensitic transformation of Fe-24Mn alloys has been investigated by the resistivity, dilation, tensile properties measurement and microstructure examination. The results have shown that C decreases T_N; increases the thermal expansion coefficients both above and below the T_N; increases the resistivity above the T_N and antiferromagnetic scattering resistivity below T_N. It strongly depresses the γ→ε martensitic transformation and reduces the M_s of Fe-24Mn alloys. Moreover, it increases the lattice parameter of austenite, enhances the tensile ductility, but almost does not affect the tensile strength. With increasing C content from 0.014 to 0.19 wt pct, the yield strength of Fe-24Mn alloy decreases obviously arising from the decreasing of preexisting ε martensite. but it increases from 0.19 to 0.39 wt pct C due to the solution hardening of C.展开更多
In ground tests of hypersonic scramjet, the highenthalpy airstream produced by burning hydrocarbon fuels often contains contaminants of water vapor and carbon dioxide. The contaminants may change the ignition characte...In ground tests of hypersonic scramjet, the highenthalpy airstream produced by burning hydrocarbon fuels often contains contaminants of water vapor and carbon dioxide. The contaminants may change the ignition characteristics of fuels between ground tests and real flights. In order to properly assess the influence of the contaminants on ignition characteristics of hydrocarbon fuels, the effect of water vapor and carbon dioxide on the ignition delay times of China RP-3 kerosene was studied behind reflected shock waves in a preheated shock tube. Experiments were conducted over a wider temperature range of 800-1 500 K, at a pressure of 0.3 MPa, equivalence ratios of 0.5 and 1, and oxygen concentration of 20%. Ignition delay times were determined from the onset of the excited radical OH emission together with the pressure profile. Ignition delay times were measured for four cases: (1) clean gas, (2) gas vitiated with 10% and 20% water vapor in mole, (3) gas vitiated with 10% carbon dioxide in mole, and (4) gas vitiated with 10% water vapor and 10% carbon dioxide, 20% water vapor and 10% carbon dioxide in mole. The results show that carbon dioxide produces an inhibiting effect at temperatures below 1 300 K when Ф = 0.5, whereas water vapor appears to accelerate the ignition process below a critical temperature of about 1 000 K when Ф = 0.5. When both water vapor and carbon dioxide exist together, a minor inhibiting effect is observed at Ф = 0.5, while no effect is found at Ф = 1.0. The results are also discussed preliminary by considering both the combustion reaction mechanism and the thermophysics properties of the fuel mixtures. The current measurements demonstrate vitiation effects of water vapor and carbon dioxide on the autoignition characteristics of China RP-3 kerosene at air-like O2 concentration. It is important to account for such effects when data are extrapolated from ground testing to real flight conditions.展开更多
The use of exogenous carbon monoxide releasing molecules(CORMs)provides promise for clinical application;however,the hazard potential of CORMs in vivo remains poorly understood.The developmental toxicity of CORM-3 w...The use of exogenous carbon monoxide releasing molecules(CORMs)provides promise for clinical application;however,the hazard potential of CORMs in vivo remains poorly understood.The developmental toxicity of CORM-3 was investigated by exposure to concentrations ranging from 6.25 to400μmol/L during 4-144 h post fertilization.Toxicity endpoints of mortality,spontaneous movement,heart rate,hatching rate,malformation,body length,and larval behavior were measured.展开更多
Propylene carbonate (PC) has a great potential to be used as an energy storage medium in the compact pulsed power sources due to its high dielectric constant and large resistivity. We investigate both the positive a...Propylene carbonate (PC) has a great potential to be used as an energy storage medium in the compact pulsed power sources due to its high dielectric constant and large resistivity. We investigate both the positive and negative breakdown characteristics of PC. The streamer patterns are obtained by ultra-high-speed cameras. The experimental results show that the positive breakdown voltage of PC is about 135% higher than the negative one, which is abnormal compared with the common liquid. The shape of the positive streamer is filamentary and branchy, while the negative streamer is tree-like and less branched. According to these experimental results, a charge layer structure model at the interface between the metal electrode and liquid is presented. It is suggested that the abnormal polarity effect basically arises from the electric field strength difference in the interface between both electrodes and PC. What is more, the recombination radiation and photoionization also play an important role in the whole discharge process.展开更多
Radiation encephalopathy is the main complication of cranial radiotherapy. It can cause necrosis of brain tissue and cognitive dysfunction. Our previous work had proved that a natural antioxidant shikonin possessed pr...Radiation encephalopathy is the main complication of cranial radiotherapy. It can cause necrosis of brain tissue and cognitive dysfunction. Our previous work had proved that a natural antioxidant shikonin possessed protective effect on cerebral ischemic injury. Here we investigated the effects of shikonin on carbon ion beam induced radiation brain injury in mice. Pretreatment with shikonin significantly increased the SOD and CAT activities and the ratio of GSH/GSSG in mouse brain tissues compared with irradiated group (P〈0.01), while obviously reduced the MDA and PCO contents and the RO$ levels derived from of the brain mitochondria.展开更多
Fluphenazine (FP) treatment (50mg/kg bw, ip in saline) 30 min before or 6 or 10 h after CCl4 administration (1 ml/kg ip in olive oil) significantly prevented the liver necrosis produced by the hepatotoxin at 24 h. FP ...Fluphenazine (FP) treatment (50mg/kg bw, ip in saline) 30 min before or 6 or 10 h after CCl4 administration (1 ml/kg ip in olive oil) significantly prevented the liver necrosis produced by the hepatotoxin at 24 h. FP had enhancing effects on the covalent binding of CCl4 reactive metabolites to cellular constituents and on CCl4 induced lipid peroaldation.FP lowered bOdy temperature of the CCl4-poisoned animals during the 24 h observation period. The obtained results are compatible but do not prove the hypothesis that calmodulin (CaM) had participation in late occurring events preceding necrosis. FP lowering action on body temperature, however, might also play a role in the effects of this drug on the onset of CCl4 induced liver necrosis. FP levels in liver tissue as determined by gas chromatography-mass spectrometry evidenced the presence of the drug in amounts suffi cient to inhibit CaM and that suggests that not all preventive effects of FP are due to its indirect actions on the central nervous system via decreased body temperature展开更多
With the goal of achieving carbon peak and carbon neutrality,this paper studies the carbon effect of agricultural land remediation.In this paper,the carbon effect mechanism and calculation method of land consolidation...With the goal of achieving carbon peak and carbon neutrality,this paper studies the carbon effect of agricultural land remediation.In this paper,the carbon effect mechanism and calculation method of land consolidation,the proposed national carbon peaking and carbon neutrality goals,and the requirements put forward by agricultural land consolidation followed were analyzed.Then,the application research on the carbon effect accounting of agricultural land consolidation was conducted.Besides,the application process of carbon effect accounting of land consolidation with the goals of carbon peaking and carbon neutrality.Therefore,we hope this study will play an effective role to advance the carbon effect research in the regulation of agricultural land.展开更多
Electrical properties of C/Ni films are studied using four mosaic targets made of pure graphite and stripes of nickel with the surface areas of 1.78,3.21,3.92 and 4.64%.The conductivity data in the temperature range o...Electrical properties of C/Ni films are studied using four mosaic targets made of pure graphite and stripes of nickel with the surface areas of 1.78,3.21,3.92 and 4.64%.The conductivity data in the temperature range of400-500 K shows the extended state conduction.The conductivity data in the temperature range of 150-300 K shows the multi-phonon hopping conduction.The Berthelot-type conduction dominates in the temperature range of 50-150 K.The conductivity of the films in the temperature range about 〈 50 K is described in terms of variable-range hopping conduction.In low temperatures,the localized density of state around Fermi level(F)for the film deposition with 3.92% nickel has a maximum value of about 56.2×10^(17)cm^(-3)eV^(-1) with the minimum average hopping distance of about 3.43 × 10^(-6) cm.展开更多
The ocean is the largest active carbon reservoir on Earth. Organic carbon(OC), as the primary species of carbon sequestration in the ocean, plays an important role in the global carbon cycle through its deposition and...The ocean is the largest active carbon reservoir on Earth. Organic carbon(OC), as the primary species of carbon sequestration in the ocean, plays an important role in the global carbon cycle through its deposition and burial. In this study,sedimentary OC data from 5796 stations, together with relevant geochemical and sedimentological parameters in the Bohai Sea,Yellow Sea, and East China Sea(BYES) were used to summarize and elucidate the distribution and burial patterns of sedimentary OC, and assess carbon sink effect of sedimentary OC burial. The results show that the OC content in the sediments of the BYES ranges from 0.00% to 2.12%, with an average content of 0.47%±0.26%. OC content is significantly correlated with finegrained sediments, with an average OC content in mud areas being 39% higher than that in non-mud areas. Modern OC buried in the BYES are mainly deposited in 7 major mud areas, with a total sedimentary OC burial flux of approximately 8.20 Mt C yr^(–1).Among them, the burial flux of biospheric OC is 6.92 Mt C yr^(–1), equivalent to the OC consumption amount of silicate weathering of the 9 major river basins in the eastern China. In its natural state, the annually sequestered OC in the sediments of the eastern China seas is equivalent to 25.37 Mt of atmospheric CO_(2), indicating a significant carbon sink effect. The distribution and burial of terrigenous OC in the BYES are mainly influenced by the large river inputs and complex marine hydrodynamic environment,while human activities such as dam construction have significantly altered the OC burial in these coastal mud areas.展开更多
We have designed and prepared β-cyclodextrin (β-CD)-functionalized multi-walled nanotubes (MWCNTs-g-CD) for the oxidation of cinnamon oil to natural benzaldehyde under aqueous condi- tions. The synergistic effec...We have designed and prepared β-cyclodextrin (β-CD)-functionalized multi-walled nanotubes (MWCNTs-g-CD) for the oxidation of cinnamon oil to natural benzaldehyde under aqueous condi- tions. The synergistic effect of combining MWCNTs with β-CD led to a remarkable increase in the performance of the MWCNTs-g-CD for the catalytic oxidation of cinnamaldehyde, which exhibited 95% cinnamaldehyde conversion and 85% selectivity to natural benzaldehyde with a short reaction time of 10 rain. The MWCNTs-g-CD also exhibited outstanding recyclability with good stability, showing no discernible decrease in their catalytic activity over five reaction cycles.展开更多
The design of a three-input logic circuit using carbon nanotube field effect transistors(CNTFETs)is presented.Ternary logic must be an exact replacement for dual logic since it performs straightforwardly in digital de...The design of a three-input logic circuit using carbon nanotube field effect transistors(CNTFETs)is presented.Ternary logic must be an exact replacement for dual logic since it performs straightforwardly in digital devices,which is why this design is so popular,and it also reduces chip area,both of which are examples of circuit overheads.The proposed module we have investigated is a triple-logic-based one,based on advanced technology CNTFETs and an emphasis on minimizing delay times at various values,as well as comparisons of the design working with various load capacitances.Comparing the proposed design with the existing design,the delay times was reduced from 66.32 to 16.41 ps,i.e.,a 75.26%reduction.However,the power dissipation was not optimized,and increased by 1.44%compared to the existing adder.The number of transistors was also reduced,and the product of power and delay(P∗D)achieved a value of 0.0498053 fJ.An improvement at 1 V was also achieved.A load capacitance(fF)was measured at different values,and the average delay measured for different values of capacitance had a maximum of 83.60 ps and a minimum of 22.54 ps,with a range of 61.06 ps.The power dissipations ranged from a minimum of 3.38μW to a maximum of 6.49μW.Based on these results,the use of this CNTFET half-adder design in multiple Boolean circuits will be a useful addition to circuit design.展开更多
The progress on novel interconnects for carbon nanotube(CNT)-based electronic circuit is by far behind the remarkable development of CNT-field effect transistors.The Cu interconnect material used in current integrated...The progress on novel interconnects for carbon nanotube(CNT)-based electronic circuit is by far behind the remarkable development of CNT-field effect transistors.The Cu interconnect material used in current integrated circuits seems not applicable for the novel interconnects,as it requires electrochemical deposition followed by chemical-mechanical polishing.We report our experimental results on the failure current density,resistivity,electromigration effect and failure mechanism of patterned stripes of Pd,Sc and Y thin-films,regarding them as the potential novel interconnects.The Pd stripes have a failure current density of(8~10)×106 A/cm^2(MA/cm^2),and they are stable when the working current density is as much as 90% of the failure current density.However,they show a resistivity around 210 μΩ·cm,which is 20 times of the bulk value and leaving room for improvement.Compared to Pd,the Sc stripes have a similar resistivity but smaller failure current density of 4~5 MA/cm^2.Y stripes seem not suitable for interconnects by showing even lower failure current density than that of Sc and evidence of oxidation.For comparison,Au stripes of the same dimensions show a failure current density of 30 MA/cm^2 and a resistivity around 4 μΩ·cm,making them also a good material as novel interconnects.展开更多
Depositing single-walled carbon nanotubes(SWNTs) with controllable density, pattern and orientation on electrodes presents a challenge in today's research. Here, we report a novel solvent evaporation method to ali...Depositing single-walled carbon nanotubes(SWNTs) with controllable density, pattern and orientation on electrodes presents a challenge in today's research. Here, we report a novel solvent evaporation method to align SWNTs in patterns having nanoscale width and micronscale length. SWNTs suspension has been introduced dropwise onto photoresist resin microchannels; and the capillary force can stretch and align SWNTs into strands with nanoscale width in the microchannels. Then these narrow and long aligned SWNTs patterns were successfully transferred to a pair of gold electrodes with different gaps to fabricate carbon nanotube field-effect transistor(CNTFET). Moreover, the electrical performance of the CNTFET show that the SWNTs strands can bridge different gaps and fabricate good electrical performance CNTFET with ON/OFF ratio around 106. This result suggests a promising and simple strategy for assembling well-aligned SWNTs into CNTFET device with good electrical performance.展开更多
Routing resources are the major bottlenecks in improving the performance and power consumption of the current FPGAs. Recently reported researches have shown that carbon nanotube field effect transistors(CNFETs) have c...Routing resources are the major bottlenecks in improving the performance and power consumption of the current FPGAs. Recently reported researches have shown that carbon nanotube field effect transistors(CNFETs) have considerable potentials for improving the delay and power consumption of the modern FPGAs. In this paper, hybrid CNFET-CMOS architecture is presented for FPGAs and then this architecture is evaluated to be used in modern FPGAs. In addition, we have designed and parameterized the CNFET-based FPGA switches and calibrated them for being utilized in FPGAs at 45 nm, 22 nm and 16 nm technology nodes.Simulation results show that the CNFET-based FPGA switches improve the current FPGAs in terms of performance, power consumption and immunity to process and temperature variations. Simulation results and analyses also demonstrate that the performance of the FPGAs is improved about 30%, on average and the average and leakage power consumptions are reduced more than 6% and 98% respectively when the CNFET switches are used instead of MOSFET FPGA switches. Moreover, this technique leads to more than 20.31%smaller area. It is worth mentioning that the advantages of CNFET-based FPGAs are more considerable when the size of FPGAs grows and also when the technology node becomes smaller.展开更多
In the context of "two-wheel drive" development mode, China's construction land shows significant expansion characteristics. The carbon emission effect of construction land changes is an important factor for the in...In the context of "two-wheel drive" development mode, China's construction land shows significant expansion characteristics. The carbon emission effect of construction land changes is an important factor for the increase of carbon emissions in the atmosphere. In this study, the drivers of carbon emissions in Anhui Province from 1997 to 2011 were quantitatively measured using the improved Kaya identity and Logarithmic Mean Divisia Index. The results show that: economic growth, expansion of construction land and changes in population density have incremental effects on carbon emissions. The average contribution rate of economic growth as the first driver is 266.32 percent. The construction land expansion is an important driving factor with annual mean carbon effect of 6.4057 million tons and annual mean contribution rate of 187.30 percent. But the change in population density has little impact on carbon emission driving. Energy structure changes and energy intensity reduction have inhibitory effects on carbon emissions, of which the annual mean contribution rate is -212.06 percent and -158.115 percent respectively. The targeted policy approaches of carbon emission reduction were put forward based on the decomposition of carbon emission factors, laying a scientific basis to rationally use the land for the Government, which is conducive to build an ecological province for Anhui and achieve the purpose of emission reduction, providing a reference for the research on carbon emission effect of changes in provincial-scale construction land.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.42171230)。
文摘Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research object(data excluding Hong Kong,Macao and Taiwan) and used the carbon emission coefficient method to quantitatively measure the food carbon emissions from 1987–2020,then analyzed the carbon emission effects under the evolution of dietary structure.The results showed that during the study period,the Chinese dietary structure gradually changed to a high-carbon consumption pattern.The dietary structure of urban residents developed to a balanced one,while that of rural residents developed to a high-quality one.During the study period,the per capita food carbon emissions and total food consumption of Chinese showed an increasing trend.The per capita food carbon emissions of residents in urban and rural showed an overall upward trend.The total food carbon emissions in urban increased significantly,while that in rural increased first and then decreased.The influence of beef and mutton on carbon emissions is the highest in dietary structure.Compared with the balanced dietary pattern,the food carbon emissions of Chinese residents had not yet reached the peak,but were evolving to a high-carbon consumption pattern.
基金supported by the National Natural Science Foundation of China(21473175)the National Instrumentation Program(2011YQ03012416)the National Basic Reserarch Program of China(973 Program,2015CB932301)
文摘The potential (E)-dependent vibrational behavior of a saturated CO adlayer on Au-core Pd-shell nanoparticle film electrodes was investigated over a wide potential range, in acidic, neutral, and basic solutions, using in situ surface-enhanced Raman spectroscopy (SERS). Over the whole of the examined potential region (-1.5 to 0.55 V vs. NHE), the peak frequencies of both the C-OM and the Pd-COM band (here, M denotes the multiply-bonded configuration) displayed three distinct linear regions: dvc oM/dE decreased from -185-207 (from -1.5 to -1.2 V) to -83-84 cm-1/V (-1.2 to -0.15 V), and then to 43 cm-1/V (-0.2 to 0.55 V); on the other hand, dvpd coM/dE changed from -10 to -8 cm I/V (from -1.5 to -1.2 V) to ^-31 to -30 cm-1/V (-1.2 to -0.15 V), and then to -15 cm-1/V (-0.2 to 0.55 V). The simultaneously recorded cyclic voltammograms revealed that at E 〈 -1.2 V, a hydro- gen evolution reaction (HER) occurred. With the help of periodic density functional theory calcula- tions using two different (2 × 2)-3CO slab models with Pd(111), the unusually high dvc-oM/dE and the small dVPd-CoM/dE in the HER region were explained as being due to the conversion of COad from bridge to hollow sites, which was induced by the co-adsorbed hydrogen atoms formed from dissociated water at negative potentials.
基金Under the auspices of the National Natural Science Foundation of China(No.41371146,41671123)National Social Science Foundation of China(No.13BJY067)
文摘Employing decoupling index and industrial structure characteristic bias index methods, this study analyzed the spatial-temporal characteristics of industrial structure transformations and their resulting carbon emissions in the Xuzhou Metropolitan Area from 2000 to 2014, with a focus on their relationships and driving factors. Our research indicates that carbon emission intensity from industrial structures in the Xuzhou Metropolitan Area at first showed an increasing trend, which then decreased. Furthermore, the relationship between emissions and industrial economic growth has been trending toward absolute decoupling. From the perspective of the center-periphery, the Xuzhou Metropolitan Area formed a concentric pattern, where both progress towards low emissions and the level of technological advancement gradually diminished from the center to the periphery. In terms of variation across provinces, the ISCB index in the eastern Henan has decreased the slowest, followed by the southern Shandong and the northern Anhui, with the northern Jiangsu ranking last. During this period, resource-and labor-intensive industries were the primary growth industries in the northern Anhui and the eastern Henan, while labor-intensive industries dominated the southern Shandong and capital-intensive industries dominated the northern Jiangsu. In terms of city types, the spatial pattern for industrial structure indicates that recession resource-based cities had higher carbon emission intensities than mature resource-based cities, followed by non-resource-based cities and regenerative resource-based cities. Generally, the industrial structure in the Xuzhou Metropolitan Area has transformed from being resource-intensive to capital-intensive, and has been trending toward technology-intensive as resource availability has been exploited to exhaustion and then been regenerated. Industrial structure has been the leading factor causing heterogeneity of carbon emission intensities between metropolitan cities. Therefore, the key to optimizing the industrial structure and layout of metropolitan areas is to promote industrial structure transformation and improve the system controlling collaborative industrial development between cities.
基金financially supported by the Science Foundation of China University of Petroleum,Beijing(Grant No.2462020BJRC005)the Joint Funds of National Natural Science Foundation of China(Grant No.U19B6003-02)。
文摘Hydrocarbon expulsion occurs only when pore fluid pressure due to hydrocarbon generation in source rock exceeds the force against migration in the adjacent carrier beds.Taking the Middle-Upper Ordovician carbonate source rock of Tarim Basin in China as an example,this paper proposes a method that identifies effective carbonate source rock based on the principles of mass balance.Data from the Well YW2 indicate that the Middle Ordovician Yijianfang Formation contains effective carbonate source rocks with low present-day TOC.Geological and geochemical analysis suggests that the hydrocarbons in the carbonate interval are likely self-generated and retained.Regular steranes from GC-MS analysis of oil extracts in this interval display similar features to those of the crude oil samples in Tabei area,indicating that the crude oil probably was migrated from the effective source rocks.By applying to other wells in the basin,the identified effective carbonate source rocks and non-source rock carbonates can be effectively identified and consistent with the actual exploration results,validating the method.Considering the contribution from the identified effective source rocks with low present-day TOC(TOC_(pd))is considered,the long-standing puzzle between the proved 3 P oil reserves and estimated resources in the basin can be reasonably explained.
基金Funded by the National Natural Science Foundation of China(Nos.51279017,51539002 and 51139001)China Postdoctoral Science Foundation Funded Project(No.2015M582213)
文摘The hydraulic concrete durability under the alternation of freeze-thaw and carbonation has been systematically investigated in this work, where both the micro part and the microscopic characteristics of concrete interface were analyzed based on computed tomography(CT) test and scanning electron microscopy(SEM). Average CT numbers of each section, declined at water-cement ratio of 0.35, increased at 0.45, and changed a little at 0.55. The specimen in the absence of fly ash exhibited less types of hydration products and the surface was observed to be a needle-like ettringite, with a relatively dense overall structure. However, with the increase of fly ash content, pores and micro-cracks of specimen structure increased. Hexagonal flake calcium hydroxide, present in the specimen after the first carbonation, was negligible in the test pieces of the first freezethaw where the main hydration products were ettringite and calcium silicate gel. Regular hexagonal plates of calcium hydroxide exhibited in the interior of the specimen in which charring first occurred but calcium hydroxide rarely existed in the interior of the specimen in which freeze-thaw first occurred.
文摘The effect of C content (0.014-0.39 wt pct) on the paramagnetic-antiferromagnetic transition and γ→ε martensitic transformation of Fe-24Mn alloys has been investigated by the resistivity, dilation, tensile properties measurement and microstructure examination. The results have shown that C decreases T_N; increases the thermal expansion coefficients both above and below the T_N; increases the resistivity above the T_N and antiferromagnetic scattering resistivity below T_N. It strongly depresses the γ→ε martensitic transformation and reduces the M_s of Fe-24Mn alloys. Moreover, it increases the lattice parameter of austenite, enhances the tensile ductility, but almost does not affect the tensile strength. With increasing C content from 0.014 to 0.19 wt pct, the yield strength of Fe-24Mn alloy decreases obviously arising from the decreasing of preexisting ε martensite. but it increases from 0.19 to 0.39 wt pct C due to the solution hardening of C.
基金supported by the National Natural Science Foundation of China(90916017)
文摘In ground tests of hypersonic scramjet, the highenthalpy airstream produced by burning hydrocarbon fuels often contains contaminants of water vapor and carbon dioxide. The contaminants may change the ignition characteristics of fuels between ground tests and real flights. In order to properly assess the influence of the contaminants on ignition characteristics of hydrocarbon fuels, the effect of water vapor and carbon dioxide on the ignition delay times of China RP-3 kerosene was studied behind reflected shock waves in a preheated shock tube. Experiments were conducted over a wider temperature range of 800-1 500 K, at a pressure of 0.3 MPa, equivalence ratios of 0.5 and 1, and oxygen concentration of 20%. Ignition delay times were determined from the onset of the excited radical OH emission together with the pressure profile. Ignition delay times were measured for four cases: (1) clean gas, (2) gas vitiated with 10% and 20% water vapor in mole, (3) gas vitiated with 10% carbon dioxide in mole, and (4) gas vitiated with 10% water vapor and 10% carbon dioxide, 20% water vapor and 10% carbon dioxide in mole. The results show that carbon dioxide produces an inhibiting effect at temperatures below 1 300 K when Ф = 0.5, whereas water vapor appears to accelerate the ignition process below a critical temperature of about 1 000 K when Ф = 0.5. When both water vapor and carbon dioxide exist together, a minor inhibiting effect is observed at Ф = 0.5, while no effect is found at Ф = 1.0. The results are also discussed preliminary by considering both the combustion reaction mechanism and the thermophysics properties of the fuel mixtures. The current measurements demonstrate vitiation effects of water vapor and carbon dioxide on the autoignition characteristics of China RP-3 kerosene at air-like O2 concentration. It is important to account for such effects when data are extrapolated from ground testing to real flight conditions.
基金supported by National Basic Research Program of China(2010CB834202)the National Natural Science Foundation of China(11305226,11175222)+1 种基金the Scientific Technology Research Projects of Lanzhou City(2015-3-75)the Western Talent Program of Chinese Academy of Sciences(Y460030XB0)
文摘The use of exogenous carbon monoxide releasing molecules(CORMs)provides promise for clinical application;however,the hazard potential of CORMs in vivo remains poorly understood.The developmental toxicity of CORM-3 was investigated by exposure to concentrations ranging from 6.25 to400μmol/L during 4-144 h post fertilization.Toxicity endpoints of mortality,spontaneous movement,heart rate,hatching rate,malformation,body length,and larval behavior were measured.
基金Supported by the National Natural Science Foundation of China under Grant No 51677190the Hunan Provincial Natural Science Foundation of China under Grant No 2017JJ1005
文摘Propylene carbonate (PC) has a great potential to be used as an energy storage medium in the compact pulsed power sources due to its high dielectric constant and large resistivity. We investigate both the positive and negative breakdown characteristics of PC. The streamer patterns are obtained by ultra-high-speed cameras. The experimental results show that the positive breakdown voltage of PC is about 135% higher than the negative one, which is abnormal compared with the common liquid. The shape of the positive streamer is filamentary and branchy, while the negative streamer is tree-like and less branched. According to these experimental results, a charge layer structure model at the interface between the metal electrode and liquid is presented. It is suggested that the abnormal polarity effect basically arises from the electric field strength difference in the interface between both electrodes and PC. What is more, the recombination radiation and photoionization also play an important role in the whole discharge process.
基金supported by Key Program of National Natural Science Foundation of China(U1432248)National Natural Science Foundation of China(11175222,11305226)
文摘Radiation encephalopathy is the main complication of cranial radiotherapy. It can cause necrosis of brain tissue and cognitive dysfunction. Our previous work had proved that a natural antioxidant shikonin possessed protective effect on cerebral ischemic injury. Here we investigated the effects of shikonin on carbon ion beam induced radiation brain injury in mice. Pretreatment with shikonin significantly increased the SOD and CAT activities and the ratio of GSH/GSSG in mouse brain tissues compared with irradiated group (P〈0.01), while obviously reduced the MDA and PCO contents and the RO$ levels derived from of the brain mitochondria.
文摘Fluphenazine (FP) treatment (50mg/kg bw, ip in saline) 30 min before or 6 or 10 h after CCl4 administration (1 ml/kg ip in olive oil) significantly prevented the liver necrosis produced by the hepatotoxin at 24 h. FP had enhancing effects on the covalent binding of CCl4 reactive metabolites to cellular constituents and on CCl4 induced lipid peroaldation.FP lowered bOdy temperature of the CCl4-poisoned animals during the 24 h observation period. The obtained results are compatible but do not prove the hypothesis that calmodulin (CaM) had participation in late occurring events preceding necrosis. FP lowering action on body temperature, however, might also play a role in the effects of this drug on the onset of CCl4 induced liver necrosis. FP levels in liver tissue as determined by gas chromatography-mass spectrometry evidenced the presence of the drug in amounts suffi cient to inhibit CaM and that suggests that not all preventive effects of FP are due to its indirect actions on the central nervous system via decreased body temperature
文摘With the goal of achieving carbon peak and carbon neutrality,this paper studies the carbon effect of agricultural land remediation.In this paper,the carbon effect mechanism and calculation method of land consolidation,the proposed national carbon peaking and carbon neutrality goals,and the requirements put forward by agricultural land consolidation followed were analyzed.Then,the application research on the carbon effect accounting of agricultural land consolidation was conducted.Besides,the application process of carbon effect accounting of land consolidation with the goals of carbon peaking and carbon neutrality.Therefore,we hope this study will play an effective role to advance the carbon effect research in the regulation of agricultural land.
文摘Electrical properties of C/Ni films are studied using four mosaic targets made of pure graphite and stripes of nickel with the surface areas of 1.78,3.21,3.92 and 4.64%.The conductivity data in the temperature range of400-500 K shows the extended state conduction.The conductivity data in the temperature range of 150-300 K shows the multi-phonon hopping conduction.The Berthelot-type conduction dominates in the temperature range of 50-150 K.The conductivity of the films in the temperature range about 〈 50 K is described in terms of variable-range hopping conduction.In low temperatures,the localized density of state around Fermi level(F)for the film deposition with 3.92% nickel has a maximum value of about 56.2×10^(17)cm^(-3)eV^(-1) with the minimum average hopping distance of about 3.43 × 10^(-6) cm.
基金supported by the Laoshan Laboratory (Grant No.LSKJ202204200)the Chinese Offshore Investigation and Assessment Project (Grant No.908~ZC~I~05)+2 种基金the National Natural Science Foundation of China-Shandong Joint Fund for Marine Science Research Centers (Grant No.U1606401)the National Natural Science Foundation of China Shiptime Sharing Project (Grant Nos.42049902,42149902)the Taishan Scholar Program of Shandong (Grant No.tspd20181216)。
文摘The ocean is the largest active carbon reservoir on Earth. Organic carbon(OC), as the primary species of carbon sequestration in the ocean, plays an important role in the global carbon cycle through its deposition and burial. In this study,sedimentary OC data from 5796 stations, together with relevant geochemical and sedimentological parameters in the Bohai Sea,Yellow Sea, and East China Sea(BYES) were used to summarize and elucidate the distribution and burial patterns of sedimentary OC, and assess carbon sink effect of sedimentary OC burial. The results show that the OC content in the sediments of the BYES ranges from 0.00% to 2.12%, with an average content of 0.47%±0.26%. OC content is significantly correlated with finegrained sediments, with an average OC content in mud areas being 39% higher than that in non-mud areas. Modern OC buried in the BYES are mainly deposited in 7 major mud areas, with a total sedimentary OC burial flux of approximately 8.20 Mt C yr^(–1).Among them, the burial flux of biospheric OC is 6.92 Mt C yr^(–1), equivalent to the OC consumption amount of silicate weathering of the 9 major river basins in the eastern China. In its natural state, the annually sequestered OC in the sediments of the eastern China seas is equivalent to 25.37 Mt of atmospheric CO_(2), indicating a significant carbon sink effect. The distribution and burial of terrigenous OC in the BYES are mainly influenced by the large river inputs and complex marine hydrodynamic environment,while human activities such as dam construction have significantly altered the OC burial in these coastal mud areas.
基金supported by the National Natural Science Foundation of China (21376279, 21276102, 21425627)Guangdong Technology Research Center for Synthesis and Separation of Thermosensitive Chemicals (2015B090903061)+1 种基金the Fundamental Research Funds for the Central Universities (14lgpy28)Guangzhou Science and Technology Plan Projects (2014J4100125)~~
文摘We have designed and prepared β-cyclodextrin (β-CD)-functionalized multi-walled nanotubes (MWCNTs-g-CD) for the oxidation of cinnamon oil to natural benzaldehyde under aqueous condi- tions. The synergistic effect of combining MWCNTs with β-CD led to a remarkable increase in the performance of the MWCNTs-g-CD for the catalytic oxidation of cinnamaldehyde, which exhibited 95% cinnamaldehyde conversion and 85% selectivity to natural benzaldehyde with a short reaction time of 10 rain. The MWCNTs-g-CD also exhibited outstanding recyclability with good stability, showing no discernible decrease in their catalytic activity over five reaction cycles.
文摘The design of a three-input logic circuit using carbon nanotube field effect transistors(CNTFETs)is presented.Ternary logic must be an exact replacement for dual logic since it performs straightforwardly in digital devices,which is why this design is so popular,and it also reduces chip area,both of which are examples of circuit overheads.The proposed module we have investigated is a triple-logic-based one,based on advanced technology CNTFETs and an emphasis on minimizing delay times at various values,as well as comparisons of the design working with various load capacitances.Comparing the proposed design with the existing design,the delay times was reduced from 66.32 to 16.41 ps,i.e.,a 75.26%reduction.However,the power dissipation was not optimized,and increased by 1.44%compared to the existing adder.The number of transistors was also reduced,and the product of power and delay(P∗D)achieved a value of 0.0498053 fJ.An improvement at 1 V was also achieved.A load capacitance(fF)was measured at different values,and the average delay measured for different values of capacitance had a maximum of 83.60 ps and a minimum of 22.54 ps,with a range of 61.06 ps.The power dissipations ranged from a minimum of 3.38μW to a maximum of 6.49μW.Based on these results,the use of this CNTFET half-adder design in multiple Boolean circuits will be a useful addition to circuit design.
基金supported by the NSF China (10774002) and the MOST China (No 2006CB932401)
文摘The progress on novel interconnects for carbon nanotube(CNT)-based electronic circuit is by far behind the remarkable development of CNT-field effect transistors.The Cu interconnect material used in current integrated circuits seems not applicable for the novel interconnects,as it requires electrochemical deposition followed by chemical-mechanical polishing.We report our experimental results on the failure current density,resistivity,electromigration effect and failure mechanism of patterned stripes of Pd,Sc and Y thin-films,regarding them as the potential novel interconnects.The Pd stripes have a failure current density of(8~10)×106 A/cm^2(MA/cm^2),and they are stable when the working current density is as much as 90% of the failure current density.However,they show a resistivity around 210 μΩ·cm,which is 20 times of the bulk value and leaving room for improvement.Compared to Pd,the Sc stripes have a similar resistivity but smaller failure current density of 4~5 MA/cm^2.Y stripes seem not suitable for interconnects by showing even lower failure current density than that of Sc and evidence of oxidation.For comparison,Au stripes of the same dimensions show a failure current density of 30 MA/cm^2 and a resistivity around 4 μΩ·cm,making them also a good material as novel interconnects.
基金the financial supports of NSFC(No.20805033 and 30901199)SRF for ROCS,SEM(2008890-19-9)Doctoral Education Fund for New Teachers(200806101048)
文摘Depositing single-walled carbon nanotubes(SWNTs) with controllable density, pattern and orientation on electrodes presents a challenge in today's research. Here, we report a novel solvent evaporation method to align SWNTs in patterns having nanoscale width and micronscale length. SWNTs suspension has been introduced dropwise onto photoresist resin microchannels; and the capillary force can stretch and align SWNTs into strands with nanoscale width in the microchannels. Then these narrow and long aligned SWNTs patterns were successfully transferred to a pair of gold electrodes with different gaps to fabricate carbon nanotube field-effect transistor(CNTFET). Moreover, the electrical performance of the CNTFET show that the SWNTs strands can bridge different gaps and fabricate good electrical performance CNTFET with ON/OFF ratio around 106. This result suggests a promising and simple strategy for assembling well-aligned SWNTs into CNTFET device with good electrical performance.
文摘Routing resources are the major bottlenecks in improving the performance and power consumption of the current FPGAs. Recently reported researches have shown that carbon nanotube field effect transistors(CNFETs) have considerable potentials for improving the delay and power consumption of the modern FPGAs. In this paper, hybrid CNFET-CMOS architecture is presented for FPGAs and then this architecture is evaluated to be used in modern FPGAs. In addition, we have designed and parameterized the CNFET-based FPGA switches and calibrated them for being utilized in FPGAs at 45 nm, 22 nm and 16 nm technology nodes.Simulation results show that the CNFET-based FPGA switches improve the current FPGAs in terms of performance, power consumption and immunity to process and temperature variations. Simulation results and analyses also demonstrate that the performance of the FPGAs is improved about 30%, on average and the average and leakage power consumptions are reduced more than 6% and 98% respectively when the CNFET switches are used instead of MOSFET FPGA switches. Moreover, this technique leads to more than 20.31%smaller area. It is worth mentioning that the advantages of CNFET-based FPGAs are more considerable when the size of FPGAs grows and also when the technology node becomes smaller.
基金the Key Research Fund of Anhui Provincial Education Department (No.2010sk502zd)the National Natural Science Foundation of China (No.41071337)
文摘In the context of "two-wheel drive" development mode, China's construction land shows significant expansion characteristics. The carbon emission effect of construction land changes is an important factor for the increase of carbon emissions in the atmosphere. In this study, the drivers of carbon emissions in Anhui Province from 1997 to 2011 were quantitatively measured using the improved Kaya identity and Logarithmic Mean Divisia Index. The results show that: economic growth, expansion of construction land and changes in population density have incremental effects on carbon emissions. The average contribution rate of economic growth as the first driver is 266.32 percent. The construction land expansion is an important driving factor with annual mean carbon effect of 6.4057 million tons and annual mean contribution rate of 187.30 percent. But the change in population density has little impact on carbon emission driving. Energy structure changes and energy intensity reduction have inhibitory effects on carbon emissions, of which the annual mean contribution rate is -212.06 percent and -158.115 percent respectively. The targeted policy approaches of carbon emission reduction were put forward based on the decomposition of carbon emission factors, laying a scientific basis to rationally use the land for the Government, which is conducive to build an ecological province for Anhui and achieve the purpose of emission reduction, providing a reference for the research on carbon emission effect of changes in provincial-scale construction land.