SYNTHESIS AND CARBON TRANSFER REACTIONS OF 12-DIMETHYL-3-ARYLSULFONYL (ARYL=p-TOLYL PHENYL)-△~2-IMIDAZOLINIUM IODIDE

As models of 5, 10-methenyl-tetrahydrofolate coenaymes imidazolinium salts 6a. b were synthesized and their carbon transfer reactions with several types of nucleophiles were studied.

The Influence of Carburizing Parameters on Carbon Transfer Coefficient

Definition of coefficient of carbon transfer in European Standard (EN 10052) is presented as: "Mass of carbon transferred from carburizing medium into the steel, per unit surface area per second for a unit difference between the carbon potential, and actual surface carbon content". In this paper, a model is presented of carbon transfer from endothermic atmospheres to carbon steel. The carbon transfer coefficient values were determined experimentally by the foil technique and on specimens, taking into account the following parameters: chemical composition of atmospheres, carbon potential, temperature and time of the carburizing process. Some examples of the variation of the carbon transfer coefficient for two steps of the carburizing process, including soaking before quenching, are given, based on results obtained. The effect of carbon transfer coefficient on carbon content at the steel surface is given.

Carbon compensation and carbon neutrality:Regional variations based on net carbon transfer of trade in China

Inter-provincial carbon compensation is an important means for a country to realize regional environmental protection and achieve coordinated regional development and realize the carbon neutral goal.It is easier to realize inter-provincial carbon compensation compared with the national level.Based on the multi-regional input-output model and the input-output data of 30 provinces in China,this study measured the carbon transfer in,carbon transfer out and net carbon transfer of each province,and based on the undesirable slacks-based measurement model under the common frontier,the provinces were given the shadow price of carbon emission in line with the situation of the local economic development,resource endowment,and industrial structure,and based on which,the amount of carbon compensation of each province was measured.The results show that:China's provinces and regions have a larger share of trade-implied carbon emissions;the net carbon transfer in areas mainly concentrated in the traditional energy provinces,which provide industrial products for other regions and undertake the transfer of carbon emissions,and become the main carbon compensation recipient areas;the net carbon transfer out is mainly concentrated in the economically developed and densely populated areas such as Beijing-Tianjin region and the eastern and southern coasts,which satisfy the end-consumption by purchasing a large number of industrial products and generate a large amount of carbon emissions.Transfer out;becoming the main carbon offset payment area.Based on the results of this study,it is proposed to improve the national provincial carbon offset mechanism and implement a differentiated and synergistic carbon emission reduction cooperation approach.The research program of this study can provide a reference for the development of inter-regional carbon offset programs.

Global air-sea surface carbon dioxide transfer velocity and flux estimated using 17 a altimeter data and a new algorithm

The global distributions of the air-sea CO2 transfer velocity and flux are retrieved from TOPEX/Poseidon and Jason altimeter data from October 1992 to December 2009 using a combined algorithm. The 17 a average global, area-weighted, Schmidt number-corrected mean gas transfer velocity is 21.26 cm/h, and the full exploration of the uncertainty of this estimate awaits further data. The average total CO2 flux （calculated by carbon） from atmosphere to ocean during the 17 a was 2.58 Pg/a. The highest transfer velocity is in the circumpolar current area, because of constant high wind speeds and currents there. This results in strong CO2 fluxes. CO2 fluxes are strong but opposite direction in the equatorial east Pacific Ocean, because the air-sea CO2 partial pressure difference is the largest in the global cceans. The results differ from the previous studies calculated using the wind speed. It is demonstrated that the air-sea transfer velocity is very important for estimating air-sea CO2 flux. It is critical to have an accurate estimation for improving calculation of CO2 flux within climate change studies.

Recovery of carbon monoxide from flue gases by reactive absorption in ionic liquid imidazolium chlorocuprate(I): Mass transfer coefficients

Recovery of carbon monoxide from flue gases by selective absorption of carbon monoxide in an imidazolium chlorocuprate（l） ionic liquid is considered in this work as an alternative to the use of molecular volatile solvents such as aromatic hydrocarbons. The present work evaluates the CO mass transfer rates from the gas phase to the ionic liquid solutions in the absence of chemical reaction. To that end, carbon dioxide was employed as an inert model gas and absorption experiments were performed to assess the influence of different process variables in a batch reactor with fiat gas-liquid interface. The experimental mass transfer coefficients showed significant var- iation with temperature, （3.4-10.9） × 10^-7 m·s^-1 between 293 and 313 K; stirring speed, （10.2- 33.1）× 10^-7 m.s 1 between 100 and 300 r·min^-1; and concentration of copper（1）, （6.6-10.2） × 10^-7 m·s^-1 between 0.25 and 2 mol· L^- 1. In addition, the mass transfer coefficients were eventually found to follow a poten- tial proportionality of the type kL ∝μ^-0.5 and the dimensionless correlation that makes the estimation of the mass transfer coefficients possible in the studied range of process variables was obtained： Sh=10^-2.64 Re^1.07 , Sc^0.75,These results constitute the first step in the kinetic analysis of the reaction between CO and imidazolium chlorocuprate（I） ionic liquid that determines the design of the separation units.

Carbon matrix effects on the micro-structure and performance of Pt nanowire cathode prepared by decal transfer method

High performance cathode for polymer electrolyte membrane fuel cell was prepared by depositing Pt nanowires in a carbon matrix coated on a substrate, and using decal transfer method to fabricate the membrane electrode assembly. The effects of carbon and ionomer contents on the electrode micro-structure and fuel cell performance are investigated by physical characterization and single cell testing. The Pt nanowires are gradient distributed across the cathode thickness, and more Pt exists near the membrane. Both the carbon and ionomer contents can affect the Pt nanowires distribution and aggregation. In addition, the carbon loading dominates the transport distance of gas and proton, and the ionomer content affects the triple phase boundaries and porosity in the cathode. The optimal structure of Pt nanowire cathode is obtained at 0.10 mg·cm^-2 carbon loading and 10 wt% ionomer.

Amelioration of carbon tetrachloride-induced cirrhosis and portal hypertension in rat using adenoviral gene transfer of Akt

AIM:To investigate whether a virus constitutively expressing active Akt is useful to prevent cirrhosis induced by carbon tetrachloride(CCl4).METHODS:Using cre-loxp technique,we created an Ad-myr-HA-Akt virus,in which Akt is labeled by a HA tag and its expression is driven by myr promoter.Further,through measuring enzyme levels and histological structure,we determined the efficacy of this Ad-myrHA-Akt virus in inhibiting the development of cirrhosis induced by CCl4in rats.Lastly,using western blotting,we examined the expression levels and/or phosphorylation status of Akt,apoptotic mediators,endothelial nitric oxide synthase(eNOS),and markers for hepatic stellate cells activation to understand the underlying mechanisms of protective role of this virus.RESULTS:The Ad-myr-HA-Akt virus was confirmed using polymerase chain reaction amplification of inserted Akt gene and sequencing for full length of inserted fragment,which was consistent with the sequence reported in the GenBank.The concentrations of Admyr-HA-Akt and adenoviral enhanced green fluorescent protein(Ad-EGFP)virus used in the current study were5.5×1011vp/mL.The portal vein diameter,peak velocity of blood flow,portal blood flow and congestion index were significantly increased in untreated,saline and Ad-EGFP cirrhosis groups when compared to normal control after the virus was introduced to animal through tail veil injection.In contrast,these parameters in the Akt cirrhosis group were comparable to normal control group.Compared to the normal control,the liver function(Alanine aminotransferase,Aspartate aminotransferase and Albumin)was significantly impaired in the untreated,saline and Ad-EGFP cirrhosis groups.The Akt cirrhosis group showed significant improvement of liver function when compared to the untreated,saline and Ad-EGFP cirrhosis groups.The Hyp level and portal vein pressure in Akt cirrhosis groups were also significantly lower than other cirrhosis groups.The results of HE and Van Gieson staining indicated that Akt group has better preservation of histological structure and less fibrosis than other cirrhosis groups.The percentage of apoptotic cell was greatly less in Akt cirrhosis group than in other cirrhosis groups.Akt group showed positive HA tag and an increased level of phosphorylated Akt as well as decreased levels of Fas.In contrast,Caspase-3 and Caspase-9 levels in Akt group were significantly lower than other cirrhosis groups.Noticeable decrease of DR5 andα-SMA and increase of phosphorylated eNOS were observed in the Akt group when compared to other cirrhosis groups.The NO level in liver was significantly higher in Akt group than other cirrhosis groups,which was consistent with the level of phosphorylated eNOS in these groups.CONCLUSION:This study suggest that Ad-myr-HA-Akt virus is a useful tool to prevent CCl4-induced cirrhosis in rat model and Akt pathway may be a therapeutic target for human cirrhosis.

Tracking Transfer of Carbon Dioxide Emissions to Countries along the Silk Roads Through Global Value Chains

The Belt and Road Initiative(BRI)has aroused rich discussions about the possible increase in carbon dioxide emission under the arduous global carbon dioxide emission reduction task.Adopting the methods of input-output technique and complex network ana-lysis,we first construct a fairer method to trace carbon dioxide emission transfer based on global value chains,then trace the source of carbon dioxide emission transfer to the Silk Roads countries with a long-term multiple regional input-output database.We find that,first,after the proposal of the BRI,the total direct carbon dioxide emissions of the Silk Roads countries and China’s proportion of carbon dioxide emission transfer to the other Silk Roads countries have both declined.Second,the Silk Roads countries are generally the net receivers of carbon dioxide emission transfer,and the inflow is mainly distributed in Southeast Asian countries and core countries in other sub-regions.Then,the transfer of carbon dioxide emission accepted by the Silk Roads countries comes mostly from large developing countries,such as China,Russia,and India,and developed countries,such as the United States,Japan,and Germany.The products are mainly concentrated in energy and chemical industries,as well as heavy industries,such as mining and quarrying,and metal products.We suggest that,due to the high degree of spatial and industrial concentrations of carbon dioxide emission transfer,it is necessary to make targeted policies for these countries and industries to reduce these transfers.

The Study of One Carbon Unit Transfer from Imidazolidine to dUMP Analogue with ONIOM Theory

ONIOM quantum mechanics method is used in this paper to study one-carbon unit transfer from imidazolidine to 6-aminouracil derivates. The computation results show that this reaction can be completed via three paths owing to the three different proton transfer modes. By calculation and analysis, we can find the direct proton transfer is the preferable pathway.

Global air-sea surface carbon-dioxide transfer velocity and flux estimated using ERS-2 data and a new parametric formula

Using data from the European remote sensing scatterometer （ERS-2） from July 1997 to August 1998, glob- al distributions of the air-sea CO2 transfer velocity and flux are retrieved. A new model of the air-sea CO2 transfer velocity with surface wind speed and wave steepness is proposed. The wave steepness （6） is re- trieved using a neural network （NN） model from ERS-2 scatterometer data, while the wind speed is directly derived by the ERS-2 scatterometer. The new model agrees well with the formulations based on the wind speed and the variation in the wind speed dependent relationships presented in many previous studies can be explained by this proposed relation with variation in wave steepness effect. Seasonally global maps of gas transfer velocity and flux are shown on the basis of the new model and the seasonal variations of the transfer velocity and flux during the 1 a period. The global mean gas transfer velocity is 30 cm/h after area-weighting and Schmidt number correction and its accuracy remains calculation with in situ data. The highest transfer velocity occurs around 60°N and 60°S, while the lowest on the equator. The total air to sea CO2 flux （calcu- lated by carbon） in that year is 1.77 Pg. The strongest source of CO2 is in the equatorial east Pacific Ocean, while the strongest sink is in the 68°N. Full exploration of the uncertainty of this estimate awaits further data. An effectual method is provided to calculate the effect of waves on the determination of air-sea CO2 transfer velociW and fluxes with ERS-2 scatterometer data.

The theoretical study of one-carbon unit transfer with H_2O participation from imidazolidine to dUMP analogue

The ONIOM quantum mechanics method is used to study the reaction of one-carbon unit transfer from an imidazolidine to 6- aminouracil model with the participation of water molecules.The computation results show that in this reaction the participation of H_2O molecule makes the energy barrier lower because of the H-bond interaction.

DFT Study on One-carbon Unit Transfer from 1,10-CH^+- tetrahydroquinoxaline to Methylamine

Density Functional Theory (DFT) method was used in this paper to study one-carbon transfer from 1,10-tetrahydroquinoxaline, an analogue of tetrahydrofolic acid, to methylamine. This reaction can be completed via two paths. From the computation result we can conclude that a general-acid catalysis exists in this reaction. By computation we find DFT has its limitation in describing a newly incorporated structure with a unit charge.

A quantitative evaluation of the factors influencing the air-sea carbon dioxide transfer velocity

The numerous factors influencing the air-sea carbon dioxide（CO_2） transfer velocity have been discussed for many years, yet the contributions of various factors have undergone little quantitative estimation. To better understand the mechanism of air-sea transfer, the effects of different factors are discussed on the air-sea transfer velocity and the various parametric models describing the phenomenon are classified and compared.Then, based on GAS EX-98 and ASGAMAGE data, wind models are evaluated and the effects of some factors are discussed quantitatively, including bubbles, waves, wind and so on by considering their interaction through a piecewise average approach. It is found that the air-sea CO_2 transfer velocity is not only the function of the wind speed, but is also affected by bubbles, wave parameters and other factors. Stepwise and linear regressions are used. When considering the wind speed, bubbles mediated and the significant wave height, the root mean square error is reduced from 34.53 cm/h to 16.96 cm/h. Discussing the various factors quantitatively can be useful in future assessments of a large spatial scale and long-term air-sea CO_2 flux and global change.

Mass transfer correlations for membrane gas-solvent contactors undergoing carbon dioxide desorption

Membrane gas-solvent contactors are a hybrid technology combining solvent absorption with membrane gas separation, which demonstrates potential for CO_2 capture through the ability of the membrane to rigidly control the mass transfer area. Membrane contactors have been successfully demonstrated for CO_2 absorption, and there is strong research interest in using membrane contactors for the complimentary CO_2 desorption process to regenerate the solvent. However, understanding and modelling the various stages of mass transfer in the desorption process is less well-known, given the existing mass transfer correlations had been developed from absorption experiments. Hence, mass transfer correlations for membrane contactors are reviewed here, and their appropriateness for desorption analysed. This is achieved through simulating CO_2 desorption through a membrane contactor from loaded 30 wt% monoethanolamine solvent to enable comparison of the correlations. It was found that the most cited correlations by Yang and Cussler were valid for shell side parallel flow, while that of Kreith and Black was viable for shell side cross flow. A limitation of all of these correlations is that they assume single phase flow on both sides of the membrane; however, the high temperature of CO_2 desorption can lead to partial solvent vaporisation and hence two phases present on one side of the membrane contactor during desorption. A mass transfer correlation is established here for two phase parallel flow on the shell side of a membrane contactor, based on experimental results for three composite and one asymmetric hollow fibre membrane contactors stripping CO_2 from loaded MEA at 105–108 °C. This correlation is comparable to that reported in the literature for mass transfer in other two phase systems, but differs from the standard format for membrane contactors in terms of the exponent on the dimensionless Schmidt and Reynolds numbers.

SOME FEATURES OF CARBON CYCLES IN KARST SYSTEM AND THE IMPLICATION FOR EPIKARSTIFICATION —An Example of Yaji Karst Experimental Site in Guilin,China

The carbon pools of biomass,littering,and SOC wre studied with regards to carbon cycles in epikarst zone,taking an example of Yaji Karst Experiemnt Site in Guilin.This study was focused on SOC and its lability,SOC decomposition rate,CO 2 regime in the soils. 13 ctracing was used to persua the relation of bicarbonate in karst water to soil carbon.The results indicated sufficient carbon pool in SOC for the driveing CO 2 in the karst system.It was revealed that about 60percent of carbon in epi-karst springs resulted from SOC during spring and summer.Thus,the CO 2,driving the karstification,was not simply due to adsorption of atmospheric CO 2 but due to carbon transfer through the pathway of air-plant-soil-water.The driving force should not be overlooked for the epi-karst formation by soil as an interface of carbon environmental geochemistry.

Carbon Fluxes and Sinks:the Consumption of Atmospheric and Soil CO_2 by Carbonate Rock Dissolution

Carbonate rock outcrops cover 9%-16% of the continental area and are the principal source of the dissolved inorganic carbon （DIC） transferred by rivers to the oceans, a consequence their dissolution. Current estimations suggest that the flux falls between 0.1-0.6 PgC/a. Taking the intermediate value （0.3 PgC/a）, it is equal to 18% of current estimates of the terrestrial vegetation net carbon sink and 38% of the soil carbon sink. In China, the carbon flux from carbonate rock dissolution is estimated to be 0.016 PgC/a, which accounts for 21%, 87.5%-150% and 2.3 times of the forest, shrub and grassland net carbon sinks respectively, as well as 23%-40% of the soil carbon sink flux. Carbonate dissolution is sensitive to environmental and climatic changes, the rate being closely correlated with precipitation, temperature, also with soil and vegetation cover. HCO3 in the water is affected by hydrophyte photosynthesis, resulting in part of the HCO~ being converted into DOC and POC, which may enhance the potential of carbon sequestration by carbonate rock dissolution. The possible turnover time of this carbon is roughly equal to that of the sea water cycle （2000a）. The uptake of atmospheric/soil CO2 by carbonate rock dissolution thus plays an important role in the global carbon cycle, being one of the most important sinks. A major research need is to better evaluate the net effect of this sink in comparison to an oceanic source from carbonate mineral precipitation.

A facile and efficient dry transfer technique for two-dimensional Van der Waals heterostructure

Two-dimensional （2D） Van der Waals heterostructures have aroused extensive concerns in recent years. Their fabrica- tion calls for facile and efficient transfer techniques for achieving well-defined structures. In this work, we report a simple and effective dry transfer method to fabricate 2D heterostructures with a clean interface. Using Propylene Carbonate （PC） films as stamps, we are able to pick up various 2D materials flakes from the substrates and unload them to the receiving substrates at an elevated temperature. Various multilayer heterostructures with ultra-clean interfaces were fabricated by this technique. Furthermore, the 2D materials can be pre-pattemed before transfer so as to fabricate desired device structures, demonstrating a facile way to promote the development of 2D heterostructures.

Direct Synthesis of Co-doped Graphene on Dielectric Substrates Using Solid Carbon Sources

Direct synthesis of high-quality doped graphene on dielectric substrates without transfer is highly desired for simplified device processing in electronic applications.However,graphene synthesis directly on substrates suitable for device applications,though highly demanded,remains unattainable and challenging.Here,a simple and transfer-free synthesis of high-quality doped graphene on the dielectric substrate has been developed using a thin Cu layer as the top catalyst and polycyclic aromatic hydrocarbons as both carbon precursors and doping sources.N-doped and N,F-co-doped graphene have been achieved using TPB and F16Cu Pc as solid carbon sources,respectively.The growth conditions were systematically optimized and the as-grown doped graphene were well characterized.The growth strategy provides a controllable transfer-free route for high-quality doped graphene synthesis,which will facilitate the practical applications of graphene.

Direct Patterning of Carbon Nanotube via Stamp Contact Printing Process for Stretchable and Sensitive Sensing Devices

Flexible and wearable sensing devices have broad application prospects in bio-monitoring such as pulse measurement,motion detection and voice recognition.In recent years,many significant improvements had been made to enhance the sensor’s performance including sensitivity,flexibility and repeatability.However,it is still extremely complicated and difficult to prepare a patterned sensor directly on a flexible substrate.Herein,inspired by typography,a lowcost,environmentally friendly stamping method for the mass production of transparent conductive carbon nanotube(CNT)film is proposed.In this dry transfer strategy,a porous CNT block was used as both the seal and the ink;and Ecoflex film was served as an object substrate.Welldesigned CNT patterns can be easily fabricated on the polymer substrate by engraving the target pattern on the CNT seal before the stamping process.Moreover,the CNT film can be directly used to fabricate ultrathin(300μm)strain sensor.This strain sensor possesses high sensitivity with a gauge factor(GF)up to 9960 at 85%strain,high stretchability(>200%)and repeatability(>5000 cycles).It has been used to measure pulse signals and detect joint motion,suggesting promising application prospects in flexible and wearable electronic devices.

A DFT Investigation on the Co-adsorption of H_2 and Ions inside the Carbon Nanotube

We studied the co-adsorption of hydrogen molecule and ions （Li, K, Mg, Ca） inside the single-walled carbon nanotubes （SWNTs） by using density-functional theory （DFT）. The band structures （BS）, density of states （DOS）, charge transfer and difference charge density are presented. We discussed the interaction between the ions （Li, K, Mg, Ca） and H2 Meanwhile, the binding energy indicates that ionization can increase the adsorption energy of H2 in CNT.