Implementing a new energy-saving electrochemical synthesis system with high commercial value is a strategy of the sustainable development for upgrading the bulk chemicals preparation technology in the future.Here,we r...Implementing a new energy-saving electrochemical synthesis system with high commercial value is a strategy of the sustainable development for upgrading the bulk chemicals preparation technology in the future.Here,we report a multiple redox-mediated linear paired electrolysis system,combining the hydrogen peroxide mediated cathode process with the I2 mediated anode process,and realize the conversion of furfural to furoic acid in both side of the dividedflow cell simultaneously.By reasonably controlling the cathode potential,the undesired water splitting reaction and furfural reduction side reactions are avoided.Under the galvanostatic electrolysis,the two-mediated electrode processes have good compatibility,which reduce the energy consumption by about 22%while improving the electronic efficiency by about 125%.This system provides a green electrochemical synthesis route with commercial prospects.展开更多
Design of a robust catalyst with high activity but the low cost for the hydrodeoxygenation(HDO) of biooils is of great importance to bring the biorefinery concept into reality.In this study,density functional theory(D...Design of a robust catalyst with high activity but the low cost for the hydrodeoxygenation(HDO) of biooils is of great importance to bring the biorefinery concept into reality.In this study,density functional theory(DFT) calculation was adopted to analyze the optimal location of Ni on MoO_(3-x) containing oxygen vacancy,and the corresponding result demonstrated that metallic Ni cluster located at the neighborhood of oxygen vacancies would significantly evoke HDO activity.Enlightened by DFT results,NiMoO_(4) was first hydrothermally synthesized and then employed to fabricate Ni-MoO_(3-x) catalyst via a low-temperature reduction,where Ni escaped from NiMoO_(4) and was reduced to its metallic state.Such an evolution of Ni species also induced the formation of oxygen vacancies around metallic Ni cluster.In the HDO of p-cresol,Ni-MoO_(3-x) exhibited high activity with a complete conversion and a methylcyclohexane selectivity of 99.4% at 150℃.Moreover,the catalyst showed good versatility in catalyzing HDO of diverse lignin-derived oxygenates and lignin oil.2D HSQC NMR,gas chromatograph and elemental analysis of the lignin oil demonstrated the high deoxygenation efficiency and saturation of the benzene ring over Ni-MoO_(3-x).In the upgrading of crude lignin oil,the deoxygenation degree was up to 99%,and the overall carbon yield of the naphthenes was as high as 69.4%.Importantly,the structures and carbon numbers of the naphthene products are similar to jet fuel-range cycloalka nes,which are expected to have a high density that can be blended into jet fuel to raise the range(or payload) of airplanes.This work demonstrates the feasibility for improving the targeted catalytic reactivity by rational tailoring the catalyst structure under the guidance of theoretical analysis,and provides an energy-efficient route for the upgrading of lignin crude oil into valuable naphthenes.展开更多
The available alkaline recovery membranes are currently dominated by polymeric materials,but they suffer from a permeation-selectivity trade-off and inferior chemical resistance.Robust two dimensional(2D) lamellar mem...The available alkaline recovery membranes are currently dominated by polymeric materials,but they suffer from a permeation-selectivity trade-off and inferior chemical resistance.Robust two dimensional(2D) lamellar membranes with sub-nanometer wide channels are promising candidates for discerning OH^(-)and other anions.Here,we report the development of alkaline recycling membranes through stacking MoS_(2) nanosheets.Benefiting from the ordered and narrow 2D channels,MoS_(2) membranes show excellent alkaline recovery performances.The OH^(-)dialysis coefficient (U_(OH)-) and separation factor (S)towards simulated OH^(-) and WO_(4)^(2-) across the 500 nm thick MoS_(2) laminates reach 6.9×10^(-3)m·h^(-1)and 34.3 respectively.Furthermore,the chemical environments of MoS_(2) laminates were modulated by intercalating ionic poly(sodium 4-styrene sulfonate)(PSS@MoS_(2)).The U_(OH)-and S values of PSS@MoS_(2) membrane further improve to 11.7×10^(-3)m·h^(-1)and 49.8 respectively.Besides,both MoS_(2) and PSS@MoS_(2) membranes exhibit promising stability.展开更多
Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures...Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures, the energy of carriers in the well splits into discrete energy levels due to the confinement of barriers in the growth direction. However, the discrete energy levels obtained at a fixed wave vector cannot accurately reflect the actual energy band structure. In this work, the band structure of the type-II quantum wells is reanalyzed. When the wave vectors of the entire Brillouin region(corresponding to the growth direction) are taken into account, the quantized energy levels of the carriers in the well are replaced by subbands with certain energy distributions. This new understanding of the energy bands of low-dimensional structures not only helps us to have a deeper cognition of the structure, but also may overturn many viewpoints in traditional band theories and serve as supplementary to the band theory of low-dimensional systems.展开更多
Agronomically optimizing the timing and rates of nitrogen(N) fertilizer application can increase crop yield and decrease N loss to the environment. Wheat(Triticum aestivum L.)–peanut(Arachis hypogaea L.) relay interc...Agronomically optimizing the timing and rates of nitrogen(N) fertilizer application can increase crop yield and decrease N loss to the environment. Wheat(Triticum aestivum L.)–peanut(Arachis hypogaea L.) relay intercropping systems are a mainstay of economic and food security in China. We performed a field experiment to investigate the effects of N fertilizer on N recovery efficiency, crop yield, and N loss rate in wheat–peanut relay intercropping systems in the Huang-Huai-Hai Plain, China during 2015–2017. The N was applied on the day before sowing, the jointing stage(G30) or the booting stage(G40) of winter wheat, and the anthesis stage(R1) of peanut in the following percentage splits: 50-50-0-0(N1), 35-35-0-30(N2), and 35-0-35-30(N3), using 300 kg N ha-1, with 0 kg N ha-1(N0) as control. ^(15)N-labeled(20.14 atom %) urea was used to trace the fate of N in microplots. The yields of wheat and peanut increased by 12.4% and 15.4% under the N2 and N3 treatments, relative to those under the N1 treatment. The ^(15)N recovery efficiencies( ^(15)NRE) were 64.9% and 58.1% for treatments N2 and N3, significantly greater than that for the N1 treatment(45.3%). The potential N loss rates for the treatments N2 and N3 were23.7% and 7.0%, significantly lower than that for treatment N1(30.1%). Withholding N supply until the booting stage(N3) did not reduce the wheat grain yield; however, it increased the N content derived from ^(15)N-labeled urea in peanuts, promoted the distribution of ^(15)N to pods, and ultimately increased pod yields in comparison with those obtained by topdressing N at jointing stage(N2). In comparison with N2, the N uptake and N recovery efficiency(NRE) of N3 was increased by 12.0% and 24.1%,respectively, while the apparent N loss decreased by 16.7%. In conclusion, applying N fertilizer with three splits and delaying topdressing fertilization until G40 of winter wheat increased total grain yields and NRE and reduced N loss. This practice could be an environment-friendly N management strategy for wheat–peanut relay intercropping systems in China.展开更多
A computer-aided ionic liquid design(CAILD) study is presented for the frequently encountered alkane/cycloalkane separations in petrochemical industry. Exhaustive experimental data are first collected to extend the UN...A computer-aided ionic liquid design(CAILD) study is presented for the frequently encountered alkane/cycloalkane separations in petrochemical industry. Exhaustive experimental data are first collected to extend the UNIFAC-IL model for this system, where the proximity effect in alkanes and cycloalkanes is considered specifically by defining distinct groups. The thermodynamic performances of a large number of ILs for 4 different alkane/cycloalkane systems are then compared to select a representative example of such separations. By applying n-heptane/methylcyclohexane extractive distillation as a case study, the CAILD task is cast as a mixed-integer nonlinear programming(MINLP) problem based on the obtained task-specific UNIFAC-IL model and two semi-empirical models for IL physical properties. The top 5 IL candidates determined by solving the MINLP problem are subsequently introduced into Aspen Plus for process simulation and economic analysis, which finally identify 1-hexadecyl-methylpiperidinium tricyanomethane([C_(16)MPip][C(CN)_3]) as the best entrainer for this separation.展开更多
Micro/nanostructured SiOx/C composite was firstly synthesized by carbothermal reduction of silica-carbon binary xerogel.The homogeneous dispersion feature of the two components in binary xerogel contributes to effecti...Micro/nanostructured SiOx/C composite was firstly synthesized by carbothermal reduction of silica-carbon binary xerogel.The homogeneous dispersion feature of the two components in binary xerogel contributes to effectively carbothermally reduce the O/Si atomic ratio,enhancing the electrochemical activity of the SiOx component.The micron-sized SiOx/C spheres are composed of many near-spherical nanoparticles.The synthesized SiOx/C exhibits a stable and high reversible capacity of 830 m A·h·g^-1 for 100 cycles,and excellent rate-capability.The homogeneous dispersion structure of phases,the micro/nanostructure and the high electrochemical activity of SiOx component combinedly contribute the excellent electrochemical performance.展开更多
This work was focused on the measurement of the solubility of hydrogen(H_2) in anthraquinone working solution at temperatures of 30.0–80.0 °C and pressures of 0.2–3.0 MPa by the method of experimental and COSMO...This work was focused on the measurement of the solubility of hydrogen(H_2) in anthraquinone working solution at temperatures of 30.0–80.0 °C and pressures of 0.2–3.0 MPa by the method of experimental and COSMO-RS model study. The influence of various factors, i.e., including pressure, temperature and solvent volume ratio, on H_2 solubility was investigated. According to the experimental results, H_2 solubility in anthraquinone working solution increases with the increase of pressure. At low pressures, the temperature had little effect on H_2 solubility while under high pressures H_2 solubility increases with increasing temperature. Henry's constant lnH has a good linear relationship with 1/T(lnH =- 1319.1/T + 9.91). The effect of volume ratio of trioctyl phosphate to trimethylbenzene on the solubility of hydrogen was studied and the results showed that increasing the amount of trimethylbenzene was conducive to the dissolution of hydrogen. In addition, there is a linear relationship between ln((P0- Pe) /(Pt- Pe)) and the time t. Gas–liquid mass transfer coefficient was obtained by calculating the slope of the line.展开更多
BACKGROUND: Scorpion venom from Buthus martensii Karsch is a kind of protein toxin secreted by scorpion tail. According to records of Pen-ts 'ao Kan-mu, the dried scorpion's body and tail are used as medicine, whic...BACKGROUND: Scorpion venom from Buthus martensii Karsch is a kind of protein toxin secreted by scorpion tail. According to records of Pen-ts 'ao Kan-mu, the dried scorpion's body and tail are used as medicine, which mainly treating rheumatism numbness, pain and convulsion. Some researches consider that scorpion toxin is the main pharmacological active component of the dried scorpion, and it has 4 times stronger analgesic effect on somatic pain than morphine. OBJECTIVE: To observe the interventional effect of scorpion venom of Buthus martensii Karsch analgesic active peptide on somatic pain. DESIGN: A randomized and controlled trial SETTING: Department of Physiology, Shenyang Medical College MATERIALS: Totally 80 Wistar rats (provided by Animal Center of Shenyang Medical College), male and female in half, aged 3 to 4 months, weighed 250 to 350 g, were used in this trial. They were randomly divided into 4 groups: experimental group, control group, morphine group and naloxone group, with 20 in each group. Analgesia active peptide from buthus martensii karsch venom (provided by Biochemical Department of Shenyang Pharmaceutical University, 1 mL/dosage), morphine (produced by Shanghai First Pharmaceutical Manufacturing Plant), naloxone (opium acceptor inhibitor, American Sigma Corporation), AT- AC-350 data-processing machine (Nihon Kohden Corporation), X-Y recording instrument (Nihon Kohden Corporation). METHODS: The experiment was conducted in the Department of Physiology, Shenyang Medical College from July 2003 to July 2005. ① After all the animals were anesthetized, common peroneal nerve is dissected and ligated at middle part. Posterior nucleus group of thalamus (PO) and the tail nuclear were oriented according to G. Paxino rat brain three-dimensional orientation atlas, Glass micro electrode was inserted into PO as guiding electrode, connected with ATAC-350 data-processing machine and X-Y recording instrument, to record the unit evoked potential of PO, taking the evoked potential discharge of the common peroneal nerve of PO as the somatic pain index.② Single square-wave stimulation of intensity 17-19 volt, wave wide 0.2 ms, time delay 20 ms was exerted on common peroneal nerve. The time interval was 5 minutes. X-Y recording instrument was used to draw the graph. 0,002 mg scorpion venom analgesic active peptide was injected into the rats of the experimental group; 0.002 mg normal saline was injected into the rats of the control group through caudate nucleus; 0.002 mg morphine was injected into the rats of morphine group through caudate nucleus; 1.0 mg/kg naloxone was intraperitoneally into the rats of naloxone group, then 0.002 mg scorpion venom was injected into the rats of control group through caudate nucleus.Changes of evoked potential of PO of 3 groups were observed. ③After experiment, 1 μA direct current was given to the guiding electrode and micro electrode , and it lasted for 5 minutes. Pontamine sky blue was used to label the peak of electrode by electrophoresis. Brain tissue was soaked in formalin for 1 week then sliced into 1.0 to 1.5 mm sections. Electrode was orientated according to blue spots. Compared with G . Parino rat brain three-dimensional orientation atlas, we confirmed if the electrode orientation is consistent with PO orientation of G. Parino rat brain three-dimensional orientation atlas. MAIN OUTCOME MEASURES : Changes of the evoked potential of PO in each group RESULTS: Totally 80 Wistar rats were enrolled in this experiment. Four rats in the experimental group and two in the morphine group died of overdose of anesthesia, and finally 74 rats entered the stage of result analysis. The inhibitory action time of evoked potential of PO has no statistical difference in between experiment group and morphine group (P 〉 0.05). The whole inhibitory action time, timeof initiate recovery and time of complete recovery of PO of experiment group were longer than those in the morphine group [(45±0.7), (50±9.2), (65±8.1):(35±7.8). (40±8.9). (50±7.6) min .P 〈 0.05].The change of evoked potential of PO was not obviously in the control group and naloxone group (P 〉 0.05), and the above-mentioned 4 indexes were nearly 0. CONCLUSION: Scorpion venom possesses obviously inhibitory effect on somatic pain, and its inhibitory effect is stronger than that of the same dosage and concentration of morphine. Scorpion venom exerts analgesic effect on somatic pain through opium acceptor.展开更多
Absorption coefficient is a physical parameter to describe electromagnetic energy absorption of materials, which is closely related to solar cells and photodetectors. We grow a series of positive-intrinsic-negative(PI...Absorption coefficient is a physical parameter to describe electromagnetic energy absorption of materials, which is closely related to solar cells and photodetectors. We grow a series of positive-intrinsic-negative(PIN) structures on silicon wafer by a gas source molecule beam epitaxy system and the investigate the absorption coefficient through the photovoltaic processes in detail. It is found that the absorption coefficient is enhanced by one order and can be tuned greatly through the thickness of the intrinsic layer in the PIN structure, which is also demonstrated by the 730-nm-wavelength laser irradiation. These results cannot be explained by the traditional absorption theory.We speculate that there could be some uncovered mechanism in this system, which will inspire us to understand the absorption process further.展开更多
The performance of lignin depolymerization is basically determined by the interunit C–O and C–C bonds.Numerous C–O bond cleavage strategies have been developed, while the cleavage of C–C bond between the primary a...The performance of lignin depolymerization is basically determined by the interunit C–O and C–C bonds.Numerous C–O bond cleavage strategies have been developed, while the cleavage of C–C bond between the primary aromatic units remains a challenging task due to the high dissociation energy of C–C bond.Herein, a multifunctional Ru Re alloy catalyst was designed, which exhibited exceptional catalytic activity for the cleavage of both C–O and C–C linkages in a broad range of lignin model compounds(β-1, a-5, 5–5,β-O-4, 4-O-5) and two stubborn lignins(kraft lignin and alkaline lignin), affording 97.5% overall yield of monocyclic compounds from model compounds and up to 129% of the maximum theoretical yield of monocyclic products based on C–O bonds cleavage from realistic lignin. Scanning transmission electron microscopy(STEM) characterization showed that Ru Re(1:1) alloy particles with hexagonal close-packed structure were homogeneously dispersed on the support. Quasi-in situ X-ray photoelectron spectroscopy(XPS), and X-ray absorption spectroscopy(XAS) indicate that Ru species were predominantly metallic state, whereas Re species were partially oxidized;meanwhile, there was a strong interaction between Ru and Re, where the electron transfer from Re to Ru was occurred, resulting in great improvement on the capability of C–O and C–C bonds cleavage in lignin conversion.展开更多
Dangerous gases widely exist in modern production and people’s daily life.Once they are used or maintained improperly,they are very easy to leak,leading to major accidents seriously endangering people’s health and a...Dangerous gases widely exist in modern production and people’s daily life.Once they are used or maintained improperly,they are very easy to leak,leading to major accidents seriously endangering people’s health and asset safety,such as fire,explosion,burns,poisoning,asphyxia,etc.In this paper,the data collected from CNKI was taken as the research object,and the relevant research in the field of leakage and diffusion of hazardous gases was analyzed through visual analysis by using the VOSviewer software,so as to provide reference for subsequent scholars.展开更多
In this paper, we conduct research on the memory ethics and thought transformation pattern and the applications on contemporary literature. Compared to scientifi c thinking, historical thinking, the thinking process c...In this paper, we conduct research on the memory ethics and thought transformation pattern and the applications on contemporary literature. Compared to scientifi c thinking, historical thinking, the thinking process characterized by direct image of literary creation of system integration, literary creation process is a fi ction. Literary psychology studies have shown that the transmission of literature as a kind of aesthetic experience, is far from perfect memories of feature, but memory, association, imagination, illusion, such as the result of the comprehensive sports psychological function, is in the creation subject specifi c emotions and as under the guidance of the appearance of the restructuring, merger. From the discussion above we can see that whether it is a literary language of authenticity, or false judgment characteristics of literary language, explain the fact that in literary text is not has direct realistic context, but a self-reference words, and it is a virtual space of the empirical. In this paper, we discuss the related theory with modifi cation that is innovative.展开更多
The in-situ growing approach was utilized in this article to construct the magnesium–aluminum layered double hydroxide(MgAl-LDH)film on the surface of a 1060 aluminum anodized film.To improve the corrosion resistance...The in-situ growing approach was utilized in this article to construct the magnesium–aluminum layered double hydroxide(MgAl-LDH)film on the surface of a 1060 aluminum anodized film.To improve the corrosion resistance and friction qualities of aluminum alloy,the MgAl-LDH coating was treated using stearic acid(SA)and thiourea(TU).The aluminum substrate and anodized aluminum film layer corroded to varying degrees after 24 h of immersion in 3.5%(mass)NaCl solution,while the modified hydrotalcite film layer continued to exhibit the same microscopic morphology even after being immersed for 7 d.The results show that the synergistic action of thiourea and stearic acid can effectively improve the corrosion resistance of the MgAl-LDH substrate.The tribological testing reveals that the hydrotalcite film layer and the modified film layer lowered the friction coefficient of the anodized aluminum surface substantially.The results of the simulations and experiments demonstrate that SA forms the dense LDH-TU interlayer film layer by exchanging NO_(3)^(-)ions between TU layers on the one hand and the LDH-SA film layer by adsorption on the surface of LDH on the other.Together,these two processes create LDH-TUSA,which can significantly increase the substrate’s corrosion resistance.This synergistically modified superhydrophobic and retardant hydrotalcite film layer offers a novel approach to the investigation of wear reduction and corrosion protection on the surface of aluminum and its alloys.展开更多
Acid soils occupy approximately 50% of potentially arable lands.Improving crop productivity in acid soils,therefore,will be crucial for ensuring food security and agricultural sustainability.High soil acidity often co...Acid soils occupy approximately 50% of potentially arable lands.Improving crop productivity in acid soils,therefore,will be crucial for ensuring food security and agricultural sustainability.High soil acidity often coexists with phosphorus(P) deficiency and aluminum(Al) toxicity,a combination that severely impedes crop growth and yield across wide areas.As roots explore soil for the nutrients and water required for plant growth and development,they also sense and respond to below-ground stresses.Within the terrestrial context of widespread P deficiency and Al toxicity pressures,plants,particularly roots,have evolved a variety of mechanisms for adapting to these stresses.As legumes,soybean(Glycine max) plants may acquire nitrogen(N) through symbiotic nitrogen fixation(SNF),an adaptation that can be useful for mitigating excessive N fertilizer use,either directly as leguminous crop participants in rotation and intercropping systems,or secondarily as green manure cover crops.In this review,we investigate legumes,especially soybean,for recent advances in our understanding of root-based mechanisms linked with root architecture modification,exudation and symbiosis,together with associated genetic and molecular strategies in adaptation to individual and/or interacting P and Al conditions in acid soils.We propose that breeding legume cultivars with superior nutrient efficiency and/or Al tolerance traits through genetic selection might become a potentially powerful strategy for producing crop varieties capable of maintaining or improving yields in more stressful soil conditions subjected to increasingly challenging environmental conditions.展开更多
Poly(ionic liquids)(PILs)combined with the macromolecular structure and unique properties of ionic liquids show unlimited potential in catalysis.In this work,a series of metal-based PIL with different ionic ratios wer...Poly(ionic liquids)(PILs)combined with the macromolecular structure and unique properties of ionic liquids show unlimited potential in catalysis.In this work,a series of metal-based PIL with different ionic ratios were prepared for the selective oxidation of cyclohexane.Characterization analysis reveals that different degrees of ionization could adjust the Co-N sites of the catalysts efficiently,leading to significant changes in their electronic structure,which strongly relate to catalytic performance in oxidation.20.07%cyclohexane conversion and 13.06%cyclohexanone and cyclohexanol(KA oil)yield can be achieved by metal-based PILs that are better than other commercial catalysts.Compared with CoCl_(2),metal-based PILs perform well,with superior conversion and KA oil yield.More interestingly,the catalyst created in this study features a malleable Co-N site,which may potentially have an impact on how oxygen species adsorb and desorb from the catalyst.Therefore,the catalyst studied in this work is used as molecular oxygen for the selective oxidation of cyclohexane to produce KA oil,and its application prospect is promising.展开更多
基金This study is supported by the National Key Research and Development Program of China(2017YFB0307500).
文摘Implementing a new energy-saving electrochemical synthesis system with high commercial value is a strategy of the sustainable development for upgrading the bulk chemicals preparation technology in the future.Here,we report a multiple redox-mediated linear paired electrolysis system,combining the hydrogen peroxide mediated cathode process with the I2 mediated anode process,and realize the conversion of furfural to furoic acid in both side of the dividedflow cell simultaneously.By reasonably controlling the cathode potential,the undesired water splitting reaction and furfural reduction side reactions are avoided.Under the galvanostatic electrolysis,the two-mediated electrode processes have good compatibility,which reduce the energy consumption by about 22%while improving the electronic efficiency by about 125%.This system provides a green electrochemical synthesis route with commercial prospects.
基金supported by the National Key R&D Program of China (2022YFB3805401, 2019YFC1905300)the National Natural Science Foundation of China (22178297)+1 种基金the Hunan Provincial Natural Science Foundation (2022JJ40425, 2022JJ40432)the Process Intensification and Green Chemical Engineering Innovation Team of Hunan Province。
文摘Design of a robust catalyst with high activity but the low cost for the hydrodeoxygenation(HDO) of biooils is of great importance to bring the biorefinery concept into reality.In this study,density functional theory(DFT) calculation was adopted to analyze the optimal location of Ni on MoO_(3-x) containing oxygen vacancy,and the corresponding result demonstrated that metallic Ni cluster located at the neighborhood of oxygen vacancies would significantly evoke HDO activity.Enlightened by DFT results,NiMoO_(4) was first hydrothermally synthesized and then employed to fabricate Ni-MoO_(3-x) catalyst via a low-temperature reduction,where Ni escaped from NiMoO_(4) and was reduced to its metallic state.Such an evolution of Ni species also induced the formation of oxygen vacancies around metallic Ni cluster.In the HDO of p-cresol,Ni-MoO_(3-x) exhibited high activity with a complete conversion and a methylcyclohexane selectivity of 99.4% at 150℃.Moreover,the catalyst showed good versatility in catalyzing HDO of diverse lignin-derived oxygenates and lignin oil.2D HSQC NMR,gas chromatograph and elemental analysis of the lignin oil demonstrated the high deoxygenation efficiency and saturation of the benzene ring over Ni-MoO_(3-x).In the upgrading of crude lignin oil,the deoxygenation degree was up to 99%,and the overall carbon yield of the naphthenes was as high as 69.4%.Importantly,the structures and carbon numbers of the naphthene products are similar to jet fuel-range cycloalka nes,which are expected to have a high density that can be blended into jet fuel to raise the range(or payload) of airplanes.This work demonstrates the feasibility for improving the targeted catalytic reactivity by rational tailoring the catalyst structure under the guidance of theoretical analysis,and provides an energy-efficient route for the upgrading of lignin crude oil into valuable naphthenes.
基金partially supported by the National Key Research and Development Program of China (2022YFB3805102)the National Natural Science Foundation of China (22278105, 21978062)。
文摘The available alkaline recovery membranes are currently dominated by polymeric materials,but they suffer from a permeation-selectivity trade-off and inferior chemical resistance.Robust two dimensional(2D) lamellar membranes with sub-nanometer wide channels are promising candidates for discerning OH^(-)and other anions.Here,we report the development of alkaline recycling membranes through stacking MoS_(2) nanosheets.Benefiting from the ordered and narrow 2D channels,MoS_(2) membranes show excellent alkaline recovery performances.The OH^(-)dialysis coefficient (U_(OH)-) and separation factor (S)towards simulated OH^(-) and WO_(4)^(2-) across the 500 nm thick MoS_(2) laminates reach 6.9×10^(-3)m·h^(-1)and 34.3 respectively.Furthermore,the chemical environments of MoS_(2) laminates were modulated by intercalating ionic poly(sodium 4-styrene sulfonate)(PSS@MoS_(2)).The U_(OH)-and S values of PSS@MoS_(2) membrane further improve to 11.7×10^(-3)m·h^(-1)and 49.8 respectively.Besides,both MoS_(2) and PSS@MoS_(2) membranes exhibit promising stability.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61991441 and 62004218)the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB01000000)Youth Innovation Promotion Association Chinese Academy of Sciences (Grant No. 2021005)。
文摘Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures, the energy of carriers in the well splits into discrete energy levels due to the confinement of barriers in the growth direction. However, the discrete energy levels obtained at a fixed wave vector cannot accurately reflect the actual energy band structure. In this work, the band structure of the type-II quantum wells is reanalyzed. When the wave vectors of the entire Brillouin region(corresponding to the growth direction) are taken into account, the quantized energy levels of the carriers in the well are replaced by subbands with certain energy distributions. This new understanding of the energy bands of low-dimensional structures not only helps us to have a deeper cognition of the structure, but also may overturn many viewpoints in traditional band theories and serve as supplementary to the band theory of low-dimensional systems.
基金supported by the National Key Technology R&D Program of China (2014BAD11B04-2)the National Natural Science Foundation of China (30840056, 31171496)Shandong Modern Agricultural Technology and Industry System (SDAIT-04-01)
文摘Agronomically optimizing the timing and rates of nitrogen(N) fertilizer application can increase crop yield and decrease N loss to the environment. Wheat(Triticum aestivum L.)–peanut(Arachis hypogaea L.) relay intercropping systems are a mainstay of economic and food security in China. We performed a field experiment to investigate the effects of N fertilizer on N recovery efficiency, crop yield, and N loss rate in wheat–peanut relay intercropping systems in the Huang-Huai-Hai Plain, China during 2015–2017. The N was applied on the day before sowing, the jointing stage(G30) or the booting stage(G40) of winter wheat, and the anthesis stage(R1) of peanut in the following percentage splits: 50-50-0-0(N1), 35-35-0-30(N2), and 35-0-35-30(N3), using 300 kg N ha-1, with 0 kg N ha-1(N0) as control. ^(15)N-labeled(20.14 atom %) urea was used to trace the fate of N in microplots. The yields of wheat and peanut increased by 12.4% and 15.4% under the N2 and N3 treatments, relative to those under the N1 treatment. The ^(15)N recovery efficiencies( ^(15)NRE) were 64.9% and 58.1% for treatments N2 and N3, significantly greater than that for the N1 treatment(45.3%). The potential N loss rates for the treatments N2 and N3 were23.7% and 7.0%, significantly lower than that for treatment N1(30.1%). Withholding N supply until the booting stage(N3) did not reduce the wheat grain yield; however, it increased the N content derived from ^(15)N-labeled urea in peanuts, promoted the distribution of ^(15)N to pods, and ultimately increased pod yields in comparison with those obtained by topdressing N at jointing stage(N2). In comparison with N2, the N uptake and N recovery efficiency(NRE) of N3 was increased by 12.0% and 24.1%,respectively, while the apparent N loss decreased by 16.7%. In conclusion, applying N fertilizer with three splits and delaying topdressing fertilization until G40 of winter wheat increased total grain yields and NRE and reduced N loss. This practice could be an environment-friendly N management strategy for wheat–peanut relay intercropping systems in China.
基金financial support from National Natural Science Foundation of China(21776074,21576081,and21861132019)
文摘A computer-aided ionic liquid design(CAILD) study is presented for the frequently encountered alkane/cycloalkane separations in petrochemical industry. Exhaustive experimental data are first collected to extend the UNIFAC-IL model for this system, where the proximity effect in alkanes and cycloalkanes is considered specifically by defining distinct groups. The thermodynamic performances of a large number of ILs for 4 different alkane/cycloalkane systems are then compared to select a representative example of such separations. By applying n-heptane/methylcyclohexane extractive distillation as a case study, the CAILD task is cast as a mixed-integer nonlinear programming(MINLP) problem based on the obtained task-specific UNIFAC-IL model and two semi-empirical models for IL physical properties. The top 5 IL candidates determined by solving the MINLP problem are subsequently introduced into Aspen Plus for process simulation and economic analysis, which finally identify 1-hexadecyl-methylpiperidinium tricyanomethane([C_(16)MPip][C(CN)_3]) as the best entrainer for this separation.
基金supported by the National Natural Science Foundation of China(51602313 and 51764008)Science and Technology Project of Guizhou Province(Qiankehe No.2016,7439).
文摘Micro/nanostructured SiOx/C composite was firstly synthesized by carbothermal reduction of silica-carbon binary xerogel.The homogeneous dispersion feature of the two components in binary xerogel contributes to effectively carbothermally reduce the O/Si atomic ratio,enhancing the electrochemical activity of the SiOx component.The micron-sized SiOx/C spheres are composed of many near-spherical nanoparticles.The synthesized SiOx/C exhibits a stable and high reversible capacity of 830 m A·h·g^-1 for 100 cycles,and excellent rate-capability.The homogeneous dispersion structure of phases,the micro/nanostructure and the high electrochemical activity of SiOx component combinedly contribute the excellent electrochemical performance.
基金Supported by the National Natural Science Foundation of China(Nos.21476009,21406007,and U1462104)
文摘This work was focused on the measurement of the solubility of hydrogen(H_2) in anthraquinone working solution at temperatures of 30.0–80.0 °C and pressures of 0.2–3.0 MPa by the method of experimental and COSMO-RS model study. The influence of various factors, i.e., including pressure, temperature and solvent volume ratio, on H_2 solubility was investigated. According to the experimental results, H_2 solubility in anthraquinone working solution increases with the increase of pressure. At low pressures, the temperature had little effect on H_2 solubility while under high pressures H_2 solubility increases with increasing temperature. Henry's constant lnH has a good linear relationship with 1/T(lnH =- 1319.1/T + 9.91). The effect of volume ratio of trioctyl phosphate to trimethylbenzene on the solubility of hydrogen was studied and the results showed that increasing the amount of trimethylbenzene was conducive to the dissolution of hydrogen. In addition, there is a linear relationship between ln((P0- Pe) /(Pt- Pe)) and the time t. Gas–liquid mass transfer coefficient was obtained by calculating the slope of the line.
文摘BACKGROUND: Scorpion venom from Buthus martensii Karsch is a kind of protein toxin secreted by scorpion tail. According to records of Pen-ts 'ao Kan-mu, the dried scorpion's body and tail are used as medicine, which mainly treating rheumatism numbness, pain and convulsion. Some researches consider that scorpion toxin is the main pharmacological active component of the dried scorpion, and it has 4 times stronger analgesic effect on somatic pain than morphine. OBJECTIVE: To observe the interventional effect of scorpion venom of Buthus martensii Karsch analgesic active peptide on somatic pain. DESIGN: A randomized and controlled trial SETTING: Department of Physiology, Shenyang Medical College MATERIALS: Totally 80 Wistar rats (provided by Animal Center of Shenyang Medical College), male and female in half, aged 3 to 4 months, weighed 250 to 350 g, were used in this trial. They were randomly divided into 4 groups: experimental group, control group, morphine group and naloxone group, with 20 in each group. Analgesia active peptide from buthus martensii karsch venom (provided by Biochemical Department of Shenyang Pharmaceutical University, 1 mL/dosage), morphine (produced by Shanghai First Pharmaceutical Manufacturing Plant), naloxone (opium acceptor inhibitor, American Sigma Corporation), AT- AC-350 data-processing machine (Nihon Kohden Corporation), X-Y recording instrument (Nihon Kohden Corporation). METHODS: The experiment was conducted in the Department of Physiology, Shenyang Medical College from July 2003 to July 2005. ① After all the animals were anesthetized, common peroneal nerve is dissected and ligated at middle part. Posterior nucleus group of thalamus (PO) and the tail nuclear were oriented according to G. Paxino rat brain three-dimensional orientation atlas, Glass micro electrode was inserted into PO as guiding electrode, connected with ATAC-350 data-processing machine and X-Y recording instrument, to record the unit evoked potential of PO, taking the evoked potential discharge of the common peroneal nerve of PO as the somatic pain index.② Single square-wave stimulation of intensity 17-19 volt, wave wide 0.2 ms, time delay 20 ms was exerted on common peroneal nerve. The time interval was 5 minutes. X-Y recording instrument was used to draw the graph. 0,002 mg scorpion venom analgesic active peptide was injected into the rats of the experimental group; 0.002 mg normal saline was injected into the rats of the control group through caudate nucleus; 0.002 mg morphine was injected into the rats of morphine group through caudate nucleus; 1.0 mg/kg naloxone was intraperitoneally into the rats of naloxone group, then 0.002 mg scorpion venom was injected into the rats of control group through caudate nucleus.Changes of evoked potential of PO of 3 groups were observed. ③After experiment, 1 μA direct current was given to the guiding electrode and micro electrode , and it lasted for 5 minutes. Pontamine sky blue was used to label the peak of electrode by electrophoresis. Brain tissue was soaked in formalin for 1 week then sliced into 1.0 to 1.5 mm sections. Electrode was orientated according to blue spots. Compared with G . Parino rat brain three-dimensional orientation atlas, we confirmed if the electrode orientation is consistent with PO orientation of G. Parino rat brain three-dimensional orientation atlas. MAIN OUTCOME MEASURES : Changes of the evoked potential of PO in each group RESULTS: Totally 80 Wistar rats were enrolled in this experiment. Four rats in the experimental group and two in the morphine group died of overdose of anesthesia, and finally 74 rats entered the stage of result analysis. The inhibitory action time of evoked potential of PO has no statistical difference in between experiment group and morphine group (P 〉 0.05). The whole inhibitory action time, timeof initiate recovery and time of complete recovery of PO of experiment group were longer than those in the morphine group [(45±0.7), (50±9.2), (65±8.1):(35±7.8). (40±8.9). (50±7.6) min .P 〈 0.05].The change of evoked potential of PO was not obviously in the control group and naloxone group (P 〉 0.05), and the above-mentioned 4 indexes were nearly 0. CONCLUSION: Scorpion venom possesses obviously inhibitory effect on somatic pain, and its inhibitory effect is stronger than that of the same dosage and concentration of morphine. Scorpion venom exerts analgesic effect on somatic pain through opium acceptor.
基金Supported by the National Natural Science Foundation of China under Grant No 11574362
文摘Absorption coefficient is a physical parameter to describe electromagnetic energy absorption of materials, which is closely related to solar cells and photodetectors. We grow a series of positive-intrinsic-negative(PIN) structures on silicon wafer by a gas source molecule beam epitaxy system and the investigate the absorption coefficient through the photovoltaic processes in detail. It is found that the absorption coefficient is enhanced by one order and can be tuned greatly through the thickness of the intrinsic layer in the PIN structure, which is also demonstrated by the 730-nm-wavelength laser irradiation. These results cannot be explained by the traditional absorption theory.We speculate that there could be some uncovered mechanism in this system, which will inspire us to understand the absorption process further.
基金The National Natural Science Foundation of China(22078317,21878288,21721004,21690083)。
文摘The performance of lignin depolymerization is basically determined by the interunit C–O and C–C bonds.Numerous C–O bond cleavage strategies have been developed, while the cleavage of C–C bond between the primary aromatic units remains a challenging task due to the high dissociation energy of C–C bond.Herein, a multifunctional Ru Re alloy catalyst was designed, which exhibited exceptional catalytic activity for the cleavage of both C–O and C–C linkages in a broad range of lignin model compounds(β-1, a-5, 5–5,β-O-4, 4-O-5) and two stubborn lignins(kraft lignin and alkaline lignin), affording 97.5% overall yield of monocyclic compounds from model compounds and up to 129% of the maximum theoretical yield of monocyclic products based on C–O bonds cleavage from realistic lignin. Scanning transmission electron microscopy(STEM) characterization showed that Ru Re(1:1) alloy particles with hexagonal close-packed structure were homogeneously dispersed on the support. Quasi-in situ X-ray photoelectron spectroscopy(XPS), and X-ray absorption spectroscopy(XAS) indicate that Ru species were predominantly metallic state, whereas Re species were partially oxidized;meanwhile, there was a strong interaction between Ru and Re, where the electron transfer from Re to Ru was occurred, resulting in great improvement on the capability of C–O and C–C bonds cleavage in lignin conversion.
文摘Dangerous gases widely exist in modern production and people’s daily life.Once they are used or maintained improperly,they are very easy to leak,leading to major accidents seriously endangering people’s health and asset safety,such as fire,explosion,burns,poisoning,asphyxia,etc.In this paper,the data collected from CNKI was taken as the research object,and the relevant research in the field of leakage and diffusion of hazardous gases was analyzed through visual analysis by using the VOSviewer software,so as to provide reference for subsequent scholars.
文摘In this paper, we conduct research on the memory ethics and thought transformation pattern and the applications on contemporary literature. Compared to scientifi c thinking, historical thinking, the thinking process characterized by direct image of literary creation of system integration, literary creation process is a fi ction. Literary psychology studies have shown that the transmission of literature as a kind of aesthetic experience, is far from perfect memories of feature, but memory, association, imagination, illusion, such as the result of the comprehensive sports psychological function, is in the creation subject specifi c emotions and as under the guidance of the appearance of the restructuring, merger. From the discussion above we can see that whether it is a literary language of authenticity, or false judgment characteristics of literary language, explain the fact that in literary text is not has direct realistic context, but a self-reference words, and it is a virtual space of the empirical. In this paper, we discuss the related theory with modifi cation that is innovative.
基金financially supported by the National Natural Science Foundation of China(51971071 and 52075112)Fundamental Research Projects of Science&Technology Innovation and development Plan in Yantai City(2022JCYJ023)。
文摘The in-situ growing approach was utilized in this article to construct the magnesium–aluminum layered double hydroxide(MgAl-LDH)film on the surface of a 1060 aluminum anodized film.To improve the corrosion resistance and friction qualities of aluminum alloy,the MgAl-LDH coating was treated using stearic acid(SA)and thiourea(TU).The aluminum substrate and anodized aluminum film layer corroded to varying degrees after 24 h of immersion in 3.5%(mass)NaCl solution,while the modified hydrotalcite film layer continued to exhibit the same microscopic morphology even after being immersed for 7 d.The results show that the synergistic action of thiourea and stearic acid can effectively improve the corrosion resistance of the MgAl-LDH substrate.The tribological testing reveals that the hydrotalcite film layer and the modified film layer lowered the friction coefficient of the anodized aluminum surface substantially.The results of the simulations and experiments demonstrate that SA forms the dense LDH-TU interlayer film layer by exchanging NO_(3)^(-)ions between TU layers on the one hand and the LDH-SA film layer by adsorption on the surface of LDH on the other.Together,these two processes create LDH-TUSA,which can significantly increase the substrate’s corrosion resistance.This synergistically modified superhydrophobic and retardant hydrotalcite film layer offers a novel approach to the investigation of wear reduction and corrosion protection on the surface of aluminum and its alloys.
基金financially supported by the National Natural Science Foundation of China (32072661)the National Key Research and Development Program of China(2021YFF1000500)。
文摘Acid soils occupy approximately 50% of potentially arable lands.Improving crop productivity in acid soils,therefore,will be crucial for ensuring food security and agricultural sustainability.High soil acidity often coexists with phosphorus(P) deficiency and aluminum(Al) toxicity,a combination that severely impedes crop growth and yield across wide areas.As roots explore soil for the nutrients and water required for plant growth and development,they also sense and respond to below-ground stresses.Within the terrestrial context of widespread P deficiency and Al toxicity pressures,plants,particularly roots,have evolved a variety of mechanisms for adapting to these stresses.As legumes,soybean(Glycine max) plants may acquire nitrogen(N) through symbiotic nitrogen fixation(SNF),an adaptation that can be useful for mitigating excessive N fertilizer use,either directly as leguminous crop participants in rotation and intercropping systems,or secondarily as green manure cover crops.In this review,we investigate legumes,especially soybean,for recent advances in our understanding of root-based mechanisms linked with root architecture modification,exudation and symbiosis,together with associated genetic and molecular strategies in adaptation to individual and/or interacting P and Al conditions in acid soils.We propose that breeding legume cultivars with superior nutrient efficiency and/or Al tolerance traits through genetic selection might become a potentially powerful strategy for producing crop varieties capable of maintaining or improving yields in more stressful soil conditions subjected to increasingly challenging environmental conditions.
基金supported by the National Science Fund for Excellent Young Scholars(22222813)Key Scientific and Technological Projects in Huizhou(2021JBZ5.1)the Joint Fund of Yulin University,and the Dalian National Laboratory for Clean Energy(Grant No.YLU-DNL Fund 2021016)
文摘Poly(ionic liquids)(PILs)combined with the macromolecular structure and unique properties of ionic liquids show unlimited potential in catalysis.In this work,a series of metal-based PIL with different ionic ratios were prepared for the selective oxidation of cyclohexane.Characterization analysis reveals that different degrees of ionization could adjust the Co-N sites of the catalysts efficiently,leading to significant changes in their electronic structure,which strongly relate to catalytic performance in oxidation.20.07%cyclohexane conversion and 13.06%cyclohexanone and cyclohexanol(KA oil)yield can be achieved by metal-based PILs that are better than other commercial catalysts.Compared with CoCl_(2),metal-based PILs perform well,with superior conversion and KA oil yield.More interestingly,the catalyst created in this study features a malleable Co-N site,which may potentially have an impact on how oxygen species adsorb and desorb from the catalyst.Therefore,the catalyst studied in this work is used as molecular oxygen for the selective oxidation of cyclohexane to produce KA oil,and its application prospect is promising.