Inconel 718 is the most popular nickel-based superalloy and is extensively used in aerospace,automotive,and energy indus-tries owing to its extraordinary thermomechanical properties.The effects of different two-step s...Inconel 718 is the most popular nickel-based superalloy and is extensively used in aerospace,automotive,and energy indus-tries owing to its extraordinary thermomechanical properties.The effects of different two-step solid solution treatments on microstructure andδphase precipitation of Inconel 718 alloy were studied,and the transformation mechanism fromγ″metastable phase toδphase was clarified.The precipitates were statistically analyzed by X-ray diffractometry.The results show that theδphase content firstly increased,and then decreased with the temperature of the second-step solid solution.The changes in microstructure andδphase were studied by scanning electron microscopy and transmission electron microscopy.An intragranularδphase formed in Inconel 718 alloy at the second-[100]_(δ)[011]γ step solid solution temperature of 925℃,and its orientation relationship withγmatrix was determined as//and(010)_(δ)//(111)γ.Furthermore,the Vickers hardness of different heat treatment samples was measured,and the sample treated by second-step solid solution at 1010℃ reached the maximum hardness of HV 446.84.展开更多
The increasing application of near balanced drilling technology to low-pressure and depleted fractured reservoirs requires the use of low-density drilling fluids to avoid formation damage. Solidsfree oil-in-water (O/...The increasing application of near balanced drilling technology to low-pressure and depleted fractured reservoirs requires the use of low-density drilling fluids to avoid formation damage. Solidsfree oil-in-water (O/W) emulsion drilling fluid is one type of low-density drilling fluid suitable for depleted fractured reservoirs. In this paper, the solids-free O/W drilling fluid was developed and has been successfully used in the Bozhong 28-1 oil and gas field, by which lost circulation, a severe problem occurred previously when drilling into fractured reservoir beds, was controlled, thereby minimizing formation damage. The O/W emulsion drilling fluid was prepared by adding 20% (by volume) No. 5 mineral oil (with high flash point, as dispersed phase) into seawater (as continuous phase). Surfactant HTO-1 (as a primary emulsifier) and non-ionic surfactant HTO-2 (as a secondary emulsifier) were added into the drilling fluid system to stabilize the emulsion; and YJD polymer was also added to seawater to improve the viscosity of the continuous phase (seawater). The drilling fluid was characterized by high flash point, good thermal stability and high stability to crude oil contamination.展开更多
Nitro aromatic compound can be obtained in high yields via nitration of aromatic compound with wet carbon-based solid acid and NaNO_3 under solvent free oxidation at room temperature.
A β”/β-Al_2O_3 solid electrolyte was prepared and used in a Na conentration galvanic cell: (-)O_2(in Ar),SnO_2,Na_2SnO_3|β"/β-Al_2O_3]NaCrO_2,Cr_2O_3,O_2(in Ar)(+).The emf measurements were carried out in te...A β”/β-Al_2O_3 solid electrolyte was prepared and used in a Na conentration galvanic cell: (-)O_2(in Ar),SnO_2,Na_2SnO_3|β"/β-Al_2O_3]NaCrO_2,Cr_2O_3,O_2(in Ar)(+).The emf measurements were carried out in temperature range of 912—1223 K:E=652.1— 0.2092 T+2.3(mV).Using this equation and cited free energies of formation of NaCrO_2, Cr_2O_3 and SnO_2,the molar free energy of formation of Na_2 SnO_3 may be calculated by ΔG°=-1050+0.2544 T±5.4(kJ mol^(-1)).展开更多
This project is explaining a laboratory development of a solid free drilling fluid formula that could be potentially used in tight gas reservoirs. The configuration of the weak gel fluid WGL-1, which is resistant to h...This project is explaining a laboratory development of a solid free drilling fluid formula that could be potentially used in tight gas reservoirs. The configuration of the weak gel fluid WGL-1, which is resistant to high temperature and high salt, was tested, and concluded that its gelling properties, salt and temperature resistance, and environmental protection were all in line with industry requirements. The final drilling fluid formula was developed as: water + (0.3% ~ 0.5%) NaOH + 5% KCl + 2% WGL-1 + 5% NaCl + (1.0% ~ 2.0%) HBFR Anti-high temperature fluid loss agent + 2% Polyol + (1.5% ~ 2.0%) SDL-1 Lubricant + 0.4% A4O1. The performance of the liquid was tested for temperature resistance, inhibition, gas formation protection effect, plugging performance, and static settlement stability. It was concluded that the temperature resistance performance is satisfied at 150°C, and the cuttings recovery rate is as high as 96.78%. It has good performance in inhibiting water dispersion and swelling of cuttings. The permeability recovery value reaches 88.9%, which meets the requirements of gas formation protection. The SSSI value shows that its settlement stability is good;under high temperature and high pressure, its sealing performance is good. This drilling fluid system has achieved the expected results and laid a foundation for further promoting the development of solid-free drilling fluid systems. The future development direction of solid-free drilling fluids is pointed out, to the improvement of properties to be applied in high temperature environment and have high salt resistance capacity.展开更多
Dummy molecularly imprinted polymers (DMIPs) for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-(a...Dummy molecularly imprinted polymers (DMIPs) for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-(acetymethylamino)-1-(3-pyridyl)-butanol, 4- (methylamino)-1-(3-pyridyl)-1-butanol, and 1-(3-pyridyl)-1,4,-butanediol. The molecular recognition characteristics of the produced polymers were evaluated by X-ray photoelec- tron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). Interactions between NNAL and methacrylic acid should be cooperative hydrogen bonds while the ni- trogen atom of the pyridine ring and the oxygen atom of the nitroso group in NNAL are two of the hydrogen-bond acceptors. It was further demonstrated that DMIP synthesized by 4-(acetymethylamino)-1-(3-pyridyl)-butanol had the best binding performance by XPS and FT-IR. Then dummy molecularly imprinted solid phase extraction (DMISPE) was developed for the determination of the analyte using the hit polymer as the sorbing material. Under optimal conditions, the recovery of NNAL dissolved in standard solution reached 93%. And the investigated polymer exhibited much higher binding of NNAL when nicotine was acted as the competitive molecule. Also the proposed method was applied to the measurement of NNAL spiked in blank urine samples with recoveries ranging from 87.2% to 101.2%.展开更多
The conventional Ni cermet anode suffers from severe carbon deposition and sulfur poisoning when fossil fuels are used. Alternative anode materials are desired for high performance hydrocarbon fuel solid oxide fuel ce...The conventional Ni cermet anode suffers from severe carbon deposition and sulfur poisoning when fossil fuels are used. Alternative anode materials are desired for high performance hydrocarbon fuel solid oxide fuel cells (SOFCs). We report the rational design of a very active Ni doped La0.6Sr0.4FeO3‐δ(LSFN) electrode for hydrocarbon fuel SOFCs. Homogeneously dispersed Ni‐Fe alloy nanoparticles were in situ extruded onto the surface of the LSFN particles during the operation of the cell. Sym‐metric SOFC single cells were prepared by impregnating a LSFN precursor solution onto a YSZ (yt‐tria stabilized zirconia) monolithic cell with a subsequent heat treatment. The open circuit voltage of the LSFN symmetric cell reached 1.18 and 1.0 V in humidified C3H8 and CH4 at 750??, respective‐ly. The peak power densities of the cells were 400 and 230 mW/cm2 in humidified C3H8 and CH4, respectively. The electrode showed good stability in long term testing, which revealed LSFN has good catalytic activity for hydrocarbon fuel oxidation.展开更多
[Objective] This study aims to reduce the free gossypol(FG) and improve utilization rate of cottonseed meal(CSM) by solid state fermentation(SSF). [Method]Bacillus subtilis GJ00141 and Saccharomyces cerevisiae GJ00079...[Objective] This study aims to reduce the free gossypol(FG) and improve utilization rate of cottonseed meal(CSM) by solid state fermentation(SSF). [Method]Bacillus subtilis GJ00141 and Saccharomyces cerevisiae GJ00079 were applied for the SSF and the optimal carbon source, nitrogen source, inorganic salt, moisture content, inoculum level, fermentation temperature, and fermentation time were investigated. The detoxifying effects of different products of GJ00141 were examined with gossypol as substrate. A total of 90 one-day-old broilers were randomized into group A [control, basal diet with 36% soybean meal(SM)], group B(basal diet with 18% SM and 18% CSM), and group C [basal diet with 18% SM and 18% fermented CSM(FCSM)] and thereby the influence of FCSM on the growth of broilers was explored. [Results] The maximum reduction rate(59%) of FG was achieved under the following fermentation conditions: solid medium composed of 96% CSM, 1%glucose, 1% ammonium sulfate, and 2% corn grits, 45% moisture content, 20%inoculum, fermentation at 30 °C for 60 h. Both the viable and inactivated cells of GJ00141 can reduce the content of gossypol, but the reduction rates were only about 20% after 72 h of incubation. Cellular contents and supernatant demonstrated strong detoxifying activity, which achieved the reduction rates of about 95% after 48 h, and the removal was free from the influence of proteinase K, heat, or EDTA. In the 42 d feeding experiment on broilers, the ratios of feed to gain were insignificantly different between the group C and group A. [Conclusion] This method achieved high rate of removing FG in CSM. The reason was the likelihood that the stable compounds in the cellular contents and supernatant of GJ00141 adsorb or bind to FG. Broilers grew well with the FCSM. Thus, it was an efficient detoxifying method for CSM.展开更多
A novel solid superacid catalyst S2O8^2-/ZrO2-CeO2 was prepared by a coprecipitation method and characterized by means of XRD FTIR, BET, TEM and DSC/TG analysis methods. The results indicated that incorporation of app...A novel solid superacid catalyst S2O8^2-/ZrO2-CeO2 was prepared by a coprecipitation method and characterized by means of XRD FTIR, BET, TEM and DSC/TG analysis methods. The results indicated that incorporation of appropriate amounts of Ce into the catalyst was beneficial to the formation of sole tetragonal ZrO2 and effectively prevented from the formation of monoclinic ZrO〉 and restrained the loss of sulfated species. XRD revealed the presence of tetragonal Ce0.16Zr0.84O2phase in the case of S2O8^2-/ZrO2-CeO2 calcined above 500 ℃. Catalytic activities of S2O8^2-/ZrO2-CeO2 for the esterification of lactic acid with n-butanol was studied. The results showed that the optimum conditions were as follows: calcination temperature of the catalyst 600 ℃, n(lactic acid):n(n-butyl alcohol)=1.0:3.0, w(S2O8^2-/ZrO2- CeO2)=12.0%, reaction temperature 145 ℃, and reaction time 2 h. The esterification efficiency of lactic acid was about 96.6%.展开更多
Background: Programmed cell death protein 4(PDCD4) is a novel tumor suppressor protein involved in pro?grammed cell death. Its association with cancer progression has been observed in multiple tumor models, but eviden...Background: Programmed cell death protein 4(PDCD4) is a novel tumor suppressor protein involved in pro?grammed cell death. Its association with cancer progression has been observed in multiple tumor models, but evidence supporting its association with solid tumors in humans remains controversial. This study aimed to determine the clinical signiicance and prognostic value of PDCD4 in solid tumors.Methods: A systematic literature review was performed to retrieve publications with available clinical informa?tion and survival data. The eligibility of the selected articles was based on the criteria of the Dutch Cochrane Centre proposed by the Meta?analysis Of Observational Studies in Epidemiology group. Pooled odds ratios(ORs), hazard ratios(HRs), and 95% conidence intervals(CIs) for survival analysis were calculated. Publication bias was examined by Begg's and Egger's tests.Results: Clinical data of 2227 cancer patients with solid tumors from 23 studies were evaluated. PDCD4 expression was signiicantly associated with the diferentiation status of head and neck cancer(OR 4.25, 95% CI 1.87–9.66) and digestive system cancer(OR 2.87, 95% CI 1.84–4.48). Down?regulation of PDCD4 was signiicantly associated with short overall survival of patients with head and neck(HR: 3.44, 95% CI 2.38–4.98), breast(HR: 1.86, 95% CI 1.36–2.54), digestive system(HR: 2.12, 95% CI 1.75–2.56), and urinary system cancers(HR: 3.16, 95% CI 1.06–9.41).Conclusions: The current evidence suggests that PDCD4 down?regulation is involved in the progression of several types of solid tumor and is a potential marker for solid tumor prognoses. Its clinical usefulness should be conirmed by large?scale prospective studies.展开更多
The three-way catalysts (TWCs) promoters Ce0.6Zr0.4- x TbxO2-y were prepared by sol-gel method. BET surface areas analysis indicated that an increase of the dopant Tb content from x = 0.05 to x = 0.15 favors an incr...The three-way catalysts (TWCs) promoters Ce0.6Zr0.4- x TbxO2-y were prepared by sol-gel method. BET surface areas analysis indicated that an increase of the dopant Tb content from x = 0.05 to x = 0.15 favors an increase of surface area from 66.8 to 80.4 m^2· g^-1 compared with the undoped sample Ce0 .6oZr0.40O2 65.1 m^2·g^- 1 after calcination at 650℃. Transmission electron microscopy (TEM) observation indicated that the doped samples have a higher thermal stability. The XRD and Raman spectra confirmed that the Ce0.6Zr0.4-xTbxO2-y cubic solid solution is formed. XPS analysis revealed that Ce and Tb mainly existed in the form of Ce^4+ and Tb^3 + , and Zr existed in the form of Zr^4+ on the surface of the samples. The doped samples were homogenous in composition ; the introduction of Tb into the CeO2-ZrO2 promoters resuited in the formation of a solid solution, and the concentration of surface lattice oxygen was increased.展开更多
SO4^2-/TiO2-MoO3, a novel solid superacid, has been prepared and its catalytic activity at different synthetic conditions was examined with esterification of n-butanoic acid and n-butyl alcohol as probing reaction.The...SO4^2-/TiO2-MoO3, a novel solid superacid, has been prepared and its catalytic activity at different synthetic conditions was examined with esterification of n-butanoic acid and n-butyl alcohol as probing reaction.The optimum conditions were also found, that is, the mass ratio of MoO3 used in the compound is 25%, the calcination temperature 450℃, and the soaked consistency of H2SO4 is 0.5mol.L^-1. Then it was applied in the catalytic synthesis of six similar important ketals and acetals as catalyst and revealed high catalytic activity. Under the condition that the molar ratio of aldehyde/ketone to glycol was 1:1.5, the mass ratio of the catalyst to the reactants was 0.5% and the reaction time 1.0 h, the yield of ketals and acetals reached up to 63.2%. The catalyst can be easily recovered and reused.展开更多
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...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.展开更多
Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. Accor...Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company, previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are:sand material, accessories baking, ladle nozzle cleaning, the process and amount of adding sand, and the rate of argon stirring during refining. Therefore, improving the ladle filler sand quality, baking all of the raw materials, controlling the addition of ladle filler sand, cleaning the ladle nozzle, and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel.展开更多
A solid phase radioimmunoassay for free triiodothyronine in serum was developed based on double-antibody coated tubes. The method was turned out to be reliable with good reproducibility, higher sensitivity and easy pe...A solid phase radioimmunoassay for free triiodothyronine in serum was developed based on double-antibody coated tubes. The method was turned out to be reliable with good reproducibility, higher sensitivity and easy performance. The measurable range of FT3 in serum was 1.2 to 38 pmol/L. The mean coefficients of variation within and between assays were 1.79%-3.18% and 4.72%-9.31%, respectively. The FT3 concentrations in euthyroid serum as determined by this method were 2.8 to 7.8pmol/L. The FT3 values determined by this new method correlated well with those measured by a commercial radioimmunoassay (r=0.853).展开更多
SO4^2- / TiO2-La2O3, a novel solid superacid, was prepared and its catalytic activities at different synthetic conditions are discussed with esterification of n-butanoic acid and n-butyl alcohol as probing reaction. T...SO4^2- / TiO2-La2O3, a novel solid superacid, was prepared and its catalytic activities at different synthetic conditions are discussed with esterification of n-butanoic acid and n-butyl alcohol as probing reaction. The optimum conditions have also been found, mole ratio of n(La^3+):n(Ti^4+) is 1:34, the soaked consistency of H2SO4 is 0.8 tool/L, the soaked time of HESO4 is 24 h, the calcining temperature is 480 ℃, the calcining time is 3 h. Then it was applied in the catalytic synthesis often important ketals and acetals as catalyst and revealed high catalytic activity. Under these conditions on which the molar ratio of aldehyde/ketone to glycol is l: 1.5, the mass ratio of the catalyst used in the reactants is 0.5%, and the reaction time is 1.0 h, the yields of ketals and acetals can reach 41.4%-95.8%.展开更多
Using microbial fermentation to increase the content of free amino acids and short peptides in the organic fertilizer for castor bean meal can effectively promote plant growth and improve fruit quality.Using free amin...Using microbial fermentation to increase the content of free amino acids and short peptides in the organic fertilizer for castor bean meal can effectively promote plant growth and improve fruit quality.Using free amino acid and short peptide content as an indicator,through single factor and response surface optimization experiments,the process parameters(moisture content,fermentation time and inoculum quantity)of castor meal solid-state fermentation were optimized.The best process parameters for the solid-state fermentation were:the moisture content 62%,the fermentation time 20 d,and the inoculum quantity 0.23%.The moisture content had the greatest impact on the conversion rate of free amino acids and short peptides,and the protein conversion rate reached 65.6%.The scale-up experiment under the optimal conditions showed that the solid-state fermentation using the inoculum had a significant beneficial effect compared with other fermentation methods.The fermentation of castor cake fertilizer provides a theoretical and practical basis for production feasibility,and has important guiding significance for the effective utilization of castor bean meal.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52201203 and 52171107)the Hebei Provincial Natural Science Foundation,China(No.E2021501026)+1 种基金the National Natural Science Foundation of China-Joint Fund of Iron and Steel Research(No.U1960204)the“333”Talent Project of Hebei Province,China(No.B20221001).
文摘Inconel 718 is the most popular nickel-based superalloy and is extensively used in aerospace,automotive,and energy indus-tries owing to its extraordinary thermomechanical properties.The effects of different two-step solid solution treatments on microstructure andδphase precipitation of Inconel 718 alloy were studied,and the transformation mechanism fromγ″metastable phase toδphase was clarified.The precipitates were statistically analyzed by X-ray diffractometry.The results show that theδphase content firstly increased,and then decreased with the temperature of the second-step solid solution.The changes in microstructure andδphase were studied by scanning electron microscopy and transmission electron microscopy.An intragranularδphase formed in Inconel 718 alloy at the second-[100]_(δ)[011]γ step solid solution temperature of 925℃,and its orientation relationship withγmatrix was determined as//and(010)_(δ)//(111)γ.Furthermore,the Vickers hardness of different heat treatment samples was measured,and the sample treated by second-step solid solution at 1010℃ reached the maximum hardness of HV 446.84.
文摘The increasing application of near balanced drilling technology to low-pressure and depleted fractured reservoirs requires the use of low-density drilling fluids to avoid formation damage. Solidsfree oil-in-water (O/W) emulsion drilling fluid is one type of low-density drilling fluid suitable for depleted fractured reservoirs. In this paper, the solids-free O/W drilling fluid was developed and has been successfully used in the Bozhong 28-1 oil and gas field, by which lost circulation, a severe problem occurred previously when drilling into fractured reservoir beds, was controlled, thereby minimizing formation damage. The O/W emulsion drilling fluid was prepared by adding 20% (by volume) No. 5 mineral oil (with high flash point, as dispersed phase) into seawater (as continuous phase). Surfactant HTO-1 (as a primary emulsifier) and non-ionic surfactant HTO-2 (as a secondary emulsifier) were added into the drilling fluid system to stabilize the emulsion; and YJD polymer was also added to seawater to improve the viscosity of the continuous phase (seawater). The drilling fluid was characterized by high flash point, good thermal stability and high stability to crude oil contamination.
文摘Nitro aromatic compound can be obtained in high yields via nitration of aromatic compound with wet carbon-based solid acid and NaNO_3 under solvent free oxidation at room temperature.
文摘A β”/β-Al_2O_3 solid electrolyte was prepared and used in a Na conentration galvanic cell: (-)O_2(in Ar),SnO_2,Na_2SnO_3|β"/β-Al_2O_3]NaCrO_2,Cr_2O_3,O_2(in Ar)(+).The emf measurements were carried out in temperature range of 912—1223 K:E=652.1— 0.2092 T+2.3(mV).Using this equation and cited free energies of formation of NaCrO_2, Cr_2O_3 and SnO_2,the molar free energy of formation of Na_2 SnO_3 may be calculated by ΔG°=-1050+0.2544 T±5.4(kJ mol^(-1)).
文摘This project is explaining a laboratory development of a solid free drilling fluid formula that could be potentially used in tight gas reservoirs. The configuration of the weak gel fluid WGL-1, which is resistant to high temperature and high salt, was tested, and concluded that its gelling properties, salt and temperature resistance, and environmental protection were all in line with industry requirements. The final drilling fluid formula was developed as: water + (0.3% ~ 0.5%) NaOH + 5% KCl + 2% WGL-1 + 5% NaCl + (1.0% ~ 2.0%) HBFR Anti-high temperature fluid loss agent + 2% Polyol + (1.5% ~ 2.0%) SDL-1 Lubricant + 0.4% A4O1. The performance of the liquid was tested for temperature resistance, inhibition, gas formation protection effect, plugging performance, and static settlement stability. It was concluded that the temperature resistance performance is satisfied at 150°C, and the cuttings recovery rate is as high as 96.78%. It has good performance in inhibiting water dispersion and swelling of cuttings. The permeability recovery value reaches 88.9%, which meets the requirements of gas formation protection. The SSSI value shows that its settlement stability is good;under high temperature and high pressure, its sealing performance is good. This drilling fluid system has achieved the expected results and laid a foundation for further promoting the development of solid-free drilling fluid systems. The future development direction of solid-free drilling fluids is pointed out, to the improvement of properties to be applied in high temperature environment and have high salt resistance capacity.
文摘Dummy molecularly imprinted polymers (DMIPs) for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-(acetymethylamino)-1-(3-pyridyl)-butanol, 4- (methylamino)-1-(3-pyridyl)-1-butanol, and 1-(3-pyridyl)-1,4,-butanediol. The molecular recognition characteristics of the produced polymers were evaluated by X-ray photoelec- tron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). Interactions between NNAL and methacrylic acid should be cooperative hydrogen bonds while the ni- trogen atom of the pyridine ring and the oxygen atom of the nitroso group in NNAL are two of the hydrogen-bond acceptors. It was further demonstrated that DMIP synthesized by 4-(acetymethylamino)-1-(3-pyridyl)-butanol had the best binding performance by XPS and FT-IR. Then dummy molecularly imprinted solid phase extraction (DMISPE) was developed for the determination of the analyte using the hit polymer as the sorbing material. Under optimal conditions, the recovery of NNAL dissolved in standard solution reached 93%. And the investigated polymer exhibited much higher binding of NNAL when nicotine was acted as the competitive molecule. Also the proposed method was applied to the measurement of NNAL spiked in blank urine samples with recoveries ranging from 87.2% to 101.2%.
基金supported by the National Natural Science Foundation of China (51372271,51172275)the National Basic Research Program of China (973 Program,2012CB215402)~~
文摘The conventional Ni cermet anode suffers from severe carbon deposition and sulfur poisoning when fossil fuels are used. Alternative anode materials are desired for high performance hydrocarbon fuel solid oxide fuel cells (SOFCs). We report the rational design of a very active Ni doped La0.6Sr0.4FeO3‐δ(LSFN) electrode for hydrocarbon fuel SOFCs. Homogeneously dispersed Ni‐Fe alloy nanoparticles were in situ extruded onto the surface of the LSFN particles during the operation of the cell. Sym‐metric SOFC single cells were prepared by impregnating a LSFN precursor solution onto a YSZ (yt‐tria stabilized zirconia) monolithic cell with a subsequent heat treatment. The open circuit voltage of the LSFN symmetric cell reached 1.18 and 1.0 V in humidified C3H8 and CH4 at 750??, respective‐ly. The peak power densities of the cells were 400 and 230 mW/cm2 in humidified C3H8 and CH4, respectively. The electrode showed good stability in long term testing, which revealed LSFN has good catalytic activity for hydrocarbon fuel oxidation.
基金Supported by the Academic Research Projects of Beijing Union University (ZK30202104, ZK20202101)。
文摘[Objective] This study aims to reduce the free gossypol(FG) and improve utilization rate of cottonseed meal(CSM) by solid state fermentation(SSF). [Method]Bacillus subtilis GJ00141 and Saccharomyces cerevisiae GJ00079 were applied for the SSF and the optimal carbon source, nitrogen source, inorganic salt, moisture content, inoculum level, fermentation temperature, and fermentation time were investigated. The detoxifying effects of different products of GJ00141 were examined with gossypol as substrate. A total of 90 one-day-old broilers were randomized into group A [control, basal diet with 36% soybean meal(SM)], group B(basal diet with 18% SM and 18% CSM), and group C [basal diet with 18% SM and 18% fermented CSM(FCSM)] and thereby the influence of FCSM on the growth of broilers was explored. [Results] The maximum reduction rate(59%) of FG was achieved under the following fermentation conditions: solid medium composed of 96% CSM, 1%glucose, 1% ammonium sulfate, and 2% corn grits, 45% moisture content, 20%inoculum, fermentation at 30 °C for 60 h. Both the viable and inactivated cells of GJ00141 can reduce the content of gossypol, but the reduction rates were only about 20% after 72 h of incubation. Cellular contents and supernatant demonstrated strong detoxifying activity, which achieved the reduction rates of about 95% after 48 h, and the removal was free from the influence of proteinase K, heat, or EDTA. In the 42 d feeding experiment on broilers, the ratios of feed to gain were insignificantly different between the group C and group A. [Conclusion] This method achieved high rate of removing FG in CSM. The reason was the likelihood that the stable compounds in the cellular contents and supernatant of GJ00141 adsorb or bind to FG. Broilers grew well with the FCSM. Thus, it was an efficient detoxifying method for CSM.
基金supported by the Science and Technique Foundation of Shaaxi Province of China (2008K07-32)the Foundation of Shaanxi Educa- tional Committee of China (08JK228)the Graduate Innovation Fund of Shaanxi University of Science and Technology
文摘A novel solid superacid catalyst S2O8^2-/ZrO2-CeO2 was prepared by a coprecipitation method and characterized by means of XRD FTIR, BET, TEM and DSC/TG analysis methods. The results indicated that incorporation of appropriate amounts of Ce into the catalyst was beneficial to the formation of sole tetragonal ZrO2 and effectively prevented from the formation of monoclinic ZrO〉 and restrained the loss of sulfated species. XRD revealed the presence of tetragonal Ce0.16Zr0.84O2phase in the case of S2O8^2-/ZrO2-CeO2 calcined above 500 ℃. Catalytic activities of S2O8^2-/ZrO2-CeO2 for the esterification of lactic acid with n-butanol was studied. The results showed that the optimum conditions were as follows: calcination temperature of the catalyst 600 ℃, n(lactic acid):n(n-butyl alcohol)=1.0:3.0, w(S2O8^2-/ZrO2- CeO2)=12.0%, reaction temperature 145 ℃, and reaction time 2 h. The esterification efficiency of lactic acid was about 96.6%.
文摘Background: Programmed cell death protein 4(PDCD4) is a novel tumor suppressor protein involved in pro?grammed cell death. Its association with cancer progression has been observed in multiple tumor models, but evidence supporting its association with solid tumors in humans remains controversial. This study aimed to determine the clinical signiicance and prognostic value of PDCD4 in solid tumors.Methods: A systematic literature review was performed to retrieve publications with available clinical informa?tion and survival data. The eligibility of the selected articles was based on the criteria of the Dutch Cochrane Centre proposed by the Meta?analysis Of Observational Studies in Epidemiology group. Pooled odds ratios(ORs), hazard ratios(HRs), and 95% conidence intervals(CIs) for survival analysis were calculated. Publication bias was examined by Begg's and Egger's tests.Results: Clinical data of 2227 cancer patients with solid tumors from 23 studies were evaluated. PDCD4 expression was signiicantly associated with the diferentiation status of head and neck cancer(OR 4.25, 95% CI 1.87–9.66) and digestive system cancer(OR 2.87, 95% CI 1.84–4.48). Down?regulation of PDCD4 was signiicantly associated with short overall survival of patients with head and neck(HR: 3.44, 95% CI 2.38–4.98), breast(HR: 1.86, 95% CI 1.36–2.54), digestive system(HR: 2.12, 95% CI 1.75–2.56), and urinary system cancers(HR: 3.16, 95% CI 1.06–9.41).Conclusions: The current evidence suggests that PDCD4 down?regulation is involved in the progression of several types of solid tumor and is a potential marker for solid tumor prognoses. Its clinical usefulness should be conirmed by large?scale prospective studies.
基金Project supported by the Natural Science Basic Research Plan in Shaanxi Province of China (2004B13)
文摘The three-way catalysts (TWCs) promoters Ce0.6Zr0.4- x TbxO2-y were prepared by sol-gel method. BET surface areas analysis indicated that an increase of the dopant Tb content from x = 0.05 to x = 0.15 favors an increase of surface area from 66.8 to 80.4 m^2· g^-1 compared with the undoped sample Ce0 .6oZr0.40O2 65.1 m^2·g^- 1 after calcination at 650℃. Transmission electron microscopy (TEM) observation indicated that the doped samples have a higher thermal stability. The XRD and Raman spectra confirmed that the Ce0.6Zr0.4-xTbxO2-y cubic solid solution is formed. XPS analysis revealed that Ce and Tb mainly existed in the form of Ce^4+ and Tb^3 + , and Zr existed in the form of Zr^4+ on the surface of the samples. The doped samples were homogenous in composition ; the introduction of Tb into the CeO2-ZrO2 promoters resuited in the formation of a solid solution, and the concentration of surface lattice oxygen was increased.
文摘SO4^2-/TiO2-MoO3, a novel solid superacid, has been prepared and its catalytic activity at different synthetic conditions was examined with esterification of n-butanoic acid and n-butyl alcohol as probing reaction.The optimum conditions were also found, that is, the mass ratio of MoO3 used in the compound is 25%, the calcination temperature 450℃, and the soaked consistency of H2SO4 is 0.5mol.L^-1. Then it was applied in the catalytic synthesis of six similar important ketals and acetals as catalyst and revealed high catalytic activity. Under the condition that the molar ratio of aldehyde/ketone to glycol was 1:1.5, the mass ratio of the catalyst to the reactants was 0.5% and the reaction time 1.0 h, the yield of ketals and acetals reached up to 63.2%. The catalyst can be easily recovered and reused.
基金supported by Natural Science Foundation of China(NSFC)(Grant No.91333112U1432249)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionssupported by Collaborative Innovation Center of Suzhou Nano Science&Technology and sponsored by Qing Lan Project
文摘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.
文摘Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company, previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are:sand material, accessories baking, ladle nozzle cleaning, the process and amount of adding sand, and the rate of argon stirring during refining. Therefore, improving the ladle filler sand quality, baking all of the raw materials, controlling the addition of ladle filler sand, cleaning the ladle nozzle, and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel.
文摘A solid phase radioimmunoassay for free triiodothyronine in serum was developed based on double-antibody coated tubes. The method was turned out to be reliable with good reproducibility, higher sensitivity and easy performance. The measurable range of FT3 in serum was 1.2 to 38 pmol/L. The mean coefficients of variation within and between assays were 1.79%-3.18% and 4.72%-9.31%, respectively. The FT3 concentrations in euthyroid serum as determined by this method were 2.8 to 7.8pmol/L. The FT3 values determined by this new method correlated well with those measured by a commercial radioimmunoassay (r=0.853).
基金Project supported by the National Natural Science Foundation of China (No. 20471044), and the Natural Science Foundation of Hubei Province (No. 2005ABA053), China
文摘SO4^2- / TiO2-La2O3, a novel solid superacid, was prepared and its catalytic activities at different synthetic conditions are discussed with esterification of n-butanoic acid and n-butyl alcohol as probing reaction. The optimum conditions have also been found, mole ratio of n(La^3+):n(Ti^4+) is 1:34, the soaked consistency of H2SO4 is 0.8 tool/L, the soaked time of HESO4 is 24 h, the calcining temperature is 480 ℃, the calcining time is 3 h. Then it was applied in the catalytic synthesis often important ketals and acetals as catalyst and revealed high catalytic activity. Under these conditions on which the molar ratio of aldehyde/ketone to glycol is l: 1.5, the mass ratio of the catalyst used in the reactants is 0.5%, and the reaction time is 1.0 h, the yields of ketals and acetals can reach 41.4%-95.8%.
基金Special Fund for International Cooperative Research of Qilu University of Technology(QLUTGJHZ2018010)。
文摘Using microbial fermentation to increase the content of free amino acids and short peptides in the organic fertilizer for castor bean meal can effectively promote plant growth and improve fruit quality.Using free amino acid and short peptide content as an indicator,through single factor and response surface optimization experiments,the process parameters(moisture content,fermentation time and inoculum quantity)of castor meal solid-state fermentation were optimized.The best process parameters for the solid-state fermentation were:the moisture content 62%,the fermentation time 20 d,and the inoculum quantity 0.23%.The moisture content had the greatest impact on the conversion rate of free amino acids and short peptides,and the protein conversion rate reached 65.6%.The scale-up experiment under the optimal conditions showed that the solid-state fermentation using the inoculum had a significant beneficial effect compared with other fermentation methods.The fermentation of castor cake fertilizer provides a theoretical and practical basis for production feasibility,and has important guiding significance for the effective utilization of castor bean meal.