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1.
Small ; 20(7): e2306227, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37806748

ABSTRACT

γ-valerolactone (GVL) is a key value-added chemical catalytically produced from levulinic acid (LA), an important biomass derivative platform chemical. Here an ultra-efficient 3D Ru catalyst generated by in situ reduction of RuZnOx nanoboxes is reported; the catalyst features a well-defined structure of highly dispersed in situ oxide-derived Ru (IOD-Ru) clusters (≈1 nm in size) spatially confined within the 3D nanocages with rich mesopores, which guarantees a maximized atom utilization with a high exposure of Ru active sites as well as a 3D accessibility for substrate molecules. The IOD-Ru exhibits ultrahigh performance for the hydrogenation of LA into GVL with a record-breaking turnover frequency (TOF) up to 59400 h-1 , 14 times higher than that of the ex situ reduction of RuZnOx nanoboxes catalyst. Structural characterizations and theoretical calculations collectively indicate that the defect-rich and coordination-unsaturated IOD-Ru sites can boost the activation of the carbonyl group in LA with a significantly lowered energy barrier of hydrogenation.

2.
Heliyon ; 9(12): e23024, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38076035

ABSTRACT

Dairy quality affects the health and quality of life of consumers. Implementing supply chain management and collaborative quality control is an effective way to solve dairy quality problems. Based on the perspective of the combination of market failure and government intervention, this paper analyzes the conditions for the realization of collaborative quality control between dairy farmers and dairy processors. At the same time, this paper uses relevant data to verify the applicability of the model and the accuracy of the conclusions. The findings show that both low yields and high spillovers lead to market failures. When farmers adopt advanced prevention strategies and dairy processors adopt advanced inspection strategies with low yields, basic prevention and basic inspection will be the best combination of quality control strategies for both parties. In this case, the government should subsidize the advanced control strategy to provide adequate subsidies. This will provide incentives for both parties to work together to ensure the quality of dairy products. Secondly, when farmers adopt advanced prevention strategies or dairy processors adopt advanced inspection strategies yields increase but spillover rates are higher. Advanced prevention, basic inspection or basic prevention, advanced inspection would be the optimal combination of strategies for both parties. At this point, the government should increase the penalties. The simulation results further indicate that the government subsidy is more effective for dairy farmers. Government penalties have both the positive and negative reinforcing effects.

3.
Chem Commun (Camb) ; 55(80): 12096-12099, 2019 Oct 03.
Article in English | MEDLINE | ID: mdl-31538994

ABSTRACT

The complete deoxygenation of palmitic acid followed by simultaneous hydro-isomerization and appropriate hydrocracking were achieved over Co/HMCM-49 bi-functional catalysts with the special structure of 12 MR cups and a low Si/Al ratio. This offered new insights into the design of bi-functional catalysts for carbon rearrangements during the upgrading of palmitic acid to jet fuel range alkanes.

4.
Iran J Public Health ; 48(3): 444-450, 2019 Mar.
Article in English | MEDLINE | ID: mdl-31223571

ABSTRACT

BACKGROUND: We aimed to investigate the analgesic effect and immune function of elderly patients with colon cancer after application of sevoflurane and isoflurane anesthesia. METHODS: Overall, 130 patients with colon cancer in Yidu Central Hospital of Weifang (Weifang, China) from February 2014 to January 2017 were collected and randomly divided into sevoflurane group (SEV group) and isoflurane group (ISO group). The pain score, immune indexes, postoperative cognitive index, extubation time, awakening time and S100R protein were analyzed. RESULTS: The pain scores in SEV group at 5 min, 1 h and 3 h during surgery were significantly lower than those in ISO group (P=0.001, respectively). The levels of IL-6 in both groups of patients were higher at T1 and T2 than those at T0 (P=0.001). The levels of TNF-α in SEV group at T2 and T3 were significantly higher than that at T0 (P=0.001). The levels of CD80 in both groups of patients at T2 and T3 were obviously higher than those at T0 (P=0.001). Moreover, the extubation time, the response time to language and awakening time in SEV group were also remarkably shorter than those in ISO group (P=0.001). After continuous anesthesia in both groups of patients, the degrees of decline in ISO group were significantly higher than those in SEV group (P=0.001). CONCLUSION: Sevoflurane has a superior anesthetic effect to isoflurane in elderly patients with colon cancer, can reduce the degree of pain, improve the awakening condition and increase the immune function, so it is worthy of clinical application.

5.
Huan Jing Ke Xue ; 40(4): 1950-1956, 2019 Apr 08.
Article in Chinese | MEDLINE | ID: mdl-31087941

ABSTRACT

Soil salinization poses a great threat to sustainable land use and the limitation of greenhouse gas emissions. In this study, three saline alkali soils, saline soil[electrical conductivity (EC) 4.80 dS·m-1], high saline-alkaline soil (EC 2.60 dS·m-1), and low saline-alkaline soil (EC 0.74 dS·m-1) in the Hetao Irrigation District of Inner Mongolia were selected as research plots. Field experiments were conducted to study the uptake of methane (CH4) in the crop-growing season (April-October) for three years (2014-2016) using the static box method. There were significant differences in the soil CH4 uptake among the soil types in 2014 (F=18.0, P<0.001), 2015 (F=23.6, P<0.001), and 2016 (F=28.4, P<0.001). The uptake of CH4 by the soil decreases with increasing soil salinity. The accumulated CH4 uptake was 150.0 mg·m-2, 119.6 mg·m-2, and 99.9 mg·m-2 in the low saline-alkaline, high saline-alkaline, and saline soil in 2014, respectively. The cumulative uptake of CH4 was 27%, 28%, and 19% lower in the high saline-alkaline soil and 35%, 35%, and 53% lower in the saline soil than in the low saline-alkaline soil in 2014, 2015, and 2016, respectively. Redundancy analysis shows that the projection of the CH4 uptake flux and EC of saline-alkaline soil are in the positive direction, and in the opposite direction to the first principal component axis. The higher the soil EC, the lower the CH4 uptake flux. Soil EC was found to be the key factor controlling the uptakes of CH4, with a correlation coefficient (r) of -0.8809 (P<0.01, n=9).

6.
Chem Asian J ; 13(9): 1180-1186, 2018 May 04.
Article in English | MEDLINE | ID: mdl-29498220

ABSTRACT

Aqueous-phase ketonization of bio-based acetic acid is important to improve the conversion efficiency of biomass resources. In this study, ZrMn mixed oxides (ZrMnOx ) with high aqueous-phase ketonization activity are synthetized through a carbonization/oxidation method (COM) and solvothermal method (STM). The results show that ZrMnOx prepared by COM possesses tetragonal ZrO2 , and hausmannite Mn3 O4 is observed only at a high oxidation temperature of 750 °C. Low-temperature and long oxidation results in decreased crystallinity and crystallite size, which is related to highly dispersed Mnn+ species. The catalysts with improved acid sites possess high ketonization activity. Surface areas and pore size of ZrMnOx synthetized by STM are controlled by the solvents for thermal treatment. Compared with water as solvent, ethanol increases the surface area and pore size, resulting in high ketonization activity.

7.
ChemSusChem ; 9(12): 1355-85, 2016 06 22.
Article in English | MEDLINE | ID: mdl-27158985

ABSTRACT

Different biobased chemicals are produced during the conversion of biomass into fuels through various feasible technologies (e.g., hydrolysis, hydrothermal liquefaction, and pyrolysis). The challenge of transforming these biobased chemicals with high hydrophilicity is ascribed to the high water content of the feedstock and the inevitable formation of water. Therefore, aqueous-phase processing is an interesting technology for the heterogeneous catalytic conversion of biobased chemicals. Different reactions, such as dehydration, isomerization, aldol condensation, ketonization, and hydrogenation, are applied for the conversion of sugars, furfural/hydroxymethylfurfural, acids, phenolics, and so on over heterogeneous catalysts. The activity, stability, and reusability of the heterogeneous catalysts in water are summarized, and deactivation processes and several strategies are introduced to improve the stability of heterogeneous catalysts in the aqueous phase.


Subject(s)
Biofuels , Water/chemistry , Biofuels/economics , Catalysis , Environment , Hydrogenation , Isomerism
8.
Bioresour Technol ; 192: 522-8, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26086085

ABSTRACT

In the current work, the co-pyrolysis kinetics of Dunaliella tertiolecta and PP were investigated via TGA, while TG-FTIR and TG-MS were used for the analysis of gas-phase components and volatiles transition. The TGA results show that PP with certain small particle size accelerates the pyrolysis process of the microalgae, while the existence of D. tertiolecta delayed that of PP. This significant interaction achieves maximum when mass ratio of PP and D. tertiolecta is 6:4. The activation energy estimated from FWO kinetic model also supports this interaction. The TG-FTIR and TG-MS results show that a significant decrease of CO2 occurs at PP and D. tertiolecta mass ratio of 6:4, indicating that small molecules (such as radicals) released by PP might react with CO2 produced by D. tertiolecta or carbonyl groups in the microalgae.


Subject(s)
Carbon Dioxide/chemistry , Cell Fractionation/methods , Heating/methods , Microalgae/chemistry , Models, Chemical , Polypropylenes/chemistry , Computer Simulation , Kinetics
9.
Bioresour Technol ; 163: 18-25, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24768943

ABSTRACT

The differences in pyrolysis process of three species of aquatic biomass (microalgae, macroalgae and duckweed) were investigated by thermogravimetric analysis (TGA). Three stages were observed during the pyrolysis process and the main decomposition stage could be divided further into three zones. The pyrolysis characteristics of various biomasses were different at each zone, which could be attributed to the differences in their components. A stepwise procedure based on iso-conversional and master-plots methods was used for the kinetic and mechanism analysis of the main decomposition stage. The calculation results based on the kinetic model was in good agreement with the experimental data of weight loss, and each biomass had an increasing activation energy of 118.35-156.13 kJ/mol, 171.85-186.46 kJ/mol and 258.51-268.71 kJ/mol in zone 1, 2 and 3, respectively. This study compares the pyrolysis behavior of various aquatic biomasses and provides basis for further applications of the biomass thermochemical conversion.


Subject(s)
Biomass , Thermogravimetry/instrumentation , Kinetics , Models, Theoretical
10.
Bioresour Technol ; 124: 190-8, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22989646

ABSTRACT

This paper presents bio-oil preparation by direct liquefaction of Dunaliella tertiolecta (D. tertiolecta) with sub/supercritical ethanol-water as the medium in a batch autoclave with high temperature and high pressure. The results indicated that ethanol and water showed synergistic effects on direct liquefaction of D. tertiolecta. The maximum bio-oil yield was 64.68%, with an optimal D. tertiolecta conversion of 98.24% in sub/supercritical ethanol-water. The detailed chemical compositional analysis of the bio-oil was performed using an EA, FT-IR, and GC-MS. The empirical formulas of the bio-oil obtained using the ethanol-water co-solvent (40%, v/v) and sole water as the reaction medium were CH(1.52)O(0.14)N(0.06) and CH(1.43)O(0.23)N(0.09), with calorific values of 34.96 and 29.80 MJ kg(-1), respectively. XPS and SEM results showed that ethanol-water is a very effective reaction medium in the liquefaction. A plausible reaction mechanism of the main chemical component in D. tertiolecta is proposed based on our results and the literatures.


Subject(s)
Chlorophyta/chemistry , Ethanol/chemistry , Oils , Water/chemistry , Gas Chromatography-Mass Spectrometry , Microscopy, Electron, Scanning , Spectroscopy, Fourier Transform Infrared , Temperature
11.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(2): 505-9, 2012 Feb.
Article in Chinese | MEDLINE | ID: mdl-22512199

ABSTRACT

In the present paper, crude biodiesel prepared with sorbifolia oil as raw material by transesterification was purified by column chromatography, then the composition of biodiesel was analyzed by gas chromatography, FTIR, GC-MS and 1H NMR. Column chromatography can separate the crude biodiesel into two fractions: petroleum ether eluted fraction (A1) and methanol eluted fraction (A2). Petroleum ether eluted fraction was mainly biodiesel fraction, which was produced from sorbifolia oil by transesterification, including methyl linoleate, methyl cis-9-octadecenoate and so on; methanol eluted fraction was mainly glycerol fraction, which came from the side reaction of transesterification. The results show that the purity of refined biodiesel increased from 77.51% to 93.872, and the product recovery rate reached up to 91.04% after the purification by column chromatography. The results obtained by FTIR and 1H NMR further showed that the column chromatography can effectively improve the purity of biodiesel. This paper provides a basis for industrialization of purification of biodiesel.


Subject(s)
Biofuels , Chromatography, Gas , Gas Chromatography-Mass Spectrometry , Glycerol , Methanol , Plant Oils
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(7): 1747-51, 2011 Jul.
Article in Chinese | MEDLINE | ID: mdl-21942016

ABSTRACT

The dehydration of bischofite is the key to the use of magnesium resource. Double salts or complex method is an important way to prepare anhydrous magnesium chloride. The crystals of bischofite and aniline hydrochloride were prepared through lowering the temperature of the mixture's aquatic solution slowly. The pyrolysis of aniline hydrochloride, bischofite and the crystals was qualitatively analyzed by TG-FTIR under 400 degrees C. We infered the reaction process through qualitative detection of escaping gas of each decomposition step. The Experimental results showed that there were three steps in the thermal decomposition of bischofite. In the first step, nearly four crystallized waters decomposed, while hydrolysis and decomposition took place together in the next two steps, but hydrolysis was the main reaction at the lower temperature (205-235 degrees C), and comparative decomposition was the main one at the higher temperature (235-287 degrees C). In the experimental temperature range, aniline hydrochloride didn't decompose. Water and aniline hydrochloride left the crystals at different temperature, and no hydrolysis reaction occurred. Anhydrous magnesium chloride can be prepared though this way.

13.
Carbohydr Res ; 346(4): 480-7, 2011 Mar 01.
Article in English | MEDLINE | ID: mdl-21276967

ABSTRACT

Al-promoted SO4 ²â»-/ZrO2SBA-15 catalysts were prepared and characterized by XRD, BET, ICP and NH3-TPD techniques. The influence of introducing aluminum on the structure and surface properties of the catalyst and the catalytic activity for dehydration of xylose to furfural has been investigated. The introduction of the Al stabilizes the tetragonal phase of the ZrO2 and thus increases the number and intensity of acid sites. Based on the characterization of the deactivated catalyst, the accumulation of byproducts is the main reason for the deactivation of the catalyst. Regeneration with H2O2 can completely recover the catalytic activity of the deactivated catalyst.


Subject(s)
Aluminum/chemistry , Furaldehyde/chemical synthesis , Silicon Dioxide/chemistry , Xylose/chemistry , Catalysis , Hydrogen Peroxide/chemistry , Surface Properties , Zirconium/chemistry
14.
Zhonghua Nan Ke Xue ; 15(9): 855-60, 2009 Sep.
Article in Chinese | MEDLINE | ID: mdl-19947573

ABSTRACT

OBJECTIVE: Shen Yan Ling Tablet is an innovative compound of traditional Chinese medicine, scientifically prepared with Tripterygium wilfordii, Radix Astragali, and others, with precise efficacy on renal diseases and reduced adverse effects of Tripterygium wilfordii. Based on the Guiding Principles for New Drug Toxicity Research Before Clinical Application, we investigated the long-term toxicity of Shen Yan Ling Tablet and its effect on the reproductive function in rats. METHODS: According to the clinical therapeutic dose and the results of the acute toxicity test of Shen Yan Ling Tablet, we equally divided 80 rats (males and females half-and-half) into a low-dose (1.25 g/kg body wt), a medium-dose (2.50 g/kg body wt), a high-dose (5.00 g/kg body wt) and a control group. After a 3-month medication, we conducted standardized long-term toxicity tests and observed the effects of Shen Yan Ling on the serum sexual hormones and epididymal sperm count. RESULTS: After 3 months of treatment with Shen Yan Ling, no death occurred, the general status remained unchanged, and the parameters of blood cytology and biochemistry fluctuated within the normal range, without any significant changes (P > 0.05). Some blood parameters, RBC, WBC, HGB, AST and TBIL, showed statistic changes (P < 0.05), but with no clinical significance. There were no significant differences in the mass coefficients of the main organs between the medication and control groups. The high-dose group exhibited slight hepatic and pulmonary pathological changes and significantly reduced sperm counts in the epididymis, but no significant changes in serum sexual hormones (P < 0.05). CONCLUSION: Three-month medication of Shen Yan Ling at 1.25 - 5.00 g/kg produced no significant accumulated toxicity on rats, but it had a negative effect on their reproductive function at a higher dose of > or = 5.00 g/kg.


Subject(s)
Epididymis/drug effects , Plant Extracts/toxicity , Toxicity Tests, Acute , Tripterygium , Animals , Drugs, Chinese Herbal/toxicity , Female , Male , Nephritis/drug therapy , Organ Size , Phytotherapy , Rats , Rats, Sprague-Dawley , Spermatozoa/drug effects , Tablets
15.
Huan Jing Ke Xue ; 29(6): 1578-81, 2008 Jun.
Article in Chinese | MEDLINE | ID: mdl-18763504

ABSTRACT

Radiolysis of aqueous solution of thiocyanate by 60Co gamma-rays was studied. In condition of pH = 1 and pH = 3,25 mg/L SCN- was decomposed under the dose of 6 kGy, with decomposition rate of 98.11% (pH = 1) and 95.97% (pH = 3) respectively. 25 mg/L SCN- (pH = 7) was decomposed under the dose of 9 kGy and the decomposition rate is 99.33%. In the alkaline condition, pH = 10 and pH = 12, the dose of 18 kGy was need, and the decomposition rate is 99.64% and 99.93% respectively. High SCN- concentration means that more radiation dose is need. From the comparison of before radiolysis and after radiolysis's TOC (total organic carbon) and TN (total nitrogen) of SCN- solution, little TOC and TN was removed. The determination of SO4(2-) and NO3- concentration indicated that sulfur element was removed and converted to SO4(2-), and nitrogen element rarely converted to NO3-, but converted to other forms of nitrogen.


Subject(s)
Gamma Rays , Thiocyanates/chemistry , Waste Disposal, Fluid/methods , Water Pollutants, Chemical/chemistry , Photolysis , Thiocyanates/isolation & purification , Water Pollutants, Chemical/isolation & purification
16.
Huan Jing Ke Xue ; 29(11): 3138-42, 2008 Nov.
Article in Chinese | MEDLINE | ID: mdl-19186817

ABSTRACT

We studied the 60Co gamma-ray radiolysis of thiocyanate aqueous solutions in the presence of free radical scavengers, determination of cyanide of radiated thiocyanate solutions, degradation of cyanide and thiocyanate complicated system and cyanide, thiocyanate and copper (I) cyanide complicated system. The presence of NaHCO3 and n-butanol made the degradation efficiency of thiocyanate decreased, in the radiation procession of thiocyanate, cyanide was produced; and the possible reaction equation is SCN(-) + 8*OH-->SO4(2-) + CN(-) +4H2O, in the cyanide and thiocyanate system, the thiocyanate degradation rate can obtained 30%, free cyanide degradation was little effected by coexistence of thiocyanate; and due to strong complex ability of copper (I), the main form of copper (I) cyanide is Cu(CN)3(2-), the total cyanide of the system can't be degraded completely and degradation rate is about 80%.


Subject(s)
Gamma Rays , Thiocyanates/radiation effects , Waste Disposal, Fluid/methods , Water Pollutants, Chemical/radiation effects , Water Purification/methods , Cobalt Radioisotopes
17.
Biotechnol Lett ; 29(7): 1051-5, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17479227

ABSTRACT

Sugarcane bagasse hemicellulose hydrolysates, pretreated by either over-liming or electrodialysis and, supplemented with nutrient materials, were fermented to ethanol using Pachysolen tannophilus DW06. Compared with detoxification by over-liming, detoxification by electrodialysis decreased the loss of sugar and increased the acetic acid removal, leading to better fermentability. A batch culture with electrodialytically pretreated hydrolysate as substrate was developed giving 21 g ethanol l(-1) with a yield of 0.35 g g(-1) sugar and productivity of 0.59 g l(-1) h(-1).


Subject(s)
Cellulose/metabolism , Ethanol/metabolism , Fermentation , Polysaccharides/metabolism , Saccharomycetales/metabolism , Saccharum/metabolism , Hydrolysis , Time Factors
18.
Biotechnol Lett ; 28(22): 1817-21, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16912919

ABSTRACT

Broth containing 152 g glycerol l(-1) from Candida krusei culture was converted to 1,3-propanediol by Klebsiella pneumoniae. Residual glucose in the broth promoted growth of K. pneumoniae while acetate was inhibitory. After desalination treatment of glycerol broth by electrodialysis, the acetate in the broth was removed. A fed-batch culture with electrodialytically pretreated broth as substrate was developed giving 53 g 1,3-propanediol l(-1) with a yield of 0.41 g g(-1) glycerol and a productivity of 0.94 g l(-1) h(-1).


Subject(s)
Biotechnology/methods , Glycerol/chemistry , Klebsiella pneumoniae/metabolism , Propylene Glycols/metabolism , Bioreactors , Candida/metabolism , Chromatography , Electrochemistry/methods , Filtration , Glycerol/metabolism , Membranes/chemistry , Propylene Glycols/chemistry , Time Factors
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 24(6): 752-5, 2004 Jun.
Article in Chinese | MEDLINE | ID: mdl-15766201

ABSTRACT

Quaternary ammonium salt has strong affinity with gold in cyanide solutions, but it is not readily stripped. Stripping with acidic thiourea solutions and air sparging shows promise. There are some reports on the process of thiourea stripping, but little about its mechanism. In this paper, the stripping mechanism of N263/sulphuric thiourea/alkaline cyanide gold solution is studied by EXAFS. According to the experiments, sulphuric acid, thiourea and gold-thiourea complex can be extracted by N263 as a neutral molecule, and the stripping process can be described as following: (1) Sulphuric acid and thiourea are extracted by N263; (2) In organic phase, gold-cyanide complex is converted to gold-thiourea complex, which exists as Au[SC(NH2)2]2HSO4, and CN- forms HCN with acid at the same time; (3) HCN is removed by air sparging, and Au[SC(NH2)2]2HSO4 is distributed between organic phase and liquor phase, most of which transfers to liquor phase and is stripped.


Subject(s)
Gold/isolation & purification , Quaternary Ammonium Compounds/chemistry , Reagent Strips/chemistry , Thiourea/chemistry , Amines , Cyanates/chemistry , Cyanides/chemistry , Electrochemistry , Environmental Monitoring , Gold/chemistry , Hydrogen-Ion Concentration , Metal Nanoparticles/chemistry , Nanotechnology , Pharmaceutical Solutions , Solutions/chemistry , Sulfuric Acids/chemistry
20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 23(2): 371-3, 2003 Apr.
Article in Chinese | MEDLINE | ID: mdl-12961899

ABSTRACT

The concentrations of gold in thiourea and sulfuric acid solutions using gold standard solutions in diluent royal water were determined by AAS. The linear range was 0.2-12 x 10(-6), and RSD < 5%. This method simplifies the analysis of gold in thiourea and sulfuric acid solution. Thiourea declines the absorbency of gold while sulfuric acid plays a contrary role. The determined value were satisfactor after being modified by the blank curve.


Subject(s)
Gold/analysis , Sulfuric Acids/chemistry , Thiourea/chemistry , Reproducibility of Results , Solutions , Spectrophotometry, Atomic/methods
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