ZSM-5 zeolite was rapidly synthesized in system containing ethylenediamine from the initial gel: (5?8) Na2O: 44 EDA:Al2O3:100 SiO2:4000 H2O. The crystals were lath-shaped. The effect of pretreatment and alkalinity on...ZSM-5 zeolite was rapidly synthesized in system containing ethylenediamine from the initial gel: (5?8) Na2O: 44 EDA:Al2O3:100 SiO2:4000 H2O. The crystals were lath-shaped. The effect of pretreatment and alkalinity on crystallinity was investigated. The pretreatment of silicate source can cut down the crystallization time. Tuning the system alkalinity and controlling crystallization time can ensure forming of pure crystal.展开更多
In this paper three methods(dilute acid pretreatment, aqueous ammonia/dilute acid pretreatment and alkaline pretreatment) were used to study the hydrolysis of corn stover and characteristics of each method were compar...In this paper three methods(dilute acid pretreatment, aqueous ammonia/dilute acid pretreatment and alkaline pretreatment) were used to study the hydrolysis of corn stover and characteristics of each method were compared. The results showed that the lignin removal rate was 71.8% when the corn stover was treated with a caustic soda solution containing 1.5% of NaOH, at a temperature of 75 ℃ for 90 min with an initial solid-liquid ratio of 1:8(w/v). Hydrolysis yield of the NaOH pretreated sample reached 78.5%, which was much higher than other control groups. These results are useful for evaluation of pretreatment technologies, and identification of key factors that limit cellulose hydrolysis, and can also serve as a basis for designing and screening appropriate pretreatment technologies.展开更多
Alkali halide clusters are interesting model systems that can provide information about how crystal properties evolve. To study these properties, a high-resolution atmospheric pressure inlet time-of-flight mass spectr...Alkali halide clusters are interesting model systems that can provide information about how crystal properties evolve. To study these properties, a high-resolution atmospheric pressure inlet time-of-flight mass spectrometry （APi-TOF-MS） study of the sequential sodium halides series, C1-（NaC1）n and Br-（NaBr）m, has been reported, and the viability of the APi-TOF- MS equipped with an electrospray ionization source in determining cluster compositions has been demonstrated. The isotopic patterns were well resolved, as n=4 and 7 were determined to be the magic numbers for C1-（NaC1）n clusters, which were particularly abundant in the mass spectra. A global minimum search based on density functional theory enabled basin hopping yield the most stable structures for the mentioned series. The structures exhibit several distinct motifs which can be roughly categorized as linear chain, rock salt, and hexag- onal ring. This work provides an effective way to discover and elucidate the nonstoichiometry sodium halide clusters. These clusters possess very high vertical detachment energies and are generally called as superhalogens, which play important roles in chemistry because they are widely used in the synthesis of new classes of charge-transfer salts.展开更多
Desertification is an environmental issue in the world. The salt-alkalization desertification land area formed by both primary and secondary salt-alkalization has extended in a large scale, which has become a signific...Desertification is an environmental issue in the world. The salt-alkalization desertification land area formed by both primary and secondary salt-alkalization has extended in a large scale, which has become a significant eco-environmental problem. Based on the characteristics of eco-environment and the situation of desertification in westem Songnen plain, this paper reports the analyzes of its formation in background and cause. An early waming system on the salt-alkalization desertification is established and the GIS technology is used to abstract the information of desertification evaluation index. Supported by the integrated technology of the GIS and ANN, the orientation and quantitative result of desertification are gained, which is helpful to the eco-environment protection and resource development in westem Songnen Plain.展开更多
基金Project (No. 29976036) supported by the National Natural Science Foundation of China
文摘ZSM-5 zeolite was rapidly synthesized in system containing ethylenediamine from the initial gel: (5?8) Na2O: 44 EDA:Al2O3:100 SiO2:4000 H2O. The crystals were lath-shaped. The effect of pretreatment and alkalinity on crystallinity was investigated. The pretreatment of silicate source can cut down the crystallization time. Tuning the system alkalinity and controlling crystallization time can ensure forming of pure crystal.
基金Financial support provided by the SINOPEC Research Program(No.S213070)
文摘In this paper three methods(dilute acid pretreatment, aqueous ammonia/dilute acid pretreatment and alkaline pretreatment) were used to study the hydrolysis of corn stover and characteristics of each method were compared. The results showed that the lignin removal rate was 71.8% when the corn stover was treated with a caustic soda solution containing 1.5% of NaOH, at a temperature of 75 ℃ for 90 min with an initial solid-liquid ratio of 1:8(w/v). Hydrolysis yield of the NaOH pretreated sample reached 78.5%, which was much higher than other control groups. These results are useful for evaluation of pretreatment technologies, and identification of key factors that limit cellulose hydrolysis, and can also serve as a basis for designing and screening appropriate pretreatment technologies.
文摘Alkali halide clusters are interesting model systems that can provide information about how crystal properties evolve. To study these properties, a high-resolution atmospheric pressure inlet time-of-flight mass spectrometry （APi-TOF-MS） study of the sequential sodium halides series, C1-（NaC1）n and Br-（NaBr）m, has been reported, and the viability of the APi-TOF- MS equipped with an electrospray ionization source in determining cluster compositions has been demonstrated. The isotopic patterns were well resolved, as n=4 and 7 were determined to be the magic numbers for C1-（NaC1）n clusters, which were particularly abundant in the mass spectra. A global minimum search based on density functional theory enabled basin hopping yield the most stable structures for the mentioned series. The structures exhibit several distinct motifs which can be roughly categorized as linear chain, rock salt, and hexag- onal ring. This work provides an effective way to discover and elucidate the nonstoichiometry sodium halide clusters. These clusters possess very high vertical detachment energies and are generally called as superhalogens, which play important roles in chemistry because they are widely used in the synthesis of new classes of charge-transfer salts.
基金the National Natural Science Foundation of China
文摘Desertification is an environmental issue in the world. The salt-alkalization desertification land area formed by both primary and secondary salt-alkalization has extended in a large scale, which has become a significant eco-environmental problem. Based on the characteristics of eco-environment and the situation of desertification in westem Songnen plain, this paper reports the analyzes of its formation in background and cause. An early waming system on the salt-alkalization desertification is established and the GIS technology is used to abstract the information of desertification evaluation index. Supported by the integrated technology of the GIS and ANN, the orientation and quantitative result of desertification are gained, which is helpful to the eco-environment protection and resource development in westem Songnen Plain.
