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Glass-forming ability and crystallization of Mg-Ni amorphous alloys with Y addition

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Rare Metals 2012年第3期31卷 244-249页

作者： liu liyan Teng Xinying Wang Yongjie liu Teng Univ Jinan Sch Mat Sci & Engn Jinan 250022 Peoples R China Univ Jinan Sch Phys & Technol Jinan 250022 Peoples R China

Mg86.33Ni13.67-xYx(x=0, 1, 3, 6, 10) amorphous alloys were obtained by single-roller melt-spinning technique and the effect of Y addition on the glass forming ability(GFA), crystallization and micro-hardness of Mg-Ni alloys were studied. The results show that the GFA of Mg86.33Ni13.67-xYx(x=0, 1, 3, 6, 10) is improved successfully with the Y addition. The highest GFA appeares at x=6, while the reduced glass transition temperature (Trg) is 0.5225 and the supercooled liquid region(ΔTx) is 42.06 K; the position of the main diffraction halo is different for the alloys, and the maximum of the main diffraction halo of alloys with x=0, 1, 3 corresponds to the main peaks of a metastable fcc-Mg6Ni or fcc-Mg6Ni + Ni-Y intermetallic phases, and for the alloys with x=6, 10, it corresponds to Mg-Y and Ni-Y intermetallic phases; the micro-hardness of the alloys is improved with Y additions, and the highest micro-hardness is obtained at x=6 at.%, which is 960 MPa.

关键词： Mg-based amorphous alloy glass forming ability crystallization micro-hardness

Influence of Na^+,K^+,Mg^(2+),Ca^(2+),and Fe^(3+) on filterability and settleability of drilling sludge

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Chinese Journal of Chemical Engineering 2017年第5期25卷 658-664页

作者： liyan liu Hao Yan Wei Tan Guorui Zhu School of Chemical Engineering and Technology Tianjin University

Solid–liquid separation is a vital step in drilling sludge disposal, and the filterability and settleability of drilling sludge are the main evaluating indicators for the separation process. The influence of Na^+,K^+,Mg^(2+),Ca^(2+),and Fe^(3+) on drilling sludge filterability and settleability was investigated in our research. The water content,filtration rate, supernatant volume and supernatant turbidity were measured to evaluate the filterability and settleability of drilling sludge. Meanwhile, the zeta potential, specific surface area of sludge flocs, particle size distribution and Fourier-transformed infrared spectra were employed to clarify the influencing *** experimental results showed that the filterability and settleability of drilling sludge were related to concentration and types of cations. Mg^(2+),Ca^(2+),and Fe^(3+) performed better than Na^+, K^+, and the cations with smaller hydrated radius got superior solid–liquid separation behavior at same valence. Finally, the spectra indicated that no chemical adsorption occurred between inorganic cations and drilling sludge flocs. The variation of surface charge and flocs growth after adding different inorganic cations were the reasons for the changes of the filterability and settleability.

关键词： Drilling sludge Inorganic cations Filtration Settleability Adsorption

Suppression of methane/air explosion by water mist with potassium halide additives driven by CO2

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Chinese Journal of Chemical Engineering 2019年第11期27卷 2742-2748页

作者： Wei Tan Dong Lü liyan liu Guorui Zhu Nan Jiang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300354China Tianjin Fire Research Institute of MEM Tianjin 300381China

To enhance the explosion suppression effects of water mist, various potassium halide additives were tested in a confined vessel filled with a 10% mixture of methane/air. Air and CO2(0.7 MPa) were used as driver gases. The results revealed that halide additives exhibit considerable suppression effects on explosion overpressure. A30% KI mist decreased the explosion overpressure by 27.46% compared with the suppression by pure water mist under the same conditions. When CO2 is used as the driver gas, it will dissolve in water under high *** synergistic effect of a CO2 solution with an effective additive afforded significant suppression. Under the same conditions, the overpressures suppressed by a mist of 30% KI + 0.7 MPa CO2 solution decreased by 33.53% compared with those suppressed by pure water mist driven by air. The synergistic suppression effect is much better than that of a 0.7 MPa CO2 solution mist or 30% KI mist alone. The multicomponent additives can be considered when suppressing methane/air explosions with pressure-formed water mist.

关键词： Methane Explosion suppression Water mist Halide CO2

Streamlined and on-demand preparation of mRNA products on a universal integrated platform

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Microsystems & Nanoengineering 2023年第4期9卷 119-128页

作者： Hongjuan Wei Zhen Rong liyan liu Ye Sang Jing Yang Shengqi Wang Bioinformatics Center of AMMS Beijing 100850P.R.China

Vaccines are used to protect human beings from various *** vaccines simplify the development process and reduce the production cost of conventional vaccines,making it possible to respond rapidly to acute and severe diseases,such as coronavirus disease *** this study,a universal integrated platform for the streamlined and ondemand preparation of mRNA products directly from DNA templates was *** DNA templates were amplified in vitro by a polymerase chain reaction module and transcribed into mRNA sequences,which were magnetically purified and encapsulated in lipid *** an initial example,enhanced green fluorescent protein(eGFP)was used to test the *** expression capacity and efficiency of the products were evaluated by transfecting them into HEK-293T *** batch production rate was estimated to be 200–300μg of eGFP mRNA in 8 ***,an mRNA vaccine encoding the receptor-binding domain(RBD)of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)spike protein was produced by this *** proposed integrated platform shows advantages for the universal and on-demand preparation of mRNA products,offering the potential to facilitate broad access to mRNA technology and enable the development of mRNA products,including the rapid supply of new mRNA-based vaccines in pandemic situations and personalized mRNA-based therapies for oncology and chronic infectious diseases,such as viral hepatitis and acquired immune deficiency syndrome.

关键词： preparation template offering

Migration of Cr_2O_7^(2-) and Butanone in Soil and Groundwater System After the Tianjin Port 8·12 Explosion

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Transactions of Tianjin University 2018年第6期24卷 522-531页

作者： liyan liu Shaopan Liang Hongchen liu Wei Tan Guorui Zhu School of Chemical Engineering and Technology Tianjin University

After the Tianjin Port 8.12 explosion, an enormous amount of potassium dichromate （K2Cr2O7） and butanone （CH3COCH2CH3） leaked into the coastal soil-groundwater system, which potentially threatened the environment and human health. Determining the transport process of hazards is necessary to establish guidelines for remediating the contaminated area. This work aims to investigate the migration of potassium dichromate and butanone in the coastal soil-groundwater system through a coupling unsaturated-saturated numerical model, incorporating the HYDRUS model into the MODFLOW/ MT3D model. In the unsaturated zone, two-dimensional HYDRUS model was applied, and its recharge flux at the bottom boundary was utilized as the input of MODFLOW/MT3D model in the saturated zone. Results showed that Cr2O^（2-）7 migrated much faster than butanone in the unsaturated zone and reached the water table in about 1 year. In comparison, butanone was unlikely to enter the aquifer even 5 years later with a migration depth of about 2.2 m. Driven by groundwater, the Cr2O^（2-）7 that entered the aquifer migrated about 161 m toward southeast 5 years later. In the saturated zone, the contamination plume covered mainly the southeast area due to the groundwater flow direction.

关键词： Potassium dichromate Butanone HYDRUS MODFLOW Coastal soil-groundwater system Tianjin Port 8·12 explosion

Estimation of the Effects of Maize Straw Return on Soil Carbon and Nutrients Using Response Surface Methodology

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Pedosphere 2018年第3期28卷 411-421页

作者： ZHOU Dongxing SU Ye NING Yucui RONG Guohua WANG Guangdong liu Di liu liyan College of Resources and Environmental Science Northeast Agricultural University Publicity and United Front Work Department Northeast Agricultural University

Straw incorporation is generally considered an effective agricultural management practice that improves nutrient cycling and maintains soil fertility. To study the interactive effects of straw returning factors on soil organic carbon and available nutrients, a17-month(May 6, 2016 to October 6, 2017) experiment was conducted on straw incorporation by using response surface methodology under a three-factor(straw length, amount, and burying depth), five-level quadratic orthogonal rotation experimental design. Weight was assigned to each indicator for soil carbon and nutrients and then a comprehensive indicator was established. Then, a second-order polynomial model of the three straw returning factors was established using response surface methodology. Results indicated that17 months after straw incorporation, straw amount and burying depth had significant effects on the comprehensive indicator of soil carbon and nutrients. Straw length and the interactions of straw amount and burying depth showed no significant effects on the comprehensive indicator of soil carbon and nutrients. It was concluded that 17 months after straw incorporation, the highest value of the comprehensive indicator of soil carbon and nutrients was achieved when the straw length, amount, and burying depth were approximately 17–20 cm, 740–840 g m^(-2), and 9–13 cm, respectively, which can be recommended as the most suitable parameters for use in straw returning in the study area.

关键词： agricultural management practice soil fertility soil organic carbon straw amount straw burying depth straw length straw returning factors

Unexpected activated carbon-catalyzed pyrrolo[1,2-a]quinoxalines synthesis in water

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Chinese Chemical Letters 2019年第7期30卷 1379-1382页

作者： Qi Sun liyan liu Yu Yang Zhenggen Zha Zhiyong Wang Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Soft Matter Chemistry & Center for Excellence in Molecular Synthesis of Chinese Academy of Sciences Collaborative Innovation Center of Suzhou Nano Science and Technology & School of Chemistry and Materials Science in University of Science and Technology of China

An interesting and recyclable activated carbon/water catalytic system for efficient synthesis of pyrrolo[1,2-a]quinoxaline derivatives was developed. The intramolecular C-N and C-C bond can be easily constructed in water under mild condition. This reaction features a broad substrate scope, a good tolerance to water and air, metal-free, additive-free and redox reagent-free.

关键词： Pyrrolo[1,2-a]quinoxalines Activated carbon C-C C-N bond-forming Metal free Water solvent

Copper-catalyzed 1,1-difunctionalization of terminal alkynes: a three-component reaction for the construction of vinyl sulfones

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Science China Chemistry 2019年第7期62卷 904-908页

作者： Qi Sun Linge Li liyan liu Yu Yang Zhenggen Zha Zhiyong Wang Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Soft Matter Chemistry & Center for Excellence in Molecular Synthesis of Chinese Academy of Sciences Collaborative Innovation Center of Suzhou Nano Science and Technology & School of Chemistry and Materials Science in University of Science and Technology of China

A copper-catalyzed 1,1-difunctionalization of terminal alkynes was achieved via a three-component reaction, providing a variety of vinyl sulfones with good yields and excellent chemo-and stereoselectivity. Preliminary mechanistic studies indicated that the reaction probably underwent a Cu-catalyzed formal C–H insertion to produce an allene intermediate, which was then trapped by a sulfonyl anion to give the corresponding product.

关键词： copper terminal alkynes germinal difunctionalization multicomponent reaction vinyl sulfones

Effects of Solvent Molecules on the Interlayer Spacing of Graphene Oxide

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Transactions of Tianjin University 2018年第6期24卷 555-562页

作者： liyan liu Ruifeng Zhang Ying liu Haonan Zhu Wei Tan Guorui Zhu Yang Wang School of Chemical Engineering and Technology Tianjin University

Graphene oxide （GO） contains numerous functional groups that facilitate the intercalation of polar solvents. The properties and applications of GO are closely related to its interlayer spacing. We report on the changes in the interlayer spacing of GO after the adsorption of water molecules and the polar organic solvents C2H602 （EG）, C3HTNO （DMF）, C5H9NO （NMP）. Experiments were conducted to investigate the variations in the functional groups and structure of GO after solvent adsorp-tion, and they play a vital role in modeling and verifying the results of molecular dynamics simulation. The most stable GO structures are obtained through molecular dynamics simulation. The expansion of the interlayer spacing of GO after the adsorption of monolayer solvent molecules corresponds to the minimum three-dimensional size of the solvent molecules. The spatial arrangement of solvent molecules also contributes to the changes in interlayer spacing. Most adsorbed molecules are oriented parallel to the carbon plane of GO. However, as additional molecules are adsorbed into the interlaminations of GO, the adsorbed molecules are oriented perpendicular to the carbon plane of GO, and a large space forms between two GO interlayers. In addition, the role of large molecules in increasing interlayer spacing becomes more crucial than that of water molecules in the adsorption of binary solvent systems by GO.

关键词： Graphene oxide Interlayer spacing Solvent adsorption