Calculating Method Study and Parameter Analysis of Slender LCFST Columns Under Axial Loading

Ting Zhou,Ziyang Ren,Baoqi Jiang,Minyang Xu,Zhiyong Lei,Zhi-Hua Chen 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.5

L-shaped columns composed of concrete-fi lled steel tubes (LCFST columns) connected by steel plates, which are important component to make sure the mono-column working together, were investigated under axial loading experiment with diff erent width and thickness of connection plates. The relationships between load and longitudinal displacement, lateral displacement, longitudinal strains and transverse strains as well as failure mode are presented. Load carrying capacity of LCFST columns increased with the width and thickness of the connection plates increasing. In addition, the integrity of the specimen was improved with increase of thickness and decrease of width of the connection plates. Failure modes obtained from the fi nite element model were consistent with the phenomenon observed in the test. Besides, the parameters of slenderness ratio, dimensions of connection plate, and transverse stiff ener spacing were analyzed. Finally, the calculating method of yield bearing capacity of axial compression was proposed based on the former analysis.

Experimental Study and Parameter Analysis of L-shaped Composite Column under Axial Loading

Ting Zhou,Minyang Xu,Xiaodun Wang,Zhi-Hua Chen,Ying Qin 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.4

A special-shaped column composed of concrete-filled steel tubes (SCFST column) is experimentally investigated in this paper. The SCFST column is composed of several small-sized concrete-filled square tubular columns (mono-columns) connected by connection plates. This kind of column is proposed because it can increase the usable space in residential buildings. The axial loading behavior of L-shaped SCFST columns is experimentally investigated. The failure mode, strain distribution, cooperation of mono-columns, bearing capacity, and the effect of a concrete core on column behavior were tested. As concluded, the SCFST column can be regarded as a useful kind of column. A finite element analysis model was proposed according to the experimental results, and the influence of connection plate size on bearing capacity was studied using the finite element model. Finally, proposed were the optimal width and thickness of connection plates for improving the design of the SCFST column.

Experimental Study on Fire Resistance Performance of Concrete-Filled Steel Plate Composite Walls

Ting Zhou,Xueshan Liu,Hongbo Liu,Yixuan Li,Pengfei Zhang,Huazhou Chen,Zhi-Hua Chen 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.2

Concrete-filled steel plate composite walls are increasingly used in high-rise buildings; their mechanical properties at room temperature have produced fruitful results. However, research on their mechanical properties in fire and at high temperatures is scarce. Moreover, published studies on the fire resistance of concrete-filled steel plate composite walls have not considered the impact of fire protection measures. Based on previous fire resistance research, a fire resistance test was designed in this study for four walls under the combined action of axial compression and a single-sided fire under the ISO-834 standard heating curve. Apart from that, the existing fire protections have the disadvantages of too thick, easy falling off and cracking or difficult to install. In order to eliminate the disadvantages of existing fire prevention measures, new composite fireproof structure using a rock wool board and a thin fire-retardant coating is proposed. The effects of no fireproof structures, autoclaved lightweight concrete plate fireproof structures, thick-coated fire-retardant structures, and new composite fireproof structures on the fire resistance of concrete-filled steel plate composite walls were studied experimentally. The results show that the fire resistance of the four test specimens meets the 3 h fire resistance limit of the primary load-bearing component in the specification. Based on the experimental results, reasonable fire protection methods are suggested for concrete-filled steel plate composite walls in actual projects, and an experimental basis is provided for further numerical simulation.

Analysis of policies to develop the teaching force in rural areas of China

Eryong Xue,Tingzhou Li 한국교육개발원 2017 KEDI Journal of Educational Policy Vol.14 No.2

To comprehensively and systematically assess problems and effectiveness of policies aimed at attracting teachers to rural areas in China in depth and clarify the direction of reforms, we analyze policies by using methods such as questionnaires, interviews, systematic analysis, text analysis, and shadow controls. Since the 18th National Congress of the Communist Party (2012), China has gradually developed special policies to attract teachers to rural areas, including policies to increase the number and improve the quality and compensation packages of rural teachers. The key factors that pose challenges to the expansion of the teaching force in rural areas of China include poor remuneration and unreasonable deployment of rural teachers and ineffective enforcement of the teacher exchange policy. Policies were introduced to increase the compensation packages to attract qualified teachers to rural schools, which establish an effective system to ensure adequate supply of resources to facilitate professional developments of rural teachers, and implement the teacher exchange and rotation system to attract more teachers to rural areas. China’s policy-makers will make further efforts to increase remuneration of rural teachers and improve the rural teacher deployment mechanism and the teacher exchange mechanism between urban and rural areas.

Efficient Isolation and Characterization of a Cellulase Hyperproducing Mutant Strain of Trichoderma reesei

( Zongsheng Zou ),( Yunying Zhao ),( Tingzhou Zhang ),( Jiaxing Xu ),( Aiyong He ),( Yu Deng ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.9

A cellulase hyperproducing mutant strain, JNDY-13, was obtained using the ARTP mutation system and with Trichoderma reesei RUT-C30 as the parent strain. Whole-genome sequencing of JNDY-13 confirmed that 105 of the 653 SNPs were point mutations, 336 mutations were deletions and 165 were insertions. Moreover, 99 mutations were insertions and duplications. Among all the mutations, the one that occurred in the galactokinase gene might be related to the production of cellulases in T. reesei JNDY-13. Moreover, the up-regulation of cellulase and hemicellulase genes in JNDY-13 might contribute to higher cellulases production. Under optimal conditions, the highest cellulase activity by batch fermentation reached 4.35 U/ml, and the highest activity of fed-batch fermentation achieved was 5.40 U/ml.

One-pot synthesis of high fructose corn syrup directly from starch with SO42−/USY solid catalyst

Yong Sun,Caixia Xiong,Huihui Chen,Xianhai Zeng,Xing Tang,Tingzhou Lei,Lu Lin 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.7

An efficient process was developed for the conversion of starch directly into high fructose corn syrup (HFCS) by using SO4 2−/USY solid catalyst in water. The SO4 2−/USY catalyst was found to act as a bifunctional catalyst with high activity for both hydrolysis of starch and isomerization of glucose, achieving a one-step preparation path of HFCS from starch. An optimal HFCS yield, containing 58.34% glucose and 27.84% fructose (mass fraction), was obtained at 150 oC for only 1 h.

Comparative transcriptome analysis to identify genes involved in terpenoid biosynthesis in Agriophyllum squarrosum, a folk medicinal herb native to Asian temperature deserts

Yin Xiaoyue,Yan-Xia Liu,Qian Chaoju,Zhou Shanshan,Fang Tingzhou,Fan Xingke,Gao yuan,Chang Yuxiao,Yang Jian,Ma Xiao-Fei 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.3

Agriophyllum squarrosum is a folk Mongolian medicine with pleiotropic pharmacological and ecological economic importance endemic to Asian temperature deserts. Terpenoids play critical roles in biotic and abiotic stresses due to their antioxidative activities. Based on non-targeted metabolomic analysis, we detected eight terpenoids enriched in the above-ground tissues of A. squarrosum, however, the molecular mechanism underlying terpenoids biosynthesis in this desert medicinal plant is rarely understood. Here, a comparative transcriptome analysis of diferent tissues in A. squarrosum was conducted to identify 84 unigenes encoding key enzymes in the upstream backbone biosynthesis and 53 unigenes encoding the downstream enzymes for terpenoid diversifcation. Most of the upstream genes exhibited signifcant high expression levels in leaf, and some of which were validated by qRT-PCR. Phylogenetic analysis showed that two downstream gene families OSCs (oxidosqualene cyclases) and TPSs (mainly in terpene synthases -g subfamily) had undergone notable gene expansions in A. squarrosum comparing with the other Amaranthaceae plant species and Arabidopsis. Nevertheless, most members from these two gene families showed the tissue-specifc expression in A. squarrosum, which supported the diversifcation and tissue-specifc enrichment of terpenoids across above-ground tissues. Considering to the habitat characteristics of A. squarrosum, we proposed that the enrichment of terpenoids and the functional diversifcation of terpenoids biosynthesis enzymes were more or less involved into its adaptation to stressful environments of deserts. These results expand the available genetic information underlying terpenoid biosynthesis in A. squarrosum, and contribute to deeper researches on pharmaceutical and eco-agricultural applications in this desert medicinal plant.

Synthesis of renewable monomer 2, 5-bishydroxymethylfuran from highly concentrated 5-hydroxymethylfurfural in deep eutectic solvents

Ting Wang,Junnan Wei,Huai Liu,Yunchao Feng,Xing Tang,Xianhai Zeng,Yong Sun,Tingzhou Lei,Lu Lin 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.81 No.-

2, 5-Bishydroxymethylfuran (BHMF) has been currently emerged as a promising biomass-derivedmonomer. It is highly desirable to proceed a chemical process at a high substrate concentration, by whicha facile and cost-effective separation of products can be expected. Herein, we report for thefirst time onthe hydrogenation of highly concentrated 5-hydroxymethylfurfural (HMF) in deep eutectic solvents(DESs), giving a near quantitative selectivity towards BHMF in ChCl-glycerol DES at 25 C in 3 h usingNaBH4 as the H-donor. DES is hailed as a new class of green solvent, in which HMF/BHMF could bestabilized by the strong hydrogen-bond interaction, and allowed the selective hydrogenation of HMF athigh concentration up to 40 wt%. Notably, the resulting BHMF could be facilely separated by extractionwith ethyl acetate, and then high purity of BHMF with a desirable isolated yield around 80% was obtainedafter removing of ethyl acetate. Additionally, the reaction efficiency of HMF hydrogenation in DESs wasverified to be strongly associated with the viscosity of DESs and the pKa value of hydrogen-bonding donor.

Soy Protein Isolate As Fluid Loss Additive in Bentonite–Water-Based Drilling Fluids

Li, Mei-Chun,Wu, Qinglin,Song, Kunlin,Lee, Sunyoung,Jin, Chunde,Ren, Suxia,Lei, Tingzhou American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.44

<P>Wellbore instability and formation collapse caused by lost circulation are vital issues during well excavation in the oil industry. This study reports the novel utilization of soy protein isolate (SPI) as fluid loss additive in bentonite–water based drilling fluids (BT-WDFs) and describes how its particle size and concentration influence on the filtration property of SPI/BT-WDFs. It was found that high pressure homogenization (HPH)-treated SPI had superior filtration property over that of native SPI due to the improved ability for the plugging pore throat. HPH treatment also caused a significant change in the surface characteristic of SPI, leading to a considerable surface interaction with BT in aqueous solution. The concentration of SPI had a significant impact on the dispersion state of SPI/BT mixtures in aquesous solution. At low SPI concentrations, strong aggregations were created, resulting in the formation of thick, loose, high-porosity and high-permeability filter cakes and high fluid loss. At high SPI concentrations, intercatlated/exfoliated structures were generated, resulting in the formation of thin, compact, low-porosity and low-permeability filter cakes and low fluid loss. The SPI/BT-WDFs exhibited superior filtration property than pure BT-WDFs at the same solid concentraion, demonstrating the potential utilization of SPI as an effective, renewable, and biodegradable fluid loss reducer in well excavation applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-44/acsami.5b07883/production/images/medium/am-2015-07883j_0012.gif'></P>

Efficient synthesis of bio-monomer 2,5-furandicarboxylic acid from concentrated 5-hydroxymethylfurfural or fructose in DMSO/H2O mixed solvent

Huai Liu,Xuejuan Cao,Ting Wang,Junnan Wei,Xing Tang,Xianhai Zeng,Yong Sun,Tingzhou Lei,Shijie Liu,Lu Lin 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.77 No.-

The conversion of concentrated 5-hydroxymethylfurfural (HMF) or fructose to 2,5-furandicarboxylic acid(FDCA), a renewable alternative to petroleum-derived terephthalate acid, is highly desirable butchallenging for FDCA production in an industrial scale. In this contribution, DMSO/H2O mixture wasdemonstrated as an effective medium for the production of FDCA from high concentration of HMF orfructose. For example, FDCA yield up to 93% was achieved at 10 wt% HMF concentration in DMSO/H2Oover commercially available Ru/C (2 equiv. NaHCO3, 130 C, 4 MPa O2 and 12 h). Furthermore, an overallFDCA yield of 65% was achieved from concentrated fructose (19 wt%) through a facile two-step process. Notably, it is so far the highest HMF or fructose concentration employed for FDCA formation. As comparedto pure water or DMSO, DMSO/H2O mixed system is able to stabilize HMF in an alkaline environment,which allows the efficient oxidation of HMF at high concentrations.