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Wei Zhu,Jiahong Liu,Kuanxiang Shi,Fei Qi,Huiping Shen,Zhu Xu,Zhilong Ma 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.9
This paper proposes a three degree-of-freedoms (DOFs) cable-driven parallel robot (CDPR), which is actuated by three groups of parallel cables and tensioned by an elastic telescopic rod with a passive spring. Firstly, the architecture of the robot is briefly illustrated with emphasis on the three parallelogram arrangements of the cables and composition of elastic telescopic rod structure. This robot has larger workspace and greater tension than previous under-constrained CDPRs. Secondly, the kinematic and dynamic models of the robot are established. On this basis, the parameters of the spring installed in the telescopic rod are optimized and determined considering both the acceleration and cable force through using the differential evolution (DE) algorithm. Thirdly, dynamic stability analysis of the robot under impulsive disturbances is performed according to the Gauss principle of least constraint (GPLC). The results of a simulation case show that this robot has better dynamic stability in comparison with conventional under-constraint CDPR because of the presence of the elastic telescopic rod. The measurement results in the workspace are obtained through dynamic simulation. Finally, the experiments are performed based on numerical simulation. The feasibility of the CDPR is verified via the experiments and simulations.
She-Min Zhu,Da-Hai Zheng,Yuesong Shen,Yun-Shun Qiu,Bing Li,Yan-Wei Zeng,Shubao Shen,Shemin Zhu 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.24 No.-
Effects of catalyst loading amount, reaction temperature, O2 concentration, NH3/NO molar ratio and SO2 on low-temperature catalytic performance of the Mn–La–Ce–Ni–Ox (Mn/La/Ce/Ni = 2.5:2.5:1:1 in mol)/ PPS for NH3-SCR of NO were mainly studied. Results showed that the filter with catalyst loading amount of 250 g/m2 obtained more than 95% NO removal efficiency at 200 8C under filtration velocity of 1 m/min. The NO removal efficiency was still above 85% by injecting 300 ppm SO2 at 200 8C. Anyway, the Mn–La– Ce–Ni–Ox/PPS catalytic filter is promising to achieve the expectation of simultaneous removing particulate and NOx from low-sulfur flue gas in cement kiln.
Derui Zhu,Jian Liu,Rui Han,Guoping Shen,Qifu Long,Xiaoxing Wei,Deli Liu 한국미생물학회 2014 The journal of microbiology Vol.52 No.2
The moderately halophilic bacterium Halomonas sp. QHL1was identified as a member of the genus Halomonas by 16SrRNA gene sequencing. HPLC analysis showed that strainQHL1 synthesizes ectoine in its cytoplasm. The genes involvedin the ectoine biosynthesis pathway were identifiedon the chromosome in the order ectABC. Subsequently, theectB gene from this strain was amplified by PCR, and theentire ectABC gene cluster (3,580 bp) was cloned using genomewalking. Analysis showed that the ectA (579 bp), ectB(1269 bp), and ectC (390 bp) genes were organized in a singletranscriptional unit and were predicted to encode threepeptides of 21.2 kDa, 46.4 kDa, and 14.7 kDa, respectively. Two putative promoters, a δ70-dependent promoter and aδ38-controlled promoter, as well as several conserved motifswith unknown function were identified. Individual ectA, ectB,and ectC genes, and the entire ectABC gene cluster were insertedinto the expression plasmid pET-28a(+) to generatethe recombinant plasmids pET-28a(+)-ectA, pET-28a(+)-ectB, pET-28a(+)-ectC and pET-28a(+)-ectABC, respectively. Heterologous expression of these proteins in Escherichiacoli BL21 (DE3) was confirmed by SDS-PAGE. The recombinantE. coli strain BL21 (pET-28a (+)-ectABC) displayeda higher salt tolerance than native E. coli cells but producedfar less ectoine than the wild-type QHL1 strain.
Jiansheng Shen,Junzhe Liu,Yidong Xu,Kanghao Jia,Fangyu Wu,Wei Chen,Dayong Zhu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.9
To study the corrosion cracking process of reinforced concrete under the combined effects of chloride and fatigue loading, the constan-current and dry-wet cycle accelerated corrosion method was used to corrosion the specimens under different stress levels for different time. The quality loss of reinforcement, the composition of corrosion products and the cracking of concrete are analyzed from the macro, micro and micro scales, and to obtain the spatial distribution as well as microscopic characteristics of corrosion products of the reinforcement bar under coupling conditions. Additionally, a model of steel rust cracking under the coupled action of chloride and fatigue loading is established. The results show that: under the same corrosion time, the concrete cracking and steel corrosion degree become more serious with the increase of stress level. The greater the stress level, the earlier corrosion occurs and the more corrosion products are, Moreover, due to the fatigue load, the concrete on the upper side of the steel bar has rust expansion cracks earlier than the lower side.
Naikun Shen,Qingyan Wang,Yan Qin,Jin Zhu,Qixi Zhu,Huizhi Mi,Yutuo Wei,Ribo Huang 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.6
A method combining a Plackett-Burman design(PBD), the steepest ascent method (SA), and a Box-Behnken design (BBD) was developed to optimize succinicacid production from cane molasses by Actinobacillussuccinogenes GXAS137. The important parameters were(g/L): total sugars of cane molasses (85 g/L), yeast extract(8.84 g/L), and MgCO3 (63.1 g/L). Verification experimentsindicated that the maximal succinic acid productionreached 57.43±0.86 g/L, which agreed with the predictedvalue (57.12 g/L). In addition, batch and fed-batchfermentations were carried out in a 1.3 L stirred bioreactor. Compared with a batch fermentation that produced 57.96g/L of succinic acid at 60 h, a fed-batch fermentation,performed to minimize the inhibition effect of the substrate,produced 64.34 g/L of succinic acid at 60 h. The combinedmethod is powerful for selection of optimized conditionsfor succinic acid production from cane molasses.
Rock bridge fracture model and stability analysis of surrounding rock in underground cavern group
Song Yu,Wei-shen Zhu,Wei-min Yang,Dun-fu Zhang,Qing-song Ma 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.3
Many hydropower stations in southwest China are located in regions of brittle rock mass with high geo-stresses. Under these conditions deep fractured zones often occur in the sidewalls of the underground caverns of a power station. The theory and methods of fracture and damage mechanics are therefore adopted to study the phenomena. First a flexibility matrix is developed to describe initial geometric imperfections of a jointed rock mass. This model takes into account the area and orientation of the fracturedsurfaces of multiple joint sets, as well as spacing and density of joints. Using the assumption of the equivalent strain principle, a damage constitutive model is established based on the brittle fracture criterion. In addition the theory of fracture mechanics is applied to analyze the occurrence of secondary cracks duringa cavern excavation. The failure criterion, for rock bridge coalescence and the damage evolution equation, has been derived and a new sub-program integrated into the FLAC-3D software. The model has then beenapplied to the stability analysis of an underground cavern group of a hydropower station in Sichuan province, China. The results of this method are compared with those obtained by using a conventional elasto-plastic model and splitting depth calculated by the splitting failure criterion proposed in a previous study. The results are also compared with the depth of the relaxation and fracture zone in the surrounding rock measured by field monitoring. The distribution of the splitting zone obtained both by the proposed model and by the field monitoring measurements are consistent to the validity of the theory developed herein.
Development of a position sensitive CsI(Tl) crystal array
Shi, Guo-Zhu,Chen, Ruo-Fu,Chen, Kun,Shen, Ai-Hua,Zhang, Xiu-Ling,Chen, Jin-Da,Du, Cheng-Ming,Hu, Zheng-Guo,Fan, Guang-Wei Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.4
A position-sensitive CsI(Tl) crystal array coupled with the multi-anode position sensitive photomultiplier tube (PS-PMT), Hamamatsu H8500C, has been developed at the Institute of Modern Physics. An effective, fast, and economical readout circuit based on discretized positioning circuit (DPC) bridge was designed for the 64-channel multi-anode flat panel PSPMT. The horizontal and vertical position resolutions are 0.58 mm and 0.63 mm respectively for the 1.0 × 1.0 × 5.0 ㎣ CsI(Tl) array, and the horizontal and vertical position resolutions are 0.86 mm and 0.80 mm respectively for the 2.0 × 2.0 × 10.0 ㎣ CsI(Tl) array. These results show that the CsI(Tl) crystal array with low cost could be applied in the fields of medical imaging and high-resolution gamma camera.
Rock bridge fracture model and stability analysis of surrounding rock in underground cavern group
Yu, Song,Zhu, Wei-Shen,Yang, Wei-Min,Zhang, Dun-Fu,Ma, Qing-Song Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.3
Many hydropower stations in southwest China are located in regions of brittle rock mass with high geo-stresses. Under these conditions deep fractured zones often occur in the sidewalls of the underground caverns of a power station. The theory and methods of fracture and damage mechanics are therefore adopted to study the phenomena. First a flexibility matrix is developed to describe initial geometric imperfections of a jointed rock mass. This model takes into account the area and orientation of the fractured surfaces of multiple joint sets, as well as spacing and density of joints. Using the assumption of the equivalent strain principle, a damage constitutive model is established based on the brittle fracture criterion. In addition the theory of fracture mechanics is applied to analyze the occurrence of secondary cracks during a cavern excavation. The failure criterion, for rock bridge coalescence and the damage evolution equation, has been derived and a new sub-program integrated into the FLAC-3D software. The model has then been applied to the stability analysis of an underground cavern group of a hydropower station in Sichuan province, China. The results of this method are compared with those obtained by using a conventional elasto-plastic model and splitting depth calculated by the splitting failure criterion proposed in a previous study. The results are also compared with the depth of the relaxation and fracture zone in the surrounding rock measured by field monitoring. The distribution of the splitting zone obtained both by the proposed model and by the field monitoring measurements are consistent to the validity of the theory developed herein.
Surface Modification with Pluronic P123 Enhances Transfection Efficiency of PAMAM Dendrimer
Xiang Wang,Shen Gao,Xin Wu,Wei Fan,Baoyue Ding,Xiaoyu Wang,Wei Zhang,Xueying Ding,Jing Gao,Quangang Zhu,Jiyong Liu,Zhen Cai 한국고분자학회 2012 Macromolecular Research Vol.20 No.2
To improve gene delivery efficiency and decrease cytotoxicity of polyamidoamine (PAMAM) polymers,P123-g-PAMAM was synthesized by modifying PAMAM with pluronic P123. The structure of the synthesized polymers was analyzed using proton nuclear magnetic resonance. The polymers were able to self-assemble with DNA,forming nanometer-scale complexes. Particle size measurement confirmed that the mean diameter of the polyplexes was 100-250 nm. The cytotoxicity and transfer efficiency were measured and compared with those of PEI and PAMAM. All of the polyplexes showed significantly low cytotoxicity in the MCF-7, HepG2, and 293T cell lines. In addition, the low level of P123 grafting to PAMAM showed significantly higher transfection efficiency than unmodified PAMAM at the optimal N/P ratio. These results suggest that P123-ylated PAMAM may prove as a useful carrier for gene delivery.