http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Bing-qiang Zhang,Qi-wen Chen,Feng-wen Lai,Fu-Quan Chen,Bin-bin Qi 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.1
A gap formation underneath pipelines could be observed during tunneling beneath existing buried pipelines, thus altering the pipeline-soil interaction behavior. However, the most existing analytical approaches typically do a full contact assumption for brevity. For such purpose, we aim to present an analytical approach coupling the effect of gap formation underneath pipelines by considering the buried pipeline as an Euler-Bernoulli beam on tensionless foundation. The pipeline can be divided into three segments according to pipeline-soil interaction behavior, and then the bending behaviors of each segment are formulated. The deflection and bending moment of the pipeline caused by tunnelling underneath from the proposed approach are compared and validated with centrifuge testing data and existing analytical solutions. The effects of pipeline-soil stiffness ratio, pipeline buried depth, tunnel buried depth, tunneling induced volume loss, and tunnel-pipeline intersection angle on the pipeline responses are further discussed. The results indicate that gap formation underneath pipeline can be observed indeed for shallowly buried pipeline and/or larger pipeline-soil stiffness ratio. The proposed analytical approach provides a theoretical guideline to predict the responses of existing pipelines to tunnelling underneath.
Bing Liu,Hai-Qiang Li,Hao-Bing Li,Jian Liu,Yi-Zhong Yang,Yan-Hui Lu,Abid Ali 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.2
Lygus pratensis distributes worldwide and is one of the common insect pests on cotton in Xinjiang Uygur Autonomous Region, the largest cotton growing region of China. This study assessed the effects of six constant temperatures (10, 15, 20, 25, 30 and 35 °C) at 60% relative humidity (RH) on egg and nymphal development of L. pratensis. Eggs failed to hatch and the newly-hatched nymphs could not normally develop at 10 °C. The developmental duration of egg and nymph decreased as temperature increased from 15 to 30 except 35 °C for egg. Based on the linear model, the lower developmental threshold and effective accumulated temperature were 10.68 °C and 150.2 DD for egg, and 12.08 °C and 208.3 DD for nymph, respectively. Among three non-linear models (Briere-1, Logan-6 and Lactin), Logan-6 provided the most accurate estimate for the mean optimum and lethal maximum temperatures (33.6 and 40.9 °C for egg, and 34.0 and 37.4 °C for nymphs). The interactive effects of three RH levels (45, 60 and 75%) and two temperatures (25 and 35 °C) on the immature developmental stages were tested. Temperature, RH and their interaction showed significant effects on egg and nymphal development. High relative humidity (75% RH) shortened the developmental duration of egg at 25 °C and nymph at 25 and 35 °C,whereas no significant difference was found for egg duration between different RH levels at 35 °C. The present study is useful for further predicting the phenology of L. pratensis and developing forecast and management strategies for this emerging mirid bug in China.
Bing-qiang Zhang,Wei Huang,Fu-quan Chen,Qi-yun Wang 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.12
Deep excavations unavoidably cause the changes in stress and displacement of surrounding soils, which further generate additional internal forces on the adjacent existing tunnel segments, and compromise the performance and stability of the tunnels. In this study, two-stage analysis method is used to theoretically calculate the additional internal forces in the tunnel segments due to laterally adjacent excavation. Based on an empirical deformation curve of diaphragm walls, the excavation-induced stress in a linear elastic soil is formulated using source-sink imaging method. A distribution model of additional external load acting on the tunnel segments due to adjacent excavation is further established, and the additional internal forces in the tunnel segments under the corresponding additional loads are estimated using elastic equation method. Parametric studies are then conducted to investigate the effects of excavation procedure, buried depth of shield tunnel, and excavation-tunnel horizontal distance on the additional internal forces in the tunnel segments. The results show that the studied parameters have significant effect on the additional internal forces in the tunnel segments due to laterally adjacent excavation. When the excavation-tunnel horizontal distance is less than the excavation depth, the accompanied effect on the additional internal forces in the tunnel segments is highly sensitive. This study can provide theoretical insights into the estimation of tunnel segment responses due to laterally adjacent excavation.
Bing Wang,Zhan-qiang Liu,Qinghua Song,Yi Wang,iaoping Ren 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.1
High energy efficient machining is beneficial for sustainable manufacture which is an important target pursued by workshops. The paper aims to prove the feasibility for reducing cutting energy consumption with ultra-high speed machining (UHSM) of super alloy Inconel 718. Firstly, orthogonal cutting experiments of Inconel 718 are performed with a wide cutting speed range. Through analyses of chip micrographs, it is found that plastic deformation accompanied with ductile fracture contributes to serrated chip formation, while fragmented chips are produced through brittle fracture. The results demonstrate that brittle regime machining can be realized for Inconel 718 with ultra-high cutting speeds. Secondly, considering varied deformation behavior for chips with different morphologies, specific cutting energy models for HSM under varied cutting parameters are developed and verified. Then the influences of cutting speed and uncut chip thickness on cutting energy consumption during HSM are revealed. The research results demonstrate the practicability for reducing cutting energy consumption with brittle regime machining of Inconel 718. At last, the relationship between AE signals and cutting energy consumption is explored, and it proves that AE signals are applicable in monitoring cutting energy consumption. The research can provide guidance for energy saving through optimizing cutting parameters.
Bing-Chi Luo,Kai Li,Ji-Qiang Zhang,Jiang-Shan Luo,Wei-Dong Wu,Yong-Jian Tang 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.4
The residual stress in beryllium films fabricated on K9 substrates by using magnetron sputtering deposition is measured by using a curvature method and is theoretically estimated by using the Nix and Clemens (NC) model. The experimental results indicate that the 1.3-μm-thick film is always in a tensile state for pressure variations in the range from 0.4 to 1.2 Pa. When the sputtering gas pressure is increased, the average stress increases at first, after which it decreases by a remarkable amount. The observed descending trend of the tensile stress when the sputtering gas pressure is beyond 0.6 Pa is mainly attributed to the grain size in the film being larger than that in the film when the pressure is below 0.6 Pa. The maximal residual stress of 552 MPa at a sputtering gas pressure of 0.6 Pa is close to the tensile strength (550 MPa) of the corresponding beryllium bulk material and is about 8 times smaller than that calculated by using the N-C model. In addition, the surface morphologies of the as-fabricated films reveal fibrous grains while the cross-sectional morphologies are characterized by a coarsening of columnar grains. The measured electric resistivity of each film strongly depends on its porosity and the sizes of its grains.
Baimantuoluosides D-G, Four New Withanolide Glucosides from the Flower of Datura metel L.
Bing-you Yang,Yong-gang Xia,Qiu-hong Wang,De-qiang Dou,Hai-xue Kuang 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.8
In our search for bioactive anti-psoriasis compounds from the flower of Datura metel L, we isolated four new withanolide glucosides, baimantuoluosides D, E, F and G (1-4). The structures of the new compounds are (5α,6α,7β,22R)-5,6,7,27-tetrahydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (1), (5α,6β,7α,22R)-5,6,7,27-tetrahydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (2), (5α,6β,7α,12β,22R)-5,6,7,12,27-pentahydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (3), and (5α,6β,22R)-5,6,27-trihydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (4) on the basis of chemical and physicochemical evidence.
Fu, Qiang,Wang, Bai-Chen,Jin, Xiang,Li, Hong-Bing,Han, Pei,Wei, Kai-Hua,Zhang, Xue-Min,Zhu, Yu-Xian Korean Society for Biochemistry and Molecular Biol 2005 Journal of biochemistry and molecular biology Vol.38 No.6
Proteins accumulated in dry, stratified Arabidopsis seeds or young seedlings, totaled 1100 to 1300 depending on the time of sampling, were analyzed by using immobilized pH gradient 2-DE gel electrophoresis. The molecular identities of 437 polypeptides, encoded by 355 independent genes, were determined by MALDI-TOF or TOF-TOF mass spectrometry. In the sum, 293 were present at all stages and 95 were accumulated during the time of radicle protrusion while another 18 appeared in later stages. Further analysis showed that 226 of the identified polypeptides could be located in different metabolic pathways. Proteins involved in carbohydrate, energy and amino acid metabolism constituted to about 1/4, and those involved in metabolism of vitamins and cofactors constituted for about 3% of the total signal intensity in gels prepared from 72 h seedlings. Enzymes related to genetic information processing increased very quickly during early imbibition and reached highest level around 30 h of germination.