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OALib Journal期刊

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Fractal evolution of a crack network in overburden rock rtratum
Guangming Yu,Heping Xie,Jianfeng Zhoa,Lun Yang
Discrete Dynamics in Nature and Society , 2000, DOI: 10.1155/s1026022600000388
Abstract: A quantitative description for the spatial distribution and the evolution of a crack network in mining rock stratum is one of the most difficult and fundamental problem in the subject of surface subsidence. In this paper, the physical models are employed to simulate the spatial distribution of a crack network. By using the fractal geometry, the self-similarity of spatial distribution of crack network is discovered. As a result, the conception of fractal crack network is proposed. Furthermore, the evolution of a crack network with the increasing of mining width is investigated. It is shown that (1) the spatial distribution of a crack network displays the fractal behavior, so, the fractal dimension can be used to describe quantitatively the evolution of the crack network, (2) the fractal dimension of the crack network increases with increasing of mining width, (3) the surface subsidence increases with the increasing of fractal dimension of crack network.
Formation of the storm-time ring current
Lun Xie,Zuyin Pu,Xuzhi Zhou,Suiyan Fu,Qiugang Zong
Chinese Science Bulletin , 2004, DOI: 10.1007/BF03184271
Abstract: An extensive study of ring current injection and intensification of the storm-time symmetric ring current is conducted with three-dimensional (3-D) test particle trajectory calculations (TPTCs) in this paper. TPTCs reveal more accurately the process of ring current injection. The main results are the following: (1) an intense convection electric field can effectively energize and inject plasma sheet particles into ring current region within 1–3 h. (2) Injection ions often follow chaotic trajectories in non-adiabatic regions, which may have implications in storm and ring current physics. (3) The shielding electric field, which arises as a consequence of enhanced convection and co-exists with injection and convection electric field, leads the original open trajectories to change into closed ones, thus may play an important role in the formation of the symmetric ring current.
Effects of darbufelone on the growth of tumor xenograft with SGC-7901 gastric cancer cells in nude mouse
Xiao-meng XU,Chun-lun LIU,Li XIE
Medical Journal of Chinese People's Liberation Army , 2011,
Abstract: Objective To evaluate the effect of darbufelone,a 5-lipoxygenase/cyclooxygenase-2(5-LOX/COX-2) dual inhibitor,on the growth of subcutaneous tumor xenograft of SGC-7901 gastric cancer cells and its mechanism.Methods The xenograft model of human gastric carcinoma with SGC-7901 gastric cancer cells was reproduced in nude mice.Fourteen nude mice were randomly divided into the darbufelone group and the control group(7 each).The mice were consecutively given intragastric administration with 45mg/(kg d) darbufelone in darbufelone group,or NS in control group for 4 weeks.The tumor volume in each group was measured regularly,and the tumor growth inhibition was calculated.The xenograft,liver,kidneys,spleen and lungs of nude mice were observed pathologically after HE staining.The expressions of mRNA and protein of 5-LOX,COX-2,PCNA,Bcl-2 and caspase-3 in transplanted tumor were detected by RT-PCR and immunohistochemistry.Results Darbufelone showed significant inhibitory effects,with an inhibition ratio of 58.42%,on the growth of tumor xenograft in vivo.The volume and weight of tumor in darbufelone group decreased significantly compared with that in control group(P < 0.05).Darbufelone inhibited the growth of tumor xenograft with no adverse effect.Immunohistochemistry and RT-PCR analyses showed that darbufelone effectively inhibited the expression of mRNA and protein of 5-LOX,COX-2,PCNA,Bcl-2,while increased the expression of caspase-3 compared with that in the control group(P < 0.05).Conclusions Darbufelone can inhibit the growth of gastric carcinoma in vivo,the mechanism may be related to inhibition of growth of cancer cells and the induction of apoptosis.
Plastic deformation wear in modified medium manganese steel
YUAN Hai-lun,XIE Jing-pei
China Foundry , 2007,
Abstract: A medium manganese steel with high wear-resistance, strength and toughness has been produced with addition of a complex modifier (or refining agent) containing Nb, N, RE and Si-Ca. The results showed that the wear resistance, strength and toughness of the modified medium manganese steel are respectively 1.92 times, 1.45 times and 3.63 times as high as that of the referenced unmodified medium manganese steel. The plastic deformation characteristic involved in the wear mechanism of the modified medium manganese steel was investigated by means of plastic-elasticity calculation and TEM electro-microscopy. The relationship between wear resistance and yield strength of the steel was established. Since the wear volume W is proportional to the square of the loading and to the numbers of the abrasives, and inversely proportional to the square of the yield strength of the materials, the wear resistance can be substantially improved by the enhancement of yield strength of the materials. The calculation results generally agreed with the experimental results.
An Element of Determinism in a Stochastic Flagellar Motor Switch
Li Xie,Tuba Altindal,Xiao-Lun Wu
Physics , 2015,
Abstract: Marine bacterium Vibrio alginolyticus uses a single polar flagellum to navigate in an aqueous environment. Similar to Escherichia coli cells, the polar flagellar motor has two states; when the motor is counter-clockwise, the cell swims forward and when the motor is clockwise, the cell swims backward. V. alginolyticus also incorporates a direction randomization step at the start of the forward swimming interval by flicking its flagellum. To gain an understanding on how the polar flagellar motor switch is regulated, distributions of the forward $\Delta_{f}$ and backward $\Delta_{b}$ intervals are investigated herein. We found that the steady-state probability density functions, $P(\Delta_{f})$ and $P(\Delta_{b})$, of freely swimming bacteria are strongly peaked at a finite time, suggesting that the motor switch is not Poissonian. The short-time inhibition is sufficiently strong and long lasting, i.e., several hundred milliseconds for both intervals, which is readily observed and characterized. Treating motor reversal dynamics as a first-passage problem, which results from conformation fluctuations of the motor switch, we calculated $P(\Delta_{f})$ and $P(\Delta_{b})$ and found good agreement with the measurements.
Implications of 3-step swimming patterns in bacterial chemotaxis
Tuba Altindal,Li Xie,Xiao-Lun Wu
Quantitative Biology , 2010, DOI: 10.1016/j.bpj.2010.12.379
Abstract: We recently found that marine bacteria Vibrio alginolyticus execute a cyclic 3-step (run- reverse-flick) motility pattern that is distinctively different from the 2-step (run-tumble) pattern of Escherichia coli. How this novel swimming pattern is regulated by cells of V. alginolyticus is not currently known, but its significance for bacterial chemotaxis is self- evident and will be delineated herein. Using an approach introduced by de Gennes, we calculated the migration speed of a cell executing the 3-step pattern in a linear chemical gradient, and found that a biphasic chemotactic response arises naturally. The implication of such a response for the cells to adapt to ocean environments and its possible connection to E. coli 's response are also discussed.
Traditional Chinese Herbal Medicine for Epilepsy Treatment Should Be Administered According to the Seizure Type and Epileptic Syndrome  [PDF]
Lun Cai
Health (Health) , 2017, DOI: 10.4236/health.2017.98087
Abstract: Traditional Chinese herbal medicine (TCHM) has long been used to treat epilepsy. Although many clinical trials and animal studies have seemingly demonstrated its effect, the question of whether TCHM is efficacious in epileptic patients has not been certified because of insufficient supportive evidence. This insufficient supportive evidence stems from the fact that most of the current studies regarding TCHM for epilepsy treatment are not designed according to the different seizure types and epileptic syndromes (STESs). Here, we explore the reasons why many studies have not considered the various STESs and explain how to treat epilepsy according to the pharmacological mechanism for different STESs and exploit the advantage of TCHM for epilepsy treatment. Then, we explain how we treat epilepsy using TCHM according to the different STESs and Bian Zheng Lun Zi.
Noised Image Segmentation Effect Evaluating Method Based on Run Length Statistic
基于游程统计的含噪图像分割效果评价方法
ZHANG Xue-feng,FAN Jiu-lun,XIE Xie,
张雪锋,范九伦,谢勰
计算机科学 , 2011,
Abstract: There is close relationship between segmentation effect of noise disturbed image and noise intensity the image contained. In order to quantize computing and analysis of segmentation effect of noise disturbed image, a evaluating function for noised image's segmentation results was presented based on segmentation image which is not noised firstly. Then a noise disturbed image segmentation effect evaluating method was presented that is based on run length testing of sequence randomness verifying. Run length function is defined based on run length statistic of segmented image's binary gray matrix and this index is quantifying computed when evaluating noised disturbed image's segmentation effect Simulation results of gray image,which is disturbed by noise,indicate that run length function is expressed simple, computing convenience, and can nicely reflect the changing relationship between segmentation effect of noise disturbed image and noise intensity the image contained.
Emotional Gait Generation for a Humanoid Robot
Lun Xie,Zhi-Liang Wang,Wei Wang,Guo-Chen Yu,
国际自动化与计算杂志 , 2010,
Abstract:
NOAA/POES observation of the sources of the relativistic electron in the magnetosphere
基于NOAA/POES卫星观测的磁层相对论电子起源的初探
XIE Lun,TU Wei-Chao,ZHANG Hui,PU Zu-Yin,
谢伦
地球物理学报 , 2007,
Abstract: Using data from low-altitude polar orbit satellite of NOAA and ACE,we investigate the possible sources of the enhancement of relativistic electron in the magnetosphere.The observation from NOAA for the different geomagnetic activity period show that substorm injections provide seed electrons for MeV electron enhancement associated with geomagnetic storms and that energetic electrons in the solar wind provide an alternative sources for the relativistic electrons in the magnetosphere during the SEP(Solar Energetic Proton) events.
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