Study on the Hydromechanical Behavior of Single Fracture under Normal Stresses

Ni Xie,Jinbao Yang,Jianfu Shao 대한토목학회 2014 KSCE JOURNAL OF CIVIL ENGINEERING Vol.18 No.6

The coupling between hydraulic and mechanical behavior of the fractured rock mass is of great significance for various civil andenvironmental engineering projects. In order to study the hydro-mechanical behavior of single fracture, seepage tests under differentconfining pressures and fracture water pressures were conducted on single shear fractures produced by triaxial loading of diabaserock samples from Danjiangkou Water Reservoir, China. Test results show that fluid pressure acting on fracture surfaces has stronginfluences on the hydraulic behavior of the fracture. Based on the classic Biot poroelasticity theory and by taking the fracture asassembling of a set of voids in rock mass, a generalized Biot coefficient is introduced to describe the interaction effect between porefluid pressure and fracture deformation. Then, a nonlinear constitutive equation for single fracture under both normal stress and fluidpressure is developed. Later, the mechanical deformation of the fracture is related to the fracture hydraulic conductivity through“cubic law”, so that a coupled mechanical-hydraulic model is proposed. All the four parameters involved in this model have theirphysical significances and can be determined through mechanical compression tests and seepage tests. A first validity of the model ismade by predicting the variation of fracture flowrates versus normal stress under different fluid pressures.

Research of Job Scheduling With Cloud Based On Trust Mechanism And SFLA

Xiaolan Xie,Ruikun Liu,Guoqing Zhou,Jinsheng Ni 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.1

Job scheduling under the cloud circumstance is the key techniques to impact on frequency of cloud calculation. Trust relationship is an important factor of cloud calculation and job scheduling. In order to satisfy the requirement of quality of cloud calculation service for job scheduling, this article introduced the term of trust mechanism and apply it to cloud calculation and job scheduling. It uses altered SFLA as scheduling strategy, and brings forward a model of job scheduling with cloud circumstance which is based on trust mechanism and SFLA. The simulation results showed that this algorithm with faster convergence speed can increase the trust benefit and accomplish job scheduling task well.

TR4 nuclear receptor functions as a fatty acid sensor to modulate CD36 expression and foam cell formation.

Xie, Shaozhen,Lee, Yi-Fen,Kim, Eungseok,Chen, Lu-Min,Ni, Jing,Fang, Lei-Ya,Liu, Su,Lin, Shin-Jen,Abe, Jun-Ichi,Berk, Bradford,Ho, Feng-Ming,Chang, Chawnshang National Academy of Sciences 2009 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.106 No.32

<P>Testicular orphan nuclear receptor 4 (TR4) is an orphan member of the nuclear receptor superfamily with diverse physiological functions. Using TR4 knockout (TR4(-/-)) mice to study its function in cardiovascular diseases, we found reduced cluster of differentiation (CD)36 expression with reduced foam cell formation in TR4(-/-) mice. Mechanistic dissection suggests that TR4 induces CD36 protein and mRNA expression via a transcriptional regulation. Interestingly, we found this TR4-mediated CD36 transactivation can be further enhanced by polyunsaturated fatty acids (PUFAs), such as omega-3 and -6 fatty acids, and their metabolites such as 15-hydroxyeico-satetraonic acid (15-HETE) and 13-hydroxy octa-deca dieonic acid (13-HODE) and thiazolidinedione (TZD)-rosiglitazone. Both electrophoretic mobility shift assays (EMSA) and chromatin immunoprecipitation (ChIP) assays demonstrate that TR4 binds to the TR4 response element located on the CD36 5'-promoter region for the induction of CD36 expression. Stably transfected TR4-siRNA or functional TR4 cDNA in the RAW264.7 macrophage cells resulted in either decreased or increased CD36 expression with decreased or increased foam cell formation. Restoring functional CD36 cDNA in the TR4 knockdown macrophage cells reversed the decreased foam cell formation. Together, these results reveal an important signaling pathway controlling CD36-mediated foam cell formation/cardiovascular diseases, and findings that TR4 transactivation can be activated via its ligands/activators, such as PUFA metabolites and TZD, may provide a platform to screen new drug(s) to battle the metabolism syndrome, diabetes, and cardiovascular diseases.</P>

Oviposition preference and offspring performance of Apoderus dimidiatus (Coleoptera: Atelabidae) between Rosa multiflora and Rubus ichangensis

Xie Meng,Du Jinying,Yang Kunqi,Song Shaoting,Lv Zonghui,Xu Huailiang,Wen An Xiang,Wang Qin,Jiang Yanzhi,Zhu Guangxiang,Wu Jiayun,Yao Yongfang,Ni Qingyong 한국곤충학회 2021 Entomological Research Vol.51 No.2

Leaf-rolling weevils (Coleoptera: Atelabidae) are considered to be specialists that oviposit only on one or two plant species. However, Apoderus dimidiatus can oviposit on at least five species. We aimed to determine whether A. dimidiatus females have different preferences for oviposition substrates, and whether differences in physical factors, nutrition and parasitism affected their choices. We observed the number of cradles, hatched larvae, pupae, emerging adults and parasitism rate during one breeding season. Weevils were given access to two host plant species, Rosa multiflora and Rubus ichangensis, and the leaf size and nutrient contents of the two plant species were investigated. We found that nutritional content, especially soluble carbohydrate, correlated with oviposition preference of weevils, and the more nutritious plant species, R. multiflora, was the preferred host in our experiment. Weevils can also use Ru. ichangensis and other plant species as hosts, likely to relieve the high parasitic pressure when laying eggs on a single host species.

Experimental test on bridge jointed twin-towered buildings to stochastic wind loads

Ni, Z.H.,He, C.K.,Xie, Z.N.,Shi, B.Q.,Chen, D.J. Techno-Press 2001 Wind and Structures, An International Journal (WAS Vol.4 No.1

This paper presents results of a study on wind loads and wind induced dynamic response of bridge jointed twin-towered buildings. Utilizing the high-frequency force balance technique, the drag and moment coefficients measured in wind tunnel tests, and the maximum acceleration rms values on the top floor of towers, are analyzed to examine the influence of building's plan shapes and of intervals between towers. The alongwind, acrosswind and torsional modal force spectra are investigated for generic bridge jointed twin-towered building models which cover twin squares, twin rhombuses, twin triangles, twin triangles with sharp corners cut off, twin rectangles and individual rectangle with the same outline aspect ratio as the twin rectangles. The analysis of the statistical correlation among three components of the aerodynamic force corroborated that the correlation between acrosswind and torsional forces is significant for bridge jointed twin-towered buildings.

Protein Kinase CK2 Modulates the Calcium Sensitivity of Type 3 Small-conductance Calcium-activated Potassium Channels in Colonic Platelet-derived Growth Factor Receptor Alpha-positive Cells From Streptozotocin-induced Diabetic Mice

Ni-Na Song,Xu Huang,Hong-Li Lu,Chen Lu,Jie Chen,Wen-Xie Xu 대한소화기 기능성질환∙운동학회 2023 Journal of Neurogastroenterology and Motility (JNM Vol.29 No.2

Background/AimsThe gastrointestinal symptom of diabetes mellitus, chronic constipation, seriously affects patients’ life. Whereas, the mechanism of chronic constipation is still ambiguous, resulting in a lack of effective therapies for this symptom. As a part of the smooth muscle cells, interstitial cells of Cajal, and platelet-derived growth factor receptor alpha-positive (PDGFRα+) cells syncytium (SIP syncytium), PDGFRα+ cells play an important role in regulating colonic motility. According to our previous study, in PDGFRα+ cells in colons of diabetic mice, the function of the P2Y1 purinergic receptor/type 3 small-conductance calcium-activated potassium (SK3) channel signaling pathway is strengthened, which may lead to colonic dysmotility. The purpose of this study is to investigate the changes in SK3 channel properties of PDGFRα+ cells in diabetic mice. MethodsWhole-cell patch clamp, Western blotting, superoxide dismutase activity measurement, and malondialdehyde measurement were main methods in the present study. ResultsThe present study revealed that when dialysed with low calcium ion (Ca2+) solution, the SK3 current density was significantly decreased in PDGFRα+ cells from diabetic mice. However, the SK3 current density in PDGFRα+ cells was enhanced from diabetic mice when dialysed with high Ca2+ solution. Moreover, hydrogen peroxide-treatment mimicked this phenomenon in SK3 transgenic HEK293 cells. The subunit of SK3 channels, protein kinase CK2, was up-regulated in colonic muscle layers and hydrogen peroxide-treated HEK293 cells. Additionally, protein phosphatase 2A, the subunit of SK3 channels, was not changed in streptozotocin-treated mouse colons or hydrogen peroxide-treated HEK293 cells. ConclusionThe diabetic oxidative stress-induced upregulation of CK2 contributed to modulating SK3 channel sensitivity to Ca2+ in colonic PDGFRα+ cells, which may result in colonic dysmotility in diabetic mice.

Efficiency optimization control of permanent magnet synchronous motors for pure electric vehicles based on GBDT

Fang Xie,Houying Wang,Shilin Ni,Chaochen An 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.2

In this paper, “Machine learning” is introduced to motor efficiency optimization control to improve the operating efficiency of the permanent magnet synchronous motors (PMSMs) for pure electric vehicles. A current distribution method based on the gradient boosting decision tree (GBDT) is proposed. The efficiency of the motor operation can be improved by coordinating the current control. First, a mathematical model of the motor efficiency is established, and the current distribution law of the optimal efficiency of the motor in different operating regions is qualitatively analyzed. The control system is based on this current distribution. Second, the sample space is established based on measured data, where the current regression model of the GBDT is introduced. Then by analyzing the importance of characteristic variables, the structure of the model is optimized, and the input and output of the model are reasonably selected, which are embedded into the control system to realize the coordinated control of the current. Finally, comparative experiment shows that the proposed method can improve the efficiency of PMSMs in the whole speed range.

An Improved Attention-based Bidirectional LSTM Model for Cyanobacterial Bloom Prediction

Jianjun Ni,Ruping Liu,Guangyi Tang,Yingjuan Xie 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.10

Cyanobacterial blooms are one of the most serious water pollution problems for freshwater lakes. The treatment of blooms requires a lot of material and financial resources, so an early accurate prediction of cyanobacterial blooms is a very important way to deal with the outbreak of them. But it is challenging to predict the cyanobacterial blooms due to the uncertainty and complexity of their growth process. To deal with this problem, an improved attention-based bidirectional long short-term memory (LSTM) model is proposed in this paper, to make multistep predictions of chlorophyll-a concentration, which is a recognized characterization of algae activity. Firstly, the convolutional neural network (CNN) is used to extract data features and spatiotemporal correlation. Secondly, the bidirectional LSTM network (BiLSTM) is used to predict the concentration of chlorophyll-a based on the extracted features. Finally, the attention mechanism is used to calculate the weights for the characteristic factors that affect the chlorophyll-a concentration. At last, some experiments are carried out based on the real monitoring data of a platform in the Taihu Lake area. Compared with the prediction results of the other four state-of-the-art deep learning methods, the results show that the proposed method in this paper has the highest prediction accuracy.

Attribute Theory Model Based Task Scheduling Algorithm on Cloud

Xiaolan XIE,Ruikun LIU,Xin Hu,Jinsheng NI 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.7

Equivalent Circuit Based Design of an Integrated 2DoF Machine for Submerged Drilling Systems

Lujia Xie,Haichao Feng,Jikai Si,Yihua Hu,Kai Ni 한국자기학회 2019 Journal of Magnetics Vol.24 No.1

Drilling is traditionally performed by multi-motor systems manually. However, the complex intermediate transmission mechanisms in the traditional design have large size and relatively low robustness. In this paper, a splitstator 2-degree-of freedom (2DoF) machine is applied. By conducting linear, rotary, and helical motion by only one machine, it provides a more compact, more integrated, more reliable, and stronger-adaptability electrically drilling machine for submerged drilling systems. On account of the adoption of the split-stator structure, the electromagnetic design of such 2DoF machine is a significant challenge. In this paper, a design method for the 2DoF machine with special split structure is proposed based on the electric decoupled equivalent circuit (EDEC). Then a 1.5 ㎾ 2DoF drilling machine is designed, and the electromagnetic performances are verified by the 3D finite element analysis (FEA). The results show the good characteristics and feasibility of applying the 2DoF machine in drilling systems.