Cavitation cloud dynamic characteristics of dual-chamber self-excited oscillatory waterjet

Dezheng Li,Yong Kang,Hanqing Shi,Yi Hu,Qi Liu,Hongchao Li,Jincheng Hu,Jiamin Li 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.12

Aiming to enhance self-excited oscillating cavitation jet performance, the effect of the dual-chamber nozzlestructure on the jet dynamical characteristics was designed and investigated. With high-speed camera technology,the cavitation phenomenon was investigated to analyze the area pattern and shedding period of the cavitation cloudunder different nozzle structures. The results showed that the dual-chamber nozzle significantly improved the jet cavitationstrength, and the cavitation cloud area increased by 76% and decreased the shedding period by 90% comparedwith the single-chamber nozzle. In the upstream chamber, the upper shrinkage ratio had a more drastic effect on thecavitation cloud area and shedding frequency than the lower shrinkage ratio with a more sensitive effect on the sheddingfrequency. In the downstream chamber, the outlet diameter ratio and chamber diameter were more sensitive tothe regulation of cavitation cloud shedding frequency and area, respectively, with the optimal regulation at the outletdiameter ratio of 1 and chamber length of 6 mm. The chamber diameter modulated the cavitation cloud most drasticallywith a comprehensive performance optimum at 12mm, which the area fluctuation reached 76.8%. The resultsprovide a basis for further research and application of dual-chamber nozzles.

Entropy-Based Reliability Evaluation Model for Network Data

Dezheng Liu 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.12

Reliability is very important in wireless network since large number of wireless standards are widely used in our daily life. The network flow ratio and workload will increase significantly as well. It is observed that network manager is not able to ensure the reliability of the network even if the network connection is smooth. This paper proposes a network reliability evaluation model using factorization approach for the small and medium-sized wireless communication network. The factorization approach is a decomposition of an object into a product of other objects or factors, which when multiplied together give the original for example a number a polynomial or a matrix. With the model, the solution algorithms are proposed to work out the corresponding defined objectives. Experiments show that, the proposed model outperforms the ergodic method which uses large number of loops to obtain the network reliability. From the experiment, when Pc = 0.9 and Pm = 0.1 as well as Pc = 0.9 and Pm = 0.01, it could be find that there are six transmission lines which are with the maximum reliability.

Olive Leaf Extract Facilitates Healing of Experimental Cartilaginous Injuries in Rabbits

Dezheng Gong,Chengyan Geng,Liping Jiang,Lihui Wang,Hiroyuki Yoshimuram,Laifu Zhong 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.3

We investigated the restorative effect of orally administered olive leaf extract (OLE) on experimentally produced cartilaginous injuries in rabbits. In total, three holes in the left stifle joint, including one in the medial trochlear ridge and two in the trochlear sulcus (proximal and distal) of articular cartilage, were prepared surgically using a drill. For the control group only tap water alone was administered daily, and for the OLE group a water-based solution of OLE (500 mg/kg/day) was administered daily. The injured areas were observed macroscopically and histologically at 3 weeks after the operation. The results indicate that OLE facilitated healing of the three holes and increased the weight of the biceps femoris muscle. Histological examination revealed that in the OLE group, matured cartilage tissues and connective tissues were mixed with regenerated or maturing cartilage tissues with massive proliferation in the injured parts, around which the proliferation of undifferentiated blast cells and the tissue with cartilage substrates were observed. The histological score of the OLE group was significantly lower than that of the control group. The percentage of proliferating cell nuclear antigen–positive cartilage cells in the OLE group was higher than in the control group. Mean density of the restored area observed with Safranin O staining was higher in the OLE group than in the control group. Therefore, OLE is effective for enhancing the healing of cartilaginous injuries. OLE may also have a beneficial effect of slowing and reducing the pathogenesis of degenerative joint diseases in humans.

Effect of Subtropical Heating on the ENSO Amplitude in the IAP/LASG Coupled GCM

Yongqiang Yu,Dezheng Sun 한국기상학회 2006 한국기상학회 학술대회 논문집 Vol.2006 No.-

IMC-based Design for Teleoperation Systems with Time Delays

Yuling Li,Yixin Yin,Dezheng Zhang 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.2

The presence of time delays in communication introduces a limitation to the stability of bilateral teleoperation systems. In this study, we address the design of Internal Model Control (IMC)-based controllers for teleoperation systems with arbitrary time delays. The two degrees of freedom IMC structure is utilized for the master and the slave respectively and thus the passivity-assumption on the external forces is not required. The stability of the overall system is analyzed by regarding the whole system as a multivariable system. A performance-oriented controller design process which guarantees the delayed tracking between the master and the slave is also given. Finally, an example is given to validate the effectiveness of the proposed method.

Measurement of Lateral and Interfacial Thermal Conductivity of Single- and Bilayer MoS₂ and MoSe₂ Using Refined Optothermal Raman Technique

Zhang, Xian,Sun, Dezheng,Li, Yilei,Lee, Gwan-Hyoung,Cui, Xu,Chenet, Daniel,You, Yumeng,Heinz, Tony F.,Hone, James C. American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.46

<P>Atomically thin materials such as graphene and semiconducting transition metal dichalcogenides (TMDCs) have attracted extensive interest in recent years, motivating investigation into multiple properties. In this work, we demonstrate a refined version of the optothermal Raman technique1,2 to measure the thermal transport properties of two TMDC materials, MoS<SUB>2</SUB> and MoSe<SUB>2</SUB>, in single-layer (1L) and bilayer (2L) forms. This new version incorporates two crucial improvements over previous implementations. First, we utilize more direct measurements of the optical absorption of the suspended samples under study and find values ∼40% lower than previously assumed. Second, by comparing the response of fully supported and suspended samples using different laser spot sizes, we are able to independently measure the interfacial thermal conductance to the substrate and the lateral thermal conductivity of the supported and suspended materials. The approach is validated by examining the response of a suspended film illuminated in different radial positions. For 1L MoS<SUB>2</SUB> and MoSe<SUB>2</SUB>, the room-temperature thermal conductivities are 84 ± 17 and 59 ± 18 W/(m·K), respectively. For 2L MoS<SUB>2</SUB> and MoSe<SUB>2</SUB>, we obtain values of 77 ± 25 W and 42 ± 13 W/(m·K). Crucially, the interfacial thermal conductance is found to be of order 0.1–1 MW/m<SUP>2</SUP> K, substantially smaller than previously assumed, a finding that has important implications for design and modeling of electronic devices.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-46/acsami.5b08580/production/images/medium/am-2015-085805_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b08580'>ACS Electronic Supporting Info</A></P>

Study on the Matching Algorithm and 3D Virtual Reality System Based on SilverLight

Hou Zhenjie,Lu Zhongqiu,Yuan Dezheng 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.1

Silverlight technology is a new generation of rich internet application technology. The paper proposes a new solution based on the Silverlight technology to achieve a 3D virtual reality system which takes the pictures around the objects with 360 degree displaying in the local computer or a web page. The 3D visual sense and image matching of this system are the key technical problems. The automatic matching technology in image synthesis field plays a very important role in the system. Based on the SURF algorithm, this paper takes strategies of density threshold suppression to reduce the number of matched feature points; using the quasi Euclidean distance to complete the feature points matching process, the improved algorithm also greatly reduces the matching time of feature points and improves the matching accuracy. Through theoretical analysis and experimental contrast, demonstrates the reliability and validity of the algorithm.

Identification of Glycine Max MicroRNAs in Response to Phosphorus Deficiency

Aihua Sha,Yinhua Chen,Hongping Ba,Zhihui Shan,Xiaojuan Zhang,Xuejun Wu,Dezheng Qiu,Shuilian Chen,Xinan Zhou 한국식물학회 2012 Journal of Plant Biology Vol.55 No.4

MicroRNAs (miRNAs) are endogenous small RNAs regulating plant development and stress responses. In addition, phosphorus (P) is an important macronutrient for plant growth and development. More than two hundred miRNAs have been identified in Glycine Max and a few of miRNAs have been shown to respond to P deficiency,however, whether there are other miRNAs involved in P deficiency response is largely unknown. In this study, we used high-throughput small RNA sequencing and wholegenome-wide mining to identify the potential miRNAs in response to P deficiency. After sequencing, we deduced 183known, 99 conserved and 126 novel miRNAs in Glycine Max. Among them, in response to P deficiency, the expressions of 27 known, 16 conserved and 12 novel miRNAs showed significant changes in roots, whereas the expressions of 34known, 14 conserved and 7 novel miRNAs were significantly different in shoots. Furthermore, we validated the predicated novel miRNAs and found that three miRNAs in roots and five miRNAs in shoots responded to P deficiency. Some miRNAs were P-induced whereas some were P-suppressed. Together these results indicated that the miRNAs identified might play important roles in regulating P signaling pathway.