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Defending Against Wormhole Attack in OLSR

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Geo-Spatial Information Science 2006年第3期9卷 229-233页

作者： HONG Liang HONG fan fu Cai Department of Information Security Huazhong University of Science and Technology Guanshan Wuhan 430074 China.

OLSR （optimal link state routing） is one of the four basic routing protocols used in mobile ad hoe Networks by the MANET working group of IETF（Internet engineering task force）. OLSR, a proactive routing protocol, is based on a multipoint relaying flooding technique to reduce the number of topology broadcast. OLSR uses periodic HELLO packets to neighbor detection. As introduced in Reference [1], the wormhole attack can form a serious threat in wireless Networks, especially against many ad hoc Network routing protocols and location-based wireless security systems. Here, a trust model to handle this attack in OLSR is provided and simulated in NS2.

关键词： mobile ad hoc Network wormhole attack OLSR securing routing

Preparation of an environmentally friendly emulsion-type lubricant based on crude rice bran wax

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Petroleum 2019年第1期5卷 77-84页

作者： Zhengqiang Xiong fan fu Xiaodong Li Yanning Li Beijing Institute of Exploration Engineering Beijing100083China

In this study,crude rice bran wax oil-in-water emulsion(named CRBWE)was prepared by agent-in-water *** critical factors influencing the sample preparation process were *** instance,the optimum hydrophile-lipophile balance value of compound emulsifier was 12.33–13.40,the content of compound emulsifier was 10 wt%,the emulsification temperature was 70°C–80°C,the agitation speed was 200 rpm,and the emulsification time was 30–45 *** performances as a lubricant of drilling fluid were also evaluated with respect to lubricity,rheology and filtration loss of *** results showed that CRBWE had good lubricity and didn't affect the rheological properties of drilling *** example,when it was added into bentonite dispersion at room temperature with the fraction of 1 wt%,the coefficient of friction of bentonite dispersion dramatically decreased to 0.077,and the coefficient of friction reduced rate was greater than 80%.Overall,these findings indicated that CRBWE would have promising applications as environmental friendly lubricant of drilling fluids to reduce torque and drag in petroleum and natural gas drilling.

关键词： Emulsion-type lubricant Crude rice bran wax Lubricity Biodegradable Water-based drilling fluids

Enhancement of MAD/MIR phasing at low resolution and a new procedure for automatic phase extension

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Chinese Physics B 2019年第7期28卷 389-395页

作者： Pu Han Yuan-Xin Gu Wei Ding Hai-fu fan Key Laboratory of Soft Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China School of Physics Science University of Chinese Academy of Sciences Beijing 100049 China

To achieve de novo protein structure determination of challenging cases, multi-wavelength anomalous diffraction(MAD) and multiple isomorphous replacement(MIR) phasing can be powerful tools to obtain low-resolution initial phases from heavy-atom derivative datasets, then phase extension is needed against high-resolution data to obtain accurate *** this context, we propose a direct-methods procedure here that could improve the initial low-resolution MAD/MIR phase *** accordingly, an automated process for extending initial phases to high resolution is also *** two procedures are both implanted in the newly released IPCAS *** cases are used to perform the test, including one set of 4.17 ? MAD data from a membrane protein and two sets of MAD/MIR data with derivatives truncated down to 6.80 ? and 6.90 ?, *** the results have shown that the initial phases generated from the direct-methods procedure are better than that from the conventional MAD/MIR *** automated phase extensions for the latter two cases starting from 6.80 ? to 3.00 ? and 6.90 ? to 2.80 ? are proved to be successful, leading to complete *** may provide convenient and reliable tools for phase improvement and phase extension in difficult low-resolution tasks.

关键词： direct methods multi-wavelength anomalous diffraction(MAD)/multiple isomorphous replacement(MIR) phasing phase extension low-resolution

Performance evaluation of laponite as a mud-making material for drilling fluids

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Petroleum Science 2019年第4期16卷 890-900页

作者： Zheng-Qiang Xiong Xiao-Dong Li fan fu Yan-Ning Li Beijing Institute of Exploration Engineering

In this study, laponite was tested as a mud-making material for drilling fluids. Laponite is a synthetic smectite clay with a structure and composition closely resembling the natural clay mineral hectorite. Commercially available laponite was characterized by X-ray di ractometry, scanning electron microscopy and infrared spectrometry. Its dispersibility, salt resistance and high-temperature resistance were evaluated. The results showed that laponite possessed superior cation exchange capacity(140.4 mmol/100 g) with interlayer cations of Na^+ and Li^+. Laponite could easily be dispersed in water to yield increased viscosity with no influence from hydration time or temperature. On the other hand, laponite dispersions displayed an excellent heat resistance, with invariant apparent viscosity at high temperatures. For instance, the apparent viscosity of the2 wt% laponite dispersion underwent changes between 22 and 24 mPa s after hot rolling at 180–240 °C for 16 h. Compared to existing mud-making materials, laponite exhibited better mud-making properties. furthermore, laponite revealed good compatibility with other additives, and the water-based drilling fluids prepared with laponite as mud-making material showed an excellent stability at elevated temperatures and superior performance–cost ratios. Overall, these findings indicated that laponite had an excellent dispersibility at high temperatures and hence would have promising applications as high-temperature mud-making material for preparing water-based drilling fluids designed for ultra-high-temperature environments.

关键词： Laponite Mud-making material Dispersibility High-temperature tolerance Ultra-high-temperature water-based drilling fluids

On the Well-posedness of the PWM Control System

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Frontiers of Electrical and Electronic Engineering in China 2006年第1期1卷 105-110页

作者： fan Qi-fu SHI Song-jiao Department of Automation Shanghai Jiaotong UniversityShanghai 200030China

One of the basic issues in the study of hybrid systems is the well-posedness(existence and uniqueness of solutions)problem of discontinuous dynamical *** paper addresses this problem for a class of piecewise affine discontinuous systems with affine inequalities such as systems with pulse-width modulator under the definition of Carathéodory solutions in terms of an analysis based on lexicographic inequalities and the smooth continuation property of ***,it is clear that when carrier signal h(t)=0,closed-loop pulse-width modulation(PWM)DC–DC converters are not well posed,and when some condition is satisfied,the closed-loop PWM DC–DC converters with a P controller are well posed.

关键词： piecewise affine systems hybrid systems discontinuous systems well-posedness lexicographic inequalities systems with pulse-width modulator

A cathodic arc enhanced middle-frequency magnetron sputter system for deposition of hard protective coatings

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Nuclear Science and Techniques 2006年第3期17卷 135-138页

作者： HUANG Zhi-Hong YANG Bing fan Xiang-Jun fu De-Jun Accelerator Laboratory Department of Physics Wuhan University Wuhan 430072 China

A new cathode arc enhanced magnetron sputter system for deposition of hard protective coatings is reported in this article. This system consists of eight targets: four outer targets are mounted on the wall of the chamber and four inner targets are placed around the center of the chamber. The outer and inner targets form four pair targets and are powered by four middle frequency power supplies. One of the outer targets can run either in the cathode arc mode or in the magnetron sputter mode. The Ti-containing diamond-like carbon nanocomposite coatings were deposited by using this system. The prepared coating exhibits high hardness (20 GPa), good adhesion (critical load is 50 N), very low friction coefficient (0.07), and excellent tribological performance with a wear rate of 1.4 × 10(?16) m(3)-·N(?1)·m(?1). Key words: Cathodic arc; Middle frequency magnetron sputtering; Diamond-like carbon

关键词：阴极弧中频磁控管溅射类金刚石碳内靶

Structure and tribological properties of Ti-containing amorphous carbon coatings prepared by cathode arc-enhanced middle-frequency magnetron sputtering

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Nuclear Science and Techniques 2006年第2期17卷 78-82页

作者： YANG Bing HUANG Zhi-Hong fan Xiang-Jun fu De-Jun Accelerator Laboratory School of Physics Wuhan University Wuhan 430072 China

Ti-containing amorphous carbon (Ti-aC) coatings were deposited on cemented carbide and Si substrates by cathode-arc-enhanced closed field middle-frequency unbalanced magnetron sputtering. The coatings were studied by using atomic force microscopy, Raman scattering, nanoindentation, and pin-on-disk testing. The measurements showed that the hardness of the coatings increased from 12 GPa at a Ti content of 1 at.% to 27 GPa at 31 at.%. The coatings exhibited different friction behaviors when facing different mating materials and changed with increasing Ti content. The coating with 4 at.% Ti exhibited excellent tribological performance with a low friction coefficient of 0.07 when facing the cemented carbide.

关键词：磁控管飞溅类金刚石碳硬度摩擦性能

Development and application of guar gum crosslinked gel with adjustable gelation time for total loss treatment

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Petroleum 2023年第4期9卷 621-628页

作者： Zhengqiang Xiong fan fu Zhifei Zou Xiaodong Li Shixian Tao Yanning Li Chinese Academy of Geological Sciences Beijing100037China Beijing Institute of Exploration Engineering Beijing100083China

To remediate the problem of severe or total losses,and meet the requirements of borehole plugging and pumping at different well depths,a novel crosslinked polymer gel(named HPG/Zr gel)with controlled gelation time and high gel strength was developed as loss circulation material,which mainly comprised hydroxypropyl guar gum,zirconium compound and *** influence of hydroxypropyl guar gum concentration,zirconium compound concentration,triethanolamine concentration and temperature on the gelation time of HPG/Zr gel was *** addition,the performance of HPG/Zr gel was investigated in terms of temperature resistance and shear resistance property,plugging ability and supporting cement slurry *** to the results,HPG/Zr gel can form a viscoelastic body with a network structure,and its gelation time can be practically *** results of the plugging experiment at different temperatures,pressures and pore sizes of quartz sand revealed that HPG/Zr gel could effectively plug sand pores at 150℃,and its pressure-bearing capacity can be up to 5 *** its flow resistance and ability of supporting cement slurry,HPG/Zr gel was successfully applied in two geological boreholes by combining with cement ***,the results of laboratory research and field tests indicate that HPG/Zr gel is useful for mitigating the lost circulation,and it is of huge importance to engineering applications.

关键词： Crosslinked gel Lost circulation treatment Hydroxypropyl guar gum Controlled gelation time Supporting cement slurry ability

Pacific oyster(Crassostrea gigas)shell growth duration in a year in Bohai Bay and implication for its carbon sink potential

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China Geology 2024年第4期7卷 653-660页

作者： Wen-yu Wang Chang-fu fan Zhao-jun Song Hong Wang fu Wang Qingdao Geotechnical Investigation and Surveying Research Institute Qingdao 266033China MRL Key laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Tianjin Centre China Geological SurveyTianjin 300170China

Oyster is a bivalve mollusk widely distributed in estuarine and shallow sea *** growth and burial process is a carbon sequestration and storage *** shell may stop growing due to suffer from freeze shock during the winter season within a temperate climate,therefore,in order to study the carbon sequestration capacity of oysters we need to know the water temperature at which the shell suffer from winter freeze *** study examinesδ^(18)O profiles across consecutive micro-growth layers found in three modern Pacific oyster shells from the northwest coast of Bohai Bay.A total of 165 oxygen isotope values from sequential samples of their left shells showed periodically varying values,and the variation fluctuation of oxygen isotope values was 4.97‰on *** to the variation range of the oxygen isotope value of the shell,combined with the sea surface temperature and the sea surface salinity data of the water in which the oysters grew,the water temperature that suffer from winter freeze shock and stops or retards the growth of Pacific oysters in Bohai Bay is about 8.3℃,and the corresponding period is from December to March of the following *** calcification time of oysters within one year is nearly a month longer than previously thought,therefore,its carbon sink potential is also improved.

关键词： Crassostrea gigas Winter freeze shock Oxygen isotope Bohai Bay Carbon sequestration and storage Environmental geological survey