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Multi-User File-Sharing Systems Based on LWE

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China Communications 2020年第7期17卷 166-182页

作者： Xuyang Wang Aiqun hu hao Fang Southeast University Nanjing 210096China Purple Mountain Laboratories Nanjing 210000China UPSEC Cyber INC.Nanjing 210096 China.

Multi-user file-sharing plays an important role in the cloud *** allows different users to share files via the ***,it usually faces many security issues because the cloud is usually public and *** overcome these issues,we propose multi-user file-sharing systems(MFS)in this *** to the date sources,we propose two frameworks of MFS based on the framework of proxy re-encryption(PRE),unique source(uni-source)MFS and multi-source *** formalize the security models,which contain ciphertext security,secret key security and master secret *** the frameworks,we propose two secure and efficient MFS schemes based on LWE,the uni-source MFS UM and the multi-source MFS *** prove that UM is secret key and ciphertext security,and MM is secret key,master secret and ciphertext security with the hardness assumptions of LWE and ***,we prove they have some useful properties,such as non-interactive and anonymous.

关键词： interactive framework LWE

Recent research and development of PLGA/PLA microspheres/nanoparticles: A review in scientific and industrial aspects

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Frontiers of Chemical Science and Engineering 2019年第1期13卷 14-27页

作者： Feng qi Jie Wu hao Li Guanghui Ma Beijing Nuokangda Pharmaceutical Technology Co. Ltd Beijing 100176 China Department of Mechanical and Aerospace Engineering University of Missouri MO 65211 USA National Key Laboratory of Biochemical Engineering Key Laboratory of Biopharmaceutical Production and Formulation Engineering PLA Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

Poly(D,L-lactic-co-glycolic acid)(PLGA)/poly (lactic acid)(PLA) microspheres/nanoparticles are one of the most successful drug delivery systems (DDS) in lab and clinic. Because of good biocompatibility and biodegradability, they can be used in various areas, such as longterm release system, vaccine adjuvant, tissue engineering, etc. There have been 15 products available on the US market, but the system still has many problems during development and manufacturing, such as wide size distribution, drug stability issues, and so on. Recently, many new and modified methods have been developed to overcome the above problems. Some of the methods are easy to scale up, and have been available on the market to achieve pilot scale or even industrial production scale. Furthermore, the relevant FDA guidance on the DDS is still incomplete, especially for abbreviated new drug application. In this review, we present some recent achievement of the PLGA/PLA microspheres/nanoparticles, and discuss some promising manufacturing methods. Finally, we focus on the current FDA guidance on the DDS. The review provides an overview on the development of the system in pharmaceutical industry.

关键词： PLGA microspheres drug delivery system stability manufacturing

Preparation and desulfurization activity of nano-CeO_2/γ-Al_2O_3 catalysts

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Rare Metals 2018年第7期37卷 554-560页

作者： qi Yang hui hu Shan-Shan Wang School of Environment Science and Engineering Huazhong University of Science and Technology Department of Urban Construction Wuchang Shouyi University Wuhan Zuoling New Town Development and Investment Co. Ltd.

γ-A12O3-supported CeO2 catalysts were pre- pared by microemulsion and impregnation methods and characterized by X-ray diffraction （XRD） and scanning electron microscope （SEM） techniques. At the same time, the desulfurization activity of catalysts was investigated. The results show that nanoscale active substances and a high desulfurization effect are achieved by microemulsion, exhibiting a significant dominance compared with traditional impregnation method. The optimal preparation condition is temperature of 30 ℃ and ratio of [H20]/[surface active agent] of 7 with slow demulsification. The activated catalysts still keep high and stable desulfurization activity during a wide temperature range of 450-600 ℃. Among a series of prepared catalysts, the desulfurization rate of 6CeOz/γ-A1203 is the highest, reaching up to 80 % when temperature is higher than 550℃. The catalytic reduction mechanism of SO2 over nano-CeOz/γ-A1203 follows redox mechanism.

关键词： Nano-CeO2/γ-Al2O3 Microemulsion Catalyst Desulfurization

Formation of I1 stacking fault by deformation defect evolution from grain boundaries in Mg

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Journal of Magnesium and Alloys 2022年第10期10卷 2717-2729页

作者： Yong-Jie hu Vaidehi Menon Liang qi Department of Materials Science and Engineering University of MichiganAnn Arbor 48109USA Department of Materials Science and Engineering Drexel UniversityPhiladelphia 19104USA

I_(1)stacking faults(SFs)in Mg alloys are regarded as the nucleation sites ofdislocations that are critical for these alloys to achieve high *** it was proposed that the formation of I_(1)SFs requires the accumulations of a large number of vacancies,which are difficult to achieve at low *** this study,molecular dynamics(MD)and molecular statics(MS)simulations based on empirical interatomic potentials were applied to investigate the deformation defect evolutions from the symmetric tilt grain boundaries(GBs)in Mg and Mg-Y alloys under external loading along-*** results show the planar faults(PFs)on Pyramidal I planes first appear due to the nucleation and glide of(1/2 c+p)partial dislocations from GBs,where p=1/3(1010).These partial dislocations with pyramidal PFs interact with other defects,including pyramidal PFs themselves,GBs,and ppartial dislocations,generating a large amount of I_(1)*** analyses show the nucleation and growth of I_(1)SFs are achieved by atomic shuffle events and deformation defect reactions without the requirements of vacancy *** simulations also suggest the Y clusters at GBs can reduce the critical stress for the formation of pyramidal PFs and I_(1)SFs,which provide a possible reason for the experimental observations that Y promotes thedislocation activities.

关键词： Magnesium alloys I1 stacking faults dislocations Grain boundaries Defect nucleation and evolution Molecular dynamics simulations

Dynamic Feedforward Control of a Novel 3-PSP 3-DOF Parallel Manipulator

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Chinese Journal of Mechanical Engineering 2011年第4期24卷 676-684页

作者： hao qi GUAN Liwen WANG Jinsong WANG Liping Department of Precision Instruments and Mechanology Tsinghua University Beijing 100084 China Department of Helicopter Mechanical Engineering Institute of Army Aviation Beijing 101123 China

Parallel manipulators with less than six degrees of freedom （DOF） have been increasingly used in high-speed hybrid machine tools. The structural features of parallel manipulators are dynamic, a characteristic that is particularly significant when these manipulators are used in high-speed machine tools. However, normal kinematic control method cannot satisfy the requirements of the control system. Many researchers use model-based dynamic control methods, such as the dynamic feedforward control method. However, these methods are rarely used in hybrid machine tools because of the complex dynamic model of the parallel manipulator. In order to study the dynamic control method of parallel manipulators, the dynamic feedforward control method is used in the dynamic control system of a 3-PSP （prismatic-spherical-prismatic） 3-DOF spatial parallel manipulator used as a spindle head in a high-speed hybrid machine tool. Using kinematic analysis as basis and the Newton-Euler method, we derive the dynamic model of the parallel manipulator. Furthermore, a model-based dynamic feedforward control system consisting of both kinematic control and dynamic control subsystems is established. The dynamic control subsystem consists of two modules. One is used to eliminate the influence of the dynamic characteristics of high-speed movement, and the other is used to eliminate the dynamic disturbances in the milling process. Finally, the simulation model of the dynamic feedforward control system of the 3-PSP parallel manipulator is constructed in Matlab/Simulink. The simulations of the control system eliminating the influence of the dynamic characteristics and dynamic disturbances are conducted. A comparative study between the simulations and the normal kinematic control method is also *** simulations prove that the dynamic feedforward control method effectively eliminates the influence of the dynamic disturbances and dynamic characteristics of the parallel manipulator on high-speed m

关键词： parallel manipulator dynamic feedforward control high-speed hybrid machine tool

ON PAIRED PRIORITIZATIONS OF CRITERIA IN THE PERSPECTIVE OF DIAGRAPHS

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Journal of Systems Science and Systems Engineering 2015年第4期24卷 466-485页

作者： Wenning hao Xiaohan Yu Zeshui Xu Xiuli qi College of Command Information Systems PLA University of Science and Technology College of Sciences PLA University of Science and Technology

It is not usually independent among criteria in multi-criteria decision making(MCDM),and various dependences of criteria greatly influence the results of decision *** an exact decision is desired,we must make clear the role of the dependences of ***,a new kind of dependences of criteria proposed recently,imply that the importance weights of criteria with lower priority for an alternative rely on whether the alternative satisfies the decision maker under criteria with higher *** has been validated that there exist lots of relevant applications in our daily ***,most existing literatures focus on how to deal with the problems of MCDM with ordered prioritizations among criteria(a special form of prioritizations).The characteristics of prioritizations are not dug *** paper constructs a new form of prioritizations,called paired prioritizations,so as to reduce or even avoid imperfect rationality of decision makers hidden in the ordered *** first represent binary paired prioritizations as a digraph,based on which we discover two kinds of imperfect rationality(inconsistency and incompleteness) produced in the period that the decision maker supplies the binary paired *** the given paired prioritizations are consistent and complete,we develop an approach to transform the paired prioritizations to ordered *** latter can be used to handle prioritized MCDM ***,uncertainty,another kind of imperfect rationality,is considered when the decision maker provides the fuzzy paired prioritizations based on a set of linguistic *** construct a fuzzy digraph whose fuzzy relations are just the fuzzy paired *** ordered prioritizations can then be derived with the aid of the fuzzy *** use cases are taken to show the process of transformations from binary/fuzzy paired prioritizations to ordered prioritizations.

关键词： Paired prioritization ordered prioritization criteria digraph fuzzy digraph

Effects of Increasing Non-Fiber Carbohydrate to Neutral Detergent Fiber Ratio on Rumen Fermentation and Microbiota in Goats

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Journal of Integrative Agriculture 2013年第2期12卷 319-326页

作者： LIU Da-cheng ZHOU Xiang-li Zhao Pei-ting GAO Min HAN hao-qi hu Hong-lian College of Veterinary Medicine Inner Mongolia Agricultural University Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease of Ministry of Agriculture Animal Nutrition Institute of Agriculture and Animal husbandry Academy of Inner Mongolia

Six rumen-cannulated lactating Guanzhong goats were used to investigate changes in ruminal fermentation pattern and the microbiota following a subacute rtmainal acidosis （SARA） inducing procedure. Induction of SARA was performed by increasing dietary non-fiber carbohydrate （NFC） to neutral detergent fiber （NDF） ratio from 1.02 （stage 1） to 1.24 （stage 2）, 1.63 （stage 3） and 2.58 （stage 4）. A dynamic pH monitoring system, real-time fluorescent quantitative PCR and conventional anaerobic culture were used to assess changes in ruminal pH and microbiota. Results indicated that rumen fermentation patterns changed significantly with increased NFC：NDF ratio. The decline in ruminal pH was caused by increased ruminal total volatile fatty acids （TVFA）, which was mainly attributed to a significant increase in ruminal butyrate, rather than the accumulation of ruminal lactic acid. In addition, in the course of SARA, the number of rumen microoganisms altered significantly, with increases in ruminal amylolytic bacteria, Lactobacilli, Streptococcus bovis and Megasphaera elsdenii, the latter particularly dramatically indicating that it may be the main factor responsible for the increase in butyrate, and decrease in protozoa.

关键词： rumen fermentation rumen microorganisms subacute ruminal acidosis goat

Responses of protists with different feeding habits to the changes of activated sludge conditions:A study based on biomass data

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Journal of Environmental Sciences 2012年第12期24卷 2127-2132页

作者： Bo hu Rong qi Wei An Min Yang State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Changes of protists, which were categorized into different functional groups primarily according to their feeding habits, in two full-scale municipal wastewater treatment systems experiencing sludge bulking were investigated over a period of 14 months. Protist biomass represented 3.7% to 5.2% of total biomass on average under normal sludge conditions, and the percentage increased significantly （p 〈 0.05） under sludge bulking conditions. The biomass of Chilodonella spp., capable of eating filamentous bacteria, tended to decrease in both systems when sludge bulking occurred, showing that the abnormal growth of filamentous bacteria did not lead to a biomass bloom of this group of protists. On the other hand, the bactivorous protists represented more than 96% of total protist biomass, and the biomass of this group, particularly the attached ciliates, increased significantly （p 〈 0.05） when sludge bulking occurred. The significant increase of the attached ciliates may have possibly facilitated the growth of filamentous bacteria through selectively preying on non-filamentous bacteria and further exacerbated sludge bulking. The redundancy analysis and correlation analysis results showed that the biomass changes of the attached ciliates were primarily related to the sludge volume index and to some extent related to five-day biochemical oxygen demand loading and hydraulic retention time.

关键词： protist biomass activated sludge feeding habit sludge bulking

Study on the damage-softening constitutive model of rock and experimental verification

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Acta Mechanica Sinica 2019年第4期35卷 786-798页

作者： Sheng-qi Yang Bo hu Peng Xu State Key Laboratory for Geomechanics and Deep Underground Engineering School of Mechanics and Civil Engineering China University of Mining and Technology Xuzhou 221116 China China Construction Third Engineering Design Bureau Co. Ltd Wuhan 430064 China

A damage-softening model is presented to describe the stress-strain curve of rock. By comparing the Hoek-Brown (H-B) and Mohr-Coulomb (M-C) yield criterion, the equivalent M-C yield criterion is selected as the strength criterion in this model. To better characterize the rock damage and failure processes with considering the relationship between damage and deformation, the concept of yield stress ratio is introduced to describe the yield strengthening deformation before rock peak stress. Damage events are described by two cumulative damage evolution laws. The evolution equations of tensile and shear damage are presented based on the equivalent plastic strains and the maximum value between tensile and shear damage represents the total damage for rock. Considering that rock cannot bear tensile load after tensile failure but still has a certain shear strength, its tensile and shear strengths are small after shear failure. The elastic modulus is affected by tensile damage, whereas the angle of internal friction, the cohesion, and dilation angles are influenced by shear damage. The proposed damage-softening model describes the strain-softening, brittle stress-drop, and residual strength of rock after peak stress, and finally the model is implemented in FLAC3D. Comparing the test and the numerical calculation results, the damage-softening model better describes the total stress-strain curve of rock.

关键词： Rock deformation Damage evolution Softening Numerical calculation