检索结果-南通市图书馆

A recoverable stress testing algorithm for compression and encryption cards

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第10期9卷 1398-1405页

作者： Bao-jun ZHANG Xue-zeng PAN Jie-bing WANG ling-di ping Network and Security Lab School of Computer Science anc~Technology Zhejiang University Hangzhou 310027 China

This study proposes a recoverable stress testing algorithm （RSTA） for such special devices as compression/decompression card and encryption/deeryption card. It uses a chaos function to generate a random sequence, and then, according to the random sequence, generates an effective command sequence. The dispatch of command obeys a special schedule strategy we designed for such devices, i.e., the commands are sent according to the command sequence, and the complete commands are put in a buffer for further result check. RSTA is used to test the HIFN compression acceleration card SAICHI-1000. Test results show that RSTA can make the card work continuously and adequately.

关键词： Stress testing Random sequence Chaos function Synchronization Concurrency

Robust lossless data hiding scheme

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第2期11卷 101-110页

作者： Xian-ting ZENG Xue-zeng PAN ling-di ping Zhuo LI School of Computer Science and Technology Zhejiang University Hangzhou 310027 China College of Information Engineering China Jiliang University Hangzhou 310018 China

This paper presents a robust lossless data hiding scheme. The original cover image can be recovered without any distortion after data extraction if the stego-image remains intact, and conversely, the hidden data can still be extracted correctly if the stego-image goes through JPEG compression to some extent. A cover image is divided into a number of non-overlapping blocks, and the arithmetic difference of each block is calculated. By shifting the arithmetic difference value, we can embed bits into the blocks. The shift quantity and shifting rule are fixed for all blocks, and reversibility is achieved. Furthermore, because the bit-0- and bit-1-zones are separated and the particularity of the arithmetic differences, minor changes applied to the stego-image generated by non-malicious attacks such as JPEG compression will not cause the bit-0- and bit-l-zones to overlap, and robustness is achieved. The new embedding mechanism can enhance embedding capacity and the addition of a threshold can make the al- gorithm more robust. Experimental results showed that, compared with previous schemes, the performance of the proposed scheme is significantly improved.

关键词： Watermarking Lossless data hiding Reversible data hiding Robust lossless data hiding Semi-fragile authentication

An efficient and DoS-resistant user authentication scheme for two-tiered wireless sensor networks

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第7期12卷 550-560页

作者： Rong FAN ,Dao-jing HE ,Xue-zeng PAN,ling-di ping (School of Computer Science and Technology,Zhejiang University,Hangzhou 310027,China) School of Computer Science and Technology Zhejiang University

Wireless sensor networks (WSNs) are vulnerable to security attacks due to their deployment and resource *** that most large-scale WSNs follow a two-tiered architecture,we propose an efficient and denial-of-service (DoS)-resistant user authentication scheme for two-tiered *** proposed approach reduces the computational load,since it performs only simple operations,such as exclusive-OR and a one-way hash *** feature is more suitable for the resource-limited sensor nodes and mobile *** it is unnecessary for master nodes to forward login request messages to the base station,or maintain a long user *** addition,pseudonym identity is introduced to preserve user *** clever design,our proposed scheme can prevent smart card ***,security and performance analysis demonstrates the effectiveness and robustness of the proposed scheme.

关键词： User authentication User anonymity Smart card Two-tiered Wireless sensor network (WSN)

Revealing effect of Al content on oxidation of novel Co-Cr-Nb-W carbide-strengthened superalloy

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4521-4534页

作者： Chen ling Shang-ping Li Jie Hou He-Li Luo Central Iron & Steel Research Institute Beijing GAONA Materials&Technology Co. Ltd.

The high-temperature oxidation behavior of novel Co-Cr-Nb-W carbide-strengthened wear-resistance alloys with different Al contents（1wt%, 2wt% and 3wt%）at 950, 1000 and 1050 °C was thoroughly investigated by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and field emission electron probe analyzer. The porous property of Nb C in-situ oxidation products（Nb2O5, Co Nb2O6and Co4Nb2O9） induces a multi-layered oxide scale with micropores and ***-Cr-Nb-W alloy with 1 wt% Al undergoes catastrophic oxidation and spalling above 1000 °C. The outward transportation of Cr and Co is effectively restrained by a continuous Al2O3scale formed around Nb C in-situ oxidation region when Al content reaches 3 wt%. The β-Co Al in Co-Cr-Nb-W alloy with 3 wt% Al has an oxidation priority over eutectic carbides and the alloy matrix which are both enriched with Cr, thereby preventing the formation of Cr-depletion area and improving the self-healing ability of the oxide film. A slight change in Al content has a remarkable influence on the cooperative effect of Al and Cr and multiplies the antioxidant capacity of Co-Cr-Nb-W alloy above 1000 °C.

关键词： High-temperature oxidation behavior Microstructure Oxidation kinetics Superalloy Wear-resistant alloy

Investigating effect of coke porosity on blast furnace performance based on multi-physical fields

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第2期31卷 357-367页

作者： Ji Chen Zhao Lei Zhe Yao Li Wang Qiang ling ping Cui Anhui Province Key Laboratory of Coal Clean Conversion and High Valued Utilization School of Chemistry and Chemical EngineeringAnhui University of TechnologyMa’anshan243002AnhuiChina Shanxi Academy of Printing Technology Research Institute Co. Ltd.Xi’an710077ShaanxiChina

Reducing coke use is an effective measure to reduce carbon emission and energy consumption in the blast furnace(BF)***,BF is a high-temperature moving bed reactor,where complex physical transformations coupled with complicated reactions *** makes it challenging to investigate the factors determining BF performance with the conventional method.A multi-physical field coupling mathematical model of BF was thus developed to describe its mass and heat transfer as well as its intrinsic ***,the proposed model was validated with the production *** coupling conditions,influences of dominating reactions on BF performance(temperature distribution,gas distribution,iron formation reaction,and direct reduction degree)were *** results indicated that coke combustion,indirect reduction,and direct reduction of iron ore mainly took place nearby the shaft tuyere,cohesive zone,and dripping zone,***,the rate of coke solution loss reaction was increased with the rising coke porosity in the cohesive *** the effect of coke porosity on the efficiency and stability of BF,the coke porosity of 0.42 was regarded as a reasonable value.

关键词： Blast furnace Mathematical model Multi-physical field Simulation Coke porosity

Experimental investigation of dynamic characteristics of leaching tubing for solution mining of salt cavern carbon and energy storage

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2703-2722页

作者： Yin-ping Li Xin-Bo Ge Xi-Lin Shi Hong-ling Ma State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences University of Chinese Academy of Sciences College of Energy and Mining Engineering Shandong University of Science and Technology State Key Laboratory of Mining disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology Shandong University of Science and Technology

Salt caverns are extensively utilized for storing various substances such as fossil energy, hydrogen,compressed air, nuclear waste, and industrial solid waste. In China, when the salt cavern is leached through single-well water solution mining with oil as a cushion, engineering challenges arise with the leaching tubing, leading to issues like damage and instability. These problems significantly hinder the progress of cavern construction and the control of cavern shape. The primary cause of this is the flowinduced vibration instability of leaching tubing within a confined space, which results in severe bending or damage to the tubing. This study presents a model experimental investigation on the dynamic characteristics of leaching tubing using a self-developed liquid-solid coupling physical model experiment apparatus. The experiment utilizes a silicone-rubber pipe(SRP) and a polycarbonate pipe(PCP) to examine the effects of various factors on the dynamic stability of cantilevered pipes conveying fluid. These factors include external space constraint, flexural rigidity, medium outside the pipe, overhanging length, and end conditions. The experiments reveal four dynamic response phenomena: water hammer, static buckling, chaotic motion, and flutter instability. The study further demonstrates that the length of the external space constraint has a direct impact on the flutter critical flow velocity of the cantilevered pipe conveying fluid. Additionally, the flutter critical flow velocity is influenced by the end conditions and different external media.

关键词： Salt cavern storage Solution mining Leaching tubing Experimental investigation Flutter instability

Three types of promising functional building units for designing metal halide nonlinear optical crystals

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2024年第6期43卷 8-11页

作者： Jiajing Wu Ru-ling Tang Sheng-ping Guo School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou225002PR China Yunnan Key Laboratory of Electromagnetic Materials and Devices National Center for International Research on Photoelectric and Energy MaterialsSchool of Material and EnergyYunnan UniversityKunming650000PR China

Nonlinear optical(NLO)crystal materials greatly extend the tunable range of laser by frequency conversion,which promotes the rapid development of laser technology and plays an important role in many civil and military *** excellent and famous NLO crystals from the ultraviolet(UV)to visible to near infrared(NIR)regions have been developed,such as borates(KBe_(2)BO_(3)F_(2),β-BaB_(2)O_(4)),phosphates(KH_(2)PO_(4),KTiOPO_(4)),chalcogenides(AgGaS_(2),AgGaSe_(2))and so on[1,2].

关键词： optical tunable designing

Research on thermal insulation materials properties under HTHP conditions for deep oil and gas reservoir rock ITP-Coring

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2625-2637页

作者： Zhi-Qiang He He-ping Xie ling Chen Jian-ping Yang Bo Yu Zi-Jie Wei Ming-Zhong Gao State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering College of Water Resource and Hydropower Sichuan University Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Institute of Deep Earth Sciences and Green Energy College of Civil and Transportation Engineering Shenzhen University School of Mechanical Engineering Sichuan University College of Polymer Science and Engineering Sichuan University

Deep oil and gas reservoirs are under high-temperature conditions, but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability, resulting in distorted resource assessments. The development of in situ temperaturepreserved coring(ITP-Coring) technology for deep reservoir rock is urgent, and thermal insulation materials are key. Therefore, hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials) were proposed as thermal insulation materials. The materials properties under coupled hightemperature and high-pressure(HTHP) conditions were tested. The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased; additionally,increasing temperature accelerated the process. High temperatures directly caused the thermal conductivity of the materials to increase; additionally, the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity. High temperatures weakened the matrix, and high pressures destroyed the HGM, which resulted in a decrease in the tensile mechanical properties of the materials. The materials entered the high elastic state at 150.C, and the mechanical properties were weakened more obviously, while the pressure led to a significant effect when the water absorption was above 10%. Meanwhile, the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86% at 100.C and 100 MPa, respectively, which meet the application requirements of the self-designed coring device. Finally, K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100.C and 100 MPa. To further improve the materials properties, the interface layer and EP matrix should be optimized. The results can provide references for the optimization and engineering application of materials and thus technical su

关键词： Deep oil and gas reservoir rock In situ temperature-preserved coring (ITP-Coring) Hollow glass microsphere/epoxy resin thermal insulation materials (HGM/EP materials) High-temperature and high-pressure (HTHP) Physical and mechanical properties ITP-Coring In situ temperature-preserved coring HGM/EP Hollow glass microsphere/epoxy resin HTHP High-temperature and high-pressure

Exogenous insulin autoimmune syndrome:A case report and review of literature

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第9期12卷 1691-1697页

作者： ling-ling Xu Jia-Xin Chen Jing-ping Cheng Ni Luo Medical College School of MedicineWuhan University of Science and TechnologyWuhan 430065Hubei ProvinceChina Department of Gerontology CR&WISCO General Hospital Affiliated to Wuhan University of Science and TechnologyWuhan 430080Hubei ProvinceChina

BACKGROUND Insulin autoimmune syndrome(IAS)is a severe manifestation of spontaneous *** is characterized by elevated levels of immune-reactive insulin and highly potent insulin autoantibodies(IAAs),which are induced by endogenous insulin circulating in the *** is distinguished by recurring instances of spontaneous hypoglycemia,the presence of IAA within the body,a substantial elevation in serum insulin levels,and an absence of prior exogenous insulin ***,recent studies show that both conventional insulin and its analogs can induce IAS episodes,giving rise to the notion of nonclassical ***,more attention should be paid to these *** SUMMARY In this case report,we present a rare case of non-classical IAS in an 83-year-old male patient who present with symptoms of a psychiatric *** symptom onset,the patient exhibited Whipple's triad(including hypoglycemia,blood glucose level less than 2.8 mmol/L during onset,and rapid relief of hypoglycemic symptoms after glucose administration).Concurrently,his serum insulin level was significantly elevated,which contradicted his C-peptide *** a comprehensive examination,the patient was diagnosed with exogenous insulin autoimmune *** that the patient had type 2 diabetes mellitus and a history of exogenous insulin use before disease onset,it was presumed that non classical IAS was induced by this *** PubMed database was used to search for previous cases of IAS and non-classical IAS to analyze their characteristics and treatment *** The occurrence of non-classical IAS is associated with exogenous insulin or its analogs,as well as with sulfhydryl *** can be effectively alleviated through the discontinuation of relevant medications,administration of hormones or immunosuppressants,plasma exchange,and lifestyle adjustments.

关键词： Insulin autoimmune syndrome Type 2 diabetes Exogenous insulin Insulin autoantibodies Hypoglycemia Case report