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A wideband CMOS variable gain low noise amplifier

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High Technology Letters 2010年第2期16卷 194-198页

作者：李海松 li Zhiqun zhang Hao li Wei wang Zhigong Institute of RF-＆OE-ICS Southeast University Nanjing 210096 P.R.China

In this paper, a novel structure of linear-in-dB gain control is introduced. Based on this structure, a wideband variable gain low noise amplifier （VGLNA） has been designed and implemented in 0.18μm RF CMOS technology. The measured resuhs show a good linear-in-dB gain control characteristic with 15 dB dynamic range. It can operate in the frequency range of MHz and consumes 30mW from 1.8V power supply. The minimum noise figure is 4.1 dB at the 48 - 860 maximum gain and the input P1dB is greater than - 16.5dBm.

关键词： low noise amplifier (LNA) wideband linear-in-dB CMOS

Optimal Operation with Dynamic Partitioning Strategy for Centralized Shared Energy Storage Station with Integration of Large-scale Renewable Energy

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 359-370页

作者： Jianlin li Zhijin Fang Qian wang Mengyuan zhang Yaxin li Weijun zhang Beijing Future Technology Innovation Centre for Electrochemical Energy Storage System Integration North China University of Technology Beijing China State Grid Fujian Electric Power Research Institute Fuzhou China

As renewable energy continues to be integrated into the grid,energy storage has become a vital technique supporting power system *** effectively promote the efficiency and economics of energy storage,centralized shared energy storage(SES)station with multiple energy storage batteries is developed to enable energy trading among a group of *** this paper,we propose the optimal operation with dynamic partitioning strategy for the centralized SES station,considering the day-ahead demands of large-scale renewable energy power *** implement a multi-entity cooperative optimization operation model based on Nash bargaining *** model is decomposed into two subproblems:the operation profit maximization problem with energy trading and the leasing payment bargaining *** distributed alternating direction multiplier method(ADMM)is employed to address the subproblems *** reveal that the optimal operation with a dynamic partitioning strategy improves the tracking of planned output of renewable energy entities,enhances the actual utilization rate of energy storage,and increases the profits of each participating *** results confirm the practicality and effectiveness of the strategy.

关键词： Shared energy storage(SES) dynamic partitioning strategy optimal operation Nash bargaining theory actual utilization rate of energy storage

Facet-dependent activation of oxalic acid over hematite nanocrystals under the irradiation of visible light for efficient degradation of pollutants

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Journal of Environmental Sciences 2024年第8期142卷 204-214页

作者： Zhixiong Yang Yuan li Xiaotian wang Jiaming li Jiquan wang Gaoke zhang Hubei Key Laboratory of Mineral Resources Processing and Environment State Key Laboratory of Silicate Materials for ArchitecturesWuhan University of TechnologyWuhan 430070China Hubei Engineering Consulting Co. Ltd.Wuhan 430071China

Naturally occurring hematite has been widely studied in the Fenton-like system for water pollutant remediation due to its abundance and ***,its inadequate catalytic activity results in difficulty in effectively degrading pollutants in the catalytic degradation system that it ***,we constructed a photochemical system composed of hematite with{001}facet of high activity facet and low-cost and non-toxic oxalic acid(OA)for the removal of various types of *** removal rate for the degradation of metronidazole,tetracycline hydrochloride,Rhodamine B,and hexavalent chromium by hematite nanoplate with the exposed{001}facet activating OA under visible light irradiation was 4.75,2.25,2.33,and 2.74 times than that by the exposed{110}facet,*** functional theory(DFT)calculation proved that the OA molecule was more easily adsorbed on the{001}facet of hematite than that on the{110}facet,which would favor the formation of the more Fe(Ⅲ)-OA complex and reactive *** addition,the reactive site of metronidazole for the attraction of radicals was identified on the basis of the DFT calculation on the molecular occupied orbitals,and the possible degradation pathway for metronidazole included carbon chain fracture,hydroxyethyl-cleavage,denitrogenation,and ***,this finding may offer a valuable direction in designing an efficient iron-based catalyst based on facet engineering for the improved activity of Fenton-like systems such as OA activation.

关键词： Hematite Facet exposure Oxalic acid activation Fenton-like system Pollutant removal

The influence of inter-band rock on rib spalling in longwall panel with large mining height

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International Journal of Mining Science and Technology 2024年第4期34卷 427-442页

作者： Jiachen wang Meng li Zhaohui wang Zheng li Han zhang Shixiong Song School of Energy and Mining Engineering China University of Mining and Technology-BeijingBeijing 100083China Coal Industry Engineering Research Center of Top-coal Caving Mining Beijing 100083China Faculty of Engineering Hokkaido UniversitySapporo 060-8628Japan

In order to improve rib stability,failure criteria and instability mode of a thick coal seam with inter-band rock layer are analysed in this study.A three-dimensional mechanical model is established for the rib by considering the rock layer.A safety factor is defined foy the rib,and it is observed that the safety factor exhibits a positive correlation with the thickness and strength of the inter-band rock.A calculation method for determining critical parameters of the rock layer is presented to ensure the rib *** is revealed that incomplete propagation of the fracture at the hard rock constitutes a fundamental prerequisite for ensuring the rib *** influence of the position of the inter-band rock in the coal seam on failure mechanism of the rib was thoroughly investigated by developing a series of physical models for the rib at the face *** best position for the inter-band rock in the coal seam is at a height of 1.5 m away from the roof line,which tends to provide a good stability state for the *** different inter-band rock positions,two ways of controlling rib by increasing supports stiffness and flexible grouting reinforcement are proposed.

关键词： Rib spalling Inter-band rock Large mining height limit analysis Physical model experiment Numerical simulation

Changes of brain neuropeptide Y and its receptors in rats with flurazepam tolerance and dependence

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Acta Pharmacologica Sinica 2005年第11期26卷 1290-1296页

作者： li-ping zhang, li wang~2 Department of Pediatrics, Peking University First Hospital, Beijing 100034, China Department of Pediatrics Peking University First Hospital Beijing China

Aim: Anticonvulsant tolerance and dependence are two obstacles that restrict the clinical use of benzodiazepines (BDZ). In order to explore the mechanism of these two adverse reactions, changes of neuropeptide Y (NPY) and its receptors in the hippocampus of rat models, in relation to flurazepam (FZP, a member of BDZ) tolerance and dependence, were investigated. Methods: The mRNA of preproNPY and its receptors (Y1, Y2, and Y5) in the hippocampus were determined by competitive RT-PCR, and the distribution of NPY in the hippocampus was examined by immunohistochemistry. Results: A decrease of preproNPY mRNA in the hippocampus was found in tolerant and dependent rats. The level of preproNPY mRNA in the hippocampus was reversely correlated with the degree of tolerance and dependence, measured by the threshold of pentylenetetrazol-induced seizures. Immunohistochemistry indicated a decrease of NPY-immunoreactive material in neurons of the CA1, CA3, and dentate gyrus regions of both tolerant and dependent rats. The mRNA of NPY receptors Y,and Y5decreased in tolerant rats but did not change in dependent rats. The mRNA of NPY receptor Y2increased in tolerant rats but decreased in dependent rats. Conclusion: A decrease of NPY in the hippocampus might be involved in anticonvulsant tolerance and dependence following long-term treatment with FZP. Y,, Y2, and Y5mRNA were also altered in FZP tolerance and dependence.

关键词： benzodiazepines neuropeptide Y flura zepam

Study of a Novel Brain Relatively Specific Gene LRRC4 Involved in Glioma Tumorigenesis Suppression Using the Tet-on System

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Acta Biochimica et Biophysica Sinica 2005年第8期37卷 532-540页

作者： Qiu-Hong zhang li-li wang li CAO Cong PENG Xiao-ling li Ke TANG Wei-Fang li Ping liAO Jie-Ru wang Gui-Yuan li~* Cancer Research Institute,Central South University,Changsha 410078,China Cancer Research Institute Central South UniversityChangsha 410078 China

LRRC4 is a novel relatively specific gene,which displays significant down-regulation inprimary brain tumor biopsies and has the potential to suppress brain tumor *** this study,we inves-tigated the growth inhibitory effect of LRRC4 on tumorigencity in vivo and on cell proliferation in vitro by atetracycline-inducible expression *** showed that LRRC4 significantly reduced the growth andmalignant grade of xenografts arising from glioblastoma U251MG *** proliferation was markedlyinhibited after U251MG Tet-on-LRRC4 cell induction with *** cytometry and Western blotanalysis demonstrated that LRRC4 mediated a delay of the cell cycle in late G1,possibly through up-regulat-ing the expressions of p21Wafl/cip 1 and p27Kip 1 and down-regulating the expressions of cyclin-dependentkinase 2,retinoblastoma protein and epidermal growth factor ***,these findings provideclues to the function of LRRC4 as a negative regulator of cell growth and underscore a link between theabove-mentioned cyclins,cyclin-associated molecules and tumorigenicity.

关键词： LRRC4 tumorigencity cell proliferation cell cycle delay

UAV image target localization method based on outlier filter and frame buffer

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Chinese Journal of Aeronautics 2024年第7期37卷 375-390页

作者： Yang wang Hongguang li Xinjun li Zhipeng wang Baochang zhang Institute of Unmanned System Beihang UniversityBeijing 100191China School of Electronics and Information Engineering Beihang UniversityBeijing 100191China Institute of Artificial Intelligence Beihang UniversityBeijing 100191China

With rapid development of UAV technology,research on UAV image analysis has gained *** the existing techniques of UAV target localization often rely on additional equipment,a method of UAV target localization based on depth estimation has been ***,the unique perspective of UAVs poses challenges such as the significant field of view variations and the presence of dynamic objects in the *** a result,the existing methods of depth estimation and scale recovery cannot be directly applied to UAV ***,there is a scarcity of depth estimation datasets tailored for UAV perspectives,which makes supervised algorithms *** address these issues,an outlier filter is introduced to enhance the applicability of depth estimation networks to target localization.A frame buffer method is proposed to achieve more accurate scale recovery,so as to handle complex scene textures in UAV *** proposed method demonstrates a 14.29%improvement over the *** with the average recovery results from UAV perspectives,the difference is only 0.88%,approaching the performance of scale recovery using ground truth ***,to overcome the limited availability of traditional UAV depth datasets,a method for generating depth labels from video sequences is *** to state-of-the-art methods,the proposed approach achieves higher accuracy in depth estimation and stands for the first attempt at target localization using image *** algorithm and dataset are available at https://***/uav-tan/uav-object-localization.

关键词： Object localization Deep learning Depth estimate Scale recovery Unmanned Aerial Vehicle(UAV)

Seepage laws of two kinds of disastrous gas in complete stress-strain process of coal

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Mining Science and Technology 2011年第6期21卷 851-856页

作者： Cao Shugang Guo Ping zhang Zunguo li Yi wang Yong State and Lock Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam Chongqing University Chongqing 400044 China

The similarities and differences in seepage flow evolution laws of CH4 and CO2 during complete stress- strain process of samples were comparatively analyzed. The results show that the seepage flow evolution laws of CH4 and CO2 are extremely similar during the stress-strain process, showing that the character- istic first decreased and then increased. A mathematical model was also established according to the rela- tionship of seepage velocity and axial strain. However, due to the strong adsorption ability of CO2, the coal samples generated a more serious ''Klinkenberg effect'' under the condition of CO2. Owing to this, the CO2 seepage flow resulted into occurrence of ''stagnation'' phenomenon during the late linear elastic stage II. In the strain consolidation stage III, the increment rate of CH4 seepage velocity was significantly greater than that of CO2. In the stress descent stage IV, when the axial load reached the peak pressure of coal, the increment rates of CH4 seepage velocity presented a turning point. But the changing rate of CO2 seepage velocity still remained slow and a turning point was presented at one time after the peak of thestrain pressure, which showed an obvious feature of hysteresis.

关键词： Outburst coal CH4 CO2 Klinkenberg effect Complete stress–strain

The adsorption effect of aquaculture residual feed on heavy metals and its impact on microbial metabolism of feed

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Ecological Processes 2024年第2期13卷 246-259页

作者： Sufeng wang Zijng wang Wen zhang Jingshan li Mingyang lin li Chen State Key Laboratory of Metastable Materials Science and Technology Hebei Key Laboratory of Heavy Metal Deep-Remediation in Water and Resource Reuse Yanshan University Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province College of Biology and Environmental EngineeringZhejiang Shuren University Hebei Ocean & Fisheries Science Research Institute

Background Intensive and large-scale aquaculture has a high biological density, and a large amount of artificial feed must be provided. As a result, residual feed would be discharged into natural water bodies with water exchange. Due to heavy metal pollution in surface water, residual feed may adsorb heavy metals in the water, affecting the subsequent microbial degradation of feed and the restoration of the water environment. The combined ecological impacts of these two types of pollution urgently need to be *** This study explored the adsorption effect of residual feed on heavy metals and its impact on microbial degradation of residual feed. The results showed that both the insoluble component（mainly fiber, ash, and ether extract, abbreviated as FAE） and soluble component（soluble protein and starch） of the feed had adsorption effects on heavy metals. As the salinity increased, the adsorption capacity of Cu2+and Cd2+decreased, while the adsorption effect on Pb2+was not changed significantly. The adsorption of heavy metals by residual feed could affect the biological degradation of residual feed. The residual feed could adsorb heavy metals and bacterial cells simultaneously, forming FAE-B（bacteria）-S（starch）-Pr（protein）-metal adsorption complex. This adsorption effect could reduce the negative impact of heavy metals on microbial degradation of residual feed. The simulated degradation experiments in actual water bodies also confirmed this. However, the accumulation of heavy metals in residual feed may bring negative effects, such as being consumed by aquatic organisms and entering the food *** The results of this study provide a basis for the collection and centralized treatment of residual feed in aquaculture, as well as the control and remediation of residual feed pollution in natural water bodies.

关键词： Residual feed Adsorption complex Feed pollution Heavy metal