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广东省农业多功能评价及复合功能空间划分研究

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农业现代化研究 2024年第1期45卷 20-32页

作者：赖焕明吴大放杨木壮刘毅华卢奕帆吴钊骏广州大学地理科学与遥感学院广东广州510006 北京大学地表过程分析与模拟教育部重点实验室北京100871

农业功能结构性失衡、功能服务区域覆盖不均是城乡发展二元化的典型特征,农业功能空间的开发与转型是破解城乡发展二元结构、推进农业现代化的有力抓手。本文通过构建农业多功能评价体系,运用耦合协调模型和空间自相关等技术方法,分析... 详细信息

农业功能结构性失衡、功能服务区域覆盖不均是城乡发展二元化的典型特征,农业功能空间的开发与转型是破解城乡发展二元结构、推进农业现代化的有力抓手。本文通过构建农业多功能评价体系,运用耦合协调模型和空间自相关等技术方法,分析广东省农业多功能及其各功能的发展状况,划分农业复合功能空间类型,辨析农业复合功能空间的发展与转型演化过程。结果表明,2010—2020年广东省农业多功能指数呈上升趋势,发展先慢后快,向非生产性主导的农业多功能转型发展,空间格局呈向沿海地区集聚的发展态势。农业各类功能指数均有所提高,生产功能呈现以粤东、粤西为中心集聚,并向粤北地区延伸,珠三角地区低值集聚的特点;社会服务功能在区域内中等水平均衡分布;农业生态服务功能形成“粤北环海”的北部生态屏障与“圈层递增”的总体格局;休闲服务功能主要分布在珠三角区域,呈现高—高集聚和低—高集聚的特点。农业复合功能空间类型主要向生态型、休闲型复合功能空间转型,形成生产—生态服务型、生产—社会服务型、生产—休闲服务型、社会—休闲服务型、社会—生态服务型5种类型的农业复合功能空间新格局。广东省农业多功能持续融合、复合功能空间类型多元化发展,但区域间农业功能模式存在异质性。因此,本文提出应统筹规划农业功能空间的开发与转型,开发与保护并举,探索因地制宜的农业功能空间协调发展路径,以期为广东省农业功能空间格局优化、农业空间集约高效利用、城乡融合发展提供理论依据。

关键词：农业多功能复合功能功能空间划分空间格局农业现代化广东省

A 20 μW 95 dB dynamic range 4th-order Delta-Sigma modulator with novel power efficient operational transconductance amplifier and resonator

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第6期12卷 486-498页

作者： Jian XU Xiao-bo wu Meng-lian zhao jun-yi SHEN Institute of VLSI Design Zhejiang University Hangzhou 310027 China

A low power high performance Delta-Sigma modulator for portable measurement applications is presented. To reduce power consumption while maintaining high performance, a fully feedforward architecture with a comprehensive system-level design is implemented. As a key building block, a novel power efficient current mirror operational transconductance amplifier (OTA) with a fast-settling less-error switched-capacitor common-mode feedback (SC CMFB) circuit is introduced, and the effects of both gain nonlinearity and 1/f noise of OTA are discussed. A new method to determine the voltage gain of an OTA is also proposed. The bottom terminal parasitic effect of poly-insulator-poly (PIP) capacitors is considered. About an extra 20% of capacitance is added to the total capacitance load. A power and area efficient resonator is adopted to realize a coefficient of 1/90 for 50% power and 75% area reduction compared with conventional designs. The chip is implemented in a low cost 0.35 μm complementary metal oxide semiconductor (CMOS) process. The total power consumption is 20 μW with a 1.5 V supply, and the measured dynamic range (DR) is 95 dB over a 1 kHz bandwidth. Experimental results show that a high figure-of-merit (FOM) is achieved for the designed modulator in comparison with those from the literature.

关键词： Low power High performance Power efficient OTA and resonator Delta-Sigma modulator

On the Location of Zeros of Higher Order Differential Equation

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Chinese Quarterly Journal of Mathematics 2010年第1期25卷 92-97页

作者： CHEN Yu-xian wu zhao-jun Department of Mathematics and Physics Xinyu College Xinyu 338031 China Department of Mathematics Xianning College Xianning 437005 China

In this paper, by using the Nevanlinna Theory on angular domain, we establish a theorem which concerns the growth of entire function and his zero. As an application, we survey the location of zero of higher order diff... 详细信息

关键词： second order exponent convergence Nevanlinna theory higher order differential equation

高变异药物等效性评估方法在Excel中的实现

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中国药物评价 2024年第2期41卷 124-127页

作者：唐韵王杰苏远吴昭君何鸽飞长沙市第一医院药剂科湖南长沙410013

目的:使用Excel建立一种简易高效的高变异药物生物等效性评估方法。方法:利用Excel内置的统计分析函数,对数据进行单因素方差分析、90%置信区间、单侧95%置信区间上限等统计学检验。结果:基于Excel进行高变异药物的生物等效性检验,其得... 详细信息

目的:使用Excel建立一种简易高效的高变异药物生物等效性评估方法。方法:利用Excel内置的统计分析函数,对数据进行单因素方差分析、90%置信区间、单侧95%置信区间上限等统计学检验。结果:基于Excel进行高变异药物的生物等效性检验,其得出的结果个体内变异系数、90%置信区间和单侧95%置信区间上限与Phoenix WinNonlin结果一致。结论:高变异药物等效性评估方法在Excel中可以实现,且整个数据处理过程高效快捷、结果可靠,是处理高变异药物生物等效性试验数据的一种理想方法。

关键词：高变异药物参比制剂校正平均生物等效性生物等效性单因素方差分析 Excel

A buffer overflow detection and defense method based on RiSC-V instruction set extension

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Cybersecurity 2024年第2期7卷 28-43页

作者： Chang Liu Yan-jun wu Jing-Zheng wu Chen zhao Intelligent Software Research Center Institute of SoftwareChinese Academy of SciencesBejingChina University of Chinese Academy of Sciences BeijingChina State Key Laboratory of Computer Science Institute of SoftwareChinese Academy of SciencesBeijingChina

Buffer overflow poses a serious threat to the memory security of modern operating *** overwrites the con-tents of other memory areas by breaking through the buffer capacity limit,destroys the system execution environ-ment,and provides implementation space for various system attacks such as program control flow *** makes it a wide range of harms.A variety of security technologies have been proposed to deal with system security problems including buffer *** example,No eXecute(NX for short)is a memory management technology commonly used in Harvard *** can refuse the execution of code which residing in a specific memory,and can effectively suppress the abnormal impact of buffer overflow on control ***,in recent years,it has also been used in the field of system security,deriving a series of solutions based on NX technology,such as ExecShield,DEP,StackGuard,***,these security solutions often rely too much on the processor archi-tecture so that the protection coverage is insufficient and the accuracy is *** in the emerging system architecture field represented by RiSC-V,there is still a lack of effective solutions for buffer overflow *** the continuous rapid development of the system architecture,it is urgent to develop defense methods that are applicable to different system application environments and oriented to all executable memory spaces to meet the needs of system security ***,we propose BOP,A new system memory security design method based on RISC-V extended instructions,to build a RISC-V buffer overflow detection and defense system and deal with the buffer overflow threat in *** to this method,NX technology can be combined with program control flow analysis,and Nx bit mechanism can be used to manage the executability of memory space,so as to achieve a more granular detection and defense of buffer overflow attacks that may occur in RISC-V system

关键词： RISc-V Operating system security Buffer overflow Control flow hijacking Nx bit Xibop

Mechanism of Oscillation Mark Formation in Continuous Casting of Steel

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International Journal of Minerals,Metallurgy and Materials 2000年第3期14卷 189-192页

作者： Kaitao Bo, Guoguang Cheng, Jie wu, Pei zhao, jun Wang (Metallurgy School, University of Science and Technology, Beijing, Beijing 100083, China) Metallurgy School University of Science and Technology Beijing Beijing 100083 China

A new mechanism of oscillation mark formation has been suggested based on the deep investigation of meniscus behavior in continuous casting of steel. It's confirmed that the meniscus form is important to oscillation mark formation. The factors related to the formation of oscillation mark are discussed in detail. The longer the solid shell existed at the root of meniscus and the smaller the contact angle between meniscus and mold wall, the deeper the oscillation mark.

关键词： continuous casting oscillation mark meniscus

On Uniqueness of Meromorphic Functions and Their Derivatives in One Angular Domain

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Journal of Mathematical Research and Exposition 2009年第5期29卷 889-894页

作者： wu zhao dun SUN Dao Chun Department of Mathematics Xianning University Hubei 437100 China School of Mathematics South China Normal University Guangzhou 510631 China

In this paper, applying the Nevanlinna theory of meromorphic function in one angular domain, we deal with a problem of uniqueness for meromorphic functions and their derivatives sharing three finite value ignoring multiplicities in an angular domain instead of the whole complex plane. Obtained results improve a recent result of Lin Weichuan and Seiki Mori.

关键词： uniqueness of meromorphic function derivative functions angular domain.

Asymmetrical Fault Current Calculation Method and Influencing Factors Analysis of Droop-Controlled Inverters

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 562-573页

作者： Huimin zhao Zhikang Shuai jun Ge An Luo Weimin wu Z.John Shen College of Electrical and Information Engineering Hunan UniversityChangsha 410006China Electrical Engineering Department Shanghai Maritime UniversityShanghai 201306China Department of Electrical and Computer Engineering Ilinois Institute of TechnologyChicagoIL 60616 USA

Since the fault dynamic of droop-controlled inverter is different from synchronous generators (SGs), protection devices may become invalid, and the fault overcurrent may damage power electronic devices and threaten the safety of the microgrid. Therefore, it is imperative to conduct a comprehensive fault analysis of the inverter to guide the design of protection schemes. However, due to the complexity of droop control strategy, existing literatures have simplified asymmetric fault analysis of droop-controlled inverters to varying degrees. Therefore, accurate fault analysis of a droop-controlled inverter is needed. In this paper, by analyzing the control system, an accurate fault model is established. Based on this, a calculation method for instantaneous asymmetrical fault current is proposed. In addition, the current components and current characteristics are analyzed. It was determined that fault currents are affected by control loops, fault types, fault distance and nonlinear limiters. In particular, the influences of limiters on the fault model, fault current calculation and fault current characteristics were analyzed. Through detailed analysis, it was found that dynamics of the control loop cannot be ignored, the fault type and fault distance determine fault current level, and part of the limiters will totally change the fault current trend. Finally, calculation and experimental results verify the correctness of the proposed method.

关键词： Asymmetrical fault analysis droop control fault current calculation method limiter transient fault characteristics

Efficient degradation of aqueous dichloromethane by an enhanced microbial electrolysis cell:Degradation kinetics,microbial community and metabolic mechanisms

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Journal of Environmental Sciences 2024年第5期139卷 150-159页

作者： Meng wu Di zhao Bing Gu ZiruWang jun Hu Zhiliang Yu Jianming Yu College of Environment College of Biotechnology and BioengineeringCollaborative Innovation Center of Yangtze River Delta Region Green PharmaceuticalsZhejiang University of TechnologyHangzhou 310014China Shentuo Environment(Hangzhou)Co.Ltd. Hangzhou 311121China Zhejiang Tianyi Environmental Co.Ltd. Hangzhou 310000China

Dichloromethane(DCM)has been listed as a toxic and harmful water pollutant,and its re moval needs *** electrolysis cells(MECs)are viewed as a promising alterna tive for pollutant removal,which can be strengthened from two aspects:microbial inocula tion and *** this study,the MEC for DCM degradation was inoculated with the ac tive sludge enhanced by Methylobacterium rhodesianum H13(strain H13)and then acclimated in the form of a microbial fuel cell(MFC).Both the introduction of strain H13 and the initi ation in MFC form significantly promoted DCM *** degradation kinetics were fitted by the Haldane model,with V_(max),K_(h),K_(i)and v_(max)values of 103.2 mg/L/hr,97.8 mg/L268.3 mg/L and 44.7 mg/L/hr/cm^(2),*** cyclic voltammogram implies that DCM redox reactions became easier with the setup of MEC,and the electrochemical impedance spectrogram shows that the acclimated and enriched microbes reduced the charge transfe resistance from the electrode to the *** the biofilm,the dominant genera shifted from Geobacter to Hyphomicrobium in acclimation ***,Methylobacterium played an increasingly important *** metabolism mainly occurred through the hydrolytic glutathione S-transferase pathway,given that the gene dcmA was identified rather than the dhlA and P450/*** exogenous electrons facilitated the reduction of GSSG,directly o indirectly accelerating the GSH-catalyzed *** study provides support fo the construction of an efficient and stable MEC for DCM removal in water environment.

关键词： Dichloromethane Microbial electrolysis cells Metabolic pathways Electron transfer Degradation kinetics