检索结果-南通市图书馆

A 10-bit low power SAR A/d converter based on 90 nm CMOS

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2009年第10期30卷 100-107页

作者：佟星元杨银堂朱樟明肖艳陈剑鸣 Institute of Microelectronics Xidian University ip-2 of d.S.division Semiconductor Manufacturing International Corporation

Traditional and some recently reported low power,high speed and high resolution approaches for SAR A/d converters are *** on SMIC 65 nm CMOS technology,two typical low power methods reported in previous works are validated by circuit design and *** challenges and considerations for high speed SAR A/d converters are ***,an R–C combination based method is also addressed and a 10-bit SAR A/d converter with this approach is implemented in SMIC 90 nm CMOS *** dNL and INL are measured to be less than 0.31 LSB and 0.59 LSB *** an input frequency of 420 kHz at 1 MS/s sampling rate, the SFdR and ENOB are measured to be 67.6 dB and 9.46 bits respectively,and the power dissipation is measured to be just 3.17 mW.

关键词： analog-to-digital converter R-C combination CMOS integrated circuits nonlinearity low power

Epidemicity indices and reproduction numbers from infectious disease data in connected human populations

在线全文

学校读者我要写书评

暂无评论

Infectious disease Modelling 2024年第3期9卷 875-891页

作者： Cristiano Trevisin Lorenzo Mari Marino Gatto Andrea Rinaldo Laboratory of Ecohydrology École Polytechnique Fédérale de LausanneStation 2Lausanne1015Switzerland dipartimento di Elettronica Informazione e BioingegneriaPolitecnico di MilanoVia Ponzio 34/5Milano20133Italy dipartimento di Ingegneria Civile Edile e Ambientale(ICEA)Universitàdi PadovaStation 2Padova35131Italy

We focus on distinctive data-driven measures of the fate of ongoing *** relevance of our pursuit is suggested by recent results proving that the short-term temporal evolution of infection spread is described by an epidemicity index related to the maximum instantaneous growth rate of new infections,echoing concepts and tools developed to study the reactivity of *** epidemicity indices can showcase the dynamics of infections,together with commonly employed effective reproduction numbers,especially when the latter assume values less than *** particular,epidemicity evaluates the short-term reactivity to perturbations of a disease-free ***,we show that sufficient epidemicity thresholds to prevent transient epidemic outbreaks in a spatially connected setting can be estimated by generalizing existing analogues derived when spatial effects are *** specifically account for the discrete nature,in both space and time,of surveillance data of the type typically employed to estimate effective reproduction numbers that formed the bulk of the communication of the state of the COVId-19 pandemic and its *** analyzing the effects of spatial heterogeneity on the considered prognostic indicators,we perform a short-and long-term analysis on the COVId-19 pandemic in Italy,showing that endemic conditions were maintained throughout the duration of our simulation despite stringent control *** method provides a portfolio of prognostic indices that are essential to pinpoint the ongoing pandemic in both a qualitative and quantitative manner,as our results *** base our conclusions on extended investigations of the effects of spatial fragmentation of communities of different sizes owing to connectivity by human mobility and contact scenarios,within real geographic contexts and synthetic setups designed to test our framework.

关键词： COVId-19 Ecological reactivity Epidemicity Reproduction numbersLeslie matrix Metapopulation Mobility

Life history and life table analysis of the whitefly predator delphastus catalinae （Coleoptera： Coccinellidae） on collards

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2005年第2期12卷 129-135页

作者： TONG-XIANLIU Vegetable ip Mlaboratory Department of EntomologyTexas Agricultural Experiment StationTexas A&M UniversityWeslacoTexasUSA

The ladybeetle, delphastus catalinae (Horn), is one of the most commonly usedpredacious natural enemies being commercially reared for controlling whiteflies, including Bemisiatabaci (Gennadius) biotype B (= B. argentifolii Bellows and Perring), on various ornamental andvegetable crops under greenhouse conditions. The development, survivorship, and fecundity of *** feeding on B. tabaci biotype B on collard plants were determined in the laboratory, andthe age-specific life table parameters were analyzed based on the life history data. developmentaltime was 4.0,1.9,1.1,1.4,5.2, and 5.3 days for eggs, first, second, third, fourth instars, andpupae, respectively, with an average of 18.9 days from oviposition to adult emergence for bothsexes, 19.0 days for females, and 18.8 days for males. Adult longevities averaged 146.6 days forboth sexes, 122.6 days for females, and 170.5 days for males. After an average 4.9 dayspreoviposition period, females laid a mean of 5.6 eggs per day over a 97.0-day period. Netreproductive rate (R_0) and gross reproductive rate (Σm_x) were estimated by life table analysis at276.8 and 325.1, respectively. Generation time (T) and doubling time (dT) were 35.6 and 4.8 daysrespectively, and the intrinsic rate of natural population increase (r_m) was estimated at 0.158, orl= 1.171 for the finite rate of increase. The r_m value of d. catalinae is similar to or higherthan those of the whitefly feeding on most vegetable and ornamental crops, indicating that theladybeetle is capable of regulating populations of B. tabaci biotype B and other whiteflies undergreenhouse conditions.

关键词： coccinellids whiteflies biological control greenhouse life table predation

No-tillage effects on grain yield and nitrogen requirements in hybrid rice transplanted with single seedlings: Results of a long-term experiment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2019年第1期18卷 24-32页

作者： HUANG Min CHEN Jia-na CAO Fang-bo ZOU Ying-bin Norman Uphoff Southern Regional Collaborative Innovation Center for Grain and Oil Crops (CICGO) Hunan Agricultural University International Programs-College of Agriculture and Life Sciences (ip-CALS) Cornell University

This study was conducted to determine whether,and if so how,the grain yield and nitrogen(N) requirements of hybrid rice transplanted as single seedlings are affected by no-tillage(NT) practices.A fixed field experiment was done at the Experimental Farm of Hunan Agricultural University in Changsha,Hunan Province,China,from 2004 to *** yield and yield attributes(panicle number per m2,spikelet number per panicle,spikelet filling percentage,grain weight,total biomass,and harvest index) were evaluated as well as the N-use characteristics(total N uptake,internal N-use efficiency,and N requirements) of hybrid rice transplanted as single seedlings comparing NT with conventional tillage(CT).A significant finding was that there were no significant differences in grain yield,yield attributes,and N-use characteristics between CT and *** across the 11 years,grain yield and N requirements were 9.51 t ha^(-1) and 20.2 kg t^(-1) under CT and 9.33 t ha^(-1) and 20.0 kg t^(-1) under NT,*** were significant yearly variations in grain yield,yield attributes,and N-use characteristics observed under both CT and *** yearly variation in grain yield was related to simultaneous changes in spikelet number per panicle,grain weight,total biomass,and harvest ***,it was found that grain yield was positively correlated with internal N-use efficiency but negatively correlated with N *** is concluded that grain yield and N requirements in hybrid rice when transplanted as single seedlings are not affected adversely by *** results of this study suggest that(1) compatible relationships among yield attributes can be established in hybrid rice that is transplanted as single seedlings,and(2) higher grain yield and higher N-use efficiency can be concurrently achieved in hybrid rice transplanted as single seedlings.

关键词： grain yield hybrid rice nitrogen requirements no-tillage transplanting of single seedlings

The potentially crucial role of quasi-particle interferences for the growth of silicene on graphite

在线全文

学校读者我要写书评

暂无评论

Nano Research 2020年第9期13卷 2378-2383页

作者： Fatme Jardali Christoph Lechner Maurizio de Crescenzi Manuela Scarselli Isabelle Berbezier Paola Castrucci Holger Vach LPICM CNRSEcole PolytechniqueIP ParisPalaiseau 91128France dipartimento di Fisica Universita di Roma"Tor Vergata"Roma 00133Italy CNRS Aix-Marseille UniversiteIM2NPMarseille 13397France

A comprehensive picture of the initial stages of silicene growth on graphite is *** is shown that quasiparticle interferences play a crucial role in the formation of the observed silicene *** propose,on one hand,that the charge modulations caused by those quantum interferences serve as templates and guide the incoming Si atoms to self-assemble to the unique(√3 x√3)R30°honeycomb atomic *** the other hand,their limited extension limits the growth to about 150 Si atoms under our present deposition *** here proposed electrostatic interaction finally explains the unexpected stability of the observed silicene islands over time and with *** the robust guiding nature of those quantum interferences during the early growth phase,we demonstrate that the window of experimental conditions for silicene growth is quite narrow,making it an extremely challenging experimental ***,it is shown that the experimentally observed threedimensional silicon clusters might very well be the simple result of the end of the silicene growth resulting from the limited extent of the quasi-particle interferences.

关键词： silicene growth highly oriented pyrolytic graphite(HOPG) ab initio calculations scanning tunneling microscopy(STM) quasi-particle interferences two-dimensional(2d)self-assembly

design and implementation of a novel enterprise network defense system by maneuvering multi-dimensional network properties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2019年第2期20卷 238-252页

作者： Yang CHEN Hong-chao HU Guo-zhen CHENG National digital Switching System Engineering & Technological R&d Center

Although the perimeter security model works well enough when all internal hosts are credible, it is becoming increasingly difficult to enforce as companies adopt mobile and cloud technologies, i.e., the rise of bring your own device(BYOd). It is observed that advanced targeted cyber-attacks usually follow a cyber kill chain;for instance, advanced targeted attacks often rely on network scanning techniques to gather information about potential targets. In response to this attack method, we propose a novel approach, i.e., an "isolating and dynamic"cyber defense, which cuts these potential chains to reduce the cumulative availability of the gathered ***, we build a zero-trust network environment through network isolation, and then multiple network properties are maneuvered so that the host characteristics and locations needed to identify vulnerabilities cannot be ***, we propose a software-defined proactive cyber defense solution(SPd) for enterprise networks and design a general framework to strategically maneuver the ip address, network port, domain name, and path, while limiting the performance impact on the benign network user. Third, we implement our SPd proof-of-concept system over a software-defined network controller(Opendaylight). Finally, we build an experimental platform to verify the system's ability to prevent scanning, eavesdropping, and denial-of-service attacks. The results suggest that our system can significantly reduce the availability of network reconnaissance scan information, block network eavesdropping, and sharply increase the cost of cyber-attacks.

关键词： Intranet defense Software-defined network Multi-dimensional maneuvering

Real-Time Monitoring of Climactic and Geotechnical Variables during Landslides on the Slopes of Serra do Mar and Serra da Mantiqueira (São Paulo State, Brazil)

在线全文

学校读者我要写书评

暂无评论

Engineering（科研） 2015年第3期7卷 140-159页

作者： Rodolfo Moreda Mendes Mário Valé rio Filho National Center for Monitoring and Warning of Natural disasters-CEMAdEN S&atilde o José dos Campos Brazil ip & d Vale do Paraíba University S&atilde o José dos Campos Brazil

The municipalities of Ubatuba, Campos do Jord?o, and S?o José dos Campos are located in the region of S?o Paulo State (Brazil). These municipalities are recognized nationally for having an elevated number of recorded landslides on slopes and embankments. In addition, these municipalities contain multiple areas that are at risk for landslides. Various soil landslides occurred in these municipalities in January 2013, when real-time climactic and geotechnical variables were monitored by automatic rain gauges, humidity sensors and soil temperature and suction devices. The resulting data were used to understand the functions of each variable in the occurrence of land- slides. Analyses of rainfall, humidity and soil temperature were used with field investigations to formulate a hypothesis regarding the predominant rupture mechanism and the role of each monitored variable in the deflagration of the soil landslides that occurred in the three studied municipalities. The geotechnical variable data revealed that both temperature and soil moisture contents played fundamental roles in the deflagration of shallow planar landslides in urban areas. The hourly rain intensity and/or rainfall accumulation for 24 and/or 72 h were responsible for the deflagration of the landslides that occurred in the studied areas, along with the existing anthropic constraints in the risk areas. Significant variations did not occur in the soil suction data during the landslides, principally due to the unsatisfactory sensor precision when reading field suction between –10 and?–100 kPA (±25%).

关键词： Landslides Urban Area Real-Time Monitoring Analysis of Rainfall and Geotechnical Parameters

A 10-bit 200-kS/s SAR AdC ip core for a touch screen SoC

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Semiconductors 2010年第10期31卷 121-125页

作者：佟星元杨银堂朱樟明盛文芳 Institute of Microelectronics Xidian University Corp d.S. Semiconductor Manufacturing International Corporation

Based on a 5 MSBs （most-significant-bits）-plus-5 LSBs （least-significant-bits） C-R hybrid d/A conver sion and low-offset pseudo-differential comparison approach, with capacitor array axially symmetric layout topology and resistor string low gradient mismatch placement method, an 8-channel 10-bit 200-kS/s SAR AdC （successiveapproximation-register analog-to-digital converter） ip core for a touch screen SoC （system-on-chip） is implemented in a 0.18 μm 1P5M CMOS logic process. design considerations for the touch screen SAR AdC are included. With a 1.8 V power supply, the dNL （differential non-linearity） and INL （integral non-linearity） of this converter are measured to be about 0.32 LSB and 0.81 LSB respectively. With an input frequency of 91 kHz at 200-kS/s sampling rate, the spurious-free dynamic range and effective-number-of-bits are measured to be 63.2 dB and 9.15 bits respectively, and the power is about 136 μW. This converter occupies an area of about 0.08 mm^2. The design results show that it is very suitable for touch screen SoC applications.

关键词： analog-to-digital converter SAR touch screen SoC CMOS integrated circuits low power

AACE 2011- Comprehensive Guideline for diabetes Care

在线全文

学校读者我要写书评

暂无评论

AACE 2011- Comprehensive Guideline for Diabetes Care