OALib Journal期刊

ISSN: 2333-9721




2019 ( 7 )

2018 ( 12 )

2017 ( 4 )

2016 ( 104 )


匹配条件: “<br>江晨” ,找到相关结果约259222条。
A multi-path gated ring oscillator based time-to-digital converter in 65 nm CMOS technology

Jiang Chen,Huang Yumei,Hong Zhiliang,<br>,黄煜梅,洪志良
半导体学报 , 2013,
Abstract: A gated ring oscillator (GRO) based time-to-digital converter (TDC) is presented. To enhance the resolution of the TDC, a multi-path structure for the GRO is used to achieve a higher oscillation frequency and an input stage is also presented to equivalently amplify the input time difference with a gain of 2. The GRO based TDC circuit is fabricated in TSMC 65 nm CMOS technology and the core area is about 0.02 mm2. According to the measurement results, the effective resolution of this circuit is better than 4.22 ps under a 50 MHz clock frequency. With a 1 ns input range, the maximum clock frequency of this circuit is larger than 200 MHz. Under a 1 V power supply, with a 200-800 ps input time difference, the measured power consumption is 1.24 to 1.72 mW at 50 MHz clock frequency and 1.73 to 2.20 mW at 200 MHz clock frequency.
Influence of Nd on the mechanical properties and high temperature creep properties of AM50 magnesium alloy

HUANG Xiaofeng FU Penghuai LU Chen DING Wenjiang,<br>黄晓锋,付彭怀,,丁文
材料研究学报 , 2004,
Abstract: 对加Nd的AM50镁合金铸态试样进行固溶处理(420℃/12 h),研究了Nd对其显微组织、力学性能和抗高温蠕变性能的影响.结果表明:Nd的加入细化了晶粒,导致AM50合金室温力学性能的提高.Nd在AM50合金中形成了Al11Nd3高温稳定相,Al11Nd3的存在使加Nd的AM50合金在200℃的稳态蠕变率及高温(150℃)力学性能大幅度提高.
Influence of Si on the mechanical properties and high temperature creep properties of AM50 magnesium alloy

HUANG Xiaofeng WANG Qudong LU Chen DING Wenjiang,<br>黄晓锋,王渠东,,丁文
材料研究学报 , 2004,
Abstract: 在基体合金AM50中分别加入Si和Ca,研究了Si和Ca对AM50-xSi合金的微观组织、力学性能及蠕变性能的影响.结果表明:加入Si后,合金高温蠕变性能随Si量的增加而增加并超过了AS41的水平;在AM50-xSi中加入微量Ca以后,合金中的Mg2Si相得到细化,从汉字状转变成颗粒状,室温及150℃拉伸性能明显提高.
Boundedness of Solutions for a Class of Second-Order Isochronous Periodic Systems

, 李哲晟, 孙泉, 舜君
Pure Mathematics (PM) , 2014, DOI: 10.12677/PM.2014.41007
Abstract: 在本文中,我们将研究下面的二阶周期性系统:\"\"通过Ortega的小扭转定理,对\"\"做适当假设,我们得到拟周期解的存在性,从而得出所有解的有界性。
In this paper, we will study the following second-order periodic system:\"\"
Under some assumptions on the\"\" , by Ortega’s small twist theorem, we obtain the existence of quasi-periodic solutions and boundedness of all the solutions.

中南民族大学学报(自然科学版) , 2010,
Abstract: 目前国内OCR及其特征提取技术主要应用于汉字的识别,对于少数民族文字,特别是女书,没有提出一种有效的特征提取算法.在分析全局笔画方向密度特征(G-DCD)和局部笔画方向密度特征(L-DCD)的基础上,将周边方向贡献度特征提取算法应用到女书文字的特征提取.实验结果表明:该方法不仅克服了手写体女书字符不规范而造成的误识率高的缺点,并且识别率较前两种方法有明显的提高.
Electronic conductivity effective masses along arbitrary directional channel in uniaxial strained Si(001)

Jin Zhao,Qiao Li-Ping,Guo Chen,Wang Jiang-An,Richard C Liu,<br>靳钊,乔丽萍,,,刘策
物理学报 , 2013,
Abstract: Electronic conductivity effective mass is one of the key parameters studing electron mobility enhancement in unixial strained Si material. Its in-depth study has the significant theoretical and practical values. In this paper, we first establish the E-k relation for conduction band in a unixial strained Si material. And the model of electronic conductivity effective mass along an arbitrary directional channel in the uniaxial strained Si (001) is obtained. Our concluding results are described as follows. 1) Tensile stress should be used to enhance electron mobility for unixial trained Si. 2) In the case of tensile stress application, both 110]/(001) and 100]/(001) directions are the desirable ones from the evaluation of electronic conductivity effective mass. And 110]/(001) direction should be preferable when the density of state effective mass is taken into consideration. 3) If 100] direction becomes the channel direction under 110]/(001) uniaxial strain, the further electron mobility enhancement will occur. The results above can provide valuable reference for the conduction channel design related to stress and orientation in the strained Si nMOS device.
A dual-mode analog baseband with digital-assisted DC-offset calibration for WCDMA/GSM receivers

Xie Renzhong,Jiang Chen,Li Weinan,Huang Yumei,Hong Zhiliang,<br>谢任重,,李伟男,黄煜梅,洪志良
半导体学报 , 2011,
Abstract: A dual-mode analog baseband with digital-assisted DC-offset calibration (DCOC) for WCDMA/GSM receiver is presented. A digital-assisted DCOC is proposed to solve the DC-offset problem by removing the DC-offset component only. This method has no bandwidth sacrifice. After calibration the measured output residual offset voltage is within 5 mV at most gain settings and the IIP2 is more than 60 dBm. The baseband is designed to be reconfigurable at bandwidths of 200 kHz and 2.1 MHz. Total baseband gain can be programmed from 6 to 54 dB. The chip is manufactured with 0.13 μm CMOS technology and consumes 10 mA from a 1.5 V supply in the GSM mode including an on-chip buffer while the core area occupies 1.2 mm2.
Social capital and local economic development: The case study of Xinhui in Guangdong Province

MENG Xiao-chen,ZHAO Xing-shuo,MAIMAI Ti-jiang,<br>孟晓,赵星烁,买买提
地理研究 , 2007,
Abstract: Since the formal use by Prof.Pierre Bourdieu,the concept of social capital has been discussed and expanded in international academic field.In this paper,the authors definite social capital as social network and take it as the channel of resources distribution.The study paid attention to the impact of capital flow through the social network on local economy and its change with time.The social network chosen in the study is overseas relationship and the case studied is Xinhui,the famous overseas Chinese hometown in Guangdong province,with 713,000 overseas fellows that is 82% of the total population. Based on the analysis of statistical data,questionnaires and interviews,the authors found there are three ways of capital flow into local economy through social network,emigrant remittance,donation and direct investment.Emigrant remittance is the source of civil capital accumulation.Donation improved the local infrastructure.Direct investment contributes to the local economic growth directly.The importance of the three ways is different with time,but all played the key roles in the taking off of local economy. The authors also found that the impact of social network has a trend of weakening down.The amount of emigrant remittance and donation increased in the 1980s and then decreased in the 1990s.At the same time,direct investment has over past the former two ways.Considering the background of China's economic reform from planned economy to market economy since the early 1980s,social network played a compensation role between weakened planning and immature market.With the improvement of market institution,social network is withdrawing from the resources distribution.For local sustainable development,market building and environment improvement are more important in the future.
Experimental Study on Stribeck Curves Based on Characteristic Roughness

MA Chen-bo,ZHU Hua,LU Bin-bin,JIANG Wei,<br>马,朱华,陆斌斌,
摩擦学学报 , 2010,
Abstract: To research the influence of surface roughness on Stribeck curves, the variation of friction coefficient was investigated based on the frictional pairs of stainless steel pins with different surface roughness and 45# steel disc under oil-immersed condition. The results showed that, the rougher the surface, the bigger the mixed lubrication area on Stribeck curve and the smaller the slope of the curve, which led to the non-uniqueness of the experimental model of friction coefficient for different surface roughness. Thus, the characteristic roughness, which was derived from fractal parameter, was adopted to be taken as the rough surfaces and was pulled into the Stribeck hydrodynamic parameter to create a new hydrodynamic parameter. Under the new hydrodynamic parameter, the Stribeck curves of frictional pairs with different surface roughness had a good consistency and can be used to determine the experimental model of friction coefficient which was independent of the surface roughness.
环境化学 , 2015,
Abstract: 近年来,水环境质量引起了人们的广泛关注,一些水中微量的有害污染物也成为环境科研工作者重点研究的对象,药品和个人护理用品(PPCPs)也是其中之一.抗生素作为应用最广,用量最大的医药品,其中的磺胺甲噁唑抗菌作用很强,在中国使用的范围很广,使用量也很大,其在水环境中的含量虽小,但是危害不容忽视,长期使用会对肾脏造成损害,更重要的是能够对微生物抗药性的发展和传播产生潜在的影响.目前,在我国还没有专项治理该类物质的条例,也没有治理这类物质的标准方法.在给水系统中,对水样的要求比较高,需要做到即采即测,因此建立给水系统中磺胺甲噁唑含量测定的方便快捷的方法十分必要.

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