Design of the low power wake-up receiver for internet of things communication

A wake-up receiver with high energy efficiency and low power consumption is proposed for solving the power consuming problems of wireless nodes communication in the Internet of Things. The proposed wake-up receiver based on the wake-up mechanism can effectively schedule the network nodes communication, and use the simple envelope detection structure to achieve frequency down-conversion, which can flexibly manage energy and reduce power consumption. Based on UMC 65nm CMOS process technology, the wake-up receiver is designed and simulated. The results show that it can achieve S₁₁ of -21dBm and a sensitivity of -75dBm at a data rate of 1Mb/s, when operating at the central frequency of 780MHz and input signal adopting an on-off keying (OOK) modulation, and the power consumption is 82μW at 1.2V voltage supply.     

高分2号图像业务化大气校正查找表的设计与实现

为实现高分2号图像(GF2)业务化大气校正,利用矢量6S模型(6SV)将辐射传输散射与吸收进行分离计算,其中散射部分采用涵盖各种大气模式、气溶胶类型、成像几何等条件下的大气校正查找表(look-up tables,LUTs)表示,大气吸收部分采用6SV拟合计算的6种大气模式下大气透过率的经验公式表示,这种处理有效简化了查找表大小.在内存4 GB、主频3.10 GHz条件下,通过比较基于本查找表方法和基于FLAASH大气校正软件对北京地区一景GF2数据处理.结果表明:以6SV模型直接大气校正法结果作为真值,两者的绝对误差分别为0.8%和2.6%,处理时间分别为77 s和240 s,该大气校正查找表在处理精度和效率更加适合业务化大气校正.     

频率响应法研究噻吩在CeY分子筛上的吸附行为

以NaY、液相Ce离子交换改性的Y型分子筛(L-CeY)为研究对象,运用N2吸附、XRD、NH3-TPD和Py-FTIR等实验方法表征两种Y型分子筛的物化性能。采用频率响应技术(FR)和智能重量分析仪(IGA)研究噻吩在两种分子筛上的吸附行为,并考察噻吩在稀土离子改性Y型分子筛上的不同吸附作用模式。结果表明,频率响应技术能够有效识别分子筛孔道内发生的不同传质过程。噻吩在NaY分子筛上的吸附行为较为简单,存在孔道吸附和π电子相互作用两种吸附过程;而在L-CeY分子筛上吸附行为较为复杂,同时存在孔道吸附和"S-M"吸附等多种吸附过程,另外,在高温条件下,还存在复杂的催化反应过程。     

液压系统进、旁油路联合调速回路分析

在定量液压泵供油的系统中给出进、旁油路联合调速的回路,通过对2种进、旁油路联合调速的定量分析,推导出理论计算依据,得出这2种进、旁油路联合调速的调速特点。     

Oxidation behavior and mechanism of aluminum oxynitride (AlON) at elevated temperatures

The oxidation behavior and mechanism of aluminum oxynitride (AlON) powder exposed to air at elevated temperatures between 800°C and 1300°C was investigated by X-ray diffractometry (XRD), scanning electron microscope (SEM), electron spin resonance (ESR), nuclear magnetic resonance (NMR), and simultaneous thermogravimetry, differential thermal analysis, and mass spectrometry techniques (TG-DTA-MS). The weight of AlON gradually increases to a maximum value at 1150°C and then decreases with further heating. Meanwhile, AlON powder undergoes chemical changes, as evidenced by lattice expansion, and turns eventually into alumina. ESR spectra reveal the occurrence of lone pair electrons in the oxidized products and the intensity of corresponding resonance signal increases before disappearing with the increase in temperature. Combined with the results of NMR and TG-DTA-MS, the measured data suggest that Al-N in [AlO₃N] tetrahedron and [AlO₅N] octahedron are gradually oxidized into Al-O-N group with lone pair electrons, which causes continuous weight gain and lattice expansion. Further oxidation at higher temperatures results in alumina and N₂.     

Degradability and biocompatibility of bioglass/poly(amino acid) composites with different surface bioactivity as bone repair materials

Bioglass (BG) possesses excellent bioactivity and has been widely used in the manufacture of biomaterials. In this study, a composite with different surface bioactivity was fabricated via in situ melting polymerization by incorporating BG and poly(amino acid) (PAA) at a suitable ratio. The structure of the composite was characterized by Fourier transform infrared spectroscopy and XRD. The compressive strength of the BG/PAA composites was 139 MPa (BG:PAA = 30:70). The BG/PAA composites were degradable, and higher BG in composite showed higher weight loss after 4 weeks of incubation in simulated body fluid. In addition, the BG/PAA composite maintained adequate residual compressive strength during the degradation period. The SEM results showed the differences in surface bioactivities of the composites directly, and 30BG/PAA composite showed thicker apatite layer and higher Ca/p than 15BG/PAA. in vitro MG-63 cell culture experiments showed that the composite was noncytotoxic and thus allows cells to adhere, proliferate, and differentiate. This indicates that the composite has good biocompatibility. The implantations in the bone defects of rabbits for 4 and 12 weeks were studied. The composites had good biocompatibility and were capable of guiding new bone formation without causing any inflammation. The composite may be successfully used in the development of bone implants.     

高温预析出对Al-Zn-Mg-Cu铝合金显微组织、强度和应力腐蚀抗力的影响

通过改变固溶条件 ,对Al Zn Mg Cu高强铝合金采用先高温后低温的两步固溶处理 (高温预析出 )来改善晶内和晶界的析出状态 ,研究了高温预析出对Al Zn Mg Cu铝合金的金相组织、强度和应力腐蚀性能的影响。结果表明 ,4 6 5℃高温预析出在保持较高强度和塑性的同时 ,可以改善合金的抗应力腐蚀性能     

冶炼不锈钢泡沫渣的实验研究

从理论上阐述冶炼不锈钢时熔渣的发泡机理。并根据上海三钢公司的情况，在2500Hz的中频感应炉上时熔渣进行发泡高度的实验，找出发泡性能较好的渣系，研究渣中各成分对发泡性能的影响。     

用计算机图形处理软件定量分析SEM图像

用图形处理软件PHOTOSHOP对SEM图像进行图像定量分析，对高温合金K23σ析出相的体积分数和M8钢样的夹杂物颗粒尺寸进行了定量测定。结果表明，该方法操作方便，有一定的可行性。     

φ114mm直缘成型焊管机组的研制

简介了研制的φ１１４ｍｍ直缘成型焊管机组的技术性能和工艺特点。与普通辊式成型机组相比，该机组工艺先进，焊管精度高。