排序方式: 共有26条查询结果,搜索用时 187 毫秒
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为了让地源热泵管线在土壤与建筑的基础上完成复合埋设,并减少建设成本,增加使用年限,提升对成品的保护力度,开展土壤与建筑基础复合埋设管网的地源热泵系统综合建造关键技术研究。本文以“世界计算·长沙智谷”项目为例,通过应用地埋管施工技术、地埋管试压技术、管道保压稳压技术等实现对地源热泵管网系统地埋管的综合施工。 相似文献
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Apower-efficient 12-bit40-MS/spipelineanalog-to-digitalconverter(ADC)implementedina0.13 μm CMOS technology is presented. A novel CMOS bootstrapping switch, which offers a constant on-resistance over the entire input signal range, is used at the sample-and-hold front-end to enhance the dynamic performance of the pipelined ADC. By implementing with 2.5-bit-per-stage and a simplified amplifier sharing architecture between two successive pipeline stages, a very competitive power consumption and small die area can be achieved. Meanwhile, the substrate-biasing-effect attenuated T-type switches are introduced to reduce the crosstalk between the two op- amp sharing successive stages. Moreover, a two-stage gain boosted recycling folded cascode (RFC) amplifier with hybrid frequency compensation is developed to further reduce the power consumption and maintain the ADC's performance simultaneously. The measured results imply that the ADC achieves a spurious-free dynamic range (SFDR) of 75.7 dB and a signal-to-noise-plus-distortion ratio (SNDR) of 62.74 dB with a 4.3 MHz input signal; the SNDR maintains over 58.25 dB for input signals up to 19.3MHz. The measured differential nonlinearity (DNL) and integral nonlinearity (INL) are -0.43 to +0.48 LSB and -1.62 to + 1.89 LSB respectively. The prototype ADC consumes 28.4 mW under a 1.2-V nominal power supply and 40 MHz sampling rate, transferring to a figure- of-merit (FOM) of 0.63 pJ per conversion-step. 相似文献
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聚乙烯膜表面改性的目的是在膜表面引入极性基团,提高膜表面的粗糙度,消除弱界面层,提高膜表面能.综述了聚乙烯膜的几种表面改性方法,包括化学改性法、火焰及热处理法、表面接枝法、等离子体处理法、电晕处理法、共混改性法、共同作用法等,并对比了各改性方法的优缺点.聚乙烯是非极性材料,表面能比较低(30~32 dynes/cm),其表面呈惰性和疏水性,因此不易与其他材料相复合或相混合,从而造成其亲水性、印刷性、染色性、抗静电性、粘接性以及与其他极性聚合物或无机填料的相容性差,限制了聚乙烯的进一步应用.通过文献检索、效果及机理分析、对比、评论等方法,综合展现和比较聚乙烯膜表面改性.化学法、共混法操作简单,化学法、接枝法、共混法效果稳定,共同作用法操作条件温和且效果持久,添加剂掺入量为1000 mg/L时,能够维持表面能38 dynes/cm三个月以上,且添加剂对极性溶剂稳定,不影响聚乙烯本体的性能,具有工业应用价值. 相似文献