MIS开发中c/s模式与b/s模式的比较分析

随着Internet的发展,管理信息系统(MIS)的发展迈进了新时代,企业MIS开发大量应用Web Server新技术,但不能将此新模式完全替代传统模式,或者与传统模式完全对立,应发挥各自长处,找到最佳结合方法,基于此,本文将两种开发模式加以比较.     

嵌入式语音播放电路的设计与实现

语音芯片ISD4004是美国ISD公司的产品,此芯片具有独特的存储方式,无须A／D转换和压缩就可以直接储存,没有A／D转换误差,在一个记录位（bit）可存储250级声音信号,相当于通常的A／D记录的8倍。其片内集成了晶体振荡器、麦克风前置放人器、自动增益控制等电路,只需很少的外围器件,就可以构成一个完整的语音播放系统。本文向大家介绍一种基于ISD4004芯片的语音播放电路。该电路的特点是可以嵌入到其它基于单片机的控制系统中,成为其有机组成部分。软件上重点介绍如何用AT89C51模拟SPI（Serial Peripheral Interface）总线技术,实现对ISD4004的控制。     

基于ARM的三种无线家庭网关的设计方案及比较分析

用不同芯片PLC2214、S3C2410、S3C4510B设计的三种家庭网关方案,并对它们实现无线组网所采用的蓝牙、Zigbee、红外线技术进行了比较分析。     

基于CC1100的无线手持终端的设计

以Silicon Labs公司的C8051F340 SoC为微中央处理器、Chipcon公司的CC1100为射频收发器,设计了一种能广泛应用于消费、物流、监控等领域的低成本、低功耗、短距离对等通信的无线数据通信手持终端设备。对CC1100的编程特点进行了详细阐述。     

基于ARM的非接触IC卡网络系统

基于ARM的非接触IC卡网络系统设计。在ARM上移植μC/OS-II操作系统,嵌入TCP/IP协议实现以太网通信;建立SQLServer2000数据库,编写Delphi管理软件,建立ASP动态网站。该系统具有很强的实时性,其功能和性能都满足大规模的非接触IC卡网络管理要求,非接触IC卡的识别时间小于11ms。     

Hierarchical composite of biomass derived magnetic carbon framework and phytic acid doped polyanilne with prominent electromagnetic wave absorption capacity

To solve the electromagnetic pollution,herein,a CoFe₂O₄/C/PANI composite was developed by a green route,which was constructed with spinel of metal oxide,graphitized carbon and conductive polymer composites.Benefiting from the designable interfaces and increased dipoles,the microwave dielectric response capability can be boosted significantly and resulted in the enhanced microwave absorbing performance.As revealed by the reflection loss curve,the minimum reflection loss(RLmin) reached-51.81 dB at 12.4 GHz under a matched thickness of 2.57 mm.At 2.5 mm,the effective absorbing band covered 8.88 GHz,suggesting the desirable wideband feature.In our case,the method of utilization of a novel green way to fabricate multiple-component EM absorber can be a promising candidate for high-performance EM absorber.     

Combined Treatment with Cryptocaryone and Ultraviolet C Promotes Antiproliferation and Apoptosis of Oral Cancer Cells

Cryptocaryone (CPC) was previously reported as preferential for killing natural products in oral cancer cells. However, its radiosensitizing potential combined with ultraviolet C (UVC) cell killing of oral cancer cells remains unclear. This study evaluates the combined anti-proliferation effect and clarifies the mechanism of combined UVC/CPC effects on oral cancer cells. UVC/CPC shows higher anti-proliferation than individual and control treatments in a low cytotoxic environment on normal oral cells. Mechanistically, combined UVC/CPC generates high levels of reactive oxygen species and induces mitochondrial dysfunction by generating mitochondrial superoxide, increasing mitochondrial mass and causing the potential destruction of the mitochondrial membrane compared to individual treatments. Moreover, combined UVC/CPC causes higher G2/M arrest and triggers apoptosis, with greater evidence of cell cycle disturbance, annexin V, pancaspase, caspases 3/7 expression or activity in oral cancer cells than individual treatments. Western blotting further indicates that UVC/CPC induces overexpression for cleaved types of poly (ADP-ribose) polymerase and caspase 3 more than individual treatments. Additionally, UVC/CPC highly induces γH2AX and 8-hydroxy-2’-deoxyguanosine adducts as DNA damage in oral cancer cells. Taken together, CPC shows a radiosensitizing anti-proliferation effect on UVC irradiated oral cancer cells with combined effects through oxidative stress, apoptosis and DNA damage.     

Metabolomics Mechanism and Lignin Response to Laxogenin C,a Natural Regulator of Plants Growth

Laxogenin C (LGC) is a natural spirostanol deriving from plant hormone which has shown growing regulation similar to those of brassinosteroids. In the present study, LGC showed a promoting effect on tomato seed germination and seedling growth in a dose-dependent manner. We applied LC-MS/MS to investigate metabolome variations in the tomato treated with LGC, which revealed 10 differential metabolites (DMs) related to KEGG metabolites, associated with low and high doses of LGC. Enrichment and pathway mapping based on the KEGG database indicated that LGC regulated expressions of 2-hydroxycinnamic acid and l-phenylalanine to interfere with phenylalanine metabolism and phenylpropanoids biosynthesis. The two pathways are closely related to plant growth and lignin formation. In our further phenotypic verification, LGC was confirmed to affect seedling lignification and related phenylpropanoids, trans-ferulic acid and l-phenylalanine levels. These findings provided a metabolomic aspect on the plant hormone derivates and revealed the affected metabolites. Elucidating their regulation mechanisms can contribute to the development of sustainable agriculture. Further studies on agrichemical development would provide eco-friendly and efficient regulators for plant growth control and quality improvement.     

燕山碳五分离装置异戊二烯损失率高原因分析

裂解碳五馏分中富含大量双烯烃,其中异戊二烯(IP)作为生产多种橡胶的原料,具有较高的利用价值。燕山碳五分离装置采用二甲基甲酰胺(DMF)萃取精馏法,生产聚合级异戊二烯,装置设计IP损失率为9%,但在实际上产中,IP损失率高达30%。碳五双烯烃容易发生聚和反应,因此主要从聚合反应和轻组分采出两方面,分析IP损失率高的原因。结果显示,溶剂含水量高、亚硝酸钠含量低、低负荷下热二聚反应停留时间长等因素导致的IP聚合反应损失,占IP损失量的50%;物料过量返回引起的预脱轻塔和第一萃取塔塔顶轻组分采出损失,分别占IP损失量的37%和13%。双烯烃聚合反应直接影响装置的平稳运行,聚合反应不但会引起IP聚合损失,也会造成萃取单元再沸器加热能力变差,烃类不能与溶剂完全分离,进一步导致装置内返回量超标,预脱轻塔进料中IP组分浓度从17%提高至28%,调整不当会使轻组分中IP含量超标。因此,控制双烯烃聚合是降低IP产品损失率的关键。