隧道埋深及开挖方法对于二衬支护时机的影响

为了研究隧道埋深和施工方法对二衬支护时机的影响,以广梧高速公路牛车顶隧道为工程背景,建立数值计算模型,分别改变隧道埋深和施工方法,得到相应的隧道二衬支护时机.结果表明：通过数值计算,可定量得到二衬及掌子面之间的允许距离和埋深的关系;当埋深较小时,二衬与掌子面的允许距离随着埋深的增加而增加;当埋深超过某一限值时,隧道二衬与掌子面的允许距离基本不变;开挖工法对二衬与掌子面间的允许距离影响比较显著,而对仰拱与掌子面的允许距离影响很小.随着开挖断面分部的增加,开挖对围岩的扰动减小,因而可以适当延缓构筑二衬时机.若选取Ⅲ级围岩中的全断面开挖法作为参考基准,则围岩中二衬与掌子面的允许距离将由于选择不同工法需进行修正,相应的修正值为：全断面法1.0,上下台阶法和中隔壁法均为1.5.     

广义分布式天线系统上行分集性能分析

针对广泛存在于无线通信环境中的阴影效应对系统性能影响非常大的问题,采用与传统的微分集技术相比,能够有效地对抗这种阴影衰落的分布式天线技术来解决这个问题.为了获得该条件下系统的理论性能,分析了采用最大比合并和相干等增益合并分集的广义分布式天线系统.借助lognormal近似法,给出了其中断概率和误码率性能的高精度解析结果.分析表明,在存在阴影衰落的情况下,这种广义分布式天线系统能够同时获得较大的微/宏分集增益,非常适合未来的无线小区环境.     

Methane absorption and application of mixed organic aggregate prepared from Span80 and alkaline salt

The water-based materials for mine gas absorption and explosion suppression were prepared, in which the mixed organic aggregate of Span80 and alkaline salt can be used as methane absorbent. Methane was used as a model of mine gas, and the absorptions of methane with different complex materials were studied using head space gas chromatography. Then the state of aqueous material was characterized with laser light scattering instrument and the effects of different complex materials on explosion suppression were preliminarily studied in explosion chamber which can simulate mine gas explosion. The research results showed that complex material could absorb methane and there was some correlation between the mean diameter of organic aggregate in aqueous material and the absorption effect. Additionally, the aqueous material could suppress the methane explosion to some degree. The material can absorb mine gas in atomization condition, therefore, degrease mine gas concentration and influence the distribution of mine gas in the space, and then suppress the mine gas explosion to some extent.     

一种基于SRT-8算法的SIMD浮点除法器的设计与实现

在科学计算、数字信号处理、通信和图像处理等应用中,除法运算是常用的基本操作之一。基于SRT 8除法算法,设计一个SIMD结构的IEEE 754标准浮点除法器,在同一硬件平台上能够实现双精度浮点除法和两个并行的单精度浮点除法。通过优化SRT 8迭代除法结构,提出商选择和余数加法的并行处理,并采用商数字存储技术降低迭代除法的计算延时,提高频率。同时,采用复用策略减少硬件资源开销,节省面积。实验表明,在40nm工艺下,本设计综合cell面积为18601.9681 μm2,运行频率可达2.5GHz,相对传统的SRT 8实现关键延迟减少了23.81%。     

创新型嵌入式实验教学模式研究

结合军校计算机专业人才培养的具体需求,深入阐述了嵌入式计算机实验教学模式面临的问题,分析了当前军队院校实验教学现状及存在的不足,提出了嵌入式计算机实验教学的改革措施和原则,最后给出了发展创新型实验教学模式的思路。     

Excel VBA在对口中职招生考试中的应用

通过对Excel进行适当的设置,函数合理应用以及结合VBA编程,针对对口中职招生考试的实际情况,设计完成了一个界面友好、使用方便、高效的绿色电子答题平台.重点对Excel数据安全作了阐述和设计,在实际应用中取得了较好的效果.     

杀虫涂料的研究进展

从杀虫涂料的作用原理、杀虫涂料的配方设计、杀虫涂料性能评价方法三个方面对杀虫涂料的研究开发进行了论述,并对杀虫涂料研究的新进展及方向做了简要阐述。     

Controllable synthesis of poly(N-vinylpyrrolidone) and its block copolymers by atom transfer radical polymerization

At room temperature atom transfer radical polymerization (ATRP) of N-vinylpyrrolidone (NVP) was carried out using 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetra-azacyclo-tetradecane (Me₆Cyclam) as ligand in 1,4-dioxane/isopropanol mixture. Methyl 2-chloropropionate (MCP) and copper(I) chloride were used as initiator and catalyst, respectively. The polymerization of NVP via ATRP could be mediated by the addition of CuCl₂. The resultant poly(N-vinylpyrrolidone) (PNVP) has high conversion of up to 65% in 3 h, a controlled molecular weight close to the theoretical values and narrow molecular weight distribution between 1.2 and 1.3. The living nature of the ATRP for NVP was confirmed by the experiments of PNVP chain extension. With PNVP-Cl as macroinitiator and N-methacryloyl-N′-(α-naphthyl)thiourea (MANTU) as a hydrophobic monomer, novel fluorescent amphiphilic copolymers poly(N-vinylpyrrolidone)-b-poly(N-methacryloyl-N′-(α-naphthyl)thiourea) (PNVP-b-PMANTU) were synthesized by ATRP. PNVP-b-PMANTU copolymers were characterized by ¹H NMR, GPC-MALLS and fluorescence measurements. The results revealed that PNVP-b-PMANTU presented a blocky architecture.     

相转移催化合成癸二酸二甲酯

使用相转移催化剂BTEAC(氯化三乙基苄胺 )合成癸二酸二甲酯。条件为 :10g癸二酸 ,80mL甲醇 ,0 .5mL硫酸 ( 98% )和 0 .0 5gBTEAC。癸二酸二甲酯产率达到 90 .4 %     

水溶性氨基丙烯酸漆的研制

研制了高温烘烤 (145～ 15 0℃ )和中温烘烤 (12 0～ 12 5℃ )两种水溶性氨基丙烯酸漆。当羟基树脂的玻璃化温度为 - 5～ 0℃ ,丙烯酸和丙烯酸羟乙酯占总单体的质量分数分别为 7 5 %～ 8 5 %和 8 0 %～ 12 0 % ,羟基树脂和氨基树脂的质量比为 (0 0 5∶1 0 0 )～ (0 10∶1 0 0 ) ,颜基质量比为 0 2 9∶1 0 0时 ,两种漆的附着力达到 1级 ,抗冲击强度 >490N·cm ,柔软性 <1mm ,硬度 >2H ,光泽度 >80 (45℃ ) ,耐水 (2 0～ 2 5℃ ) 1d以上 ,遮盖力及施工性能良好