摘要：A numerical solution of the weight function for a two-electrode electromagnetic flowmeter was proposed. The solution was obtained by using the finite element method based on the basic equation of a traditional two-electrode electromagnetic flowmeter. The two-dimensional distribution of the weight function of the electromagnetic flowmeter obtained was verified by the analytical solution. Three-dimensional distribution of the weight function was also presented in the paper. It can be employed to analyze the sensitivity and linearity of the electromagnetic flowmeter with non-uniform magnetic field, and even to assist the design of the excitation coil pair.

摘要：波段选择是导弹助推段天基红外探测系统设计首先需要解决的问题.无论是中心波长的确定,还是波段宽度的设定,都应有合理的依据.本文提出了导弹助推段天基探测的像面照度模型,并根据模型得到导弹助推段天基红外探测系统的目标与背景信杂比作为目标函数,利用信杂比的最大化作为波段宽度选择的依据,进行探测波段的选择.分析结果表明,以H2O,CO2吸收带2.7μm和4.3μm为作为红外探测系统的中心波长有其固有的合理性,不同的波段宽度选择将使信杂比产生显著变化.本文所建立的像面照度模型对遥感器设计和性能估计亦有重要意义.

摘要：结合某紧凑型涂装线的实际情况,对项目的设计目标、设计依据、涂装工艺特点、涂装工艺流程解析等相关内容进行了探讨。

摘要：本文介绍了线性和非线性控制法则两种控制律设计方法在小型直升机上的应用,采用双时域衡量分析方法来分析直升机系统动力学特性。紧子系统和慢子系统分别用于分析直升机转动和平动动力学特性,紧子系统的稳定性是由李亚普诺夫方程保证,同时采用反馈线性化方法稳定控制内回路。此外,在给出线性控制律缺点的同时给出了改进后的非线性控制律,该控制律可以在无人直升机执行大角度、快速度飞行运动科目时更稳定可靠的控制直升机。

摘要：道路照明系统是一个城市不可或缺的公用设备,目前远程路灯监控系统已广泛应用,然而其监控范围仅达到路灯变电站,不能对单个路灯进行监控。本文基于LabWindows/CVI设计了城市路灯监控系统的中心控制软件,结合GPRS和电力线载波等技术实现了对单个路灯进行亮度和开关灯控制,并且可以实现对路灯好坏状态进行巡检。

摘要：本文介绍了一种基于GPRS、电力线载波等技术的节能型城市路灯监控系统,该系统将路灯监控范围扩展到了单个路灯,通过对每个路灯的开关和照度进行控制,达到了减小能耗的目的。另外,该系统可对每个路灯好坏状态进行巡检,从而有效避免了人工巡检中存在的巡检不及时、劳动强度大等难题。

摘要：The demand of high-end electromagnetic wave absorbing materials puts forward higher requirements on comprehensive performances of small thickness,lightweight,broadband,and strong ***,a novel multi-layer stepped metamaterial absorber with gradient electromagnetic properties is *** complex permittivity and permeability of each layer are tailored via the proportion of carbonyliron and carbon-fiber dispersing into the epoxy *** proposed metamaterial is further optimized via adjusting the electromagnetic parameters and geometric sizes of each *** with the four-layer composite with gradient electromagnetic properties which could only realize reflection loss(RL)of less than−6 dB in 2.0-40 GHz,the optimized stepped metamaterial with the same thickness and electromagnetic properties realizes less than−10 dB in the relevant frequency ***,the RL of less than−15 dB is achieved in the frequency range of 11.2-21.4 GHz and 28.5-40 *** multiple electromagnetic wave absorption mechanism is discussed based on the experimental and simulation results,which is believed to be attributed to the synergy effect induced by multi-scale structures of the ***,combining multi-layer structures and periodic stepped structures into a novel gradient absorbing metamaterial would give new insights into designing microwave absorption devices for broadband electromagnetic protections.

摘要：探讨不同类型基质对附着细菌定殖演替规律和群落结构特征的影响,为利用周丛生物技术开展水生态修复提供参考。通过原位实验,探究5种基质表面附着细菌的定殖演替规律和群落结构特征。结果表明:变形菌门(Proteobacteria)、放线菌门(Actinobacteriota)、拟杆菌门(Bacteroidota)、厚壁菌门(Firmicutes)和蓝细菌门(Cyano-bacteria)是各基质表面附着细菌的主要组成类群,变形菌门在各基质表面都是最先定殖,蓝细菌门和拟杆菌门一般在8 d后才会逐渐成为优势类群,厚壁菌门一般在16 d后才成为优势类群;PCoA结果显示,实验前中期(4~16 d)各基质表面附着细菌群落结构差异显著,实验结束时(第20天)各基质表面附着细菌群落结构趋同,虽有差异但不显著,基质材料物化特性对附着细菌群落结构影响主要在细菌早期发育或定殖阶段;网络结构分析和FA-PROTAX功能预测结果表明,有机质类基质(竹子和木头)表面附着细菌群落共发生网络的复杂性、稳定性、传输性能和效率更高,网络节点间的关系更加密切;其细菌群落功能中的化能异养型和好氧化能异养型功能占比最高,消化分解水中有机物的能力更强。后期开展水生态修复时,应考虑多种类型基质相结合的模式。

摘要：本研究以磷酸氢钙(DCP)为参照物,以断奶仔猪生长性能、日粮消化率、血清和骨骼指标等为对象,评价高温烧结法饲用磷酸三钙(TCP)的相对生物学利用率。试验采用2×3因子完全随机试验设计,DCP和TCP各设3个磷添加水平,分别为0.08%、0.16%和0.24%,两种磷源共用一个基础日粮对照组。选择7~8周龄,体重、日龄相近的杜×长×大杂交断奶仔猪140头,按体重、性别、年龄一致的原则分为7个处理,每处理设4个重复,每重复5头猪。试验期共38 d,预试期3 d,正试期35 d。结果表明:磷源、磷添加水平及其交互作用对断奶仔猪生长性能无显著影响(P>0.05),磷添加水平显著影响仔猪对日粮钙、磷的表观消化率,胫骨和掌骨磷含量,股骨和掌骨断裂强度等指标,且呈现剂量效应(P<0.05),与DCP相比,TCP显著提高了仔猪表观可消化磷采食量、股骨断裂强度、掌骨磷含量等指标(P<0.05)。综合日粮钙、磷表观消化率,表观可消化磷,以及股骨和掌骨强度、掌骨钙和磷等敏感指标,以DCP生物学利用率为参考(100%),高温烧结法TCP的相对生物学利用率为109%。综上所述,断奶仔猪对高温烧结法TCP中磷的利用率优于DCP,有利于促进骨骼钙、磷沉积和增强骨骼强度。

摘要：Reaction runaway has longtime been an issue in chemical industry as it often leads to severe accidents if not controlled and inhibited *** we have reviewed several key considerations and procedures to prevent such phenomena,including inherently safer reactor design,thermal risk assessment and early warning detection of runaway,and pointed out that the basic principle underlying is necessary heat management and construction of resilient *** inherently safer reactor design,important factors such as heat removal,heat capacitance,flow behaviors and explosive behaviors have been *** survey shows that heat exchanger(HEX) reactor and microreactor outperform traditional ***,we have looked into the effect of thermal risk ranking and safety operation region determining for thermal risk assessment,and the influence of runaway criteria and construction methods for early detection of reaction runaway as *** shows that thermal risk assessment plays a key role on process design,and early warning detection system(EWDS) is preferable on prevention of reaction *** the end,perspectives regarding inherently safer designs with the measures discussed above have been provided.