精密测距器专用检测设备设计与验证

精密测距器主要为空中飞机提供连续、精准的距离导航信息,是确保飞行安全的重要设备之一。针对精密测距器周边电磁干扰环境复杂多变、需进行常态化性能指标检测标校的实际应用情况,文中采用ARM微处理器、DSP和FPGA等技术设计一种便携式专用检测设备。综合运用C/C++、汇编语言、VHDL与Verilog等,在不同编程环境下开发软硬件测试程序。在实现对精密测距器在IA和FA模式下的应答延时、目标距离、应答效率等常规测试的基础上,创新性地加入接收机灵敏度、动态范围、邻波道抑制和通频带等高级测试功能,并结合精密测距系统进行测试实验。实验结果表明,所设计的专用检测设备测距精度误差满足指标要求(优于±30 m),能够有效满足精密测距器常态化检测的需求。

碎屑锆石U⁃Pb年代学定量物源分析的基本原理与影响因素——以现代河流砂为例

碎屑锆石U-Pb年代学数据获取快,物源对比精确度高,还可以估算源区剥蚀量,在定量物源分析方面具有显著优势,广受沉积学界青睐。但由于采样、实验过程中的不确定性,常常导致一些物源判别结果存在多解性,甚至产生了很多争议。从碎屑锆石U-Pb年代学定量物源分析的原理入手,综述了由于沉积水动力、母岩锆石产率、沉积再旋回、人类活动、以及数据获取与处理5方面因素对年龄谱可能产生的影响。结果表明,河流砂相比地层中的沉积岩,物源区母岩性质明确,运移路径非常清晰,可以进行锆石产率的准确测定,并能够同时开展混合模型正演和反演,是理想的定量物源分析研究对象。对开展基于现代河流砂的定量物源分析机理研究进行了展望,指出应用新技术、新方法开展小流域碎屑锆石U-Pb年代学研究是揭示锆石侵蚀、搬运和沉积过程行为机理的重要手段、也是构建定量物源分析方法的重要基础,将为规范开展沉积地层的物源研究提供重要的理论依据。

一种便携式机载雷达罩外场电性能测试系统

雷达罩在使用过程中可能会出现进水、蒙皮脱落、蒙皮穿孔等损伤,这些损伤会影响着雷达罩的电性能;针对外场条件下对机载雷达罩电性能测试需求,设计了一种便携式、易操作的雷达罩电性能测试系统;给出了透波率、插入相移、介质常数等雷达罩电性能参数测试方案,并对雷达罩样品的电性能参数进行了测试;结果表明:该系统在外场条件下能够方便的测量雷达罩电性能参数,测试结果真实有效。

High-pressing preparation of rock glasses and their elastic properties

Melt glasses for seven types of rock ranging from acid to basic were prepared under 1.0 GPa on a multi-anvil pressure apparatus, YJ-3000 ton press. Densities and elastic properties of the melt glasses were compared with those described in previous studies. It was found that the glasses melted under 1.0 GPa were consistent in density with both naturally-occurring glassy rocks and artificially prepared glasses melted at ambient pressure. The densities of glasses are negatively correlated with the SiO2 contents and positively correlated with the (MgO+FeO) contents. The compressive velocity (Vp) of glass tends to increase with decreasing SiO2 contents and increasing (MgO+FeO) contents. The shear velocity (Vs) of glass tends to increase slightly with increasing SiO2 contents, which has little connection with the (MgO+FeO) contents. It was calculated from densities and velocities that the elastic moduli of glasses are negatively correlated with the SiO2 contents and positively correlated with the (MgO+FeO) contents.

无线光通信系统中极化码编译码技术

大气无线光通信系统中的湍流运动会降低系统误码性能。为此,将Polar编译码技术引入无线光通信系统中,研究了极化码编码方法及其加入循环冗余校验的列表连续消除(Cyclic Redundancy Check-Successive Cancella-tion List,CRC-SCL)译码原理,并分别在高斯和湍流信道条件下进行了误码性能的蒙特卡洛仿真。结果分析表明,Polar编码对大气湍流信道的无线光通信系统可靠性有明显改善,在误码率为10-3时,相较于未编码系统,基于CRC-SCL译码的Polar编码技术可获得约6.3 dB的编码增益。同时,码长越长,码率越低,编码系统误码性能越佳。

P-Wave Velocity in Rocks of Dabieshan, China at High Pressure and High Temperature: Constraints for Composition of Lower Crust and Crust-Mantle Recycling

P-wave velocities in the rocks of Dabieshan, central China were measured at pressures up to 5.0 GPa and temperatures up to 1 300℃. The ultrahigh pressure eclogites have the highest density and P-wave velocity (Vp) and lower anisotropy. Pressure derivatives of the eclogites range from 0. 22 to 0. 33 km. s-1 GPa-1. Average temperature derivative of the eclogites is - 3. 41×10-4 km. s-1. °C -1. The density and VP of the eclogites imply that there will be two united possibilities related to crust-mantle recycling after the eclogite formed in the deep lithosphere. One is that some eclogites in the deep lithosphere were detached and sunk into deeper mantle due to their denser density. Another is that some eclogites returned to the crust and exposed to the surface.Small amounts (<12%) of eclogites may be still exist in the deep crust beneath Dabieshan based on our calculation.

Study on the Electrical Conductivity of 0.025 mol NaCl Solution at 0.25-3.75 GPa and 20-370℃

The electrical conductance of 0.025 mol NaCl solution was measured at0.25-3.75 GPa and 20-370℃. As shown by the results, the conductance increases with temper-ature, and there is a liner relation between the reciprocal of temperature and the logarithm ofthe conductance but their slopes are different at different pressures. The relations between theconductance and pressure is rather complex and there are some discontinuities: in the range of2.25-3.75 GPa, the conductance increases with the pressure; in the range of 1.25-2.0 GPa, theconductance is not related to the pressure; and at a pressure of 0.75 GPa, the conductance ishigher than that at the pressures nearby. This reflects that the NaCl solution has rather differentproperties of electronic chemistry at various pressures, and probably is an important cause forthe existence of the layers with high electrical conductance and low velocity in the Earth's crustand mantle.

Experimental Study of the Influence of Hydrous Minerals on the Melting Behaviour of Rocks at High Temperatures and Pressures

The experimental study on the melting of potassic basalt and eclogite with about 2% waterat 800-1300℃ and 1.0-3.5 GPa shows that the solidi of both rocks are significantly lower thanthose obtained from the previous experiments of the same type of rocks under dry conditions,and the former which is enriched in potassium has a lower melting point than the latter. It is con-sistent with the previous study. The melting temperature of eclogite increases with pressure,whereas potassic basalt has similar properties only at 1.5—2.5 GPa and>3.0 GPa, and at 2.5—3.0 GPa the melting temperature decreases with pressure. This can be explained as follows: (1)eclogite only has one hydrous mineral amphibole and the dehydous temperature is lower than thewet solidus of the rock. (2) Amphibole exists in potassic basalt at the pressures lower than 2.5GPa and phlogopite exists at pressures higher than 2.5 GPa, and the special compositions of bothminerals determine that amphibole has a dehydration temperature higher than or close to that ofthe wet solidus of the rocks, while phlogopite has a dehydration temperature lower than that ofthe wet solidus. On the other hand the features of the continuous solidus in the experiment ofhydrous eclogite were produced by the fact that the dehydration temperature of its amphibolelower than or close to the melting temperature of the hydrous conditions. So the melting tempera-ture lowers at higher pressures. Therefore, the composition of the rocks in the lithosphere and thetypes of hydrous minerals and their stable P-T conditions are the important factors controllingthe solidi of rocks. It can quite well explain the partial melting of rocks and the origin of the lowvelocity zone in the deep lithosphere.

高精度微波引导设备角度数据检测系统设计与实现

针对当前某高精度微波引导设备的角度制导性能精准检测难度大的问题,基于ARM+DSP+FPGA的总体架构,研究并搭建了高精度角度数据检测系统的硬件电路结构,基于C/C++、VHDL和Verilog开发了角度数据测试软硬件程序,实现了对微波引导设备空间角度、数据信号的接收、处理、解算和测量;并进行试验验证,结果表明该系统实现了设计功能、达到了指标要求,对高精度微波引导设备角度测量方位角优于0.16°,仰角优于0.18°,数据字与设备预置信息一致,满足高精度角度、数据的检测要求,对有效提高该微波引导设备的可靠性具有重要意义。

着舰引导雷达动态校验系统的设计与实现

着舰引导雷达是一种高精度的着舰引导系统,在引导舰载机安全着舰中发挥着不可替代的作用。为保证着舰引导雷达的精度和可靠性,必须定期对其进行飞行校验。针对着舰引导雷达的动态校验问题,结合飞行校验基准的精度指标要求,提出了校验系统的总体结构,重点对基于移动基准站实时动态载波相位差分定位(MB-RTK)的校验基准获取与校验数据的误差处理等关键技术进行了研究。通过地面实验和飞行实验验证了方案的可行性和有效性,研究成果对舰载航空导航设备动态校验的发展具有一定的理论指导意义,对提高着舰引导系统的可靠性也具有一定的实践价值。

微波着舰引导设备动态校验系统设计与技术实现

微波着舰引导系统是一种高精度的舰载航空导航系统,在引导舰载机安全着舰过程中发挥着不可替代的作用;为确保微波着舰引导设备引导的精准度和运行的可靠性,必须对其开展定期或不定期的动态飞行校验工作;针对微波着舰引导设备的动态飞行校验问题,结合飞行校验基准的精度指标要求,研究提出了飞行校验系统的总体结构设计方案,重点研究了基于移动基准站实时动态载波相位差分定位(MB-RTK)的校验基准获取以及校验数据的误差处理等关键技术;通过计算机仿真和飞行实验数据,验证了校验系统设计与技术实现的可行性和有效性;研究成果对提高微波着舰引导设备的安全性与可靠性具有较好的军事应用价值和推广前景。

Influence of Hydrogen on the Thermoelastic Properties of the Major Rock-Forming Minerals in the Upper Mantle

Objective Anhydrous mineral phases in the Earth＇s upper mantle may serve as a large internal reservoir of water that has profound implications for the Earth＇s evolution as a water planet.Water plays important roles in the phase transformation kinetics in the Earth＇s interior,which affects the mantle dynamics.

三线式宽带短波天线建模与仿真

三线式宽带短波天线是一种新型的短波通信天线,为充分发挥该天线在全向通信与定向通信中的性能,本文首先采用矩量法分析计算三线天线在不同工种频率的辐射阻抗与天线方向图,并得到了天线方向性系数随工作频率变化的曲线,从而有效指导天线在全向通信或定向通信中的频率选择;利用电磁仿真软件FEKO建立了三线天线与典型地物的仿真模型,得到了典型工作频率、不同地物影响下天线方向图的畸变规律,总结出高度参数对三线天线方向图的影响最为明显,为三线天线选址架设等工程实践提供参考。

Experimental study to confirm the existence of hydrocarbon under high pressure and temperature of deep lithosphere

Pyrolysis of lignite was conducted at high temperatures from 400 to 700℃ and high pres- sures of 1 and 3 GPa in a closed system in order to investigate pressure and temperature effects on or- ganic matter maturation. The data indicated that the total yield of liquid hydrocarbons decreased with increasing pressure and the maximum of production was obtained at a higher temperature. The alkanes show more mature characteristics with increasing temperature at a given pressure, conversely, high pressure significantly hinders the thermal evolution of geological organic matter. The experimental results also demonstrated that the relative abundance of high molecular weight hydrocarbons may exist under the conditions of the lower lithosphere, which not only breaks through the traditional concept that alkanes mainly present at stage of “oil window”, but also en- hances the possibility to find the oil in the high tem- perature and pressure areas.