基于圆光栅的示度不一致检测装置

分析了瞄准具示度不一致原理与形成原因,设计开发了一种基于圆光栅传感器的火炮示度不一致检查与调整装置,阐述其结构、原理及关键技术,并进行了精度分析,通过实验得出:本测试装置测量准确、使用操作方便、提高了测量效率。

基于多任务学习的同行评审细粒度情感分析模型

学术论文同行评审能够直接反映审稿人对论文的主观评价,对审稿文本进行情感分析有利于挖掘审稿人对论文多维度的评价信息。现有的情感分析模型仅能挖掘专家单一的评审维度和相应的情感倾向,本文提出了一种基于多任务学习的同行评审细粒度情感分析模型。该模型在多任务学习框架下,通过在BERT-LCF模型的基础上增加BiLSTM-CRF模块,使其具备了同时完成属性词抽取和细粒度情感分析任务的能力。与传统的基于Pipeline模式的单任务细粒度情感分析模型相比,本模型在保证精度的情况下可以同时完成评审属性提取和情感分析任务。在这两项任务中,所提出模型的F1分数分别达到了89.01%和90.71%。对比实验证明,在多任务场景下,引入BiLSTM-CRF模块对评审文本属性词提取任务有一定的提升作用。

汉字“示音度”的定量研究——浅谈汉语研究中的“家族论”

作为汉字直接构件的“字符”分为三种:“声符”、“意符”和“标符”。形声字“声符”的功能是“准确表音”吗?为了回答此问题,本文简介了基于数据库的对汉字“示音度”的定量研究。统计结果表明:形声字“声符”的功能是“邻近示音”,而不是“准确表音”。文章给出了区别“声符”和“标符”的算式,并提出了“声符示音六边形”。最后讨论了在汉语研究中的“家族论”。

对乙酰氨基酚片的差示分光光度测定法

对乙酰氨基酚片是常用的解热镇痛药。其含量测定方法有直接紫外分光光度法[中国药典,1985年版],水解后比色法[SanghaviNM:Indian J Pharm Sci,1980,42:10]和柱层析后紫外分光光度法[USP,XXI]。前两种由于共存的水解产物4-氨基酚的干扰.

差示紫外分光光度法测定氧氟沙星片剂的含量

目的 建立差示光谱法测定氧氟沙星片剂的含量 ,消除辅料的干扰。方法 在波长 2 98nm处 ,以氧氟沙星在 0 .1mol/L氢氧化钠溶液和 0 .1mol/L盐酸溶液中不同的紫外光谱 ,测得差示吸收值 (△A)为定量依据。结果 平均回收率为 10 1.2 % ,RSD =0 .5 2 %。结论 本方法简便 。

一种基于示向度聚集度的单站移动监测定位算法研究及实现

在城市复杂电磁环境中开展无线电移动监测定位工作时,由于建筑物的遮挡和反射等原因引起的信号衰落和多径传输,导致车载移动测向误差较大,难以判定准确的来波方向。本文基于现有无线电移动测向设备,分析其示向度、移动距离和信号源的关系,提出基于示向度聚集度的单站移动监测定位算法,通过示向度聚集度计算信号源的最大概率方向,引导监测车辆快速逼近信号源。实际测试结果表明,该算法可大幅提高测向结果准确度,可信度较高,移动定位误差小。

Experimental investigation of crystallization process of nanofluid by DSC

A water-TiO2nanofluid with a weight fraction of 5% and an average particle size of 75 nm is used to investigate the effect of TiO2 nanoparticles on the crystallization and melting behaviors of deionized water by using differential scanning calorimetry（DSC）at four different cooling rates,3,5,7,9 ℃/min.The DSC experimental results show that the water-TiO2 nanofluid has a lower supercooling degree and a faster crystallization rate than the deionized water.With the increase in the cooling rate,the influence of the TiO2 nanoparticles on the supercooling degree of the deionized water becomes greater,but on the crystallization rate it turns lower.During the melting process,compared with the deionized water,the water-TiO2 nanofluid has a lower melting temperature,a less latent heat and a higher melting rate.

Anti-cracking mechanism of diatomite asphalt and diatomite asphalt mixture at low temperature

A kind of neat asphalt and three kinds of diatomite asphalt are tested using differential scanning calorimetry（DSC）. The anti-cracking mechanism of diatomite asphalt is analyzed by DSC and the thermal stress restrained specimen test（TSRST） of the asphalt mixtures. The results show that the low temperature performance of diatomite asphalt is better than that of neat asphalt. The glass transition temperature can reflect the low temperature performance of the diatomite asphalt better and has a good relationship with breaking temperatures. Besides, the TSRST, the bending test, the compressing test and the contraction coefficient test are used to study the low temperature performance of the diatomite asphalt mixture. The results prove that the low temperature performance of the diatomite asphalt mixture is better than that of the neat asphalt mixture. The critical bending strain energy density and the compressing strain energy density of the diatomite asphalt mixture are greater than those of the neat asphalt mixture. After adding diatomite to the asphalt mixture, the contraction coefficient is reduced. Based on the above results, the anti-cracking mechanism of the diatomite asphalt mixture is analyzed from the angle of contraction performance and breaking energy.

A 64-Step Gray Scale Driver Chip for a 132×64-Pixel Passive Matrix OLED

A mixed-signal driver chip for a 132 × 64-pixel passive matrix OLED panel is presented. The chip has a 64-step gray scale control using the PWM method and two-step voltage pre-charge technology to pre-charge the OLED pixels. It consists of a digital controller,SRAM for display data memory,a DC-DC voltage converter,reference current generators,a pre-charge voltage generator,64 common drivers, and 132 segment drivers. The single chip is a typical current-drive circuit. It has been implemented in a Chartered 0.35/μm 18V HV （DDD） CMOS process with a die area of 10mm× 2mm. Test results show that the power consumption of the whole chip and all pixels with a constant driving current of 100μA while displaying the highest gray scale is 294mW with a 12V high voltage supply and a 3V low voltage supply.

“形容词后置”问题刍议

大多数的英语形容词在句子里可以放在两个位置上,具有两种不同的功能。即与名词连用,处于定语位置,在句中做定语;或者放在系动词后,处于表语位置做表语。例如: 1)The new book doesn’t to me. (定语位置) 这本新书不是我的。 2)He looks happy.(表语定置)

水泥中SiO_2含量的快速测定

报道了一种用差示分光光度法中的标准加入法快速测定水泥中 Si O2 含量的方法。利用硅与钼酸铵生成硅钼黄 ,在酸性介质中和抗坏血酸还原剂作用生成硅钼兰 ,其最大吸收波长为 760nm,ε=2 .0 0× 1 0 4L/ (mol·cm)。

A 0.5mV High Sensitivity 200Mbps CMOS Limiting Amplifier with RSSI for Optical Receivers

A 0. 5mV high sensitivity,200Mbps CMOS limiting amplifier （LA） with 72dB ultra wide dynamic range is described. A novel active DC offset cancellation loop is elaborately analyzed and designed to achieve this performance. Using a signal path, a received signal strength indicator （RSSI）, based on the piecewise-linear approximation, is realized with a ± 2dB logarithmic accuracy in a 60dB indicating range. The architecture of the LA and RSSI employed is determined by the optimal sensitivity and RSSI accuracy for a specified speed, gain, and power consumption. It consumes 60mW from a single 5V supply. The active area is 1.05mm^2 using standard 5V 0.6μm CMOS technology.

由地温表的安置浅谈内在质量

观测仪器是整个地面观测工作的基础，而潜在于仪器安置的每个环节的内在质量往往为大家所忽视，它直接影响着内在质量的提高。就以地温表的安置为例，谈一谈地温表安置对于记录的影响。按规范的精神，地温场为２ｍ×４ｍ，要求地面三支温度表感应部分及表身，一半埋入土中...

Dynamics of Motorized Vehicle Flow under Mixed Traffic Circumstance

To study the dynamics of mixed traffic flow consisting of motorized and non-motorized vehicles, a carfollowing model based on the principle of collision free and cautious driving is proposed. Lateral friction and overlapping driving are introduced to describe the interactions between motorized vehicles and non-motorized vehicles. By numerical simulations, the flux-density relation, the temporal-spatial dynamics, and the velocity evolution are investigated in detail The results indicate non-motorized vehicles have a significant impact on the motorized vehicle flow and cause the maximum flux to decline by about 13%. Non-motorized vehicles can decrease the motorized vehicle velocity and cause velocity oscillation when the motorized vehicle density is low. Moreover, non-motorized vehicles show a significant damping effect on the oscillating velocity when the density is medium and high, and such an effect weakens as motorized vehicle density increases. The results also stress the necessity for separating motorized vehicles from non-motorized vehicles.

Research of Temperature Tracer Method to Detect Tubular Leakage Passage in Earth-Dam

The location, intensity and scope of concentrated leakage must be determined in order to repair earth-Dam scoured by the leakage. In this paper, firstly, heat tracer theory and distribution laws of temperature in soil body with leakage are discussed. Then temperature tracer model is established according to stable heat conduction theory. In such model, the concentrated seepage passage is simplified into a circular pipe as a boundary condition. The location, scope and flow-velocity of the concentrated leakage are estimated via ichnography of the lowest temperature based on temperature data from detecting wells by quantitative computation and qualitative analysis. In case study, the distribution characteristic of temperature (including temperature data of water in reservoir, drainage pipes and tail pond) can be interpreted by this model. A modified model is also set up, applied for detected data at different cross-sections of the leakage passage, in which the temperature data are rectified according to distances from data locations to calculating section. Finally, the model is solved by numerical iterative method, and the possible error of this theoretical model is discussed. The permeability coefficient in leakage area is identical with that of normal soil in magnitude after anti-seepage repairing accomplished, which indicates this model is effective.

Underdetermined Blind Source Separation of Adjacent Satellite Interference Based on Sparseness

The problem of underdetermined blind source separation of adjacent satellite interference is proposed in this paper. Density Clustering algorithm(DC-algorithm) presented in this article is different from traditional methods. Sparseness representation has been applied in underdetermined blind signal source separation. However, some difficulties have not been considered, such as the number of sources is unknown or the mixed matrix is ill-conditioned. In order to find out the number of the mixed signals, Short Time Fourier Transform(STFT) is employed to segment received mixtures. Then, we formulate the blind source signal as cluster problem. Furthermore, we construct Cost Function Pair and Decision Coordinate System by using density clustering. At the end of this paper, we discuss the performance of the proposed method and verify the novel method based on several simulations. We verify the proposed method on numerical experiments with real signal transmission, which demonstrates the validity of the proposed method.

3D numerical investigation of effects of density and surface tension on mixing time in bottom-blown gas-stirred ladles

In molten phase metallurgical processes,mixing via gas injection has a vital role in obtaining a homogeneous product.The efficiency of mixing depends on operational variables such as gas flow rate and slag height as well as physical properties of the molten phases.A numerical simulation is conducted to study the above parameters in the flow behavior of a bottom-blown bath.The molten metal and the slag are modeled by water and oil,respectively.The numerical results,particularly the mixing time,are validated against experimental data.The results show that mixing time increases as the slag height increases and decreases as the density of the slag material increases.The mixing time decreases with an increase in the density of the primary phase;however,it increases as the surface tension between air and water increases.A case with properties close to a real molten metal is also modeled.The performance of the system is influenced by the momentum rather than the dissipative forces.Thus,the effect of the density of the molten phase on the mixing process is more pronounced compared to the effect of the surface tension between the air and the molten phase.