日本相机在国内的销售情况

根据对大约一千家照相机商店的调查,尼康相机(1979年)销售量仍然保持领先,占22.7％(1978年为25％);卡农相机占22.5％(1978年为22％);Asahi相机占22.4％(1978年为20％);奥林巴斯相机占12.2％(1978年为11％);万能达相机占9.4％(1978年为10％);丽确相机占3.9％(1978年为2％);富士     

1991年全国房间空调器和家用电冰箱产量

据国家统计局工交司资料《1991年全国主要家用电器产品产量》介绍,1991年全国房间空调器产量为59.74万台,比1990年增长172％。其中广东省产量居首位,为22.17万台(增长250.2％);江苏省第二,产量为13万台(增长141.2％);湖北省第三,产量为5.94万台(增长209.4％);浙江省第四,为5.23万台(增长149％),上海第五,为2.42万台(增长272.3％)。     

日本1990年气体市场概况

日本1990年气体市场为31.83亿美元,其中各种气体所占比例为:氧(O_2):20.2％,氮(N_2):18.4％,氢(H_2):5.2％,氩(Ar):10.0％,氦(He):1.7％,CO_2:13.2％,氟碳化物:13.9％,乙炔:7.4%,电子气体:2.3％,其它:7.7％。 1.氧 1990年日本氧气销售量为16.35亿米~3,比上年增长4.4％;销售额为3.48亿美元(不计钢瓶气)。液氧销售量为9.34亿米~3,比上年     

防雾抗菌聚乙烯薄膜的制备及性能

目的 制备一种具有抗菌和防雾效果的改性薄膜.方法 防雾添加剂选择聚甘油脂肪酸酯(PGFE)和实验室自制的母粒(YS),抗菌剂选择丙酸钙(CP)和脱氢乙酸钠(以下称为DHA-S),将抗菌剂、防雾剂及PE粒子混合造粒,然后在流延机上流延得到防雾抗菌聚乙烯(PE)活性包装薄膜,并通过正交实验优化薄膜的制备配方.结果 与纯PE薄膜相比(抗张强度为8.64 MPa;质量分数为88.46％;断裂伸长率纵向为551.72％,横向为589.86％),添加YS(均以质量分数表示)(3％),PGFE(3％),DHA-S(1％)和CP(1％)的薄膜具有较好的防雾性、抗张强度(14.58 MPa)以及对试验菌较好的抗菌性能,但是薄膜透光率(82.68％)、断裂伸长率(纵向272.20％,横向140.20％)和阻隔性较差.结论 经过防雾剂和抗菌剂改性的聚乙烯薄膜,因其抗菌和防雾效果较好,以及其物理性能良好,可以作为食品包装材料使用.     

福橘果皮挥发油化学成分的研究

采用气相色谱—质谱—计算机联用技术,对闽产福橘干燥成熟果皮中挥发油的化学成分进行了研究。色谱分离出50多个峰,质谱鉴定出其中29份成分,占总挥发油的98.84％。主要成分为d-柠檬烯(91.72％)、异松油烯(2.82％)、β-蒎烯(1.18％),芳樟醇(1.14％),α-蒎烯(0.62％)等。     

PP/PBAT薄膜阻隔性对沙葱采后品质及菌相结构的影响

目的 探讨不同组成的共混膜阻隔性对沙葱采后品质和微生物菌群结构的影响.方法 采用熔融共混法制备不同组分的聚对苯二甲酸-己二酸-丁二醇酯(PBAT)和聚丙烯(PP)共混薄膜,分析共混膜的阻隔性能;采用共混膜包装沙葱,分析沙葱的生理指标和微生物群落结构的变化.结果 当PBAT的质量分数为30％时,CO2透过系数(CDP)提高了49.7％,CO2和O2透过比(CDP/OP)提高了50.7％,H2O透过系数(WVP)提高了145.5％.厚度为35μm的PP/PBAT(30％)(PBAT质量分数为30％)薄膜包装沙葱,能够形成与沙葱匹配的气体环境(O2体积分数为0.48％～0.66％,CO2体积分数为5.98％～6.53％);低浓度O2高浓度CO2环境有效抑制了沙葱表面嗜温菌(Aerobic Bacterial Count,ABC)、嗜冷菌(Psychrophile Plate Count,PPC)、假单胞菌(Pseudomonas Count,PC)、霉菌和酵母菌(Yeast and Molds,YAM)的增殖,与PP包装比较,ABC降低了1.1 lg CFU/g,PPC降低了1.3 lg CFU/g,PC降低了1.47 lg CFU/g.结论 厚度为35μm的PP/PBAT(30％)薄膜包装沙葱能够有效降低呼吸速率和微生物的增殖侵染,维持稳定的采后品质.     

胶束电动毛细管色谱法测定冬虫夏草中核苷及核苷碱基的含量

目的:测定冬虫夏草、虫体和子座部分核苷及核苷碱基的含量,为质量评定提供检测方法。方法:用胶束电动毛细管色谱法(MECC)测定,以黄嘌呤核苷为内标,电泳缓冲液为V(20mmol·L~(-1)硼砂,25mmol·L~(-1)十二烷基硫酸钠即SDS):V(乙腈)=95:5,电压25KV,柱温30℃,检测波长260nm,进样量5mmHg·S。结果:可同时测定出腺嘌呤(Ⅰ)、腺苷(Ⅱ)、次黄嘌呤(Ⅲ)、鸟苷(Ⅳ)、尿苷(Ⅴ)和次黄嘌呤核苷(Ⅵ)的含量,回收率分别为102.5％,102.7％,98.83％,101.1％,100.8％和101.4％,RSD小于2％。结论:正品虫草中都含有1～Ⅵ6个化合物,子座中Ⅰ～Ⅴ5个化合物的含量均明显高于虫体,虫草中Ⅱ、Ⅳ、Ⅴ、Ⅵ4种核苷的含量较高且相对稳定。     

乳液基碳化硅纳米工作液的沉降稳定性、流变性与介电性

目前混粉电火花加工液添加的粉末粒径主要局限于微米级,与工作基液不能形成均匀、稳定的悬浮液.本研究以乳化液为基液,纳米碳化硅粉体(SiC)为分散相,十二烷基苯磺酸钠(SDBS)、羧甲基纤维素钠(CMC)等作分散剂,采用两步法制备了乳液基SiC纳米工作液,研究不同分散条件下SiC粉体在乳化液中的分散行为,分析了乳液基SiC纳米工作液的沉降稳定性、流变性和介电性.结果表明:质量分数为0.3％～0.6％的CMC对SiC纳米粒子的润湿、分散作用显著,而SDBS作用不明显;CMC分别与SDBS、SDS协同作用时,工作液均具有很好的沉降稳定性;当SDBS质量分数为0.3％,CMC为0.3％～0.6％时,工作液黏度呈非线性增加;当CMC质量分数为0.3％,SDBS为0.3％～1.4％时,工作液黏度先增大后快速降低;工作液电导率随CMC、SDBS分散剂质量分数的增加、液体温度的升高而增大.因此,当SiC质量分数为0.3％、添加0.3％～0.5％(质量分数)的CMC和0.3％～0.7％(质量分数)的SDBS,乳液基SiC纳米工作液有较好的沉降稳定性、流变性和介电性.     

热电偶用AlN-Al_2O_3-Mo基保护管的制作与使用试验

热电偶用AIN—Al_2O_3—Mo基保护管是采用在工业陶瓷中广泛应用的热塑浆铸法制作的。选用的原材料为纯级氧化铝(0.05％SiO_2、0.024％Fe_2O_3),顿涅茨化学试剂厂生产的纯级氮化铝(65.6％AI和32.9％N)和粒度为5微米以下的钼粉(99.7％Mo,0.22％O_2,0.001％Ni,0.01％     

正氢与仲氢的转化问题

一般的氢由二种形态组成,一种称它为正氢(O—H_2),另一种为仲氢(P—H_2)真,在室温时成平衡状态的组成正氢75％,仲氢25％,在77°K时正氢占51％,仲氢占49％,在液氢沸点时(20.4°K)正氢仅占0.2％,仲氢占99.8％。     

基于边缘的背景差法在车流量检测中的应用

针对视频车流量检测容易受车辆阴影和车辆变道影响的问题,笔者提出了一种基于边缘信息的背景差车流量检测方法.该方法利用边缘信息作为车辆的检测特征,实时自动提取和更新背景边缘并采用动态开窗的方式来进行车辆计数.实验结果表明,与传统背景差法相比,该方法受车辆阴影和车辆变道影响较小,检测准确率达97.3%,是一种实用有效的车流量检测方法.     

高噪声环境下的麦克风阵列VAD算法研究

首先介绍一种基于频带方差的语音活动检测（VAD）算法，然后在此基础上，给出一种对麦克风阵列各通道信号同时进行VAD的新算法（ICA—VAD）：经ICA分离出的相对纯净的语音信号作为参考信号，其VAD结果用于指导阵列信号的语音检测。实验结果表明该方法在恶劣的噪声环境下仍可以获得准确的检测结果，且计算机模拟显示这是一种比较好的抗噪语音检测方案。     

A reliable method for the counting and control of single ions for single-dopant controlled devices

By 2016, transistor device size will be just 10?nm. However, a transistor that is doped at a typical concentration of 10(18)?atoms?cm(-3) has only one dopant atom in the active channel region. Therefore, it can be predicted that conventional doping methods such as ion implantation and thermal diffusion will not be available ten years from now. We have been developing a single-ion implantation (SII) method that enables us to implant dopant ions one-by-one into semiconductors until the desired number is reached. Here we report a simple but reliable method to control the number of single-dopant atoms by detecting the change in drain current induced by single-ion implantation. The drain current decreases in a stepwise fashion as a result of the clusters of displaced Si atoms created by every single-ion incidence. This result indicates that the single-ion detection method we have developed is capable of detecting single-ion incidence with 100% efficiency. Our method potentially could pave the way to future single-atom devices, including a solid-state quantum computer.     

The Stability of Aspirin in a Moisture Containing Direct Compression Tablet Formulation

Studies were conducted on the stability of a direct compression tablet formulation containing aspirin as a model hydrolabile drug. Emdex^R (a mixed-sugar diluent containing approximately 8 percent moisture) and stearic acid (a lubricant) made up the remainder of the formulation. Both tablets and uncompressed powder blend were manufactured, packaged in storage containers and placed on stability at different storage temperatures. Stability samples were assayed for aspirin and salicylic acid using a stability indicating analytical method. Analysis of the stability data showed that the rate of aspirin decomposition accelerated with time. Also, the aspirin decomposition rate increased with temperature. The data were fit to the empirical equation y = 100 - ktⁿ, where y is the percent aspirin remaining, t is time, and k and n are constants. The formulation showed good stability, with less than one percent decomposition occuring after 1.75 years of storage at room temperature. This result indicates that although the aspirin formulation contained approximately 8 percent moisture, at room temperature the majority of the moisture present in the formulation is not available to react with the aspirin. The apparent activation energy of the solid-state aspirin decomposition was 46 kcal/mole, which is higher than expected. This result may be due to a temperature dependent release of moisture from the Emdex^R. Further studies are needed to verify this explanation.     

A Laser Microcalorimeter

A new type of microcalorimeter as the laser power standard in Japan has been developed at the Electrotechnical Laboratory. This is a double calorimeter in which the laser power is measured by a dc substitution method using the thermopile unit, and simultaneous measurement is also made using the Peltier cooling-type calorimeter by dc substitution. The CW power of the gas laser (He-Ne) is controlled with high stability (±0.05 percent) by the automatic power control system using the Faraday rotation component. By this method and equipment, the "effective efficiency" of the standard thermopile unit is determined precisely. The errors in this microcalorimetric technique are investigated with the aid of heat flow analysis and auxiliary experiments. As a result, the absolute accuracy of the CW power measurement of laser beams (6328?, 1.15?) is evaluated with high accuracy better than 0.5 percent. The experiments have been successful at 6328? and 1.15 ?, and this method is considered to be available at the region of infrared and far-infrared wavelength.     

复杂背景下导弹目标的分光检测

针对电视制导系统从各种复杂自然背景和野战环境的图像中提取导弹目标信号的要求,从导弹目标和背景的光谱特性出发,提出了导弹目标的分光检测原理与方法,设计了双CCD分光检测光学系统,使含有导弹目标的图像进入主CCD,背景图像进入次CDD,最终由背景减法电路实现主次CCD图像相减,得到导弹目标图像.实验结果证明,该方法能可靠地从背景中检测出导弹目标.     

Brain Tumor Detection and Classification Using PSO and Convolutional Neural Network

Tumor detection has been an active research topic in recent years due to the high mortality rate. Computer vision (CV) and image processing techniques have recently become popular for detecting tumors in MRI images. The automated detection process is simpler and takes less time than manual processing. In addition, the difference in the expanding shape of brain tumor tissues complicates and complicates tumor detection for clinicians. We proposed a new framework for tumor detection as well as tumor classification into relevant categories in this paper. For tumor segmentation, the proposed framework employs the Particle Swarm Optimization (PSO) algorithm, and for classification, the convolutional neural network (CNN) algorithm. Popular preprocessing techniques such as noise removal, image sharpening, and skull stripping are used at the start of the segmentation process. Then, PSO-based segmentation is applied. In the classification step, two pre-trained CNN models, alexnet and inception-V3, are used and trained using transfer learning. Using a serial approach, features are extracted from both trained models and fused features for final classification. For classification, a variety of machine learning classifiers are used. Average dice values on datasets BRATS-2018 and BRATS-2017 are 98.11 percent and 98.25 percent, respectively, whereas average jaccard values are 96.30 percent and 96.57% (Segmentation Results). The results were extended on the same datasets for classification and achieved 99.0% accuracy, sensitivity of 0.99, specificity of 0.99, and precision of 0.99. Finally, the proposed method is compared to state-of-the-art existing methods and outperforms them.     

基于核主成分分析及支持向量机的水轮机叶片裂纹源定位

结合核主成分分析(KPCA)以及支持向量机对水轮机转轮叶片裂纹源的声发射信号进行定位。结果表明,利用核主成分分析提取的特征参数进行定位的精度高于原始参数的定位精度,即输入9个特征参数时,支持向量机在叶片区域的识别率为100%,在裂纹源对焊缝距离的支持向量回归分析中的最大误差为20cm。因而结合KPCA和支持向量机对复杂的大尺寸结构进行定位是一种较好的方法,既减少了输入信号的维数,又提高了定位精度。     

The Stability of Aspirin in a Moisture Containing Direct Compression Tablet Formulation

Abstract

Studies were conducted on the stability of a direct compression tablet formulation containing aspirin as a model hydrolabile drug. Emdex^R (a mixed-sugar diluent containing approximately 8 percent moisture) and stearic acid (a lubricant) made up the remainder of the formulation. Both tablets and uncompressed powder blend were manufactured, packaged in storage containers and placed on stability at different storage temperatures. Stability samples were assayed for aspirin and salicylic acid using a stability indicating analytical method. Analysis of the stability data showed that the rate of aspirin decomposition accelerated with time. Also, the aspirin decomposition rate increased with temperature. The data were fit to the empirical equation y = 100 – ktⁿ, where y is the percent aspirin remaining, t is time, and k and n are constants. The formulation showed good stability, with less than one percent decomposition occuring after 1.75 years of storage at room temperature. This result indicates that although the aspirin formulation contained approximately 8 percent moisture, at room temperature the majority of the moisture present in the formulation is not available to react with the aspirin. The apparent activation energy of the solid-state aspirin decomposition was 46 kcal/mole, which is higher than expected. This result may be due to a temperature dependent release of moisture from the Emdex^R. Further studies are needed to verify this explanation.     

单曲率多面壳体液压胀形壁厚分布研究

本文对单曲率多面壳体胀形过程中壁厚分布规律进行了研究．结果表明单曲率多面壳体胀形成球后壁厚的分布是不均匀的，焊缝附近部分的减薄率较小，甚至取负值，而远离焊缝的部分的减薄率较大。在极带板上最大减薄率发生在中心部位，而在单曲率柱面壳板上最大减薄率发生在经向对称线和纬向对称线的相交部位。