测时法

The pressure distribution on external surface of the test vehicle was analyzed when it passed the anemology station on the east of"Mengjin"from upward and downward. The vehicle aerodynamic forces by piecewise integrating technology were obtained.

摘 要：对试验列车上、下行通过"猛进东"测风点时的车体表面压力分布情况进行分析，采用分块积分法得出试验列车上、下行通过"猛进东"测风点的气动力。

The conductivity of the membrane was measured by AC impedance method ,it was showed that the conductivity of the membrane prepared by electrodeposit method could get up to 10 -2 S/cm,the denseness of the membrane was investigated with a lab made negative pressure system,and it was found that the permeability of the membrane decreased by over 95% in the case of ca 2% phosphate deposit.

采用电化学沉积法和溶胶凝胶法制备了一种磷酸盐无机质子传导膜，交流阻抗法测得电化学沉积法制得的膜的电导率可达 10 -2 S/cm ，负压渗透系统研究膜的密实性表明：在磷酸盐沉积量为 2 %左右时，膜的透过性可降低 95 %以上。

In the past, the high frequency resonance technique is usually applied in the envelope detection for a vibration signal with amplitude modulation. When applying the Hilbert transform in the high frequency resonance technique for the envelope detection of vibration signals, the computing burden is very high. On the other hand, when applying the linear least squares analysis method, the computing burden is lower. When applying the envelope detection in the lowest vibration mode, an accelerometer with the low-pass filtering cutoff frequency at 4kHz should be choose.

在过去的研究方法中，振动讯号之振幅调变通常以高频解调分析法应用於包络讯号侦测，而高频解调方法应用希尔伯特转换的包络分析，所需要的计算量是非常的高，若以线性最小平方分析法应用於高频解调分析法中，则所需要的计算量较小，如果以最低模态来估测包络讯号时，可以适当的选取加速规来代替低通滤波器，而加速规的截止频带必须在4kHz左右。

The purpose of this research is to measure the different EOG (Electro-Oculography, EOG) signals resulted from eye movements. The measured voltages will be transmitted to VCO (Voltage Controled Oscilloator, VCO), and then VCO will transfer the different voltages to different frequencies of square waveform signals. The square waveform signals can replace the pulse trains generated by circle disk encoder, as the input signal of infra red sensor in the mechanical mouse.

本论文主要研究目的，乃是应用眼电图法(Electro-Oculography， EOG)来量测眼球运动所产生的电压讯号，以EOG方式量测到的电压，再经由电压控制震荡器(Voltage Controled Oscilloator，VCO)转换成不同频率的方波，VCO并将方波讯号传送给滑鼠的红外线感应器，以替代轨迹球滚动时其带动圆盘编码器所产生的脉波。

This dissertation researches in the vibrant clipped data of a plane, proposes regression analysis, BP learning algorithm and cubic spline interpolation to forecast the clipped data.

以国产某型无人机空飞时振动传感器测得的振动削波数据为研究对象，选用回归分析法、BP神经网络法和三次样条插值法对削波数据进行预测恢复。

In this paper, total logistics amounts are chosen as evaluation index, and artificial time series are designed to solve the shortness of statistical data in Chinese logistics. Spectrum estimation theory depicts time characteristics in frequency domain thus has such benefit than time domain methods. This paper evaluates the period of Chinese logistics using spectrum estimation. Stationarity of artificial series is verified, parameter sensitivity of truncation point is analyzed, six periods with different delay window are compared, and significance of period evaluated is tested.

中国物流统计数据缺乏，客观上限制了对其周期规律的研究，本文选取社会物流总额作为测度指标，设计了一种人工序列，解决了统计数据过短问题；谱估计法从频域角度揭示客观事物的时间特性，在研究时间序列周期波动方面具有时域分析法所不具备的优势，作者采用谱估计法对中国物流发展周期进行测定，检验了指标序列平稳性，分析了截断点参数灵敏度，比较了6种不同滞后窗下周期值，并检验了所测得周期的显著性。

By time-varying filtering, we realize the signal selectivity and interference suppression, especially for the signals with time-varying power spectrum. It is shown herein that conventional eigenstructure based methods are lower dimensional special case of the time-frequency subspace fitting method. The closed-form array response estimation algorithms for blind source separation in wireless communication is also developed in the dissertation by exploiting the data structure of second-order statistics of the array output in the presence of multipath. The proposed method achieves array response estimation with little constraint on signal property and propagation environment such as scatters or angular spread. Moreover, the array utilized here can be of arbitrary geometry and even uncalibrated. Since the closed-form solution is obtained, no misconvergency may occur and large amount of computation can be saved. The equivalent feed model and corresponding optimization designation are proposed to realize the downlink multi-user selective transmission. By coherent and non-coherent superposition of the electromagnetical field, multiple beams can be formed using a single array, so that each co-channel user signal is transmitted in each beam and will not interfered with each other. The proposed system scheme implements the digital beamforming and the channel allocation in the base band, therefore is suitable for the utilization of the radio software technology. The feasibility and effectiveness of the proposed model are proved by the RF experiment.

在窄带条件下，GSC－SSF方法还可以提高阵列的虚拟孔径，从而提高估计的性能；可以证明，Cyclic DOA 和SC-SSF方法可看作该方法的特例或近似； 3、提出了二维GSC－SSF方法和宽带谱相关DOA矩阵方法，利用信号的循环平稳特性解决了宽带条件下二维 DOA 估计问题，并具有阵元数少、计算量较小的特点； 4、提出了时频子空间拟合和宽带时频DOA估计算法，将联合时频分析的理论和方法引入到阵列信号的空间谱估计研究中，利用时变滤波实现信号选择性测向和干扰抑制，特别适合于谱时变信号；可以证明传统特征结构法可看作是时频子空间拟合方法的特例； 5、提出了多用户环境下阵列响应的估计方法——CARE方法，该方法对信号结构和传播参数（主要是散射源分布与角度散布）的约束较少，适用于各种几何结构的阵列甚至未校准的阵列，能够直接得到阵列响应的闭式解，因此计算量小、稳健性好，不存在收敛问题； 6、提出了针对多用户下行选择性发送的阵列等效激励模型、优化设计方法及其系统实现方案，通过空间场的相干叠加与非相干叠加使得单一阵列能够形成多个波束，并保证各波束内的用户信号各不相同且相互干扰最小；其系统方案具有在基带实现数字波束成形、信道分配并便于软件无线电实现的特点，其有效性已得到外场实测数据的证实。

The biomechanical tests showed that two kinds of artificial bones had not significant difference on compressive strength and Young\'s modulus(P＞0.05),while the flexural strength of nano-nacre artificial bone was less than the control group(P＜0.05).3.The results of CCK-8 showed that the difference were not significant in each group,the proliferation of osteoblast reached the peak at the 5th day;7 days after being co-cultured,the total protein content of study group was higher than control group and blank group(P＜0.05),while the difference between control group and blank group was not significantP＞0.05The difference of alkaline phosphatase activities among three groups was not significant(P＞0.05The SEM view showed that osteoblast attached and grew well in two kinds of artificial bone.4.X-ray photography showed that two kinds of powder started to degrade in 2 weeks;this phenomenon became more appear in 4 weeks,nano-nacre powder degraded faster than micron-nacre powder,while the hole shadow was easy to be found;in 8 weeks,all the femoral holes recovered and returned to normal bone mineral density in all groups.Analysis of tetracycline fluorescent double marks in the hard tissue grinding slices indicated that new bone grew fastest around the bone defect area in study group,while most slowly in blank groupP＜0.05 SEM(scanning electron microscope observation showed that nano-nacre powder degraded more quickly.The same result can be found through the demineralized sections morphometric analysis,and both of the composite artificial bones made from those two kinds of nacre powder had the good connection with the adjacent tissue in rats body without apparent inflammatory response.5.X-ray photography showed that rabbit\'s bone defects healed faster in study group since NNAB implanted than in control group since MNAB implanted.At 24 weeks after operation,bone density in radial defects had nearly accessed to the normal area,while lower in control group,and turned up nonunion in blank group;The checking of BMD showed that results in study group were higher than those in control group at 8,16 and 24 week(P＜0.05), and the difference between the BMD values in study group at 24 week and those in blank group was not significant(P＞0.05).The gross specimens showed satisfactory histocompatibility both in study group and in control group,with bone tissue growing from two sides into the center of implanted materials; Normal slices in HE stain and hard tissue grinding slices in Stevenel\'s blue/Van Geison\'s picro-fuchsin stain showed that the bone growth tendency was better in study group than that in control group,and the medullary cavity had been penetrated to the implanted materials in study group at 24 week;Analysis of tetracycline fluorescent double marks in the hard tissue grinding slices indicated that new bone in both groups grew fastest 8 weeks after surgery,while slow down at 16 week.

纳米珍珠层/消旋聚乳酸复合人工骨与微米珍珠层/消旋聚乳酸复合人工骨分别与成骨细胞共培养后，其各时间点CCK-8法检测值与空白对照无显著差异(P＞0.05)，成骨细胞均在第5天达到增殖高峰期；培养7天后，实验组细胞蛋白含量高于对照组及空白组(P＜0.05)，后两者之间则无显著差异P＞0.05碱性磷酸酶活性在三组间均无显著差异(P＞0.05电镜下可见成骨细胞在两种人工骨上都有良好生长贴附能力。4.X-ray显示两种粉体在大鼠股骨骨洞植入第2周时都开始出现了降解，第4周时更为明显，纳米珍珠层粉较之微米珍珠层粉降解更快，而空白对照组骨洞阴影仍可见，至8周时，则所有组骨洞均己闭合修复，X-ray下已不可见原钻孔痕迹，恢复正常骨质密度；硬组织磨片四环素荧光双标记结果显示纳米珍珠层粉植入组较其余两组在骨缺损区周围新骨生长速度更快，空白组速度最慢P＜0.05电镜观察及常规脱钙切片亦可见到纳米粉体降解较快；由以上两种原材料制得的纳米珍珠层/消旋聚乳酸复合人工骨与微米珍珠层/消旋聚乳酸复合人工骨在大鼠体内均与周围组织结合良好，无明显炎症反应。5.X-ray显示纳米珍珠层/消旋聚乳酸复合人工骨植入兔桡骨缺损区后其骨愈合速度较对照组微米珍珠层/消旋聚乳酸复合人工骨植入的快，至植入术后24周，实验组骨缺损区接近正常骨密度，对照组骨缺损区密度较低，空白组则呈现骨不连状态；骨密度测量结果显示术后8周、16周、24周实验组的骨密度值高于对照组(P＜0.05，24周实验组的骨密度值与术前所测得的正常值无显著性差异P＞0.05动物取材大体所见均显示组织相容性良好，骨组织逐渐由植入材料两端向中央生长；常规切片HE染色及硬组织磨片Stevenel\'s blue/Van Geison\'s picro-fuchsin联合染色均可见实验组骨缺损区长势优于对照组，至术后24周，实验组骨髓腔与材料已呈相交通状；硬组织磨片荧光显微镜下观察，两组材料在术后8周处于骨生长最快速时期，16周时速度开始减慢，术后4、8、16周时实验组的新骨生长速度均较对照组的快

Methods Marrow-derived mesenchymal stem cells were isolated and purified from mouse femoral bone and shinbones using differential adherent methods. Cells at the third passage were induced by 20% FBS in conditioned medium, conditioned medium alone, 20% FBS or 10% FBS alone respectively. Mouse aortic smooth muscle cells were cultured as the positive control. Levels of mRNA and protein expression of myoeardin and several smooth muscle cells marker genes were determined by immumofluorescenee, RT-PCR and Western blot before and 3, 7, 10, 14d after the induction. The presence of smooth muscle myofilaments was detected by using transmission electron microscope.

采用伞骨髓贴壁法分离骨髓问充质干细胞，CM联合20%FBS诱导骨髓间充质干细胞，同时设立持续10%FBS、单20%FBS及单CM诱导下的骨髓间充质十细胞对照组和SMC阳性对照组，分别于诱导前及诱导3、7、10和14 d时观察细胞形态的变化，并在相应的时间点用免疫荧光法、逆转录聚合酶链反应法、Western blot半定量分析法榆测myocardin以及SMC表面各种标志基因的表达变化，用透射电镜检测诱导后细胞内肌丝存在以此来证实诱导分化成功。

In addition to trilateration and offset method with tapes and walking measuring wheels, a total station is employed to measuring angles and distances. With the measured angles and distances, the correct positions are calculated with the geometric principles.

从实验所获的的数据，本研究发现﹕运用直角坐标法，可获得接近电子光波经纬仪的量测结果；亦即，在绘制交通事故现场图时，直角坐标法所获的结果较三定点法佳。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。