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91.
92.
基于能量法和Archard磨损模型,提出了一种考虑磨损的齿轮啮合刚度数值计算方法。根据展成法原理,建立了精确的齿廓曲线方程。利用能量法计算齿轮单齿啮合刚度,并通过分段1阶傅里叶级数拟合获得齿轮总啮合刚度。以Archard磨损模型为基础,计算得到齿面法向磨损量与啮合点处压力角的关系。计算分析了不同磨损量对齿轮啮合刚度的影响。结果表明,磨损量在齿根、齿顶处较大,在节点处的理论磨损量为0 mm,随着压力角的逐渐增加,磨损量先减小后增大;齿面非均匀磨损会降低齿轮啮合刚度,随着磨损量的逐渐增加,啮合刚度逐渐减小。该方法为考虑磨损的齿轮系统动力学建模提供了理论基础。 相似文献
93.
为了分析高速列车齿轮传动系统在轨道不平顺激励影响下的振动特性变化规律,利用动力学软件SIMPACK建立包含齿轮传动系统的整车动力学模型,分别在大、小齿轮内部布置测点,进行无轨道不平顺和有轨道不平顺工况下的动力学仿真实验,获得高速列车时速250 km/h时大、小齿轮的振动加速度。对大、小齿轮横向、纵向和垂向振动加速度幅值进行频域分析,并对比分析了齿轮传动系统在有、无轨道不平顺工况的振动幅值、频谱分布。结果表明,由于轨道不平顺激励的影响,高速列车齿轮传动系统的横向、纵向和垂向振动加强,振动加速度均增幅明显,其中,垂向振动加速度变化幅值最大。齿轮传动系统的振动频率主要集中在0~400 Hz,小齿轮和大齿轮横向振动受轨道不平顺的影响规律一致,但小齿轮受到纵向振动的影响略小于大齿轮,小齿轮受到垂向振动的影响略大于大齿轮。 相似文献
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95.
错齿盘铣刀可用于齿轮的成形铣齿加工,具有多刃断续切削和变切屑厚度等特点,属于非自由强力铣削。切削载荷、加工精度逐渐成为切削机制的主要内容。通过试验方法,测量获得铣齿加工的典型载荷,可知切入、切中、切出三个阶段具有不同的特征。通过三坐标测量加工精度,分析得出齿向呈现了倒锥形的结果。其中切中阶段,加工精度为正并逐渐提高;而切出阶段,加工精度为负。基于对三向切削载荷及机床主轴箱体的悬伸对加工精度的直接影响分析,解释了"收口"现象的主要原因。该类实时的切削数据可用于现场分析与控制,进而实现精度补偿。 相似文献
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98.
《Measurement》2016
Helical gears are widely used in gearboxes due to its low noise and high load carrying capacity, but it is difficult to diagnose their early faults based on the signals produced by condition monitoring systems, particularly when the gears rotate at low speed. In this paper, a new concept of Root Mean Square (RMS) value calculation using angle domain signals within small angular ranges is proposed. With this concept, a new diagnosis algorithm based on the time pulses of an encoder is developed to overcome the difficulty of fault diagnosis for helical gears at low rotational speeds. In this proposed algorithm, both acceleration signals and encoder impulse signal are acquired at the same time. The sampling rate and data length in angular domain are determined based on the rotational speed and size of the gear. The vibration signals in angular domain are obtained by re-sampling the vibration signal of the gear in the time domain according to the encoder pulse signal. The fault features of the helical gear at low rotational speed are then obtained with reference to the RMS values in small angular ranges and the order tracking spectrum following the Angular Domain Synchronous Average processing (ADSA). The new algorithm is not only able to reduce the noise and improves the signal to noise ratio by the ADSA method, but also extracts the features of helical gear fault from the meshing position of the faulty gear teeth, hence overcoming the difficulty of fault diagnosis of helical gears rotating at low speed. The experimental results have shown that the new algorithm is more effective than traditional diagnosis methods. The paper concludes that the proposed helical gear fault diagnosis method based on time pulses of encoder algorithm provides a new means of helical gear fault detection and diagnosis. 相似文献
99.
《Measurement》2016
This paper describes the design and validation of an upgraded grinding wheel scanner system that controls the position of a Nanovea CHR-150 Axial Chromatism sensor along the x- and y-directions of the wheel surface to measure and characterize wheel surface topography. The scanner features a novel homing system that enables the wheel to be removed from the scanner, used on a grinding machine and then re-mounted and re-homed so that the same location on the wheel surface can be repeatedly measured and monitored. The average standard deviation for homing was 27.6 μm and 19.3 μm in the x- and y-directions, respectively, which is more than adequate for typical area scans of 25 mm2. After homing, the scanner was able to repeatedly measure features that were similar in size to an abrasive grain (∼200 μm diameter) with an average error of 9.3 μm and 5.9 μm in the x- and y-directions, respectively. The resulting topography measurements were compared with Scanning Electron Microscope images to demonstrate the accuracy of the scanner. A custom particle filter was developed to process the resulting data and a novel analysis technique involving the rate of change of measured area was proposed as a method for establishing the reference wheel surface from which desired wheel topography results can be reported such as the number of cutting edges, cutting edge width and cutting edge area as a function of radial depth. 相似文献
100.
《Measurement》2016
The curve-face gear pair is proposed as a new type of gear pair which was put forward in recent years. It can achieve variable ratio transmission of motion and power between the intersection axes. In the matter of the inspection of the pitch deviations of this gear pair, there is no practical possibility for a reliable metrological traceability to national or international measurement standards can be provided. Hence, a new method was proposed in this article, which was based on the CNC gear measuring center, aimed at the gear artefacts processed by the five-axis machining center. With the coordinate data which were obtained by the gear measuring center, the pitch deviations of the gear pair were obtained. In addition, based on the values of the pitch deviations, the angular deviations of curve-face gear pair can be worked out, and the results turn out that the measurement method is feasible. 相似文献