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排序方式: 共有291条查询结果,搜索用时 15 毫秒
1.
Resin cure following mold filling is an essential element in resin transfer molding. To fabricate a composite part with high dimensional stability and minimize residual stress, uniform resin cure should be achieved. This study considers a three-part resin system composed of epoxy, hardener and accelerator. The cure kinetics can be controlled by the accelerator concentration at the injection gate. A numerical method that can predict degree of cure distribution based on accelerator concentration at the gate was proposed. The degree of cure distribution is obtained by solving the resin flow, heat transfer, accelerator concentration and cure problems sequentially. Utilizing this numerical method, an optimal variation of accelerator concentration during mold filling was sought by solving a constrained optimization problem. The effect of accelerator control on degree of cure distribution was investigated and its validity was examined for two different geometries.  相似文献   
2.
Tributyltin (TBT) released into seawater from ship hulls is a stable marine pollutant and obviously remains in marine environments. We isolated a TBT resistant marine Pseudoalteromonas sp. TBT1 from sediment of a ship’s ballast water. The isolate (109.3 ± 0.2 colony-forming units mL−1) adsorbed TBT in proportion to the concentrations of TBTCl externally added up to 3 mM, where the number of TBT adsorbed by a single cell was estimated to be 108.2. The value was reduced to about one-fifth when the lysozyme-treated cells were used. The surface of ethanol treated cells became rough, but the capacity of TBT adsorption was the same as that for native cells. These results indicate that the function of the cell surface, rather than that structure, plays an important role to the adsorption of TBT. The adsorption state of TBT seems to be multi-layer when the number of more than 106.8 TBT molecules is adsorbed by a single cell.  相似文献   
3.
周景兮 《核技术》1993,16(3):161-165
描述了用于加速器磁场测量的霍尔多探头装置,它包括一个具有三只恒温盒(内有58只霍尔片)的测磁长臂,高精度磁场检定系统以及数据自动获取系统。分别叙述了霍尔片的定位、恒温、校准、数据采集、处理等内容。并提出了多探头装置测量中霍尔片稳定性的重要性。给出了在我们条件下的一些具体数据。本装置已应用在兰州重离子研究装置(HIRFL)的建造过程中,实践证明它能有效地高质量地满足加速器磁场测量的要求。  相似文献   
4.
孟宪德  马培瑜 《弹性体》1995,5(2):34-38
研究了促进剂的种类,促进剂并用及硫化温度等条件对平衡硫化体系(EC)硫化天然橡胶(NR)的影响。结果表明,噻唑类促进剂具有较低的硫化返原率,尤其是促进剂DM,在130~170℃的硫化温度范围内,硫化2小时的硫化返原率均为0;当促进剂NOBS或CZ与DM并用时,可缩短正硫化时间;当DM摩尔分数分别为40%和50%左右时,不仅使硫化2小时的硫化返原率为0,而且可使300%定伸应力保持恒定;以NOBS或CZ为主促进剂时,正硫化时具有较高的拉伸强度和撕裂强度,但硫化2小时时的降低幅度比DM大。  相似文献   
5.
《核技术(英文版)》2016,(6):168-174
Abstracts High-accuracy position monitoring of key components is required for modern synchrotron sources, such as free-electron lasers and diffraction-limited storage rings. Although various position monitoring sensors have been adopted to monitor the displacement of key compo-nents in each direction in real time, these monitoring sys-tems are usually based on their own coordinate system. Data from such systems are meaningful when evaluating and examining the data from each positioning monitoring system in a unified coordinate system. This paper presents the design and construction of a multi-sensor position monitoring system (MPMS). A hydrostatic levelling sys-tem, a wire position sensor (WPS) and a tiltmeter are fixed to a stainless steel plate that has been calibrated by a coordinate-measurement machine. Several plates form the MPMS. The system must compensate for the sag of the stretched wires so that the WPSs create a straight line. The method of the coordinate transformation from the sensor coordinate system to the MPMS coordinate system was thoroughly studied. An experimental MPMS that includes five plates was setup in a 20-m tunnel, and a validation study to verify fully the feasibility of the MPMS was performed.  相似文献   
6.
The concentration of the natural ultra-trace radionuclides CI and U in the uranium depended on the neutron flux.In this article,a method for measuring 36C1 and 236U in the same uranium mineral with accelerator mass spectrometry was developed in China Institute of Atomic Energy,providing a protocol of the potential application of 236U in uranium mining,environmental,and geological research.The two samples were from Guangxi and Shanxi province,China,and their ratios 36Cl/C1 and 236U/238U were measured.More experimental data conduced to understand the natural nuclides in the uranium mineral.We plan to conduct more efforts on the research.  相似文献   
7.
Measuring -emitters such as (234,235,236,238U, 238,239,240,242,244Pu, 237Np, 241,243Am, …), in solid radioactive waste allows us to quantify the -activity in a drum and then to classify it. The simultaneous photon and neutron interrogation experiment (SIMPHONIE) method dealt with in this paper, combines both active neutron interrogation and induced photofission interrogation techniques simultaneously. Its purpose is to quantify fissile (235U, 239,241Pu, …) and non-fissile (236,238U, 238,240Pu, …) elements separately in only one measurement. This paper presents the principle of the method, the experimental setup, and the first experimental results obtained using the DGA/ETCA Linac and MiniLinatron pulsed linear electron accelerators located at Arcueil, France. First studies were carried out with U and Pu bare samples.  相似文献   
8.
设计了一种基于FPGA的低功耗深度可分离卷积加速核;根据PW卷积和DW卷积计算中的共性,采用一种固定乘法阵列通过改变特征和权重输入数据流的方式实现两种卷积的计算结构,最大化DSP的利用率;针对8位非对称量化中符号位可能会溢出的问题,采用符号位单独处理的方法重新封装了双乘法器结构;通过层内7级流水结构保证每个周期数据处理的并行度;在Zynq UltraScale+系列FPGA上成功部署了加速结构;经实验测试,提出的加速结构在提高网络推理速度的同时降低了片上资源的依赖度和整体功耗,原生MobilenetV2在所提FPGA加速器上的平均吞吐率高达130.6GOPS且整体功耗只有4.1w,满足实时边缘计算的要求;相比其他硬件平台,能效比有明显提升;与FPGA上的同类型加速器相比,在性能密度(GOPS/LUT)、功率效率(GOPS/W)和DSP效率(GOPS/DSP)上均有优势。  相似文献   
9.
添加剂对化学镀镍过程的影响   总被引:2,自引:0,他引:2  
利用循环发技术及阴、阳极极化等方法研究了化学镀镍磷合金的沉积过程及加速剂的影响。结果表明,Ni^2+的还原反应与H2PO2^-的氧化反应之间存在的着重要的相互作用即诱地共析作用;加速剂的加入,提高了H2PO2^-的氧化能力,使反应激活能降低,因而加速了化学镀镍沉积反应。  相似文献   
10.
以优质高铝矾土熟料(体积密度3.18 g·cm-3)或致密刚玉及烧结α-Al2O3微粉为主要原料,采用固体磷酸二氢铝作为结合剂,研究了分散剂SiO2超细粉、促凝剂矾土水泥、抑制剂NH-66和骨料粒度组成对新型磷酸盐耐火散状料性能的影响.结果表明,SiO2超细粉、矾土水泥、NH-66外加量分别为3.5%、2.5%和0.12%,喷补料骨料临界粒度为4 mm,浇注料粒度组成为10~5访m及≤5 mm的两级连续通料时,所研制散状料具有施工简便,强度高,耐磨性优,可以快速进行热处理的特点.通过试验生产验证,研制的材料致密性、耐磨损性和抗冲刷性能比现有的浇注料要好,能满足相关的使用条件和要求.  相似文献   
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