新型高时效金刚石钻头试验研究

根据勘探工程钻进的特点,研制开发了一种新型的金刚石钻头。现场应用情况表明,该种钻头具有高时效、寿命较长、成本较低的优点,能更好的适应勘探工程的需要。

高时效金刚石钻进的实践与认识

在均质地层条件下,采用高时效金刚石钻进,可充分发挥绳索取心技术的优越性,且对钻头寿命影响并不大.

5700高时效双侧向仪器组合常见故障及处理方法

5700高时效双侧向仪器,用于测量地层电阻率,研究地层径向电阻率变化。5700高时效双侧向仪器,用于测量地层电阻率,研究地层径向电阻率变化。讨论5700高时效双侧向仪器在施工中常见故障产生原因和解决方法。

高时效6515阵列感应测井仪故障分析及解决方法

高时效6515高分辨率阵列感应测井仪,采用多种先进的数字处理技术,可以采集详细的地层信息,优化测井解释工作的实际水平。需要注意的是,测井资料对于进一步有效提取薄储层信息以及搜索低阻油层而言具有非常重要的研究价值。本文就简要分析了6515高分辨率阵列感应测井仪的仪器结构,并根据作者的实际维修经验,通过对6515阵列感应测井仪工作过程中产生的故障进行原因分析,并提出解决问题的方法。对高时效6515阵列感应测井仪的维修有一定的参考价值。

Ultrahigh strength and improved electrical conductivity in an aging strengthened copper alloy processed by combination of equal channel angular pressing and thermomechanical treatment

In this paper,equal channel angular pressing and thermomechanical treatment was employed to improve the strength and electrical conductivity of an aging strengthened Cu-Ti-Cr-Mg alloy,and the microstructure and properties of the alloy were investigated in detail.The results showed that the samples deformed by the combination of cryogenic equal channel angular pressing(ECAP)and rolling had good comprehensive properties after aging at 400℃.The tensile strength of the peak-aged and over-aged samples was 1120 MPa and 940 MPa,with their corresponding electrical conductivity of 14.7%IACS and 22.1%IACS,respectively.ECAP and cryogenic rolling introduced high density dislocations,leading to the inhibition of the softening effects and refinement of the grains.After a long time aging at 400℃,the alloy exhibited ultra-high strength with obvious increasing electrical conductivity.The high strength was attributed to the synergistic effect of work hardening,grain refinement strengthening and precipitation strengthening.The precipitation of a large amount of Ti atoms from the matrix led to the high electrical conductivity of the over-aged sample.

High density dislocations enhance creep ageing response and mechanical properties in 2195 alloy sheet

The creep strain of conventionally treated 2195 alloy is very low,increasing the difficulty of manufacturing Al-Cu-Li alloy sheet parts by creep age forming.Therefore,finding a solution to improve the creep formability of Al-Cu-Li alloy is vital.A thorough comparison of the effects of cryo-deformation and ambient temperature large pre-deformation(LPD)on the creep ageing response in the 2195 alloy sheet at 160℃with different stresses has been made.The evolution of dislocations and precipitates during creep ageing of LPD alloys are revealed by X-ray diffraction and transmission electron microscopy.High-quality 2195 alloy sheet largely pre-deformed by 80%without edge-cracking is obtained by cryo-rolling at liquid nitrogen temperature,while severe edge-cracking occurs during room temperature rolling.The creep formability and strength of the 2195 alloy are both enhanced by introducing pre-existing dislocations with a density over 1.4×10^(15)m^(−2).At 160℃and 150 MPa,creep strain and creep-aged strength generally increases by 4−6 times and 30−50 MPa in the LPD sample,respectively,compared to conventional T3 alloy counterpart.The elongation of creep-aged LPD sample is low but remains relevant for application.The high-density dislocations,though existing in the form of dislocation tangles,promote the formation of refined T1 precipitates with a uniform dispersion.

一种适用于大偏心率轨道密集星历精密计算的快速处理方法

空间目标探测和编目是航天器安全的重要课题,空间目标数量巨大,造成轨道计算的工作量十分繁重.分析方法虽然计算速度快,却不能适应高精度观测资料的处理工作,因而数值方法将成为目标轨道计算的重要方法.空间目标编目工作普遍涉及密集星历的产生和计算问题,针对这一问题的大偏心率轨道数值计算目前尚未形成兼具计算精度和计算效率的有效技术手段,难以满足编目工作的处理要求.在此背景下,提出一种适用于大偏心率轨道密集星历精密计算的快速处理方法,并通过数值实验对模型参数进行优选,最后通过计算实例证实了该计算方案的优越性.

用于卫星模拟飞行测试的太阳电池阵动态模拟系统设计

现阶段卫星模拟飞行测试中,太阳电池阵模拟器(SAS)伏安特性曲线数目有限,无法连续动态模拟卫星在轨运行中太阳电池阵实际电能输出情况。为此,基于模拟飞行测试环境,设计太阳电池阵动态模拟系统。该动态模拟系统由电源、控制和测控等测试系统组成。为保证动态模拟系统的高时效性和精确性,对参数实时获取传递、曲线建模计算和功率输出等各环节开展分析。利用某卫星太阳电池阵对动态模拟系统设计进行验证,结果表明系统能精确模拟太阳电池阵伏安曲线和功率输出变化。将仿真结果与实际在轨卫星数据进行比较,结果显示系统可很好地模拟时变太阳电池阵输出特性,证明了动态模拟系统设计对太阳电池阵动态输出模拟的有效性。

气象大数据平台的数据采集与处理系统初探

气象资料是典型的具有时间和空间属性的地球科学数据,其组成种类繁多,体量巨大,且实际应用中具有高时效性要求,因此快速获取和处理实时气象数据是开展气象数据应用的关键。通过阐述基于组件的不同种类数据可视化采集处理方法的设计和实现,完成大数据平台前端各类气象数据的快速采集,具有较强的借鉴意义。

Microstructure evolution of a new directionally solidified Ni-based superalloy after long-term aging at 950 ℃ upto 1 000 h

The microstructure evolution of a new directionally solidified（DS） Ni-based superalloy used for gas turbine blades after long-term aging at 950 ℃ was investigated.The results show that the γ ＇ phase becomes more regular in dendritic arm and interdendritic area,while both the mass fraction and the size of γ ＇ phase increase gradually with increasing aging time.During long-term aging,the MC carbide dissolves on the edge to provide the carbon for the formation of M23C6 carbide by the precipitation of Cr at the grain boundary.The rose-shaped γ ＇/γ eutectic partly dissolves into γ matrix and the aging promotes it transform into raft-shape γ ＇.The microstructure is generally stable and no needle-like topologically close-packed phase（TCP） can be found after aging for 1 000 h.

Effects of high temperature pre-straining on natural aging and bake hardening response of Al-Mg-Si alloys

The influences of high temperature pre-straining (HT-PS) on the natural aging and bake hardening of Al?Mg?Si alloys were investigated by Vickers microhardness measurements, differential scanning calorimetry (DSC) analysis and transmission electron microscopy (TEM) characterization. The results show that pre-straining at 170 °C immediately after quenching can effectively resolve the rather high T4 temper hardness caused by the conventional room temperature (RT) pre-straining treatment, and give a better bake hardening response (BHR) after paint-bake cycle. HT-PS 7% at 170 °C for 10 min is chosen as the optimum process as it provides lower T4 temper hardness and better BHR. The simultaneous introduction of dislocations and Cluster (2) can significantly suppress the natural aging and promote the precipitation of β″ phase, and reduce the effects of deformation hardening by dynamic recovery.

Microstructure and microhardness of directionally solidified and heat-treated Nb-Ti-Si based ultrahigh temperature alloy

Directionally solidified （DS） specimens of Nb-Ti-Si based ultrahigh temperature alloy were heat-treated at （1 500 ℃, 50 h） and （1 500 ℃, 50 h） ＋ （1 100 ℃, 50 h）, respectively. The results show that the microstructures become uniform, the long and big primary （Nb,X）sSi3 （X represents Ti and Hf elements） plates in the DS specimens are broken into small ones, and the eutectic cells lose their lamellar morphology and their interfaces become blurry after heat-treatment. Meanwhile, the （Nb,X）sSi3 slices in the eutectic cells of the DS specimens coarsen obviously after heat-treatment. Homogenizing and aging treatments could effectively eliminate elemental microsegregation, and the segregation ratios of all elements in niobium solid solution （Nbss） in different regions tend to 1. After heat-treatment, the microhardness of retained eutectic cells increases evidently, and the maximum value reaches HV1 404.57 for the specimen directionally solidified with a withdrawing rate of 100 μm/s and then heat-treated at （1 500 ℃, 50 h） ＋ （1 100 ℃, 50 h）, which is 72.8 % higher than that under DS condition.

Corrosion evolution of high-temperature formed oxide film on pure Sn solder substrate

The evolution of morphology, composition, thickness and corrosion resistance of the oxide film on pure Sn solder substrate submitted to high-temperature aging in 150 °C dry atmosphere was investigated. The results indicate that high-temperature aging accelerates the dehydration of Sn(OH)_(4)in the pre-existing native oxide film to form SnO_(2)and facilitates the oxidation of fresh Sn substrate, resulting in the gradual increase in oxide film thickness and surface roughness with prolonging aging time. However, the corrosion resistance of the film initially is enhanced and then deteriorated with an extending aging time. Besides, the formation and evolution mechanisms of the oxide film with aging time were discussed.

电感耦合等离子体原子发射光谱法测定铈矿中微量的砷、锑

采用过氧化钠熔融试样 ,用盐酸调节试液酸度 ,对电感耦合等离子体原子发射光谱 (ICP AES)法同时测定铈矿中微量砷和锑进行了研究 ,考察了铈基体及共存元素 。

Effect of Cu addition on overaging behaviour,room and high temperature tensile and fatigue properties of A357 alloy

The aims of the present work are to evaluate the overaging behaviour of the investigated Cu-enriched alloy and to assess its mechanical behaviour,in terms of the tensile and fatigue strength,at room temperature and at 200℃,and to correlate the mechanical performance with its microstructure,in particular with the secondary dendrite arm spacing(SDAS).The mechanical tests carried out on the overaged alloy at 200℃ indicate that the addition of about 1.3 wt.%Cu to the A357 alloy enables to maintain ultimate tensile strength and yield strength values close to 210 and 200 MPa,respectively,and fatigue strength at about 100 MPa.Compared to the quaternary(Al−Si−Cu−Mg)alloy C355,the A357−Cu alloy has greater mechanical properties at room temperature and comparable mechanical behaviour in the overaged condition at 200℃.The microstructural analyses highlight that SDAS affects the mechanical behaviour of the peak-aged A357−Cu alloy at room temperature,while its influence is negligible on the tensile and fatigue properties of the overaged alloy at 200℃.

Simultaneous Determination of Ceftazidime and Tazobactam in Injectable Powder by Reversed-Phase High Performance Liquid Chromatography

A reversed-phase high performance liquid chromatographic (RP-HPLC) method wasdeveloped and validated for the simultaneous deteimination of ceftazidime and tazobactam ininject-able powder. Methods Chromatography was carried out on Zorbax 300SB-C_(18) column using amixture of methanol and aqueous solution of phosphate buffer (pH = 5.6) as mobile phase. The UVdetection wavelength was 220 run. Results The linear ranges of ceftazidime and tazobactam were 0.62- 631.8 μg·mL^(-1) and 0.66 - 677.50 μg·mL^(-1), respectively. The average recoveries were 98.8%- 101.4% for ceftazidime, and 99,1% - 100.2% for tazobactam. The RSD values of inter-day andintra-day assays were lower than 1.5% for ceftazidime and 2.6% for tazobactam. Conclusion Thismethod is reproducible, simple, precise, and rapid for the quality control of ceftazidime andtazobactam in injectable powder.

Influence of long-term isothermal aging on microstructure and creep rupture properties of Ni-base superalloy M4706

After a standard heat treatment,the microstructural evolution with time during isothermal aging at 850°C and its effect on the creep rupture properties of the Ni-base superalloy M4706 at 870°C and 370 MPa are investigated.It is found that as the aging time increases from 0 to 5000 h,the average diameter of coarseγ′increases from 241 to 484 nm,and the distribution of the carbides at grain boundaries changes from discontinuous to continuous.Moreover,experimental observations on the microstructures of all the crept specimens reveal that dislocation bypassing controls the creep deformation.Thus,it is concluded that the transitions in the microstructures result in the degeneration of the creep rupture properties of the experimental alloy with aging time.

Time-dependent behaviors and volumetric recovery phenomenon of sandstone under triaxial loading and unloading

The time-dependent behaviors of coal and rocks were easily ignored. Besides, “three-stage” triaxial loading and unloading mechanics tests of sandstone were conducted based on the idea of the initial high in-situ stress state recovery according to the full-life cycle evolution characteristics of surrounding rocks in deep mines(pre-excavation,excavation and post-excavation). The time-dependent stress-strain curves of sandstone were obtained. Meanwhile, the deformation and strength fitting relationships with time of sandstone were also built. Furthermore, the dilatancy and volumetric recovery mechanical mechanisms of sandstone were revealed. The results showed that: 1) There were significant time-dependent evolution characteristics on the deformation and strength of sandstone;2) There were significant correlations among the internal friction angle, cohesion and the simulated depths;3) Volumetric recovery phenomenon of sandstone was observed for the first time, which mainly occurred at the simulated depth of 2000 m. The above research conclusions could provide a certain theoretical basis for the stability control of surrounding rocks in deep mines.

An Exact Propagator for Solving the Triatomic Reactive Schrodinger Equation

The exact short time propagator, in a form similar to the Crank-Nicholson method but in the spirit of spectrally transformed Hamiltonian, was proposed to solve the triatomic reactive time-dependent schrodinger equation. This new propagator is exact and unconditionally convergent for calculating reactive scattering processes with large time step sizes. In order to improve the computational efficiency, the spectral difference method was applied. This resulted the Hamiltonian with elements confined in a narrow diagonal band. In contrast to our previous theoretical work, the discrete variable representation was applied and resulted in full Hamiltonian matrix. As examples, the collision energy-dependent probability of the triatomic H＋H2 and O＋O2 reaction are calculated. The numerical results demonstrate that this new propagator is numerically accurate and capable of propagating the wave packet with large time steps. However, the efficiency and accuracy of this new propagator strongly depend on the mathematical method for solving the involved linear equations and the choice of preconditioner.