查询词典 tungsten

Self-made tungsten trioxide (WO_3) by calcining ammonium paratungstate was selected as the raw material to produce ultrafme and homogenous tungsten powder by oxidation-reduction method.

通过研究，得到如下结论：(1)本研究选取的三氧化钨原料，通过氧化—还原法(4次氧化5次还原)是可以制备出超细钨粉的；所得金属钨粉的平均粒度约为0.38μm。

The results showed that 7-day-precultured embryogenic calli had the best responses for bombardment among 2-7 day' preculture duration. Enhanced transformation efficiency was found in the explants treated with high osmotic medium 4h prior to till 24 h after bombardment. Particles of gold and tungsten were both found suitable for rice transformation and there was no adverse effect when tungsten particles were reduced to 1/3 standard amount for DNA precipitation on transient GUS gene expression. However, it was found that gold particle had higher GUS expression at 120 h post-bombardment. A preliminary microprojectile transformation system with an average of 15-20 blue spots/explant GUS expression was routinely obtained for 'Tainung 67' by using the particle gun with 1,100 psi rupture disk, 6 or 9 cm microcarrier flight distance and 4 mm of macrocarrier flight distance setting.

初步结果显示，以预培养2~7日之胚性癒合组织逐日测试转殖率，以预培养7日之培植体表现最佳；培植体於转殖前4小时至转殖后24小时以高渗透压培养基处理，有助於转殖效率之提高；比较金、钨粒子对转殖率在转殖后48h並无不同，但转殖后120 h取样，则金粒子组有较高之蓝点数；钨粒子用量可减少至1/3標准用量对转殖率並无影响；利用基因鎗在使用1， 100 psi裂碟片、大载片至挡片之距离为4 mm、微载髁至射击目標之飞行距离6或9 cm之设定，GUS基因表现之平均蓝点数均可达15~20个／培植体。

For AC current, the electrode is either pure tungsten or tungsten with a small amount (up to 0.5%) of zirconia to aid arc reignition and to reduce electrode erosion.

交流电流，电极要么是纯钨，或是钨极中含有少量锆(达0.5%)，有助于电弧重新引燃并减少电极侵蚀。

The mechanical properties of torqued and non-torqued tungsten alloy are also investigated. A constitutive model that describes rate-hardening and strain-hardening effects is also established for these tungsten alloys.

同时对预扭转和未扭转钨合金材料进行了动态力学性能实验研究，建立了考虑应变率硬化、应变硬化效应的动态本构模型。

The results show that the coverage area of tungsten film on diamond surface is above 90% and the steady tungstenic carbides WC and W2C are created by this technology. The tungsten film coated on diamond is realized.

结果表明，该方法可在金刚石表面镀覆上一层覆盖面达到90%以上的金属钨膜，且生成稳定的碳化物WC和W2C，得到由难熔金属钨包覆的金刚石。

Properties of fine tungsten powder and fine tungsten carbide powder from violet tungstic oxide are studied.The result shows that the process of violet tungstic oxide preparation is advanced and reasonab...

结果表明，紫钨制取工艺先进合理，由紫钨制得的钨粉、碳化钨粉细而均匀，分散性好，是制取高性能硬质合金的优质原料。

Composite electrodeposits of nickel-cobalt-tungsten carbide were prepared by adding tungsten carbide particles in the nickel-cobalt alloy solution.

研究了在镍钴合金镀液中加入碳化钨微粒形成镍－钴－碳化钨复合镀层的共沉积过程。

The effect of suspended tungsten carbide particles, bath temperature and cathodic current densities on the content of tungsten carbide in the electrodeposits was studied, the preferred plating parameters were also optimized by orthogonal test.

分析了镀液中碳化钨微粒的悬浮量、镀液温度及阴极电流密度对镀层中碳化钨含量的影响，并进一步通过正交试验优选出一种较佳的操作条件。

The weight loss rate in 600 ℃ sodium containing 30 μg/g oxygen is about 1×10~(-4) mm·a~(-1) and 2×10~(-4 mm·a~(-1), respectively for the rotary swaging tungsten and polishing tungsten.

在600℃、含30μg/g氧的金属钠中，旋锻钨和抛光钨的失重速率分别为1×10-4mm·a-1和2×10-4mm·a-1，两种钨与钠均有良好的相容性。

It was shown by further research that the formed tungsten oxide had an obvious layer-like structure, where from outer to inner layer the valence of tungsten increased and the reduction degree decreased. The carbonization of W depended on the replacement of W atom at the center of the body-centered cubic by C atom and the minor adjustment of C atom position and the lattice parameters.

深入研究表明，氧化钨碳还原颗粒具有明显的层状结构，自外到内钨的化合价递增，还原程度降低；钨的碳化是碳原子替换体心立方钨晶胞的中心钨原子，然后碳原子转换到钨原子点阵间隙再经晶胞常数微调而形成。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。