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1.
In the present work it is found that the pyrotechnic composition VS-2 can be initiated with flash lamps IFC-500 and EVIS. VS-2 pyrotechnic composition contains 90% of mercury(Ⅱ) 5-hydrazinotetrazolate perchlorate and 10% of optically transparent copolymer of 2-methyl-5-vinyltetrazole and methacrylic acid (PVMT). We have found that the flash lamps make it possible to initiate combustion of VS-2 composition with its transition to detonation both in cylindrical charges placed in brass caps of 5 mm diameter and 2 mm high, and film charges with 10 mm×80 mm in size and surface weights of 60 mg·cm-2 and 90 mg·cm-2, showing ignition delay times 10 μs and 3 μs, respectively. We also measured detonation velocities for VS-2 composition film charges, which were 4375-4505 m·s-1 (of the charge being surface mass 60 mg·cm-2) and 4221-4281 m·s-1 (of the charge being surface mass 90 mg·cm-2) and their blasting action on the aluminum plate. The depths of the normal shock wave imprints at the charge-barrier interface were 0.6-0.7 mm (for surface mass of the film charges 60 mg·cm-2) and 1.2-1.3 mm (for surface mass of the film charges 90 mg·cm-2).  相似文献   
2.
曲线锚索沿程预应力损失是影响衬砌结构应力分布的关键因素,获取摩擦系数和偏差系数尤其重要。开展不同加载状态曲线锚索沿程预应力损失研究,建立了模型试验平台,进行了不分级加载、分级加载和分级循环加载测试,分析了锚固端和张拉端受力特征、预应力损失变化规律、摩擦系数和偏差系数取值,并结合实际工程计算了曲线锚索任意点受力值。结果表明:曲线锚索沿程损失摩擦系数和偏差系数不仅与材料自身属性有关,还受到力学加载状态影响;与不分级相比,分级加载曲线锚索平均预应力损失由 8.47% 降低至 3.63%,且各级荷载必须给予足够停滞时间,以保持预应力传递;分级循环加载曲线锚索预应力沿程损失大幅降低,而加载时长却较久,不适宜作为常规加载方式,宜作为极个别曲线锚索预应力值不能达标时的应急处置方案。  相似文献   
3.
李鹏  王先科 《中州煤炭》2022,(9):276-278
为了方便煤炭的运输,某矿使用了矿用履带式搬运车。履带运输车解决了轮式运输车在恶劣道路条件下不能行走的问题,这种履带车是一种新型的运输工具,其特点是体积小、转弯灵活、动力强大,可在不受场地限制的情况下轻松通过狭窄的地方,能有效解决山区、土壤、陡坡等恶劣条件下物料的运输问题,适合普通运输车辆无法通行的地方。介绍了矿用履带式搬运车的主要结构以及工作原理,并给出了实际应用中应注意的事项。  相似文献   
4.
Production routes were recorded on available reactions for 111Ag production from nuclear reactors or cyclotrons using a natural palladium target based on 110Pd(n, γ) and 110pd(d, n) reactions, respectively.natCd(γ,x) based on 110Cd(γ, p) has also been studied as a prospective reaction for the production of 111Ag. Unfortunately, these nuclear reactions are difficult to utilize because, in some cases, they reduce the specific activi...  相似文献   
5.
介绍了浙江石油化工有限公司新建的3 Mt/a柴油加氢精制装置,其配套使用中国石化石油化工科学研究院有限公司开发的催化剂级配技术,并实施了可根据原料供应及市场产品需求情况灵活调整切换的2种生产技术方案。1 a的安稳生产运行结果表明:该装置以直馏柴油为主原料,通过分馏塔的馏分切割及其侧线抽出,实现了稳产国Ⅵ柴油并兼产喷气燃料技术方案的工业化应用;在实施以兼产喷气燃料为主的生产技术方案时,通过调整常一线柴油的掺炼量,不仅可以生产含硫量小于10.0 μg/g的精制柴油产品,同时兼产所得到的喷气燃料产品含硫量小于0.5 μg/g,赛波特颜色号值大于30;在实施主产精制柴油组分方案时,通过掺炼质量分数为20%~40%的催化柴油,并使所提炼得到的精制柴油组分含硫量小于6.0 μg/g的前提下,这些精制柴油组分产品既可直接作为满足国Ⅵ柴油产品出厂待售,也可作为柴油调和组分储存待用于产品的进一步优化。  相似文献   
6.
Suzuki-Miyaura (S-M) is regarded the most powerful way for synthesis biaryls, triaryls, or incorporating of substituted aryl moieties in organic preparation by the cross-coupling of aryl boronic acid with aryl halides using the Pd catalyst. This work reports the combining of the hydrothermal and microwave-assisted protocol to convert the glucose to magnetic carbon spheres (Fe3O4-CSPs) decorated with Pd nanoparticles (NPs) as the catalyst for Suzuki-Miyaura cross-coupling reactions. The physicochemical properties in the produced composite were examined using FESEM, HRTEM, nitrogen isotherms, Raman spectroscopy, FTIR, XPS, and XRD. The as-fabricated composite Pd/Fe3O4-CSPs is mostly spherical with a core–shell structure and possesses a great surface area of 253.2 m2·g-1. Its catalytic performance demonstrates that the composite has excellent stability and high tolerance Suzuki-Miyaura cross-coupling reactions in 30 min at 80 ℃. Both activated and deactivated aryl halides provided excellent yield. The as-fabricated catalyst was recycled for up to four catalytic cycles without a substantial decline in performance. Moreover, this research offers a facile roadmap for synthesizing Pd/Fe3O4-CSPs composites and promoting the practical implementation of Pd/Fe3O4-CSPs catalysts for organic transformation processes.  相似文献   
7.
8.
Laser aided additive manufacturing(LAAM)was used to fabricate bulk Fe49.5Mn30Co10Cr10C0.5 interstitial multicomponent alloy using pre-alloyed powder.The room temperature yield strength(σy),ultimate tensile strength(σUTS)and elongation(εUST)were 645 MPa,917 MPa and 27.0%respectively.The as-built sample consisted of equiaxed and dendritic cellular structures formed by elemental segregation.These cellular structures together with oxide particle inclusions were deemed to strengthen the material.The other contributing components include dislocation strengthening,friction stress and grain bound-ary strengthening.The high εUTS was attributed to dislocation motion and activation of both twinning and transformation-induced plasticity(TWIP and TRIP).Tensile tests performed at-40℃and-130℃demonstrated superior tensile strength of 1041 MPa and 1267 MPa respectively.However,almost no twinning was observed in the fractured sample tested at-40℃and-130℃.Instead,higher fraction of strain-induced hexagonal close-packed(HCP)ε phase transformation of 21.2%were observed for fractured sample tested at-40℃,compared with 6.3%in fractured room temperature sample.  相似文献   
9.
The uniform refinement mechanisms and methods of deformed mixed and coarse grains inside a solution-treatment Ni-based superalloy during two-stage annealing treatment have been investigated.The two-stage heat treatment experiments include an aging annealing treatment(AT)and a subsequent recrystallization annealing treatment(RT).The object of AT is to precipitate some δ phases and consume part of storage energy to inhibit the grain growth during RT,while the RT is to refine mixed and coarse grains by recrystallization.It can be found that the recrystallization grains will quickly grow up to a large size when the AT time is too low or the RT temperature is too high,while the deformed coarse grains cannot be eliminated when the AT time is too long or the RT temperature is too low.In addition,the mixed microstructure composed of some abnormal coarse recrystallization grains(ACRGs)and a large number of fine grains can be observed in the annealed specimen when the AT time is 3 h and RT tem-perature is 980℃.The phenomenon attributes to the uneven distribution of δ phase resulted from the heterogeneous deformation energy when the AT time is too short.In the regions with a large number of δ phases,the recrystallization nucleation rate is promoted and the growth of grains is limited,which results in fine grains.However,in the regions with few δ phases,the recrystallization grains around grain boundaries can easily grow up,and the new recrystallization nucleus is difficult to form inside grain,which leads to ACRGs.Thus,in order to obtain uniform and fine annealed microstructure,it is a prereq-uisite to precipitate even-distributed δ phase by choosing a suitable AT time,such as 12 h.Moreover,a relative high RT temperature is also needed to promote the recrystallization nucleation around δ phase.The optimal annealing parameters range for uniformly refining mixed crystal can be summarized as:900℃×12 h+990℃×(40-60 min)and 900℃×12 h+1000℃×(10-15 min).  相似文献   
10.
采用X射线荧光分析仪、X射线衍射仪、N2物理吸附仪、场发射扫描电子显微镜等仪器表征了苏州、广西和美国佐治亚州3个产地的高岭土,并以此3种高岭土为原料制备了模型催化裂化(FCC)催化剂,在ACE评价装置上对比了模型催化剂的反应性能。结果表明:苏州及广西高岭土主要组分为高岭石,佐治亚高岭土主要组分为地开石及珍珠陶土;苏州高岭土呈片状,还含有少量棒状颗粒;广西高岭土呈多层片状,晶粒粒径较大;佐治亚高岭土呈薄片状,晶粒粒径较小;3种高岭土制备的模型催化剂反应活性、Na2O及RE2O3质量分数相近;广西高岭土制备的模型催化剂具有最大的孔体积和磨损指数,但比表面积最小,具有较强的重油转化能力,其目标产物(液化气+汽油)和副产物(干气+焦炭)收率都高于苏州、佐治亚高岭土制备的催化剂的。  相似文献   
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