A method has been developed for the direct determination of Cu,Si,Mg,Zn,Al,Fe,S,Pb,Ca,As,K,Cd and Mn in zinc concentrate samples using a fusion method by Axios PW4400 XRF spectrometer.The conditions for pre-oxidation on sample preparation were studied using the wet chemical method.A 0.3 g sample with 1 g lithium nitrate and 0.5 mL liquid hydrogen(30%) were loaded into a platinum-gold crucible at room temperature.The sample and oxidants were mixed well by shaking the crucible.The higher sample/flux ratio increased the intensities of the trace elements signals in XRF.A lithium tetraborate fusion agent was applied to reduce the matrix effects among elements.The formula and calibration models of gain on ignition are discussed in this paper.The gain on ignition of the actual sample,which cannot be corrected by the software,was converted to the loss on ignition of a virtual sample.The matrix effects among different elements were corrected by theoretical alpha coefficients and empirical coefficients.The precision(RSD,n=12) of the method was less than 3% for all components except Cd.The detection limits of the method were 6.55-111.24 μg/g.Due to the analysis of CRM(GBW 07163 and GBW 07170 were mixed in a mass ratio of 1∶5) by this method,the obtained results are consistent with certified values.

Percussion drilling has been widely used in oil and gas exploration,while there are still some problems,such as severe damages to drilling tools,low energy transfer efficiency and low rock breaking efficiency.Thus it is necessary to further reveal the hammer bit rock interaction mechanism in geophysical percussion drilling to provide theoretical basis for the structural optimization.Using explicit dynamic analysis software LS-DYNA,a finite element model of rock breaking for geophysical prospecting hammer bit is established.The stress-time curves of the centre teeth,second-row teeth and peripheral teeth,and the stress wave propagation in bit were obtained using simulation.Simulation results indicate that the stress of each tooth changed significantly during rock breaking.The stress of second-row teeth is the greatest,followed by the centre teeth,and then the peripheral teeth.The nozzles'stress is much greater than that of the centre-head face or the junk slot.When the stress wave propagated in the bit,the hazardous area passed from drill bit to nozzles and then to teeth.

In the electronic assembly process,manual soldering has been an indispensable operation means,Electric iron is the main tool of manual soldering.Through the engineering practice,analyze the relation of electric iron idle temperature to soldering temperature,the change of electric iron and solder joint temperature in soldering process and so on.

针对普光气田气体钻井过程中存在的钻具断裂频繁的问题,在对现场事故统计分析的基础上,从特殊的钻井介质、不同的破岩方式以及钻井过程中钻柱共振等方面定性分析了钻具断裂的原因;通过对钻具断口宏观、微观及材质分析,找到了钻具断裂失效的规律和主要形式--疲劳断裂.提出以下建议:①结合气体钻井情况,研制适合气体钻井工况的专用钻具,制定符合气体钻井钻具的新的API标准;②开展牙轮钻井条件下,钻柱纵振对钻具疲劳断裂的量化影响,尤其应考虑不同钻压下钻柱纵振对钻具疲劳断裂的作用机理研究.以期为预防气体钻井钻具断裂、降低钻井成本、推广应用气体钻井技术提供理论依据.

For high-reliability products,lead technics are often still used,but with the development of lead-free process,lead components have been unavailable in the market for some components.So lead and lead-free components being mixed in process,then how could the soldering quality of lead and lead-free components be simultaneously guaranteed? The problems in lead and lead-free mixed assembly technics with lead process are discussed by analyzing the composition of the components solderable leadframe/termination coatings,and considering the component package,then the countermeasures are proposed.

Taking the QF— Ⅱ downhole bit as a prototype, and using the dynamic analysis software LS—DYNA, an interactive model of the bit and the rock is established and the underground rock— breaking simulation is analyzed for downhole bits. It comes to a conclusion: for structure, the middle tooth distribution of the site prototype bit is unreasonable.Therefore,based on the transverse tooth distribution of the prototype bit,adding one carbide tooth can increase single rock-breaking volume,rock-breaking efficiency and drilling rate,reduce the probability of the tooth failure,prolong the bit life and provide the theoretical basis for the optimal tooth distribution.

This paper described the reason of choosing Baozai and tobacco,the hail suppression ratio of input-output and gave Some suggestion of increasing hail suppression investment.

The content values of poisonous and harmful elements among imported laterite nickel ores were analyzed.The results showed that the content values of Hg,Pb and Zn were acceptable,while the content values of Cr,Cd and As in some batches were rather high,indicating to the risk of pollution on the environment to some extent.Especially,the content values of Cd and As were rather high at the same time,indicating to a higher risk of pollution to the environment.Therefore more attention should be paid and some more strict control managements should be taken.

Measurement input-output model of disaster direct and indirect economic loss were widespread.Most of the methods ignored the calculation of disaster damage on the stability of economic system.Determinant conditions should be added to judge whether the input-output model could be used in calculating economic loss after the damage of economic system,which made the input-output model more accurate in calculating disaster loss.

This paper describes that the performance of impactor has a matter of importance to rotary drilling technology,and there are some problems in the process of research and design impactor.This paper introduces several major test method of impactor,including stress wave method,photoelectric shift differential,electromagnetic induction,contacts,depression,high-speed photography.Further this paper explains the testing theory and existing problems of every method,and finally sums up the advantages and disadvantages of every method.The test of dynamic rule of the impactor that has a matter of the research,design and application of the impactor will be the emphasis of testing work in future.

政府防灾机制可以看做为一个制度,中国政府防灾制度内存在着交易成本,本文将其定义为协调成本,并且运用产权等制度经济学方法分析了协调成本存在的原因,并提出了相应的对策。

By means of dynamic analysis software ANSYS/LS-DYNA,a kinetic model that contains the rock and the bit to analyze the process of the rock-breaking is buil.Through analyzing the process of the rock-breaking,the stress of the bit,the shape and the distribution of the fragmentary pits and the displacement of the cutters and the rock fragmentation principle are described completely and some conclusions is obtained,in the process of the rock-breaking,there are three phases, center teeth breaks the rock to form the breaking pit,side teeth breaks the rock to form the breaking pit,the rebounding phase of the pit.In the process of the bit invading the rock,the bit has both longtitude displacement and latitude displacement.In the process of the rock-breaking,he stress of the bit tooth three is maximal,and apt to be destroyed.

[目的]选定X射线荧光光谱法测定Cr、Fe、Si、S、P等元素的背景,找出谱线重叠的校正方法.[方法]采用熔融法制样,用X射线荧光光谱仪对铬矿中Cr、Fe、Si、S、P等组分进行测定,用理论α系数法进行基体效应和谱线重叠干扰校正.[结果] 用该法测定进口铬矿样品,其测试结果与化学分析值基本相符,回收率96.3%～103.2%范围.[结论]该方法简便、快速、准确,能满足日常分析要求.

[目的]建立一个高灵敏度、准确、快速测定河豚鱼中的河豚毒素的检测方法.[方法]研究河豚鱼中河豚毒素的提取净化和HPLC/MS/MS测定条件的优化,并且对19份样本的检测结果与生物法进行对比.[结果]本方法的检测限为1.7 ng/g,加标回收率在73.0%～96.0%之间,相对标准偏差5.46%～8.67%.[结论]本方法前处理简单,灵敏度高,线性范围广,能准确地测定多范围含量的河豚毒素.