震源药柱用低爆速炸药的研制

文章根据地震勘探震源药柱对低爆速炸药的要求 ,确定炸药的组分、配方及其混药工艺 ,产品经 2 3m井下传爆试验表明 ,该炸药爆速满足 16 0 0 m· s-1～ 2 30 0 m· s-1的要求 ,起爆和传爆性能可靠     

低速爆轰管对黑火药的点传火性能研究

文章采用中心点火管结构的实验装置研究了黑火药的点传火性能。用低速爆轰 (L VD)中心点火管来点燃黑火药时 ,1# ～ 3# 大粒黑药的传火速度为 70 0 m· s-1～ 80 0 m· s-1数量级 ,燃烧波宽度在 3.1ms～ 3.5 ms,最大压力峰值 :1# 为 36 .4 MPa,2 # 为 2 4 .0 MPa,3# 为 38.0 MPa。用普通中心点火管点燃黑火药时 ,2 # 、3# 和钝化 2 # 大粒黑的传火速度分别为 6 1.2 m· s-1、6 8.2 m·s-1和 4 0 .1m· s-1,最大燃烧波宽度分别为 9.2 ms、6 .3ms和 9.5 ms。燃烧波表明 ,L VD中心传火管与普通中心传火管相比较 ,在传火管的不同位置处 ,前者的 P- t曲线一致性远高于后者。     

基于高速摄像技术对折打结导爆管传爆可靠性的研究

采用高速摄像技术对180°对折、缓结、轻度死结和严重死结4种特殊情况下的导爆管传爆可靠性进行了室内实验研究,实验采用的导爆管爆速平均为1750 m/s.通过对高速摄像图片的精细观察和计算分析,得出:导爆管经过180°对折后仍能成功传爆,但整体传爆时间平均延迟29μs;缓节和死结不会导致传爆中断,但打结力度越严重,对打结处传爆速度下降和传爆时间延长的影响越大,死结导爆管结点传爆时间平均延迟32 μs,整体延迟37.2 μs.爆轰波经过对折点和死结处后,爆速剧降,通过精细观测定量确定了爆速复原正常值的历程和时间.实验结论可对爆破施工现场的网路连接提供防范参考.     

高药粉粘附性导爆管的设计及性能测试

针对导爆药的塑料粘附性差而导致导爆管破孔率高及导爆管雷管易拒爆的现状,采用共混改性和分子定向迁移理论,通过配方优化,开发出一系列高药粉粘附性的导爆管专用塑料。根据导爆管传爆过程中对药粉粘附性的要求,确定了导爆药脱落率为16.0%的导爆管最佳专用塑料配方。试验表明:与常用牌号N210和1I2A制备的导爆管相比,高药粉粘附性导爆管震动后每15 m的破孔数由N210、1I2A制备时的4个、2个下降到0;50℃下每15m的破孔数由N210、1I2A制备时的4个、2个下降到0;雷管拒爆现象由N210、1I2A制备时的10%、6%下降到0。     

示踪剂的添加对导爆管传爆性能的影响

为了对导爆管进行溯源,在导爆管中添加一定量的惰性示踪剂,同时对添加不同示踪剂及同种示踪剂不同量的聚乙烯导爆管进行爆速、起爆感度以及传爆性能的测试。试验结果表明:温度为25℃时,示踪剂A与母体导爆药(RDX与Al粉)的比例在0.1/99.9～10/90范围内,爆速的变化范围为1745～1854 m/s,同时添加相同比例的示踪剂A、B、C混合物为总装药量的0.6%与1.5%,爆速分别为1852 m/s与1827 m/s,都符合工业导爆管爆速的要求;另外,添加示踪剂的导爆管均被可靠起爆,未见其感度降低和传爆不可靠。说明示踪剂的添加既满足了导爆管的溯源功能,又不影响导爆管的起爆与传爆性能。     

基于高速摄影法对孔桩内导爆管准爆的探究

针对贵阳花果园V区孔桩爆破中塑料导爆管多次产生拒爆的实际情况,为降低盲炮的产生、提高准爆率,特对导爆管传爆性能进行研究。首先,利用高速摄像机进行完整导爆管的传爆试验,获得所使用导爆管的稳定爆速为1650 m/s;然后进行切缝试验,得出切缝长度在12 cm以上导爆管将产生断爆,断爆爆速临界值为525 m/s;最后进行注水试验,当注水长度达2 mm必断爆。结果表明:施工误操作破损后的塑料导爆管使用在含水的孔桩内,盲炮率较高,切缝是导致拒爆的诱导因素,注水是主导因素;施工过程中应采取有效措施减少孔内积水及确保导爆管完整无缝隙,防止积水渗入导爆管导致拒爆,可有效降低盲炮率。     

基于高速摄像技术的破孔导爆管传爆可靠性研究

采用高速摄像技术对单一、连续破孔特殊情况下的导爆管传爆可靠性进行了室内试验研究,试验采用的导爆管爆速平均为1750m/s。通过对高速摄像图的精细观察和测量分析,得出破孔导致导爆管管道效应被破坏后,对于单一破孔,维持导爆管可靠传爆的半破槽长度最大为15mm;15³0mm之间可能传爆,传爆几率随着半破槽长度增加而减小;超过30mm传爆失败;20mm单一半破槽导致的传爆延迟时间至少为195μs。对于连续破孔,半破槽长度及密集度越大,传爆可靠度越低,连续3个5mm半破槽的导爆管整体传爆时间延迟255μs。试验结论可对爆破施工现场的网路连接提供防范参考。     

活性炭净化废水处理研究

通过动态实验优选出粒状活性炭水处理工艺 ,设计出适合于家庭和饮食摊、店餐具洗涤废水处理的净化装置“净化节水器” ,并进行了试运行。实验表明 ,洗餐具净化水处理单元操作的最佳工艺参数为 :混凝剂投加量30mg·L- 1 ,反应池流速 0 .0 3m·s- 1 ,消毒剂用量 2 5mg·L- 1 ～ 30mg·L- 1 。“净化节水器”初步使用效果良好 ,为水资源重复利用和消毒灭菌提供了途径     

快淬速度对(Nd,Pr)10.5(FeCoZr)83.5B6显微结构和磁性能的影响

采用部分过快淬加后续晶化退火处理工艺,研究了快淬速度对低稀土含量双相复合(Nd,Pr)10.5(FeCoZr)83.5B6合金显微结构和粘结磁体磁性能的影响.合金快淬转轮线速度为24,26,28和30 m·s-1,退火温度655～715℃,退火时间5～20min.快淬速度直接影响条带的显微结构和磁体磁性能.以26m·s-1速度快淬出的条带,快淬态由非晶和微晶混合组成,在700℃经10min晶化处理,可获得平均晶粒尺寸约30nm的均匀、细小显微组织,磁性能也最佳.用3.25wt%环氧树脂粘结的磁体磁性能为Br=0.703T,Hci=544 kA·m-1,Hcb=351 kA·m-1,(BH)m=70 KJ·m-3.     

两起早爆事故的原因分析与预防措施

(一)1983年11月30日9时30分.武钢东露天北邦狮子山132水平进行爆破作业时,发生一起正常作业情况下的意外早爆事故,造成死亡1人,轻伤4人。1.事故经过采场的岩性为闪长岩(f=12～14),用导爆管起爆系统进行深孔大爆破,爆区共深孔47个。起爆弹为重1.85kg、密度1.56g·cm~(-3)的     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.