宽铅带连冲板栅的制造过程及特点

本文介绍了铅酸蓄电池宽铅带连冲板栅的应用现状,对宽铅带连冲正极板栅的微观结构、金相组织及耐腐蚀性能等特点进行了评述,并简要概括了宽铅带连冲板栅的优势和缺点。

冲床“连冲”故障的分析及对策

分析了冲床“连冲”故障的原因，提出了解决“连冲”故障的对策。

Timing Optimization by Inserting Minimum Buffers with Accurate Delay Models

An algorithm of minimizing the number of buffers under certain delay constraint with accurate delay models is presented.Given a two-terminal net,the algorithm can minimize the total number of buffers inserted to meet the delay constraint.A high order delay model is applied to estimate interconnect delay and a nonlinear delay model based on look-up table is for buffer delay estimation.The experimental results show that the algorithm can efficiently achieve the trade-offs between number of buffers and delay,and avoid needless power and area cost.The running time is satisfactory.

Effect of electropulsing treatment on corrosion behavior of nickel base corrosion-resistant alloy

Electropulsing treatment（EPT） was performed on a nickel base corrosion resistant alloy during aging.The effect of EPT on the microstructure and corrosion resistance of the alloy and the mechanisms were investigated.The results show that the intergranular corrosion resistance can be improved substantially without the degradation of mechanical properties of the alloy by EPT.The EPT has an effect of enhancing the interface diffusion rate of the alloying element,which is higher than the body diffusion rate.And thus discontinuous precipitation of M23C6 type carbides appears at the grain boundary in the alloy by EPT,which decreases the depletion extent of the alloying elements at the grain boundary substantially.As a result,the intergranular corrosion resistance of the alloy can be improved by the EPT without any degradation of mechanical properties.

AGM起停电池轻量化&降成本关键技术探讨

AGM起停电池铅耗重,导致生产成本高,故售价远高于同型号EFB起停电池,因此AGM轻量化及降本已成为各大起停电池制造企业的关注点。本文中,围绕AGM起停电池轻量化降本技术(板栅和活性物质轻量化)及其关键生产设备、工艺升级转化进行详细阐述,在大幅度降低AGM起停电池重量的前提下,进一步提升AGM起停电池的关键性能指标,提升企业生产效率及利润空间。

THE IMPLICIT CONTINUITY OF DISCONTINUOUS SYSTEMS

An example is presented to introduce the concept of implicit continuity proposed as contrasted with the explicit continuity.A sufficient and necessary condition of the implicit continuity is given and proved in forms of implicit system.This condition also offers the solution of initial values at the points where the dynamic system is discontinuous.Some discussions are contributed to the physical significance of implicit continuity.

Path-Based Timing Optimization by Buffer Insertion with Accurate Delay Model

An algorithm of path based timing optimization by buffer insertion is presented.The algorithm adopts a high order model to estimate interconnect delay and a nonlinear delay model based on look up table for gate delay estimation.And heuristic method of buffer insertion is presented to reduce delay.The algorithm is tested by industral circuit case.Experimental results show that the algorithm can optimize the timing of circuit efficiently and the timing constraint is satisfied.

Use of a submodel method to check the bolt strength of marine equipment

A submodel method was proposed that works from computational models of marine gear cases to verify that the proposed bolts will give it sufficient structural integrity. Calculations for marine equipment using this system accorded well with conventional results. As an example, an anti-shock computation was processed for a gear case, and the submodel was then employed to check the strength of individual components. The results showed that the gear case connecting structure can satisfy relative anti-shock requirements, and the dynamic response characteristics seen in the bolt structures had a close relationship with the method used for attaching the bolt. This provides a new means for checking the strength of connecting structures on large-scale equipment and thus has significant reference value.

Partial transient-liquid-phase bonding of TiC cermet to stainless steel using impulse pressuring with Ti/Cu/Nb interlayer

Partial transient liquid phase （PTLP） bonding of TiC cermet to 06Cr19Ni10 stainless steel was carried out. Impulse pressuring was used to reduce the bonding time, and a Ti/Cu/Nb interlayer was employed to alleviate the detrimental effect of interfacial reaction products on the bonding strength. Successful bonding was achieved at 885℃ under a pulsed pressure of 2-10 MPa within durations in the range of 2-8 min, which was notably shortened in comparison with conventional PTLP bonding. Microstructure characterization revealed the o- phase with a limit solubility of Nb, a sequence of Ti-Cu intermetallic phases and solid solutions of Ni and Cu in α＋β Ti in the reaction zone. The maximum shear strength of 106.7 MPa was obtained when the joint was bonded for 5 rain, indicating that a robust metallurgical bonding was achieved. Upon shear loading, the joints fractured along the Ti-Cu intermetallics interface and spread to the interior of TiC cermet in a brittle cleavage manner.

Numerical simulation of the pulsing air separation field based on CFD

The flow field of pulsing air separation is normally in an unsteady turbulence state.With the application of the basic principles of multiphase turbulent flows,we established the dynamical computational model,which shows a remarkable variation of the unstable pulsing air flow field.CFD(computational fluid dynamics) was used to conduct the numerical simulation of the actual geometric model of the classifier.The inside velocity of the flowing fields was analyzed later.The simulation results indicate that the designed structure of the active pulsing air classifier provided a favorable environment for the separation of the particles with different physical characters by density.We shot the movement behaviors of the typical tracer grains in the active pulsing flow field using a high speed dynamic camera.The displacement and velocity curves of the particles in the continuous impulse periods were then analyzed.The experimental results indicate that the effective separation by density of the particles with the same settling velocity and different ranges of the density and particle size can be achieved in the active pulsing airflow field.The experimental results provide an agreement with the simulation results.

A Review on Fiber Lasers

After a half century of development, fiber laser has evolved from a concept to a great family penetrating into various fields of applications. This paper reviews the history and current development of fiber lasers, with topics covering both continuous wave and short pulse fiber lasers. Important issues such as the major rare earth dopants, fiber laser brightness, polarization effects, clad pumping technology, beam combination, mode locking and pulse shaping are discussed in this paper.

nvestigation of Structural Steel Webs for Punching Shear

Shear tab connections or simple connections are widely used in structural steel structures. There are several limit states associated with these connections such bolt shear, bolt bearing, block shear, shear yielding and shear rupture. A modified version of the shear tab has been developed during the last decade, which is extended shear tab connections. In developing design provisions for the extended shear tab connections, experimental work showed that there are additional limit states other than those mentioned above that limit the capacity of the extended shear connection. Extended shear tab connections could be used to frame beam-to-column or beam-to-girder. In the case where a beam is framed into girder, a new limit state develops in the web of the supporting girder. This limit state is punching shear of the supporting girder web which is due to a higher moment. The higher moment in extended shear tab connections is due to the larger moment arm （eccentricity） from the bolt line, the location of the shear force, to the support, which is in this case the girder＇s web. This study investigates the supporting girder web using experimental work, finite element analysis, and yield line theory. This paper shows the result of this investigation and proposes an evaluation of the web capacity equation which should be used when calculating the beam-to-girder connection capacity.

Influences of gap size and cyclic-thermal-shock treatment on mechanical properties of TLP bonded IN-738LC superalloy

Influences of gap size and cyclic-thermal-shock treatment on the mechanical properties of transient liquid phase（TLP） bonded IN-738 LC superalloy were investigated. For this purpose, TLP bonding of IN-738 LC superalloy was carried out in a vacuum furnace using powdered AMS 4777 as the filler metal. The results showed that isothermal solidified zone（ISZ） consisted of Ni solid-solution and the distribution of alloying elements was homogeneous. High hardness of HV 409 and high shear strength of 506 MPa were observed in 40 μm gap sample. Alloying elements formed γ′ precipitates and the solid-solution in the ISZ. Hardness and shear strength of bonds were reduced with increasing the gap size（in range of 40-120 μm）. The fractured surfaces of complete isothermal solidified bonds showed dimpled rupture, but athermal solidified bonds showed cleavage fracture surface. 10, 20, 30 and 40 thermal-shock cycles were applied to 80 μm gap samples, respectively. The shear strength of the bond was measured to be 268 MPa after the 40 th thermal-shock cycle. The sample with gap size of 80 μm was failed due to crack nucleation on faying surface at 45 th thermal-shock cycle. The amount of the produced brittleness due to quenching the samples in water bath was attributed to the number of thermal-shock cycles.

Buffer and Switch： Road-to-Road Routing Scheme for Intermittently Connected Vehicular Networks

Due to the road-constrained data delivery and highly dynamic topology of vehicle nodes in a Vehicular Ad Hoc Network (VANET), it is better to construct routing based on the road-to-road pattern than the traditional node-to-node routing pattern in MANETs. However, the challenging issue is the opportunistic forwarding at intersections. Therefore, we propose a novel routing scheme, called Buffer and Switch (BAS). In BAS, each road buffers the data packets with multiple duplicates propagation in order to provide more opportunities for packet switching at intersections. Different from conventional protocols in VANETs, the propagation of duplicates in BAS is bidirectional along the routing path. Moreover, BAS's cost is much lower than other flooding-based protocols due to its spatio-temporally controlled duplicates propagation. Different from recent researches, BAS can deliver packets not only to a stationary node, but also to the stationary or mobile nodes in a specified area. We conduct the extensive simulations to evaluate the performance of BAS based on the road map of a real city collected from Google Earth. The simulation results show that BAS can outperform the existing protocols, especially when the network resources are limited.

Numerical and Experimental Study of Steel Space Truss with Stamped Connection

Tubular section members made of steel are common in space trusses. There are several types of connections to attach these members. The most popular is the staking end-flattened connection. The reduced cost and the fast assemblage of the truss are among the advantages of the staking end-flattened connection on 3D trusses. However, such connections present disadvantages like eccentricities and stiffness weakening of the tubular members. In this work, based on computer simulations and experimental lab tests on prototypes, small changes on the staking end-flattened connections such as reinforcement and eccentricity correction are evaluated. The results show an increase of 68% for local collapse and 17% for global collapse in the truss load carrying capacity when the suggested changes proposed in this article are used for the staking end-flattened connections.

Exploration and determination of the principles of rotary-percussive underground slimhole drilling

A possibility of the efficient use of rotary percussive drilling to provide drilling smaller diameter holes(40–70 mm) both in mining and prospecting is disclosed herein. A new construction designed for the nipple thread connection is described. The relative amplitude variation, change of power pulse time and energy in their propagation throughout the drilling tool are determined. A possibility of the efficient power pulse transfer along the drill string to the rock destruction tools with new nipple connections which allow automating the make-up and breakout system of drill pipe was supported by experiments.

HMPT-BOF-RH-CSP process for SPHE substrate of cold rolled deep drawing steel

Based on hot metal pretreatment （HMPT）-basic oxygen furnace （BOF）-Rheinstahl Heraeus （RH）-compact strip production （CSP） process, parameters controlling on cold rolling deep drawing substrate SPHE were investigated during smelting and rolling process by composition design and technology control. The influence of parameters on chemical compositions, mechanical properties and microstructure was revealed by scanning electron microscope （SEM）. The results show that, 1） main chemical components in SPHE are w（C）_〈40×10^-6, w（Si）_〈 0.01%, w（S）_〈0.009%, w（N）〈20×10^-6, w（O）〈_ 25×10^-6; 2） main mechanical properties of the SPHE are Crs=274 MPa, 00=334 MPa, A=48.9%; 3） main performances of deep drawing quality （DDQ） grade steel produced by SPHE are as follows, transversely crs=167 MPa, 00=298 MPa, n=0.219, r=2.46; vertically σs=166 MPa, 00=298 MPa, n=0.226, r=2.39; in 45° direction σ=171 MPa, 00=308 MPa, n=0.214, t=2.26; 4） microstrueture of DDQ is ferrite, average grain size is Grade 7.5, and inclusion size is 3-10μm.

Measurement of Collision Conditions in Magnetic Pulse Welding Processes

MPW （magnetic pulse welding） is a solid state joining technology that allows for the generation of strong metallic bonds, even between dissimilar metals. Due to the absence of external heat, critical intermetallic phases can largely be avoided. In this process, Lorentz forces are utilized for the rapid acceleration of at least one of the two metallic joining partners leading to the controlled high velocity impact between them. The measurement of the collision conditions and their targeted manipulation are the key factors of a successful process development. Optical measuring techniques are preferred, since they are not influenced by the prevalent strong magnetic field in the vicinity of the working coil. In this paper, the characteristic high velocity impact flash during MPW was monitored and evaluated using phototransistors in order to measure the time of the impact. The results are in good accordance with the established PDV （photon Doppler velocimetry） and show a good repeatability. Furthermore, the collision front velocity was investigated using adapted part geometries within a series of tests. This velocity component is one of the key parameters in MPW; its value decreases along the weld zone. With the help of this newly introduced measurement tool, the magnetic pressure distribution or the joining geometry can be adjusted more effectively.

智斗电鱼者

看了《中国钓鱼》2002年第六期《我五次管“闲事”的故事》一文后,想起了我自己一次“制止”非法电鱼的趣事,也算是管闲事吧。 那是1999年的夏天,黛溪河下了山洪,接连冲垮了上游的几个大鱼塘。一时间。