Study of the Combustion Process inside an Ethanol-Diesel Dual Direct Injection Engine Based on a Non-Uniform Injection Approach

The use of ethanol is a promising method to reduce the emissions of diesel engines.The present study has been based on the installation of a gasoline electronic injection system in a single-cylinder diesel engine to control the amount of ethanol entering the cylinder during the compression(while diesel has been injected into the cylinder by the original pump injection system).The injection time has been controlled by crank angle signal collected by an AVL angle indicator.In the tests ethanol and diesel each accounted for half of the fuel volume,and the total heat energy supply of the fuel was equivalent to that of the diesel under the operating conditions of the original engine.A three-dimensional combustion model of the diesel engine has been implemented by using the CFD software FIRE.Simulations have been carried out assuming uniform and non-uniform injections rate for the different holes and the different results have been compared.According to these results,a non-uniform injection rate can produce early ignition and cause an increase in the maximum in-cylinder pressure and the maximum average incylinder temperature.Moreover,in such conditions NO emissions are larger while soot emission is slightly lower.

New DDSCR structure with high holding voltage for robust ESD applications

A novel dual direction silicon-controlled rectifier(DDSCR)with an additional P-type doping and gate(APGDDSCR)is proposed and demonstrated.Compared with the conventional low-voltage trigger DDSCR(LVTDDSCR)that has positive and negative holding voltages of 13.371 V and 14.038 V,respectively,the new DDSCR has high positive and negative holding voltages of 18.781 V and 18.912 V in a single finger device,respectively,and it exhibits suitable enough positive and negative holding voltages of 14.60 V and 14.319 V in a four-finger device for±12-V application.The failure current of APGDDSCR is almost the same as that of LVT-DDSCR in the single finger device,and the four-finger APGDDSCR can achieve positive and negative human-body model(HBM)protection capabilities of 22.281 kV and 23.45 kV,respectively,under 40-V voltage of core circuit failure,benefitting from the additional structure.The new structure can generate a snapback voltage on gate A to increase the current gain of the parasitic PNP in holding voltage.Thus,a sufficiently high holding voltage increased by the structure can ensure that a multi-finger device can also reach a sufficient holding voltage,it is equivalent to solving the non-uniform triggering problem of multi-finger device.The operating mechanism and the gate voltage are both discussed and verified in two-dimensional(2D)simulation and experiemnt.

■-law collision and system state recognition

Using dual function one direction S-rough sets, this article gives the f-law, the F-law, law distance and the concept of system law collided by the F-law. The characteristics presented by the system law collided by the F-law, the recognition of these characteristics and recognition criterion are also proposed. The dual function one direction S-rough sets is one of the basic forms of function S-rough sets. Its basic theory and application in the study of system law collision are reviewed.

F-knowledge and Its F-reduction Theorems

By using the dual of one direction singular rough sets,the concepts of F-knowledge and its F-reduction were given;F-reduction theorem of F-knowledge and attribute supplement redundant principle of F-reduction are presented;the dual of one direction singular rough sets is one of the basic forms of singular rough sets;knowledge reduction is a new research direction on rough sets and rough system theory.

Design Analysis of a Novel Low Triggering Voltage Dual Direction SCR ESD Device in 0.18μm Mixed Mode RFCMOS Technology

A novel SCR on-chip ESD device is proposed to protect IC chips against ESD stressing in two opposite direc- tions. The triggering voltages of four types of dual direction SCRs （DDSCR） are compared and analyzed, pMOS or nMOS are embedded into the structures to adjust their triggering voltages. Both MOSFETs embedded DDSCRs have tunable triggering voltage,low DC leakage （～pA）, and fast turn on speed snapback I-V characteristics without latch-up problem. It achieves high ESD performance of ～94V/μm. The new ESD protection devices are area efficient and can reduce the parasitic effects significantly.