Design of High Precise Focusing System in Laser Direct Writer

Design of A Novel High Precise Direct Current Negative High Voltage Power Supply

This paper introduces a high precise direct current (DC) negative high voltage power supply. The supply’s output voltage is 25kV and its maximal output current is 100mA. The power supply uses BOOST converter for power factor correction and voltage regulation. It converts DC to high frequency (HF) alternating current (AC) square wave with phase-shifted full bridge. The voltage of the AC square w...

Direct visualization of laser-driven focusing shock waves.

Direct real-time visualization and measurement of laser-driven shock generation, propagation, and 2D focusing in a sample are demonstrated. A substantial increase of the pressure at the convergence of the cylindrical acoustic shock front is observed experimentally and simulated numerically. Single-shot acquisitions using a streak camera reveal that at the convergence of the shock wave in water ...

synthesis of platinum nanostructures in two phase system

چکیده پلاتین، فلزی نجیب، پایدار و گران قیمت با خاصیت کاتالیزوری زیاد است که کاربرد های صنعتی فراوانی دارد. کمپلکس های پلاتین(ii) به عنوان دارو های ضد سرطان شناخته شدند و در شیمی درمانی بیماران سرطانی کاربرد دارند. خاصیت کاتالیزوری و عملکرد گزینشی پلاتین مستقیماً به اندازه و- شکل ماده ی پلاتینی بستگی دارد. بعضی از نانو ذرات فلزی در سطح مشترک مایع- مایع سنتز شده اند، اما نانو ساختار های پلاتین ب...

Direct High-speed Exhaust Gas Measurement System Using Semiconductor Laser

the effects of collaborative strategic reading and direct instruction in persuasion on iranian second grade of high school students persuasive writing and attitudes

this study examined the effects of collaborative strategic reading and direct instruction in persuasion on iranian high school students persuasive writing and attitudes. students in three intact classes were assigned to one of three treatment conditions: collaborative strategic reading and direct instruction in persuasion or direct instruction in persuasion or a control group. treatment effects...