[Two case report of death from acute compound chlorfenapyr poisoning]

Chlorfenapyr is a moderately dangerous insecticide widely used in agriculture. The mortality of acute poisoning patients is high, and there is no effective treatment. This paper retrospectively analyzes the clinical data of two cases of compound chlorfenapyr poisoning. The main symptoms of the patients were high fever, sweating, gradual coma, increased creatine kinase and myoglobin, with delayed poisoning symptoms. Despite comprehensive treatment, both patients died eventually. It indicated that chlorfenapyr was highly toxic and had a high mortality. In addition to routine symptomatic treatment for patients with acute poisoning, blood purification treatment should be actively carried out in the early stage.

Using fast moving electrode to achieve overvoltage breakdown of gas switch stressed with high direct voltages

A small-scale fast risetime gas switch attached to a 50 Ω pulse forming line is tested. It includes a fast moving electrode and a fixed electrode. For the applied direct voltages, such as 2.8 kV, 2.0 kV, and 1.0 kV, the risetimes of this switch are tested to be ∼3.8 ns, ∼2.3 ns, and ∼1.1 ns, respectively, while the risetimes of a switch with two fixed electrodes are about ∼10.1 ns, ∼9.0 ns, and ∼3.6 ns. The results of high-speed photography and laser interferometry reveal that the moving electrode will obviously shorten discharge spark length but almost will not change the inter-electrodes gas pressure. The reason of shortening spark length is the existence of the discharge time delay of gas switch. After moving to the static breakdown spacing, the fast moving electrode will move on for an additional distance within the discharge time delay, which makes gas switch achieve overvoltage breakdown under high direct voltages and therefore leads to shorter spark length and faster switch risetime.