Fast-sweeping Langmuir probes:what happens to theⅠ–Ⅴtrace when sweeping frequency is higher than the ion plasma frequency?

Limited particle transit time is one of several limiting factors which determine the maximum temporal resolution of a Langmuir probe.In this work,we have revisited the known fast sweep Langmuir probe techniques in a uniform,quiescent multi-dipole confined hot cathode discharge with two operation scenarios:one in which the probe sweeping frequency fsweepis much lower than the ion plasma frequency fpi,another one where fsweepis much greater than fpi,respectively.This allows investigation into the effect of limited ion-motion on I–V traces.Serious distortions of I–V traces at high frequencies,previously claimed to be an ion-motion limitation effect,were not found unless shunt resistance is sufficiently high,despite a f;/f;ratio of~3.On the other hand,evidences of sheath capacitance on the I–V traces have been observed.Distortions of I–V traces qualitatively agree with predictions of sheath capacitance response to the sweeping voltage.Additionally,techniques in fast sweep Langmuir probe are briefly discussed.The comparison between the high-speed dual Langmuir probe(HDLP)and the single probe setup shows that the capacitive response can be removed via subtracting a leakage current for the single probe setup almost as effectively as using the HDLP setup,but the HDLP setup does remain advantageous in its facilitation of better recovery of weak current signal commonly in low density plasma.

Efficacy and Safety of Qiaoshao Formula(翘芍方) on Patients with Lifelong Premature Ejaculation of Gan(Liver) Depression and Shen(Kidney) Deficiency Syndrome:A Randomized Controlled Trial

Objective： To observe the efficacy and safety of Qiaoshao Formula（翘芍方, QSF） on patients with lifelong premature ejaculation（LPE） of Gan（Liver） depression and Shen（Kidney） deficiency syndrome. Methods： A total of 60 LPE patients were randomly divided into treatment（QSF） and control（dapoxetine） groups. The treatment group received QSF twice a day and the control group received dapoxetine 1 to 2 h prior to planned sexual intercourse for 4 weeks. The outcomes included intra-vaginal ejaculation latency time（IELT）, premature ejaculation diagnostic tool（PEDT）, clinical global impression of change（CGIC）, scores of Chinese medicine symptoms（CMSS）, sex life satisfaction（SLS） and adverse events（AEs）. Results： In the treatment group, the median IELT was 3 min vs. 1.5 min before and after treatment（P〈0.05）. PEDT in the treatment group was reduced to 11.76±1.68 from 15.83±2.30 after treatment（P〈0.05）. Besides, patient＇s SLS was improved from 1.30±0.05 to 6.30±0.04（P〈0.05）, and spouse＇s SLS was increased from 1.30±0.08 to 6.10±0.06（P〈0.05）; CMSS was decrease from 14.86±3.02 to 9.62±2.87（P〈0.05）. In addition, no significant AE was observed in both groups. Conclusion： QSF may be effective and safe on LPE patients with Gan depression and Shen deficiency syndrome.