Some field experience with subsynchronous vibration of centrifugal compressors

A lot of large chemical fertilizer plants producing 1000 ton NH3/day and 1700 ton urea/day were constructed in the 1970's in China. During operation, subsynchronous vibration takes place occasionally in some of the large turbine-compressor sets and has resulted in heavy economic losses. Two cases of subsynchronous vibration are described: Self-excited vibration of the low-pressure (LP) cylinder of one kind of N2-H2 multistage compressor; and Forced subsynchronous vibration of the high-pressure (HP) cylinder of the CO2 compressor

Biofeedback Therapy Combined with Traditional Chinese Medicine Prescription Improves the Symptoms, Surface Myoelectricity, and Anal Canal Pressure of the Patients with Spleen Deficiency Constipation

In order to observe the clinical therapeutic effects of Yiqi Kaimi Prescription and biofeedback therapy on treating constipation with deficiency of spleen qi, the 30 cases in the control group were given oral administration of Yiqi Kaimi Prescription, in combination with anus-lifting exercise; the 30 cases in the treatment group were given biofeedback therapy on the basis of the afore mentioned methods for the control group. The TCM symptom scores and anorectal pressures before and after treatment were observed and evaluated. There were significant differences in TCM symptom scores, anorectal pressure, and clinical recovery rate before and after treatment. In the treatment group, the total recovery rate was 86.66%, while in the control group it was 50%; there were significant differences between the two groups (P<0.01). Yiqi Kaimi Prescription coupled with biofeedback therapy is clinically effective for treating constipation with deficiency of spleen qi, and thus this method is applicable for functional constipation with deficiency of spleen qi

贴片式动态心电记录仪在临床教学中可行性研究

Objective: To explore effectiveness of clinical application of the patch type dynamic ecg recorder by comparing with conventional dynamic ecg recorder Holter. And the clinical ecg teaching models is discussed in this paper. Methods: Using parallel controlled trial method, 60 patients in two hospitals received Holter examination, and patch heart testing at the same time. A comparative analysis of two kinds of inspection methods on testing the average heart rate, supraventricular premature beats and ventricular premature beat was made. Results: The average heart rate of patch type ECG and Holter were 71.87±9.28 and 72.55±9.06 (P = 0.0879). Two kinds of detection methods, chamber on the coincidence rate of premature beat (PPS) was 98.33%, 95% CI (91.06, 99.96), Kappa = 0.9462, 95% CI (0.84, 1.00), good consistency. The accuracy of ventricular premature beat (PPS) was 98.33%, 95% CI (91.06, 99.63), Kappa = 0.9850, 95% CI (0.90, 1.00), good consistency. Patch type heart all platform is suitable for self-study and clinical care study, and professional skill assessment,etc.Conclusion: The effectiveness of patch type heart all on testing the average heart rate, supraventricular premature beat is the same as Holter. it is also suitable for to carry out clinical ECG teaching at the same time.目的 通过和常规动态心电记录仪 Holter比较，研究贴片式的动态心电记录仪临床应用的有效性。并探讨其在临床心电教学中的模式。方法 采用自身平行对照试验方法，在两医院60例患者用Holter检查时，同时用贴片心电仪检测，比较分析两种检查方法在检测平均心率、室上性早搏和室性早搏方面的情况。结果 贴片式心电仪和Holter的平均心率分别为71.87±9.28和72.55±9.06（P＝0.0879）。两种检测方法，室上性早搏的符合率（PPS）为 98.33%，95%CI为（91.06,99.96），Kappa=0.9462, 95%CI为（0.84,1.00）,一致性良好。室性早搏的符合率（PPS）为 98.33%，95%CI为（91.06,99.63），Kappa=0.9850, 95%CI为（0.90, 1.00）。贴片式心电仪平台适合自学、临床监护学习、大课和专业技能考核等临床心电教学。结论 贴片式心电仪在检测平均心率、室上性早搏和室性早搏方面的有效性和Holter相同。同时也适合以此平台开展临床心电教学

Large transport critical currents of powder-in-tube Sr0.6K0.4Fe2As2/Ag superconducting wires and tapes

We report significant transport critical currents firstly achieved in Sr0.6K0.4Fe2As2 wires and tapes with a Tc = 34 K, which were fabricated through an in-situ powder-in-tube process. Silver was used as a chemical addition as well as a sheath material. Transport measurements were performed by a standard four-probe resistive method. All the wire and tape samples have shown transport properties. Critical current density Jc was enhanced upon silver addition, and at 4.2 K, a best Jc of ~1200 A/cm^2 (Ic = 9 A) was achieved for 20 % silver added tapes, which is the highest in iron-based wires and tapes so far. The Jc is almost field independent between 1 T and 10 T, exhibiting a strong vortex pinning. Such a high transport critical current density is attributed to the absence of reaction layer between the silver sheath and superconducting core, as well as an improved connectivity between grains. We also identify a weak-link behavior from the creep drop of Jc at low fields and a hysteretic phenomenon. Finally, we found that compared to Fe, Ta and Nb tubes, Ag was the best sheath material for the fabrication of high-performance 122 type pnictide wires and tapes.Comment: 14 pages, 4 figure