Interruption of torus doubling bifurcation and genesis of strange nonchaotic attractors in a quasiperiodically forced map : Mechanisms and their characterizations

A simple quasiperiodically forced one-dimensional cubic map is shown to exhibit very many types of routes to chaos via strange nonchaotic attractors (SNAs) with reference to a two-parameter $(A-f)$ space. The routes include transitions to chaos via SNAs from both one frequency torus and period doubled torus. In the former case, we identify the fractalization and type I intermittency routes. In the latter case, we point out that atleast four distinct routes through which the truncation of torus doubling bifurcation and the birth of SNAs take place in this model. In particular, the formation of SNAs through Heagy-Hammel, fractalization and type--III intermittent mechanisms are described. In addition, it has been found that in this system there are some regions in the parameter space where a novel dynamics involving a sudden expansion of the attractor which tames the growth of period-doubling bifurcation takes place, giving birth to SNA. The SNAs created through different mechanisms are characterized by the behaviour of the Lyapunov exponents and their variance, by the estimation of phase sensitivity exponent as well as through the distribution of finite-time Lyapunov exponents.Comment: 27 pages, RevTeX 4, 16 EPS figures. Phys. Rev. E (2001) to appea

Study of e+e−→ppˉe^+e^- \rightarrow p\bar{p} in the vicinity of ψ(3770)\psi(3770)

Using 2917 $\rm{pb}^{-1}$ of data accumulated at 3.773~$\rm{GeV}$, 44.5~$\rm{pb}^{-1}$ of data accumulated at 3.65~$\rm{GeV}$ and data accumulated during a $\psi(3770)$ line-shape scan with the BESIII detector, the reaction $e^+e^-\rightarrow p\bar{p}$ is studied considering a possible interference between resonant and continuum amplitudes. The cross section of $e^+e^-\rightarrow\psi(3770)\rightarrow p\bar{p}$, $\sigma(e^+e^-\rightarrow\psi(3770)\rightarrow p\bar{p})$, is found to have two solutions, determined to be ($0.059\pm0.032\pm0.012$) pb with the phase angle $\phi = (255.8\pm37.9\pm4.8)^\circ$ ($<$0.11 pb at the 90% confidence level), or $\sigma(e^+e^-\rightarrow\psi(3770)\rightarrow p\bar{p}) = (2.57\pm0.12\pm0.12$) pb with $\phi = (266.9\pm6.1\pm0.9)^\circ$ both of which agree with a destructive interference. Using the obtained cross section of $\psi(3770)\rightarrow p\bar{p}$, the cross section of $p\bar{p}\rightarrow \psi(3770)$, which is useful information for the future PANDA experiment, is estimated to be either ($9.8\pm5.7$) nb ($<17.2$ nb at 90% C.L.) or $(425.6\pm42.9)$ nb

Patients&#039; attitudes to the perioperative application of acupuncture: A Chinese survey

The primary purpose of this survey was to investigate the attitudes of patients undergoing elective surgery, towards the application of acupuncture to reduce perioperative complications, and to identify the possible factors that influenced their attitudes. Methods The survey was conducted in the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine in China. A 20-item questionnaire was developed and piloted over a period of eight weeks. Results 176 adult surgical inpatients completed the survey with a response rate of 98.9%. Only about one quarter of the participants had past experience of acupuncture treatment (n = 46, 26.1%) and one third thought acupuncture was effective (n = 61, 34.7%). Less than half of them were willing to use acupuncture for postoperative nausea and vomiting (PONV) (n = 70, 39.8%), postoperative pain (n = 79, 44.9%), preoperative anxiety and insomnia (n = 65, 36.9%), postoperative gastrointestinal dysfunction (n = 76, 43.2%), postoperative urinary retention (n = 81, 46.0%). Patients who were professionals or office workers (chi square = 26.181, p = 0.001) or with better education (chi square = 14.583, p = 0.024) were more willing to use acupuncture, while age or gender did not affect their attitudes. A majority of patients would follow the doctor&#039;s advice about acupuncture (n = 111, 63.1%). Those who had history of PONV were less likely to receive acupuncture (chi square = 10.664, p = 0.005). Conclusions Overall, the surveyed Chinese patients had limited experience and knowledge of acupuncture, and less than half had positive attitudes towards using acupuncture for reducing perioperative complications. Education of patients and their doctors may be promising strategies for improving patients&#039; willingness to use acupuncture

Effects of water deck on rock blasting performance

Water in the blasthole causes adverse effects on blasting performances, e.g., the incomplete explosion of explosive and toxic fume generation. It is normally pumped out before explosive loading to prevent explosive deterioration. In this study, a new blasting concept – water deck blasting (WDB) is introduced which sealed the water at the blasthole bottom to prevent adverse effects of water as well as maximise the beneficial effect of water on rock breakage performances. A field experiment was conducted in a quarry, bench blasting including twenty-three watery holes among 139 blastholes. Promising results were observed as there was no evidence of toxic fume during blasting and achieved a competent level of fragmentation with even toe-cut at the bottom level. The WBD and a normal charge blast were simulated using ANSYS/AUTODYN and multi-peak oscillations were investigated for the WBD. The advantageous rock breakage performances of the relatively small amount of water rather than the amount of explosive have not been verified but have been discussed referring to the extreme water and the steam explosion phenomenon. The WBD blasting method expects to bring advantageous effects to surface mine blasting