The beam energy measurement system for the Beijing electron-positron collider

The beam energy measurement system (BEMS) for the upgraded Beijing electron-positron collider BEPC-II is described. The system is based on measuring the energies of Compton back-scattered photons. The relative systematic uncertainty of the electron and positron beam energy determination is estimated as 2 \cdot 10^{-5}. The relative uncertainty of the beam's energy spread is about 6 %

Intraoperative risk of bleeding and its prevention during transcervical myomectomy

In this study clinical, functional and morphological assessment of the effectiveness of synthetic analogue of vasopressin (terlipressin) has been made. The aim of the study was to assess study drug prevention efficasy of excessive bleeding during hysteroscopic myomectomy in patients with submucosal uterine leiomyoma. In 19 women with uterine leiomyoma 15 minutes prior to surgery terlipressin was administered in para¬cervical route in the dosage 0.6 mg in 10 ml of normal saline. In the comparison group, which was also consisted of 19 women in the presence of significant blood loss during myoma resection intravenous oxytocin was used. The use of terlipressin helped to reduce the volume of blood loss during surgery almost by 2 times, reduced the duration of surgery and the risk of postoperative complications. On the basis of the ultrasonic doppler blood flow studies in uterine vessels, morphological and immunohistochemical studies of hemocapillars density in removed myoma nodules it was found that terlipressin contributes significantly to reduction of the number of functioning blood vessels and also to reduction of blood flow in all parts of the vascular system both in uterus and in leiomyoma, whereas oxytocin was not observed to decrease myometrium perfusion. It conclusion the study results showed that terlipressin use is the most effective method of prevention of excessive blood loss during hysteroscopic myoma resection

Hot wall growth and properties of lead telluride films doped by germanium and gallium

The researches results of films (PbTe)₁₋y(GaTe)y and (Pb₁₋xGexTe)₁₋y(GaTe)y of n-type conductivity with carrier concentration within (2⋅10¹⁷÷9⋅10¹⁸) cm⁻³ are represented. The films were growth by modified hot wall technology on barium fluoride substrate. A state of films surface was investigated by Atomic Force Microscope using both contact and taping modes. Hall coefficient, specific resistivity and thermoelectromotive force of films were measured in the temperature range 77-300 K. The investigation showed that the presence of germanium leads to an appearance of significant features on temperature dependencies of termoelectro-motive force which are connected with phase transition of displacement type. Doping gallium leads to n-type conductivity of films which increases with impurity concentration. The ionization energies of Ga impurities levels (n - exp(-E/2kT)) were within 3÷10 meV. The change of energy position and width of impurity level with increase of impurity concentration is established. The unusual protrusions on terraces of growth were discovered. The tops of protrusions can be considered as quantum dots. Inasmuch as composition of protrusions is expected to be distinguished from that of the terraces, they can create pieces of quantum wires

Two-photon exchange contribution in elastic electron-proton scattering, experiment at the VEPP-3 storage ring

We describe a precise measurement of the ratio of the (e+ p) to (e− p) elastic scattering cross sections. This comparison is sensitive to the effect of two-photon exchange contributions which may be the cause for inconsistent extractions of the proton form factors obtained using different methods. The experiment was performed at storage ring VEPP–3, Novosibirsk at energies of positron/electron beams of 1.0 and 1.6 GeV with electron/positron scattering angles θ = 65÷105° for the first case and 15÷25° and 55÷75° for the second case. Details of the experiment and the preliminary results are presented

Two-photon exchange contribution in elastic electron-proton scattering, experiment at the VEPP-3 storage ring

We describe a precise measurement of the ratio of the (e+ p) to (e− p) elastic scattering cross sections. This comparison is sensitive to the effect of two-photon exchange contributions which may be the cause for inconsistent extractions of the proton form factors obtained using different methods. The experiment was performed at storage ring VEPP–3, Novosibirsk at energies of positron/electron beams of 1.0 and 1.6 GeV with electron/positron scattering angles θ = 65÷105° for the first case and 15÷25° and 55÷75° for the second case. Details of the experiment and the preliminary results are presented