Focusing high-energy x-rays by a P MMA compound x-ray lens on Beijing synchrotron radiation facility

The x-ray compound lens is a novel refractive x-ray optical device. This paper reports the authors＇ recent research on a polymethyl methacrylate （PMMA） compound x-ray lens. Firstly the designing and LIGA fabrication process for the PMMA compound x-ray lens are briefly described. Then, a method for theoretical analysis, as well as the experimental system for measurement is also introduced. Finally, the focusing spots for 8keV monochromatic x-rays by the PMMA compound x-ray lens are measured and analysed. According to the experimental results, it is concluded that the PMMA compound x-ray lens promises a good focusing performance under the high-energy x-rays.

Nondestructive technique for identifying nuclides using neutron resonance transmission analysis at CSNS Back-n

Nondestructive and noninvasive neutron assays are essential applications of neutron techniques.Neutron resonance transmission analysis(NRTA)is a powerful nondestructive method for investigating the elemental composition of an object.The back-streaming neutron line(Back-n)is a newly built time-of-flight facility at the China Spallation Neutron Source(CSNS)that provides neutrons in the eV to 300 MeV range.A feasibility study of the NRTA method for nuclide identification was conducted at the CSNS Back-n via two test experiments.The results demonstrate that it is feasible to identify different elements and isotopes in samples using the NRTA method at Back-n.This study reveals its potential future applications.

Symmetry energy of strange quark matter and tidal deformability of strange quark stars

Research performed during the past decade revealed an important role of symmetry energy in the equation of state(EOS)of strange quark matter(SQM).By introducing an isospin-dependent term into the quark mass scaling,the SQM stability window in the equivparticle model was studied.The results show that a sufficiently strong isospin dependence C_(I)can significantly widen the SQM region of absolute stability,yielding results that simultaneously satisfy the constraints of the astrophysical observations of PSR J1614-2230 with 1.928±0.017 Mand tidal deformability 70≤Λ_(1:4)≤580 measured in the event GW170817.With increasing C_(I),the difference between the u,d,and s quark fractions for the SQM inβ-equilibrium becomes inconspicuous for C>0,leading to small isospin asymmetryδ,and further resulting in similar EOS and structures of strange quark stars(SQSs).Moreover,unlike the behavior of the maximum mass of ud QSs,which varies with C_(I)depending on the sign of the parameter C,the maximum mass of the SQSs decreases monotonously with increasing CI.

CHANGES OF PSYCHOLOGICAL STRESS STATE AND THE EFFECT OF ACPUNCTURE INTERVENTION IN ARMED ANTI-TERRORISM POLICEMEN

Objective:To observe psychological changes of the armed policemen under stress state and the effect of acupuncture intervention for exploring possible measures in raising the armed policemen's capability in dealing with the suddenly-occurred accidents. Methods: In the first part of the study for observing psychological changes, a total of 90 volunteer armed policemen participating in anti-terrorism maneuver were randomly and evenly divided into anti-chemical weapon group, flight reconnaissance group and hostage-rescuing group. 30 logistic personals were selected to form control group. Symptom Checklist-90 (SCL-90) questionnaire was used to assess the psychological state of these anti-terrorism policemen. In the second part of the study for observing the effect of acupuncture, 60 policemen with anxiety and depression who were determined by Self-Rating Depression Scale (SDS) and Self-Rating Anxiety Scale (SAS) were randomly and evenly divided into non-acupuncture and acupuncture groups, and other 30 policemen with normal psychological state were selected to form control group. Two weeks before anti-terrorism maneuver, participants of acupuncture group were asked to receive continuous acupuncture treatment of bilateral Neiguan (内关 PC 6) and Zusanli (足三里 ST 36), once daily, 15 min every time. Results:Comparison among the first 4 groups displayed that the total scores, scores of body feeling reactions, interpersonal relation, depression, anxiety, terror, and psychological problems of flight reconnaissance and hostage-rescuing groups were significantly higher than those of control group (P<0.05-0.01), suggesting that the psychological stress pressure was strongest in flight reconnaissance policemen and secondary in hostage-rescuing policemen, followed by anti-chemical weapon policemen. Following administration of acupuncture intervention, scores of both SDS and SAS in acupuncture group were considerably lower than those of non-acupuncture group (P< 0.01), showing that acupuncture intervention could reduce psychological stress reactions in the armed policemen undergoing anti-terrorism exercise. Conclusion: Before anti-terrorism exercise,neerly all the armed policemen have different degrees of psychological problems, while acupuncture intervention can improve their psychological state.

Molecular Gas Distribution around the Supernova Remnant G40.5-0.5

The distribution of dense molecular gas around the supernova rem- nant G40.5-0.5 has been investigated by radio spectroscopic observations in the CO （J=1 - 0） transition. The molecular gas is found to extend over the entire region of G40.5-0.5. A molecular shell, with a diameter of ～ 26′, coincides with the ionized gas as revealed by the cm-radio observations. This coincidence, along with the velocity discontinuity following the shell, provides direct evidence for interaction between the ionized gas and the dense molecular gas. No clear evidence for cosmic-ray accelera- tion can be identified from this SNR as previously suggested, due to positional uncertainty in relating the SNR shell defined by CO to the EGRET gamma-ray sources, GRO J1904＋06, from the gamma-ray observations.