RESUMO
For a noncooperative target, multiple-dimension detection is required to determine its spatial location. A microwave photonic radar is proposed for simultaneous detection of the distance and direction of targets. At the transmitter, a linear frequency modulation (LFM) signal with a large instantaneous bandwidth was obtained by frequency doubling. Meanwhile, the optical reference signal was supplied. At the receiver, two antennas with a certain baseline length were used to receive the echo signal. The dechirp process and fixed-length cable are combined to decouple the distance and direction and distinguish between the positive and negative directions of a target. Theoretical derivation has already verified that the distance and direction can be resolved simultaneously by dechirping of the echo modulation signal and reference signal. In experiments, an LFM signal with an instantaneous bandwidth of 2 GHz (2-4 GHz) was generated and launched as the detection signal. Targets at different distances with positive and negative angles were detected. The results show that the directional measurement ranges from -72.5° to 72.5°, and the error is less than 1.6°. The measured distance was found to be quite similar to the actual distance. The proposed approach can confirm the spatial location of a noncooperative target by combining the detection of both distance and direction. Furthermore, the baseline length need not be less than half the wavelength of the echo signal, and large antennas can be chosen to improve the detection distance and range accuracy.
RESUMO
Objective: This study mainly discusses the influence of the continuous nursing intervention on the treatment compliance of patients with depression. Methods: The clinical data of 120 patients with depression admitted to our hospital were collected by retrospective analysis. According to the different implementation of nursing methods, patients were subordinated to the conventional group (n = 48, conventional nursing) and the continuous group (n = 72, continuous nursing). The treatment compliance, depression degree, quality of life, nursing satisfaction, Insight and Treatment Attitude Questionnaire (ITAQ), and recurrence rate of patients in the two groups were compared. Results: The continuous group had a higher treatment compliance rate, slighter depression, higher physiological function, psychological function, social function, environmental adaptability, total quality of life, nursing satisfaction, and ITAQ score, and lower recurrence rate, with statistically significant differences (P < 0.05). Conclusion: The implementation of continuous nursing intervention for patients with depression could enhance their treatment compliance and relieve depressive symptoms; improve the quality of life and self-awareness; reduce the risk of relapse; and improve nursing satisfaction.
RESUMO
By using a new saturable absorber, Co(2+):LaMgAl(11)O(19) (Co:LMA) crystal, the passive Q-switched operation of a flash lamp pumped 1.54 mum Er:glass laser is realized. With different transmissions of the output mirror, the properties of static output and dynamic output of the laser are studied. The experimental results show that, when transmission of the output coupler is 15%, the static output curve has higher slope efficiency and higher energy conversion efficiency and meanwhile the Q-switched output pulses with higher single-pulse energy and narrower pulse width can be obtained.
RESUMO
The static and dynamic 1.34 mum laser output performance of the Nd:Y(x)Gd(1-x)VO(4) mixed crystal pumped by flash-lamp is investigated with different transmissions of output couplers (T=15%, 30% and 40%) in a plano-concave laser cavity. With the output coupler transmission of T=30%, the static output energy of 62 mJ is obtained when the pump energy is 24.2 J, and the corresponding electric-optical conversion efficiency is 0.26%. By using a new saturable absorber: Co(2+):LaMgAl(11)O(19) (Co:LMA), the passive Q-switching at 1.34 mum is realized when the second threshold condition of passive Q-switching is satisfied. With the cavity length of 245 mm and pump energy of 24.2 J, the single-pulse output energy, pulse width and peak power are obtained to be 3.5 mJ, 45 ns and 77.8 kW, respectively.