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1.
A technique for locating a transmission path failure in an inline cascade of semiconductor laser amplifier repeaters to within one fibre span is demonstrated. If a fault occurs, the loss of signal is detected in the following repeaters and a locally generated tone modulates the spontaneous emission of the repeater, signalling the fault to the system terminals.<>  相似文献   
2.
A linear homodyne optical phase-locked-loop has been demonstrated using a semiconductor local oscillator laser and has been shown to exhibit good dynamic response to environmental influences. The receiver phase noise in this experiment was dominated by Rayleigh backscatter from the fibre link.  相似文献   
3.
Healey  P. Malyon  D.J. 《Electronics letters》1982,18(20):862-863
Heterodyne detection has led to a significant improvement in the range performance of an optical time-domain reflectometer designed to operate on single-mode fibre at a wavelength of 1.52 ?m. With only 5 ?W peak launched power a range of 30 km was achieved.  相似文献   
4.
Examines the psychological reactions of gay males who have been diagnosed as having acquired immune deficiency syndrome (AIDS), which may include fear of death and dying, guilt, fear of lifestyle exposure, fear of contagion, loss of self-esteem, fear of loss of physical attractiveness, fear of decreased social support, fear of increased isolation and stigmatization, loss of occupational and financial status, concerns and confusion over options for medical treatment, and the strong sense of gloom and helplessness associated with a degenerative illness. Many AIDS patients have reported that their psychological needs were not being adequately addressed. Programs designed to meet these needs, such as the special care ward for AIDS patients opened by San Francisco General Hospital, are described. Support groups have become an integral part of the mental health treatment of AIDS patients. Gay males who have symptoms described as "pre-AIDS," "lesser AIDS," or "prodromal AIDS" or who are asymptomatic have also begun to manifest acute psychological symptoms. Anxiety, uncertainty, isolation, and hypochondriasis are some of the reactions typically displayed by men in these groups. As a result of AIDS, psychotherapy with gay males in general has changed to some extent: Common topics now include grieving for friends' deaths from AIDS, feeling alone and helpless, and experiencing one's own mortality. Psychologists must adopt a delicate balance of remaining sex-positive and gay-affirmative while working toward an educational model of safe sex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
5.
Signal polarisation rotation due to polarisation dependent loss has been observed for the first time in an optical communications transmission system. In particular its effect as a limiting factor in solitonic polarisation multiplexed systems is discussed. An analytic expression for the degree of rotation is presented and experimentally verified. Additionally, 5 Gbit/s solitons have been transmitted a distance of 11000 km without transmission control  相似文献   
6.
The performance of a packaged semiconductor laser amplifier has been investigated for use in an optical transmission system at 5 Gbit/s. With optical filtering at the receiver input only small system penalties were found, as expected from the analysis of the dominant noise contributions.<>  相似文献   
7.
Contends that during adolesence when homosexual self-labeling first occurs, the simultaneous awareness of homoerotic desires and the social odium associated with them tends to bring about conflict and a suppression of homosexual promptings among many homosexual males. The most common developmental consequence of this inhibition is a confounding of the process of identity formation. A biphasic pattern of identity development may occur so that during the 3rd decade or later unfinished psychological tasks of primary adolescence are resumed. It is suggested that the psychodynamics and phenomenology of this 2nd phase of identity formation bear a striking resemblance to those of primary psychological adolescence. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
8.
Malyon  D.J. Stallard  W.A. 《Electronics letters》1990,26(22):1863-1865
A four channel direct detection FDM operating at 565 Mbit/s with a channel spacing of 12 GHz which achieves a receiver sensitivity of -40 dBm is reported. A laser preamplifier is used to overcome the optical processing loss of the channel selective filter.<>  相似文献   
9.
Measurements of the receiver sensitivity for an experimental optical PSK homodyne system, operating at 140 Mbit/s and at a wavelength of 1.52 ?m, have given a 19 dB sensitivity improvement over direct detection, and at ?64 dBm is approximately 2 dB away from the theoretically predicted value.  相似文献   
10.
OBJECTIVES: To find the acceptance and efficacy of our protocol for exercises of the pelvic floor over short and long periods for women with urinary stress incontinence seen at our health centre. DESIGN: A prospective intervention study. SETTING: Marquesado Health Area: a rural zone to the east of Granada. PARTICIPANTS: 72 women between the ages of 20 and 65 with genuine urinary stress incontinence. INTERVENTION: Application of a pelvic physiotherapy procedure of two simple exercises. At the consultation with doctor and nurse on inclusion in the programme, a questionnaire was filled, the exercises were explained and an explanatory leaflet was given out. Nursing staff attended the women on days 1, 2, 7, 15, 25, 40 and 60. MEASUREMENTS AND RESULTS: 72 women with genuine urinary stress incontinence were studied. Their ages ran from 20 to 65 (average 53). 55 women (76.3%) completed the treatment protocol at 60 days. Of these 55, 24 (43.8%) were dry at two months, 12 (21.1%) had improved, 18 (32.7%) experienced no change and 1 (1.8%) reported an increase in her incontinence. We assessed the amount of urine loss, by means of a continence apparatus and through the patients' subjective view. 67.7% of the women with slight incontinence were fully cured, whereas none of those with considerable incontinence were. CONCLUSIONS: Both the efficacy and efficacy of the protocol are highly satisfactory in our community. Our protocol is more efficacious for young women and those with little incontinence.  相似文献   
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