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排序方式: 共有108条查询结果,搜索用时 281 毫秒
1.
A rare case associated with congenital hematometrocolpos in a circumcised 13 years old Somalian girl is presented. Emphasis on proper history is highlighted. Mutilation caused by bad cultural practice of female circumcision which is although not a problem in Pakistan, is brought into notice for those who may be unaware of perineal appearance of a circumcised female and stitched over vagina. 相似文献
2.
Prepulse inhibition (PPI) refers to a reduction in the startle response to a strong sensory stimulus when this stimulus is preceded by a weaker stimulus--the prepulse. PPI reflects a nonlearned sensorimotor gating mechanism and also shows a robust gender difference, with women exhibiting lower PPI than men. The present study examined the eyeblink startle responses to acoustic stimuli of 59 healthy heterosexual and homosexual men and women. Homosexual women showed significantly masculinized PPI compared with heterosexual women, whereas no difference was observed in PPI between homosexual and heterosexual men. These data provide the first evidence for within-gender differences in basic sensorimotor gating mechanisms and implicate the known neural substrates of PPI in human sexual orientation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
Raina Aman Qazi Mohammad Saleem Khan Luqman Ali Shah Rizwan Ullah Ayesha Kausar Rozina Khattak 《Polymer-Plastics Technology and Engineering》2020,59(9):928-951
ABSTRACTFabrication of electronic materials from nanocomposite of biopolyesters reinforced with carbon nanotubes can be regarded as the effective alternative for conventional nanocomposites consisting of non-biodegradable polymers. Commercial availability of biopolyester-based nanocomposites is limited because of their high cost compared to other polymers, but the factor of their compostable nature is worthless for environmental protection. Such nanocomposites have potential applications in biodegradable sensors, EMI materials, etc. In this review, the current progress of biopolyester/CNTs nanocomposites in the field of biodegradable electronics is reviewed and also the impact of CNTs dispersion on electrical, thermal and mechanical properties of eco composites is stipulated. 相似文献
4.
Shams Qazi Raad Raad Yi Mu Willy Susilo 《Journal of Network and Computer Applications》2013,36(2):582-592
A wormhole attack is one of the hardest problems to detect whereas it can be easily implanted in any type of wireless ad hoc network. A wormhole attack can easily be launched by the attacker without having knowledge of the network or compromising any legitimate nodes. Most existing solutions either require special hardware devices or make strong assumptions in order to detect wormhole attacks which limit the usability of these solutions. In this paper, we present a security enhancement to dynamic source routing (DSR) protocol against wormhole attacks for ad hoc networks which relies on calculation of round trip time (RTT). Our protocol secures DSR against a wormhole attack in ad hoc networks for multirate transmissions. We also consider the processing and queuing delays of each participating node in the calculation of RTTs between neighbors which to date has not been addressed in the existing literature. This work provides two test cases that show that not taking multirate transmission into consideration results in miss identifying a wormhole attack. 相似文献
5.
Imtnan-Ul-Haque Qazi Author Vitae Olivier Alata Author Vitae Author Vitae Ahmed Moussa Author Vitae Author Vitae 《Pattern recognition》2011,44(1):16-31
This article presents a comparison of different color spaces including RGB, IHLS and L?a*b* for color texture characterization. This comparison is based on the fusion of the independent spatial structure and color feature cues. In IHLS and L*a*b*, two channel complex color images are created from the luminance and the chrominance values. For such images, two dimensional complex multichannel linear prediction models are used to perform parametric power spectrum estimation and the structure feature cues are computed from this estimated power spectrum. Quantitative comparison of auto spectra of luminance and combined chrominance channels for different color spaces is done. This comparison is based on the degree of decorrelation between luminance and chrominance information provided by different color space transformations. Three dimensional histograms are used as color feature cues. Then, to classify color textures, Kullback-Leibler divergence based symmetric distance measures are calculated for pure color, luminance structure and chrominance structure feature cues. Individual as well as combined effect of information from all feature cues on classification results is then compared for different color spaces and different color texture data sets. The proposed color texture classification method performs better than the state of the art methods in certain cases. The L*a*b* color space gives us a better characterization of the chrominance spatial structure as well as the overall spatial structure for all of the chosen data sets. Experimental results on pixel classification of color textures are also presented and discussed. 相似文献
6.
J. I. Qazi H. J. Rack B. Marquardt 《JOM Journal of the Minerals, Metals and Materials Society》2004,56(11):49-51
This investigation has shown that the strength of low-modulus metastable beta-titanium alloys can be increased by increasing
their oxygen content and/or aging. Yield strength as high as 1,288 MPa along with reasonable ductility was obtained by aging
Ti-35Nb-7Zr-5Ta-0.7O at 482°C for 8 h. Strengthening of these alloys is discussed in terms of ω-and α-phase precipitates.
For more information, contact H.J. Rack, Clemson University, School of Materials Science and Engineering, Clemson, SC 29634-0907;
(864) 656-5636; e-mail rackh@ces.clemson.edu. 相似文献
7.
Single-phase ceramics in the SrLa4?x Pr x La4Ti5O17 (0 ≤ x ≤ 4) series were processed via a solid-state sintering route. X-ray diffraction analysis revealed single-phase ceramics for all the compositions. The molar volume (V m) decreased while the theoretical density (ρ th) increased with increase in the Pr content. Substitution of Pr3+ decreased the relative permittivity (ε r) and temperature coefficient of resonant frequency (τ f) due to its smaller ionic polarizability (α d) and ionic radius than La3+. In the present study, ε r ≈ 54.2, Q u f 0 ≈ 7935 GHz, and τ f ≈ ?20.3 ppm/°C were achieved for the composition with x = 2 (i.e., SrLa2Pr2Ti5O17). 相似文献
8.
Ca2Ce2Ti5O16 dielectric ceramics prepared by conventional solid-state ceramic route was investigated. Phase composition and microwave dielectric properties were measured using XRD and Vector network analyzer, respectively. XRD analysis of the calcined and sintered samples revealed the formation of CeO2 and another unidentified phase (that vanished at ? 1400 °C) as secondary phases along with the parent Ca2Ce2Ti5O16 phase. The amount of the parent Ca2Ce2Ti5O16 phase increased with increasing sintering temperature from 1350 °C to 1450 °C accompanied by a decrease in the apparent density. The density decreased but ? r and Q u f o increased with sintering temperature. An ? r ~ 81.5, Q u f o ~ 5915 GHz and τ f ~ 219 GHz were achieved for the sample sintered at 1450 °C. 相似文献
9.
During spatial navigation, women typically navigate an environment using a landmark strategy, whereas men typically use an orientation strategy. To examine the as yet unknown effects of sexual orientation on these normative sex differences, this study required 80 healthy heterosexual and homosexual adult men and women to provide directions from experimental maps for 4 routes. The frequency and type of strategy used by each participant were computed. Expected sex differences were demonstrated, and a robust cross-sex shift was shown by homosexual men in using landmarks. This remained after controlling for differences in mental rotation, directional sense, and general intelligence. The findings may limit the number of putative neurodevelopmental pathways responsible for sex differences in navigation strategy utility. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.