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排序方式: 共有100条查询结果,搜索用时 31 毫秒
1.
Wireless Personal Communications - The ongoing technological developments have totally transformed the lives of human beings. With the emergence of the smart era and the smart city concept, a few... 相似文献
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A technique for designing efficient checkers for conventional Berger code is proposed in this paper. The check bits are derived by partitioning the information bits into two blocks, and then using an addition array to sum the number of 1's in each block. The check bit generator circuit uses a specially designed 4-input 1's counter. Two other types of 1's counters having 2 and 3 inputs are also used to realize checkers for variable length information bits. Several variations of 2-bit adder circuits are used to add the number of 1's. The check bit generator circuit uses gates with fan-in of less than or equal to 4 to simplify implementation in CMOS. The technique achieves significant improvement in gate count as well as speed over existing approaches. 相似文献
4.
A Scoppola P De Paolis G Menzinger A Lala S Di Giulio 《Canadian Metallurgical Quarterly》1997,51(3):908-912
Mevalonic acid (mevalonate or MVA), is an obligate precursor in the biosynthetic pathway of cholesterol. It is partially metabolized by the kidneys and its plasma concentrations are an index of endogenous cholesterol synthesis. The aim of the present study was to evaluate plasma MVA concentrations in uremic patients with different degrees of chronic renal failure (CRF; group A), and the effects of a single hemodialysis treatment on plasma MVA in a group of patients with end-stage renal disease (ESRD; group B). CRF patients exhibited a higher mean basal mevalonate concentration (13.3 +/- 6.5 ng/ml) than control subjects (4.68 +/- 1.32 ng/ml; P < 0.001). A statistically significant direct correlation was evident in CRF patients between mevalonate and creatinine plasma levels (r = 0.86; P < 0.001). A single hemodialysis treatment was associated with a significant reduction of plasma mevalonate concentrations four hours after the hemodialysis session (-57%; P < 0.001) and an increase up to the basal values 24 hours after the end of the treatment. In conclusion, our results demonstrated: (i) higher plasma MVA concentrations in patients with decreased renal function; (ii) a direct relationship between plasma MVA levels and the degree of kidney failure as expressed by creatinine plasma concentrations; and (iii) a clear cut reduction of elevated plasma MVA levels after a single hemodialysis treatment. 相似文献
5.
A compact spark pre-ionized pulser sustainer TE-CO2 laser that can produce an output energy of one joule with an overall efficiency of 12.4% is presented. Optical pulses have
durations of 7.15 μs FWHM. Here, the laser uses all solid-state excitation (ASSE) circuit and the discharge formed between
two uniform field electrodes placed 1.5 cm apart ultimately leads to a discharge volume of 50 cm × 1.5 cm × 1.5 cm 相似文献
6.
Wireless Personal Communications - A Wireless Mesh Network (WMN) is a multi-hop network that gains the benefits of low deployment cost, fast access speed, expanded service coverage and large... 相似文献
7.
Sandeep Panda Pradeep Chandra Rout Chinmaya Kumar Sarangi Srabani Mishra Nilotpala Pradhan Umaballav Mohapatra Tondepu Subbaiah Lala Behari Sukla Barada Kanta Mishra 《Korean Journal of Chemical Engineering》2014,31(3):452-460
Bioleaching studies for chalcopyrite contained ball mill spillages are very scarce in the literature. We developed a process flow sheet for the recovery of copper metal from surface activated (600 °C, 15 min) ball mill spillage through bio-hydrometallurgical processing route. Bioleaching of the activated sample using a mixed meso-acidophilic bacterial consortium predominantly A. ferrooxidans strains was found to be effective at a lixiviant flow rate of 1.5 L/h, enabling a maximum 72.36% copper recovery in 20 days. Mineralogical as well as morphological changes over the sample surface were seen to trigger the bioleaching efficiency of meso-acidophiles, thereby contributing towards an enhanced copper recovery from the ball mill spillage. The bio-leach liquor containing 1.84 g/L Cu was purified through solvent extraction using LIX 84I in kerosene prior to the recovery of copper metal by electrowinning. Purity of the copper produced through this process was 99.99%. 相似文献
8.
Threshold stress, σth, for reorientation of hydrides in cold worked and stress-relieved (CWSR) Zr-2.5Nb pressure tube material was determined in the temperature range of 523-673 K. Using tapered gage tensile specimen, mean value of σth was experimentally determined by two methods, half thickness method and area compensation method. The difference between local values of σth measured across the thickness of the tube and the mean σth values yielded the residual stress variation across the tube thickness. It was observed that both the mean threshold stress and residual stress decrease with increase in reorientation temperature. Also, the maximum value of residual stresses was observed near the midsection of the tube. 相似文献
9.
R Lala P Matarazzo P Chiabotto F Gennari MG Cortese F Canavese C de Sanctis 《Canadian Metallurgical Quarterly》1997,157(5):1898-1901
PURPOSE: We investigated the efficacy of early gonadotropin treatment of cryptorchidism for promoting testicular descent and ameliorating testicular histology. MATERIALS AND METHODS: We treated 319 cryptorchid testes in 281 boys 4 months to 3 years old with luteinizing hormone-releasing hormone and human chorionic gonadotropin sequential therapy. Surgery was done on the 207 testes that did not respond to medical treatment. Microscopic biopsies were performed in 134 of these 207 testes. Histological findings were compared to those of 30 cryptorchid testes in boys younger than 1 year who underwent surgery without previous hormonal treatment. RESULTS: Combined luteinizing hormone-releasing hormone and human chorionic gonadotropin treatment induced scrotal descent of a percentage of cryptorchid testes depending on clinical position. Therapeutic success was greater when testes were in a lower position and results were not age dependent. Hormonal treatment of cryptorchidism during the first year of life stimulated spermatogonia maturation. CONCLUSIONS: When administered at the end of age 6 months, hormonal treatment can be considered an effective and timely substitution for gonadotropin and testosterone insufficiency in cryptorchid infants. Therefore, we recommend this therapeutic procedure combined with surgery in the first year of life. 相似文献
10.
高台民居位于喀什噶尔老城东北端的悬崖上,两千年前就已存在,一千多年前有维吾尔先民在此建房安家。相传东汉名将班超、耿恭曾在此留下足迹。公元九世纪中期喀什拉汗王朝时,就把王宫建在这个高崖的北面。经过千年历史的发展,高崖上形成了奇特的民居建筑。有意思的是,这里并未 相似文献