检索结果-南通市图书馆

One and Two Photon Excitation of Radiofrequency Trapped Ca

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2009年第2期22卷 119-122页

作者： C. Zumsteg C. Champenois D. guyomarc'h g. Hagel M. Houssin M. Knoop Physique des Interactions Ioniques et Moléculaires (CNRS UMR 6633) Université de Provence Centre de Saint Jérome Case C21 13397 Marseille Cedex 20 France

Radiofrequency （rf） trapped ions are versatile candidates for a large panel of applications ranging from quantum information to the creation of cold molecules. Sample size can range from a single to 10^6 ions, and the internal and external energy states of the atoms can be controlled with high precision. In the experiment, we focus on different protocols related to frequency metrology using rf trapped Ca.

关键词： Radiofrequency trapped ion Frequency metrology Laser stabilisation

Evaluation of trend in semen analysis for 11 years in subjects attending a fertility clinic in India

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2003年第3期5卷 221-225页

作者： P.Marimuthu M.C.Kapilashrami M.M.Misro g.Singh National Institute of Health and Family Welfare Munirka New Delhi-110067 IndiaNational Institute of Health and Family Welfare Munirka New Delhi-110067 IndiaNational Institute of Health and Family Welfare Munirka New Delhi-110067 IndiaNational Institute of Health and Family Welfare Munirka New Delhi-110067 India

Aim: The data on semen analysis of subjects attending the Fertility Clinic at NIHFW (National Institute of Health and Family Welfare) Munirka, New Delhi for the last 11 years were analyzed to verify the claims and speculations on declining sperm counts in men. Methods: Approximately 10 % of the records every year starting from 1990 to 2000 (numbering 1176 in total) were randomly selected for analysis. Subjects with azoospermia or severe oligozoospermia were excluded from analysis. Results: The average age of the men attending the infertility clinic was 31.2 years. The average semen volume and sperm count were found to be (2.6 ±0.1) mL and (60.6 ± 0.9) × 106/mL, respectively. No significant decline in sperm counts was observed in any year during the entire study period. Only 1.8 % of the total number of sperm counts in the random sampling were less then 20 × 106/mL. On the basis of WHO criteria on motility, the total percentage of non-progressive and non-motile sperm in the ejaculate was higher (63 %) as compared to the combined categories of slow and rapid linear progressive. Conclusion: The present study has confirmed similar findings from other different countries that declining sperm counts in humans is not a global phenomenon.

关键词： semen analysis sperm motility declining sperm count male infertility

POTENTIAL INDIRECT EFFECTS OF AEROSOL ON TROPICAL CYCLONE INTENSITY:CONVECTIVE FLUXES AND COLD-POOL ACTIVITY

在线全文

学校读者我要写书评

暂无评论

Tropical Cyclone Research and Review 2012年第3期1卷 293-306页

作者： W.R.COTTON g.M.KRALL g.g.CARRIó Department of Atmospheric Science Colorado State University

We investigated the impacts of elevated aerosol concentrations on 2008 Western Pacific typhoon(NURI). Based on satellite and global aerosol model output, pollution levels were estimated. The typhoon was simulated for 96 hours beginning 17 August, 2008. During the final 60 hours CCN concentrations were enhanced as it neared the Philippines and coastal *** during the ingestion of enhanced CCN, precipitation was reduced due to suppressed collision and coalescence, and storm winds strengthened. Subsequently, greater amounts of condensate were thrust into supercooled levels where the drops froze resulting in greater latent heating. Convection thereby intensified which resulted in enhanced rainfall and more vigorous convectively-produced downdrafts. As the convection intensified in the outer rainbands the storm drifted over the developing cold-pools, and low level wind speeds diminished. Very high amounts of pollution aerosols resulted in large amounts of condensate being thrust into the storm anvil which weakened convective downdrafts and cold-pools, yet reductions in wind speed(although weaker) occurred compared with the clean control run. While the simulated storm was weaker than the observed storm, making it a borderline tropical storm or typhoon, the simulated response to aerosols was much different than anticipated based on previous simulations of aerosol impacts on tropical cyclones. In particular, the storm strengthened during the first period of aerosol ingestion followed by an extended period of storm weakening. Nonetheless, this study suggests that ingestion of elevated amounts of CCN into a tropical cyclone(TC) can appreciably alter the intensity of the storm. However, the pollution aerosols have very little impact on the storm track.

关键词： TROPICAL CYCLONE EFFECTS COLD-POOL ACTIVITY

Effect of perioperative branched chain amino acids supplementationin liver cancer patients undergoing surgical intervention: Asystematic review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of gastrointestinal Surgery 2023年第11期15卷 2596-2618页

作者： Kwan Yi Yap HongHui Chi Sherryl Ng Doris HL Ng Vishal g Shelat Yong Loo Lin School of Medicine National University of SingaporeSingapore 117597Singapore Department of gastroenterology and Hepatology Tan Tock Seng HospitalSingapore 308433Singapore Lee Kong Chian School of Medicine Nanyang Technological UniversitySingapore 636921Singapore Department of general Surgery Tan Tock Seng HospitalSingapore 308433Singapore

performed independently by authors(Yap KY,Chi H,Ng S)identified 50 studies for full-text ***,12 prospective RCTs and 4 non-randomised studies(1 non-randomised trial and 3 observational studies)were included.A detailed PRISMA diagram is shown in Figure *** studies included were assessed for risk of bias,with a summary of the assessment shown in Figure 2 and Table 1 for trials and non-interventional studies,*** PRISMA checklist is appended in Supplementary Figure 1.

关键词： Branched-chain amino acid Liver cancer Liver surgery Nutritional supplement Perioperative supplementation

Divergence and constraint in the thermal sensitivity of aquatic insect swimming performance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2020年第5期66卷 555-564页

作者： Alisha A.SHAH Eva M.S.Bacmeister Juan g.Rubalcaba Cameron K.ghalambor Department of Biology Colorado State UniversityFort CollinsCO80526USA Division of Biological Sciences University of MontanaMissoulaMT59812USA Department of Biology McGill University1205 Docteur PenfieldMontrealQCCanada Department of Biology Centre for Biodiversity DynamicsNorwegian University of Science and Technology(NTNU)TrondheimNorway

Environmental temperature variation may play a significant role in the adaptive evolutionary divergence of ectotherm thermal performance curves(TPCs).However,divergence in TPCs may also be constrained due to various ***,we measured TPCs for swimming velocity of temperate and tropical mayflies(Family:Baetidae)and their stonefly predators(Family:Perlidae)from different *** predicted that differences in seasonal climatic regimes would drive divergence in TPCs between temperate and tropical *** tropical temperatures should favor the evolution of"specialists"that perform well across a narrow range of ***,variable temperatures in temperate zones,however,should favor"generalists"that perform well across a broad range of *** phylogenetically paired comparisons of mayflies and stoneflies,swimming speed was generally unaffected by experimental temperature and did not differ among populations between latitudes,suggesting a maintenance of performance breadth across elevation and *** exception was found between temperate and tropical mayflies at low elevation where climatic differences between latitudes are *** addition,TPCs did not differ between mayflies and their stonefly predators,except at tropical low *** results indicate that divergence in TPCs may be con strai ned in aquatic in sects except under the most differe nt ther・mal regimes,perhaps because of trade-offs that reduce thermal sensitivity and increase performance breadth.

关键词： aquatic insects climate variability elevation latitude predator-prey swimming performance thermal performance curve

Mediastinal lesions in children

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2023年第12期11卷 2637-2656页

作者： Hasibe gökçeÇinar Ali Osman gulmez ÇiğdemÜner Sonay Aydin Department of Pediatric Radiology Ankara Etlik City HospitalAnkara 06000Turkey Department of Radiology Erzincan Binali Yıldırım University Faculty of MedicineErzincan 24100Turkey

The mediastinum is where thoracic lesions most frequently occur in young *** histological spectrum of diseases caused by the presence of several organs in the mediastinum is *** lesions,infections,benign and malignant lesions,and vascular diseases are examples of *** should be taken to make the proper diagnosis at the time of diagnosis in order to initiate therapy *** task is currently made simpler by radiological imaging techniques.

关键词： Mediastinum Thoracic lesions Vascular pathologies Trachea and main bronchus pathologies Esophageal pressure Imaging in mediastinal lesions

Environmental monitoring of the Zhujiang Estuary and its coastal waters

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2002年第2期21卷 275-304页

作者：陈介中 L.Dong L.A.Wong g.W.Heinke Center for Coastal and Anmospheric Research Hong Kong University of Science and Technology Clear Water BayKowloon Hong Kong

The Zhujiang (Pearl River) Estuary is a complex water system whose catchments basincovers a very large part of southern China. The large quantity of fresh water carried by the river system flows into the northern coast of the South China Sea through its eight inlets. The Zhujiang River Delta has experienced the fastest economic growth in China during the past two decades. Rapid population expansion and increased industrial development coupled with insufficient waste management turned the Zhujiang Estuary into waste disposal channels just before entering the coastal waters. The water quality of the estuaries and the coastal oceans has become polluted. During the past two years, an intensive study and monitoring efforts of the pollutions of these waters have been made. A systematic and integrated monitoring task including shore-based measurements, shipboard in-situ measurements, and satellite and radar remote sensing surveys has been completed. Comprehensive collection of physical, chemical and biological parameters has been accomplished and a database has been established. Unlike the previous large scale-monitoring task in which the various pollutant concentrations were the objective, the present study aims to understand the process of the pollution from their initial disposal to their final states. The understanding of the processes makes it possible to evaluate the severity of the pollution with respect to the sustainability. Also the objective is to incorporate these processes into the mathematical models from which a predictive capability of the pollution situation can be realized. The present presentation will describe the planning, methodology and the results of this effort.

关键词： The Zhujiang Estuary environmental monitoring

Effect of various melt and heat treatment conditions on impact toughness of A356 aluminum alloy

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2016年第4期26卷 956-965页

作者： M.AMNE ELAHI S.g.SHABESTARI Center of Excellence for High Strength Alloys Technology School of Metallurgy and Materials EngineeringIran University of Science and TechnologyTehran 16846-13114Iran

The microstructure and impact behavior of A356 aluminum alloy were studied after melt treatment processes of grain refinement and modification under both non-heat treated and T6 heat treated conditions. The modification and grain refinement were done with the addition of Al-10%Sr and Al-5Ti-1B master alloys, respectively. All casting parameters were kept constant in order to focus on the influence of mentioned treatments. The results indicate that the eutectic silicon morphology is the main parameter to control the impact behavior of alloy. Consequently, the individual grain refinement of as-cast alloy does not improve the impact toughness as the modification does. While, simultaneous grain refinement and modification provide higher impact toughness in comparison with individual treatments. T6 heat treatment of the alloy improves the impact toughness under all melt-treated conditions. This is related to the further modification of eutectic silicon particles. To verify the results and clarify the mechanisms, three-point bending test and fractography were used to interpret the improvement of impact toughness of the alloy.

关键词： A356 aluminum alloy modification grain refinement impact toughness

SOLITON SOLUTIONS OF A CLASS OF gENERALIZED NONLINEAR SCHRODINgER EQUATIONS

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 1997年第4期12卷 389-398页

作者： CAOQINgJIE ZHANgTIANDE K.DJIDJELI g.W.PRice E.H.TWIZELL DepartmentofMathematicsandPhysics ShangdongUniversityofTechnologyJinan.Chlna250061 DepartmentoFMathematicsandPhysics ShangdongUniver.~ityo~Tecl~nologyJinan.China250061 DepartmentofShipScience UniversityofSouthamptonSouthamptonSo171BJEngland. DepartmentofShipScience UniversityofSouthamptonSouthamptonSO171BJEngland DepartmentofMathematicsandStatistics BrunelUniversityUxbridgeMiddlesexUB83PHEngland.

Soliton solutions of a class of generalized nonlinear evolution equations are discussed analytically and numerically. This is done by using a travelling wave method to formulate one soliton solution and the finite difference method to the numerical solutions and the interactions between the solitons for the generalized nonlinear Schrdinger equations. The characteristic behavior of the nonlinearity admitted in the system has been investigated and the soliton states of the system in the limit when α→0 and α→∞ have been studied. The results presented show that the soliton phenomenon is characteristics associated with the nonlinearities of the dynamical systems.

关键词： generalized nonlinear Schrodinger equation Soliton solution Weighted six-point scheme