全文获取类型
收费全文 | 77篇 |
免费 | 1篇 |
专业分类
化学 | 22篇 |
晶体学 | 6篇 |
数学 | 2篇 |
物理学 | 48篇 |
出版年
2022年 | 1篇 |
2019年 | 1篇 |
2015年 | 2篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 7篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有78条查询结果,搜索用时 218 毫秒
1.
2.
H. H. Güven B. Kardon H. Seyfarth 《Zeitschrift für Physik A Hadrons and Nuclei》1978,287(3-4):271-285
Theγ radiation following thermal neutron capture in104Ru has been investigated through singles, coincidence, and angular correlation measurements in order to solve existing discrepancies and to complete the knowledge about the transitional odd-N nucleus 44 105 Ru61. The resulting level andγ-decay scheme is found to be very similar to that of the odd-Z transitional nucleus 61 149 Pm88. Between the 11/2?, 15/2?, and 19/2? states which are interpreted as members of the decoupled band, built on the unique parity 11/2? single particle state, low spin states of negative parity are found at surprisingly low excitation energies above the 11/2? state. In the frame of the particleplus-rotor model their positions would require a sharp decrease of the rotational parameter with increasing collective angular momentum of the soft core. 相似文献
3.
Fischer J Hammerschmidt K Cheney DL Seyfarth RM 《The Journal of the Acoustical Society of America》2002,111(3):1465-1474
The acoustic structure of loud calls ("wahoos") recorded from free-ranging male baboons (Papio cynocephalus ursinus) in the Moremi Game Reserve, Botswana, was examined for differences between and within contexts, using calls given in response to predators (alarm wahoos), during male contests (contest wahoos), and when a male had become separated from the group (contact wahoos). Calls were recorded from adolescent, subadult, and adult males. In addition, male alarm calls were compared with those recorded from females. Despite their superficial acoustic similarity, the analysis revealed a number of significant differences between alarm, contest, and contact wahoos. Contest wahoos are given at a much higher rate, exhibit lower frequency characteristics, have a longer "hoo" duration, and a relatively louder "hoo" portion than alarm wahoos. Contact wahoos are acoustically similar to contest wahoos, but are given at a much lower rate. Both alarm and contest wahoos also exhibit significant differences among individuals. Some of the acoustic features that vary in relation to age and sex presumably reflect differences in body size, whereas others are possibly related to male stamina and endurance. The finding that calls serving markedly different functions constitute variants of the same general call type suggests that the vocal production in nonhuman primates is evolutionarily constrained. 相似文献
4.
H. Seyfarth H. H. Güven B. Kardon W. D. Lauppev G. Lhersonneau K. Sistemich S. Brant N. Kaffrell P. Maier-Komor H. K. Vonach V. Paar D. Vorkapić R. A. Meyer 《Zeitschrift für Physik A Hadrons and Nuclei》1991,339(2):269-278
The properties of the triplet of low-lying states in101Mo have been studied through spectroscopy of theγ radiation following thermal neutron capture in100Mo and β? decay of101Nb and through a measurement of the proton angular distributions in the100Mo(d,p) reaction with 14 MeV deuteron energy. The half-lives of the 13.5 keV state and the 57.0 keV 5/2+ state have been measured as 226(7) and 133(7)ns, respectively. These values and the quadrupole/dipole mixing ratios of the 13.5 keV and 43.5 keV transitions yield spin and parity 3/2+ for the 13.5 keV level. The E2 components in the 13.5 (3/2+ →1/2+) and 43.5 keV (5/2+→3/2+) transitions are ≦ 8·10?4 and 54(9)%, respectively. The possibility of an additional state near to the 57.0 keV level is discussed. IBFM/PTQM calculations, taking into consideration the transitional character of the100Mo boson core, account for the electromagnetic-transition and transfer-reaction pattern of the triplet of states. 相似文献
5.
L. Aldea B. Kardon O. W. B. Schult H. Seyfarth N. Wüst 《Zeitschrift für Physik A Hadrons and Nuclei》1977,283(4):391-395
Partial cross sections have been measured for the143Nd(n th,α)140Ce reaction and also for the two-step process143Nd(n th,γα)140Ce. The results of the present work confirm previous data, but due to lower background, better statistics and resolution improved precision has been obtained. The double-humped structure in the observed (n, γ α) spectrum can still be explained through the Porter-Thomas fluctuations of the reduced partialγ andα widths. 相似文献
6.
Yaschenko S Dymov S Kacharava A Komarov V Macharashvili G Rathmann F Barsov S Gebel R Hartmann M Khoukaz A Kulessa P Kulikov A Kurbatov V Lang N Lehmann I Lorentz B Mersmann T Merzliakov S Mikirtytchiants S Mussgiller A Nioradze M Ohm H Prasuhn D Schleichert R Seyfarth H Steffens E Stein HJ Ströher H Uzikov Y Zalikhanov B Zhuravlev N 《Physical review letters》2005,94(7):072304
A measurement of the analyzing power A(y) of the p-->d--> (p p) + n reaction was carried out at the ANKE spectrometer at COSY at beam energies of 0.5 and 0.8 GeV by detection of a fast forward proton pair of small excitation energy E(pp) < 3 MeV. The S-wave dominance in the fast diproton is experimentally demonstrated in this reaction. While at T(p) = 0.8 GeV the measured analyzing power almost vanishes, it rises to nearly unity at T(p) = 0.5 GeV for neutrons emitted at theta(c.m.)(n) = 167 degrees. The results are compared with a model taking into account one-nucleon exchange, single scattering, and Delta(1232) excitation in the intermediate state. The model describes fairly well the unpolarized cross section obtained earlier and the analyzing power at 0.8 GeV; it fails to reproduce A(y) at 0.5 GeV. 相似文献
7.
D.?GeppertEmail author L.?Seyfarth R.?de Vivie-Riedle 《Applied physics. B, Lasers and optics》2004,79(8):987-992
Molecular switches are discussed as promising nanoscale devices for various applications including data storage and information processing. For this purpose a high controllability of the complete switching process is desirable. We propose to use shaped femtosecond laser pulses to initiate and control a fast and efficient switching process mediated by conical intersections. We focus on photoreactions of bistable molecules in which the ring opening of 1,3-cyclohexadiene constitutes the key activity. The investigations of control schemes for this type of reactions are carried out in a model based on ab initio and quantum dynamical calculations of the ring-opening reaction of cyclohexadiene. By defining an intermediate target, we can achieve product control with optimized laser pulses in this model. PACS 33.80.-b; 82.40.Js; 82.20.Hf; 42.65.Re; 31.15.Qg 相似文献
8.
Subbiah Meenakshisundaram RM. Sockalingam 《Journal of molecular catalysis. A, Chemical》2000,160(2):269-275
Catalytic activity of Os(VIII) in the oxidation of some twenty organic sulfides with sodium salt of N-chlorobenzenesulfonamide (CAB) has been investigated in alkaline (pH8.7) t-butanol–water (1:1 v/v) medium. Significant retarding influence of [OH−] on the reactivity is exhibited. The catalysed reaction is strongly accelerated in the presence of Hg(II). Imperfections are observed in the linear Hammett relationship in the case of –NO2 substituents. 相似文献
9.
Structure Elucidation and Activity of Kolossin A,the D‐/L‐Pentadecapeptide Product of a Giant Nonribosomal Peptide Synthetase
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Prof. Dr. Helge B. Bode Dr. Alexander O. Brachmann Dr. Kirtikumar B. Jadhav Dr. Lydia Seyfarth Dipl.‐Chem. Christina Dauth Dr. Sebastian W. Fuchs Dr. Marcel Kaiser Dr. Nick R. Waterfield Dipl.‐Phys. Holger Sack Prof. Dr. Stefan H. Heinemann Prof. Dr. Hans‐Dieter Arndt 《Angewandte Chemie (International ed. in English)》2015,54(35):10352-10355
The largest continuous bacterial nonribosomal peptide synthetase discovered so far is described. It consists of 15 consecutive modules arising from an uninterrupted, fully functional gene in the entomopathogenic bacterium Photorhabdus luminescens. The identification of its cryptic biosynthesis product was achieved by using a combination of genome analysis, promoter exchange, isotopic labeling experiments, and total synthesis of a focused collection of peptide candidates. Although it belongs to the growing class of D ‐/ L ‐peptide natural products, the encoded metabolite kolossin A was found to be largely devoid of antibiotic activity and is likely involved in interspecies communication. A stereoisomer of this peculiar natural product displayed high activity against Trypanosoma brucei rhodesiense, a recalcitrant parasite that causes the deadly disease African sleeping sickness. 相似文献
10.
Nano titanium dioxide (nTiO2), generally considered to be toxicologically inert, is manufactured in large quantities and extensively applied in consumer products. The small size and large surface area endow them with an active group or intrinsic toxicity. Advances in instrumentation are making Raman spectroscopy the tool of choice for an increasing number of (bio) chemical applications. One of the great advantages of this technique is its ability to provide information on the concentration, structure and interaction of biochemical molecules in their microenvironments within intact cells and tissues, non-destructively. Zebrafish (Danio rerio), one of the most important vertebrate model organisms used in developmental biology, are increasingly used in biomedical research, particularly as a model of human disease. In the present work, an attempt is made to study the effect of titanium dioxide, both nano and bulk, on the microenvironment of the liver tissues of Zebrafish using FT-Raman spectroscopy. The results of the present study suggest that TiO2 exposure demonstrate a marked influence on the microenvironments of the liver tissues of Zebrafish. A shift to a higher wavenumber and an increase in the intensity of the band at ∼1087 cm−1 in the TiO2 exposed tissues suggest that some of the conformational changes resulting from the alkali recovery process takes place due to TiO2 exposure. The decreased intensity ratio (I3220/I3400) observed in the titanium-exposed tissues suggests a decreased water domain size, which could be interpreted in terms of weaker hydrogen-bonded molecular species of water in the TiO2 exposed tissues. The observed shift of COO− bands to higher frequencies shows the disruption of salt bridges as a result of a change in the oppositely charged partners and due to the enhanced random coil conformation. The variation in the intensity ratio of the tyrosyl doublet (I858/I825) indicates variation in the hydrogen bonding of the phenolic hydroxyl group due to TiO2 exposure. The results further suggest that the microenvironments are greatly altered due to titanium nano exposure when compared to titanium bulk. In conclusion, the results indicate that FT-Raman spectroscopy might be a useful tool for rapid assessment of nano particle biological interactions. 相似文献