全文获取类型
收费全文 | 133篇 |
免费 | 1篇 |
学科分类
数理化 | 134篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2019年 | 2篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 6篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2009年 | 2篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 4篇 |
1970年 | 8篇 |
1969年 | 9篇 |
1968年 | 4篇 |
1967年 | 3篇 |
1966年 | 4篇 |
1965年 | 1篇 |
1961年 | 1篇 |
1960年 | 1篇 |
1937年 | 1篇 |
排序方式: 共有134条查询结果,搜索用时 312 毫秒
101.
M Julia BF Flaminio Alexandre S Borges Daryl V Nydam David W Horohov Rolf Hecker Mary Beth Matychak 《Journal of immune based therapies and vaccines》2007,5(1):1-17
Background
Cytosine-phosphate-guanosine oligodeoxynucleotide (CpG-ODN) has been used successfully to induce immune responses against viral and intracellular organisms in mammals. The main objective of this study was to test the effect of CpG-ODN on antigen presenting cells of young foals. 相似文献102.
103.
104.
A protocol for transferring an unknown single qubit state evidences quantum features when the average fidelity of the outcomes is, in principle, greater than 2/3. We propose to use the probabilistic and unambiguous state extraction scheme as a mechanism to redistribute the fidelity in the outcome of the standard teleportation when the process is performed with an X-state as a noisy quantum channel. We show that the entanglement of the channel is necessary but not sufficient in order for the average fidelity fX to display quantum features, i.e., we find a threshold CX for the concurrence of the channel. On the other hand, if the mechanism for redistributing fidelity is successful then we find a filterable outcome with average fidelity fX,0 that can be greater than fX. In addition, we find the threshold concurrence of the channel CX,0 in order for the average fidelity fX,0 to display quantum features and surprisingly, the threshold concurrence CX,0 can be less than CX. Even more, we find some special cases for which the threshold values become zero. 相似文献
105.
Erich Hecker 《Fresenius' Journal of Analytical Chemistry》1961,181(1):284-303
Zusammenfassung Multiplikative Verteilungsverfahren haben sich als Routinemethoden zur Trennung von Substanzen aller Stoffklassen durchgesetzt. Neue analytische Anwendungen ergaben sich in der radioaktiven Verdünnungsanalyse. Darüber hinaus ist die Anwendung der Verfahren in den letzten Jahren besonders auf hochmolekulare Verbindungen von technologischem und biologischem Interesse ausgedehnt worden. Entscheidende Bedeutung kommt dabei der Auswahl geeigneter Lösungsmittelsysteme zu. Eine Anzahl geeigneter Phasenpaare wird diskutiert. Der Mechanismus kontinuierlicher Verfahren ist eingehend untersucht worden und hat zu mathematischen Ansätzen geführt, die eine Berechnung sämtlicher interessierenden Parameter auf elektronischen Rechenautomaten (IBM 650) ermöglichen. Die Bedeutung der kontinuierlichen Verfahren auch für analytische Probleme wird aufgezeigt. 相似文献
106.
A rapid method to investigate the metabolism of 125I-labelled or non-labelled human big endothelin to endothelin-1 by reversed-phase high-performance liquid chromatography (HPLC) and on-line radioactive flow monitoring and/or ultraviolet detection was developed. Samples were processed by solid-phase extraction (average recovery 70-80% for non-labelled and 20-25% for 125I-labelled big endothelin and endothelin-1) followed by HPLC analysis (total analysis time 20 min). The method was successfully employed to monitor the conversion of big endothelin to endothelin-1 by various blood-borne cells, such as human polymorphonuclear leukocytes or monocytes/macrophages. 相似文献
107.
Hecker EA Duraiswami C Andrea TA Diller DJ 《Journal of chemical information and computer sciences》2002,42(5):1204-1211
Using a data set comprised of literature compounds and structure-activity data for cyclin dependent kinase 2, several pharmacophore hypotheses were generated using Catalyst and evaluated using several criteria. The two best were used in retrospective searches of 10 three-dimensional databases containing over 1,000,000 proprietary compounds. The results were then analyzed for the efficiency with which the hypotheses performed in the areas of compound prioritization, library prioritization, and library design. First as a test of their compound prioritization capabilities, the pharmacophore models were used to search combinatorial libraries that were known to contain CDK active compounds to see if the pharmacophore models could selectively choose the active compounds over the inactive compounds. Second as a test of their utility in library design again the pharmacophore models were used to search the active combinatorial libraries to see if the key synthons were over represented in the hits from the pharmacophore searches. Finally as a test of their ability to prioritize combinatorial libraries, several inactive libraries were searched in addition to the active libraries in order to see if the active libraries produced significantly more hits than the inactive libraries. For this study the pharmacophore models showed potential in all three areas. For compound prioritization, one of the models selected active compounds at a rate nearly 11 times that of random compound selection though in other cases models missed the active compounds entirely. For library design, most of the key fragments were over represented in the hits from at least one of the searches though again some key fragments were missed. Finally, for library prioritization, the two active libraries both produced a significant number of hits with both pharmacophore models, whereas none of the eight inactive libraries produced a significant number of hits for both models. 相似文献
108.
de Matos Costa Anna Raffaela Santos Raquel Marques Ito Edson Noriyuki de Carvalho Laura Hecker Canedo Eduardo Luís 《Journal of Thermal Analysis and Calorimetry》2019,137(4):1341-1346
Journal of Thermal Analysis and Calorimetry - Melt and cold crystallization characteristics of poly(3-hydroxybutyrate) (PHB) and poly(butylene adipate-co-terephthalate) (PBAT), two biodegradable... 相似文献
109.
Shaokang Zhang Ru Wang Linglin Xu Andreas Hecker Horst-Michael Ludwig Peiming Wang 《Molecules (Basel, Switzerland)》2021,26(8)
This paper studies the influence of hydroxyethyl methyl cellulose (HEMC) on the properties of calcium sulfoaluminate (CSA) cement mortar. In order to explore the applicability of different HEMCs in CSA cement mortars, HEMCs with higher and lower molar substitution (MS)/degree of substitution (DS) and polyacrylamide (PAAm) modification were used. At the same time, two kinds of CSA cements with different contents of ye’elimite were selected. Properties of cement mortar in fresh and hardened states were investigated, including the fluidity, consistency and water-retention rate of fresh mortar and the compressive strength, flexural strength, tensile bond strength and dry shrinkage rate of hardened mortar. The porosity and pore size distribution were also analyzed by mercury intrusion porosimetry (MIP). Results show that HEMCs improve the fresh state properties and tensile bond strength of both types of CSA cement mortars. However, the compressive strength of CSA cement mortars is greatly decreased by the addition of HEMCs, and the flexural strength is decreased slightly. The MIP measurement shows that HEMCs increase the amount of micron-level pores and the porosity. The HEMCs with different MS/DS have different effects on the improvement of tensile bond strength in different CSA cement mortars. PAAm modification can improve the tensile bond strength of HEMC-modified CSA cement mortar. 相似文献
110.
Winkler K Lang F Thalhammer G Straten Pv Grimm R Denschlag JH 《Physical review letters》2007,98(4):043201
Using the technique of stimulated Raman adiabatic passage (STIRAP) we have coherently transferred ultracold (87)Rb(2) Feshbach molecules into a more deeply bound vibrational quantum level. Our measurements indicate a high transfer efficiency of up to 87%. Because the molecules are held in an optical lattice with not more than a single molecule per lattice site, inelastic collisions between the molecules are suppressed and we observe long molecular lifetimes of about 1 s. Using STIRAP we have created quantum superpositions of the two molecular states and tested their coherence interferometrically. These results represent an important step towards Bose-Einstein condensation of molecules in the vibrational ground state. 相似文献