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排序方式: 共有136条查询结果,搜索用时 15 毫秒
131.
Vittorio Canale Magdalena Kotaska Anna Dziubina Matylda Stefaniak Agata Siwek Gabriela Starowicz Krzysztof Marciniec Patryk Kasza Grzegorz Sataa Beata Duszyska Xavier Bantreil Frdric Lamaty Marek Bednarski Jacek Sapa Pawe Zajdel 《Molecules (Basel, Switzerland)》2021,26(13)
The complex pathophysiology of depression, together with the limits of currently available antidepressants, has resulted in the continuous quest for alternative therapeutic strategies. Numerous findings suggest that pharmacological blockade of α2-adrenoceptor might be beneficial for the treatment of depressive symptoms by increasing both norepinephrine and serotonin levels in certain brain areas. Moreover, the antidepressant properties of 5-HT7 receptor antagonists have been widely demonstrated in a large set of animal models. Considering the potential therapeutic advantages in targeting both α2-adrenoceptors and 5-HT7 receptors, we designed a small series of arylsulfonamide derivatives of (dihydrobenzofuranoxy)ethyl piperidines as dually active ligands. Following green chemistry principles, the designed compounds were synthesized entirely using a sustainable mechanochemical approach. The identified compound 8 behaved as a potent α2A/5-HT7 receptor antagonist and displayed moderate-to-high selectivity over α1-adrenoceptor subtypes and selected serotonin and dopaminergic receptors. Finally, compound 8 improved performance of mice in the forced swim test, displaying similar potency to the reference drug mirtazapine. 相似文献
132.
Christiansen SC Hedin N Epping JD Janicke MT del Amo Y Demarest M Brzezinski M Chmelka BF 《Solid state nuclear magnetic resonance》2006,29(1-3):170-182
The robustness and sensitivities of different polarization-transfer methods that exploit heteronuclear dipole-dipole couplings are compared for a series of heterogeneous solid systems, including polycrystalline tetrakis(trimethylsilyl)silane (TKS), adamantane, a physical mixture of doubly (13)C,(15)N-enriched and singly (13)C-enriched polycrystalline glycine, and a powder sample of siliceous marine diatoms, Thalossiosira pseudonana. The methods were analyzed according to their respective frequency-matching spectra or resultant signal intensities. For a series of (13)C{(1)H} cross-polarization experiments, adiabatic passage Hartmann-Hahn cross-polarization (APHH-CP) was shown to have several advantages over other methods, including Hartmann-Hahn cross-polarization (HHCP), variable-amplitude cross-polarization (VACP), and ramped-amplitude cross-polarization (RACP). For X-Y systems, such as (13)C{(15)N}, high and comparable sensitivities were obtained by using APHH-CP with Lee-Goldburg decoupling or by using the transferred-echo double resonance (TEDOR) experiment. The findings were applied to multinuclear (1)H, (13)C, (15)N, and (29)Si CP MAS characterization of a powder diatom sample, a challenging inorganic-organic hybrid solid that places high demands on NMR signal sensitivity. 相似文献
133.
Bartomiej Sadowski Marzena Kaliszewska Yevgen M. Poronik Magorzata Czichy Patryk Janasik Marzena Banasiewicz Dominik Mierzwa Wojciech Gadomski Trevor D. Lohrey John A. Clark Mieczysaw apkowski Bolesaw Kozankiewicz Valentine I. Vullev Andrzej L. Sobolewski Piotr Piatkowski Daniel T. Gryko 《Chemical science》2021,12(42):14039
Nitroaromatics seldom fluoresce. The importance of electron-deficient (n-type) conjugates, however, has inspired a number of strategies for suppressing the emission-quenching effects of the strongly electron-withdrawing nitro group. Here, we demonstrate how such strategies yield fluorescent nitroaryl derivatives of dipyrrolonaphthyridinedione (DPND). Nitro groups near the DPND core quench its fluorescence. Conversely, nitro groups placed farther from the core allow some of the highest fluorescence quantum yields ever recorded for nitroaromatics. This strategy of preventing the known processes that compete with photoemission, however, leads to the emergence of unprecedented alternative mechanisms for fluorescence quenching, involving transitions to dark nπ* singlet states and aborted photochemistry. Forming nπ* triplet states from ππ* singlets is a classical pathway for fluorescence quenching. In nitro-DPNDs, however, these ππ* and nπ* excited states are both singlets, and they are common for nitroaryl conjugates. Understanding the excited-state dynamics of such nitroaromatics is crucial for designing strongly fluorescent electron-deficient conjugates.Dipyrrolonaphthyridinedione appended with para- or meta-nitrophenyl substituents exhibits strong fluorescence from a 1ππ* S1 state. 相似文献
134.
Mariusz Tasior Pawe Kowalczyk Marta Przyby Magorzata Czichy Patryk Janasik Manon H. E. Bousquet Mieczysaw apkowski Matt Rammo Aleksander Rebane Denis Jacquemin Daniel T. Gryko 《Chemical science》2021,12(48):15935
A two-step route to strongly absorbing and efficiently orange to deep red fluorescent, doubly B/N-doped, ladder-type pyrrolo[3,2-b]pyrroles has been developed. We synthesize and study a series of derivatives of these four-coordinate boron-containing, nominally quadrupolar materials, which mostly exhibit one-photon absorption in the 500–600 nm range with the peak molar extinction coefficients reaching 150 000, and emission in the 520–670 nm range with the fluorescence quantum yields reaching 0.90. Within the family of these ultrastable dyes even small structural changes lead to significant variations of the photophysical properties, in some cases attributed to reversal of energy ordering of alternate-parity excited electronic states. Effective preservation of ground-state inversion symmetry was evidenced by very weak two-photon absorption (2PA) at excitation wavelengths corresponding to the lowest-energy, strongly one-photon allowed purely electronic transition. π-Expanded derivatives and those possessing electron-donating groups showed the most red-shifted absorption- and emission spectra, while displaying remarkably high peak 2PA cross-section (σ2PA) values reaching ∼2400 GM at around 760 nm, corresponding to a two-photon allowed higher-energy excited state. At the same time, derivatives lacking π-expansion were found to have a relatively weak 2PA peak centered at ca. 800–900 nm with the maximum σ2PA ∼50–250 GM. Our findings are augmented by theoretical calculations performed using TD-DFT method, which reproduce the main experimental trends, including the 2PA, in a nearly quantitative manner. Electrochemical studies revealed that the HOMO of the new dyes is located at ca. −5.35 eV making them relatively electron rich in spite of the presence of two B−–N+ dative bonds. These dyes undergo a fully reversible first oxidation, located on the diphenylpyrrolo[3,2-b]pyrrole core, directly to the di(radical cation) stage.Ladder-type heterocycles encompassing two B−–N+ dative bonds possess intense green to red emission, large 2PA cross-sections and superb photostability. 相似文献
135.
Nebeluk Robert Zarzycki Krzysztof Seredyński Dawid Chaber Patryk Figat Maksym Domański Paweł D. Zieliński Cezary 《Nonlinear dynamics》2023,111(9):8383-8395
Nonlinear Dynamics - Moving-object tracking using a pan–tilt camera setup is quite a well-known task in robotics. However, the presented research addresses specific properties of the tracked... 相似文献
136.