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51.
Bhawna Sharma Kamal Kishor Sandeep Sharma Roshan Makkar 《Fiber and Integrated Optics》2013,32(4):247-257
ABSTRACTIntegrated photonics enables the miniaturization of bulk optical components for biosensing applications such as optical coherence tomography (OCT) and is therefore promising for future lab-on-chip solutions. Here, we report the design and simulation of a compact low loss broadband beam splitter with arbitrary coupling ratios on silicon nitride platform for OCT systems. The reported coupler uses asymmetric waveguide-based phase control section for 10:90, 20:80, 30:70, 40:60, and 50:50 splitting ratios and is broadband over 100 nm with the central wavelength of 850 nm. The couplers are realized for transverse electric, transverse magnetic, and fully vectorial modes, and maximum excess loss for all mode types is reported to be less than 0.19 dB. The design tolerance of waveguide width and thickness of the designed coupler is further calculated and is within fabrication limit. 相似文献
52.
Analysis of Pore Pressure Distribution in Shale Formations under Hydraulic,Chemical, Thermal and Electrical Interactions 总被引:1,自引:0,他引:1
Change in pore pressure in chemically active rocks such as shale is caused by several mechanisms and numerous studies have
been carried out to investigate these mechanisms. However, some important coupling terms or driving forces have been neglected
in these studies due to simplifying assumptions. In this study, a hydro-chemo-thermo-electrical model based on finite element
method is presented to investigate the change in pore pressure in shale formations resulted from thermal, hydraulic, chemical
and electric potential gradients. The change in pore pressure is induced by hydraulic conduction, chemical, electrical and
thermal osmotic flow. In order to solve the problem of ion transfer under the influence of an electrical field, the Nernst–Planck
equation is used. In addition, ion advection is considered to investigate its possible effect on ion transfer for the range
of shale permeability. All equations are derived based on the thermodynamics of irreversible processes in a discontinuous
system. The numerical results are compared against existing and derived uncoupled analytical solutions and good agreement
is observed. The numerical results showed that the ion transfer and pore pressure are considerably affected by the electric
field in the vicinity of the wellbore. It was also found that advection can play a remarkable role in ion transfer in shale
formations. It was further shown that the change in pore pressure in shale formation is characterized by the combined effect
of hydraulic, chemical, thermal and electro osmotic flow. 相似文献
53.
Ezio Rizzardo John Chiefari Roshan Mayadunne Graeme Moad San Thang 《Macromolecular Symposia》2001,174(1):209-212
Living radical polymerization methods that allow the preparation of polymers with predetermined molecular weight, narrow molecular weight distribution and tailored architecture (e.g. block, graft, stars) are offering a vast range of new and advanced materials. With applications ranging from surfactants, dispersants, coatings and adhesives, to microelectronics, membranes, drug delivery, and biomaterials they have the potential of revolutionizing a large part of the polymer industry. 相似文献
54.
Guru R. Valicherla Roshan A. Katekar Shailesh Dadge Mohammed Riyazuddin Anees A. Syed Sandeep K. Singh Athar Husain Muhammad Wahajuddin Jiaur R. Gayen 《Molecules (Basel, Switzerland)》2022,27(2)
PSTi8 is a pancreastatin inhibitory peptide that is effective in the treatment of diabetic models. This study investigates the pharmacokinetic (PK) properties of PSTi8 in Sprague Dawley rats, for the first time. In vitro and in vivo PK studies were performed to evaluate the solubility, stability in plasma and liver microsomes, plasma protein binding, blood–plasma partitioning, bioavailability, dose proportionality, and gender difference in PK. Samples were analyzed using the validated LC-MS/MS method. The solubility of PSTi8 was found to be 9.30 and 25.75 mg/mL in simulated gastric and intestinal fluids, respectively. The protein binding of PSTi8 was estimated as >69% in rat plasma. PSTi8 showed high stability in rat plasma and liver microsomes and the blood–plasma partitioning was >2. The bioavailability of PSTi8 after intraperitoneal and subcutaneous administration was found to be 95.00 ± 12.15 and 78.47 ± 17.72%, respectively, in rats. PSTi8 showed non-linear PK in dose proportionality studies, and has no gender difference in the PK behavior in rats. The high bioavailability of PSTi8 can be due to high water solubility and plasma protein binding, low clearance and volume of distribution. Our in vitro and in vivo findings support the development of PSTi8 as an antidiabetic agent. 相似文献
55.
Muhammad Ramzan Mohmed Isaqali Karobari Artak Heboyan Roshan Noor Mohamed Mohammed Mustafa Syed Nahid Basheer Vijay Desai Salma Batool Naveed Ahmed Basit Zeshan 《Molecules (Basel, Switzerland)》2022,27(6)
Antibiotic resistance rate is rising worldwide. Silver nanoparticles (AgNPs) are potent for fighting antimicrobial resistance (AMR), independently or synergistically. The purpose of this study was to prepare AgNPs using wild ginger extracts and to evaluate the antibacterial efficacy of these AgNPs against multidrug-resistant (MDR) Staphylococcus aureus, Streptococcus mutans, and Enterococcus faecalis. AgNPs were synthesized using wild ginger extracts at room temperature through different parameters for optimization, i.e., pH and variable molar concentration. Synthesis of AgNPs was confirmed by UV/visible spectroscopy and further characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy analysis (EDXA), and Fourier-transform infrared spectroscopy (FTIR). Disc and agar well diffusion techniques were utilized to determine the in vitro antibacterial activity of plant extracts and AgNPs. The surface plasmon resonance peaks in absorption spectra for silver suspension showed the absorption maxima in the range of 400–420 nm. Functional biomolecules such as N–H, C–H, O–H, C–O, and C–O–C were present in Zingiber zerumbet (Z. zerumbet) (aqueous and organic extracts) responsible for the AgNP formation characterized by FTIR. The crystalline structure of ZZAE-AgCl-NPs and ZZEE-AgCl-NPs was displayed in the XRD analysis. SEM analysis revealed the surface morphology. The EDXA analysis also confirmed the element of silver. It was revealed that AgNPs were seemingly spherical in morphology. The biosynthesized AgNPs exhibited complete antibacterial activity against the tested MDR bacterial strains. This study indicates that AgNPs of wild ginger extracts exhibit potent antibacterial activity against MDR bacterial strains. 相似文献
56.
57.
Acoustic non-linearity parameter B/A is calculated for five binary liquid mixtures using Tong and Dong equation along with
the Flory’s statistical theory. Similar to other excess thermodynamical quantities an excess non-linearity parameter (B/A)E is defined for binary liquid mixtures. The interactions in the liquid mixtures are explained on the basis of the excess non-linearity
parameter. 相似文献
58.
Antony Godwin Ji-Won Choi Elisa Pedone Sibu Balan Roshan Jumnah Sunil Shaunak Steve Brocchini Mire Zloh 《Theoretical chemistry accounts》2007,117(2):259-265
Proteins that are used as therapeutic drugs act in the extracellular microenvironment. They usually have a small number of
intramolecular disulfide bonds to help maintain their tertiary structure in the vascular circulation. In general, most cysteine
residues are part of a disulfide bond with free sulfhydrals being uncommon. We have studied whether the site-specific chemical
reduction of disulfides and the incorporation of a 3-carbon methylene bridge between the cysteines in interferon-α 2a would
change the structure of this protein. Bridging of both of the disulfide bonds of interferon-α 2a was studied using two different
molecular simulation protocols: (1) molecular dynamics, and (2) stochastic dynamics. We have shown that the disulfide bonds
in interferon-α 2a can be reduced and chemically modified without significantly altering the tertiary structure of the protein.
This offers the novel possibility of chemically modifying therapeutically important proteins without affecting their biological
properties. 相似文献
59.
Roshan R. Kulkarni Ketaki Shurpali Vijay M. Khedkar Vedavati G. Puranik Dhiman Sarkar 《Natural product research》2016,30(6):675-681
Phytochemical investigation of the acetone extract of the aerial parts of Anisochilus verticillatus afforded a new 8,9-secopimarane diterpene (1), two new isopimarane diterpenes (2, 3) and the known ursolic acid (4), α-amyrin (5), β-amyrin (6), stigmast-5-en-3-one (7) and hydroxychavicol (8). Structures of the new compounds were elucidated with the help of 1D and 2D nuclear magnetic resonance spectroscopic data, and single crystal X-ray crystallography of compound 3. Compounds 2 and 8 inhibited Mycobacterium tuberculosis H37Ra with an IC50 of 11.3 (IC90 of 20.0 μg/mL) and 12.5 μg/mL, respectively. Correspondingly, molecular docking studies with Extra Precision Glide revealed a correlation between score and biological activity for these compounds to describe the molecular basis for the most significant SAR results. 相似文献
60.
Reconstruction of phylogenetic trees for very large datasets is a known example of a computationally hard problem. In this paper, we present a parallel computing model for the widely used Multiple Instruction Multiple Data (MIMD) architecture. Following the idea of divide-and-conquer, our model adapts the recursive-DCM3 decomposition method [Roshan, U., Moret, B.M.E., Williams, T.L., Warnow, T, 2004a. Performance of suptertree methods on various dataset decompositions. In: Binida-Emonds, O.R.P. (Eds.), Phylogenetic Supertrees: Combining Information to Reveal the Tree of Life, vol. 3 of Computational Biology, Kluwer Academics, pp. 301-328; Roshan, U., Moret, B.M.E., Williams, T.L., Warnow, T., 2004b. Rec-I-DCM3: A Fast Algorithmic Technique for reconstructing large phylogenetic trees, Proceedings of the IEEE Computational Systems Bioinformatics Conference (ICSB)] to divide datasets into smaller subproblems. It distributes computation load over multiple processors so that each processor constructs subtrees on each subproblem within a batch in parallel. It finally collects the resulting trees and merges them into a supertree. The proposed model is flexible as far as methods for dividing and merging datasets are concerned. We show that our method greatly reduces the computational time of the sequential version of the program. As a case study, our parallel approach only takes 22.1h on four processors to outperform the best score to date (Found at 123.7h by the Rec-I-DCM3 program [Roshan, U., Moret, B.M.E., Williams, T.L., Warnow, T, 2004a. Performance of suptertree methods on various dataset decompositions. In: Binida-Emonds, O.R.P. (Eds.), Phylogenetic Supertrees: Combining Information to Reveal the Tree of Life, vol. 3 of Computational Biology, Kluwer Academics, pp. 301-328; Roshan, U., Moret, B.M.E., Williams, T.L., Warnow, T., 2004b. Rec-I-DCM3: A Fast Algorithmic Technique for reconstructing large phylogenetic trees, Proceedings of the IEEE Computational Systems Bioinformatics Conference (ICSB)] on one dataset. Developed with the standard message-passing library, MPI, the program can be recompiled and run on any MIMD systems. 相似文献