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91.
This study investigates the rotating magnetohydrodynamic (MHD) flow of a third-grade fluid in a porous space. Modified Darcy's
law has been utilized for the flow modeling. The Hall effects are taken into consideration. The basic equations governing
the flow are reduced to a highly nonlinear ordinary differential equation. This equation has been solved analytically by employing
the homotopy analysis method (HAM). The effects of the various interesting parameters on the velocity distribution have been
discussed. 相似文献
92.
On Solutions of Some Non-Linear Differential Equations Arising in Newtonian and Non-Newtonian Fluids
Mohyuddin M. R. Hayat T. Mahomed F. M. Asghar S. Siddiqui A. M. 《Nonlinear dynamics》2004,35(3):229-248
Some steady as well as unsteady solutions of the equations of motion for an incompressible Newtonian and non-Newtonian (second-grade)
fluids are obtained by applying different methods including the Lie symmetry group method. The flows considered are axially
symmetric with the swirling motion, and the governing equations for second-grade fluid flow have been modeled. Expressions
for streamlines, velocity and vorticity components are constructed explicitly in each case. Exact analytical solutions in
second-grade fluid are obtained and compared with the corresponding viscous solutions. 相似文献
93.
94.
Structure and dynamics of highly PEG-ylated sterically stabilized micelles in aqueous media 总被引:1,自引:0,他引:1
Vuković L Khatib FA Drake SP Madriaga A Brandenburg KS Král P Onyuksel H 《Journal of the American Chemical Society》2011,133(34):13481-13488
Molecular assemblies of highly PEG-ylated phospholipids are important in many biomedical applications. We have studied sterically stabilized micelles (SSMs) of self-assembled DSPE–PEG2000 in pure water and isotonic HEPES-buffered saline solution. The observed SSM sizes of 2–15 nm largely depend on the solvent and the lipid concentration used. The critical micelle concentration of DSPE–PEG2000 is 10 times higher in water than in buffer, and the viscosity of the dispersion dramatically increases with the lipid concentration. To explain the experimentally observed results, we performed atomistic molecular dynamics simulations of solvated SSMs. Our modeling revealed that the observed assemblies have very different aggregation numbers (N(agg) ≈ 90 in saline solution and N(agg) < 8 in water) because of very different screening of their charged PO4(–) groups. We also demonstrate that the micelle cores can inflate and their coronas can fluctuate strongly, thus allowing storage and delivery of molecules with different chemistries. 相似文献
95.
Okadaic acid (OA), responsible for gastrointestinal problems, inhibits protein phosphatase 2A (PP2A). Therefore, the inhibition exerted by the toxin on PP2A could be used to detect the presence of OA in aqueous solution and in shellfish sample.In this work, two commercial PP2As (from ZEU Immunotec and Millipore) and one produced by molecular engineering (from GTP Technology) were tested. Enzymes were used in solution and also immobilized within a polymeric gel. In solution, best performances were obtained using PP2A purchased from ZEU Immunotec (Spain). OA was detected in aqueous solution in concentration as low as 0.0124 μg L−1 using the enzyme from ZEU Immunotec whereas the detection limits were 0.47 μg L−1 and 0.123 μg L−1 with PP2As from Millipore and GTP Technology, respectively. Considering that the immobilization step contributes to stabilize the PP2A activity, enzymes were entrapped within a photopolymer and an agarose gel. These different polymeric matrices were optimized, tested and compared. Agarose gel seems to be a good alternative to the photopolymer largely used in our group. For instance, the IC50 value obtained with the test based on PP2A from ZEU Immunotec immobilized within an agarose gel was 1.98 μg L−1. This value was 1.8-fold lower than those obtained with the photopolymer test using the same enzyme. The proposed test is sensitive, fast and does not require expensive equipment. To evaluate the efficiency of the assay, PP inhibition tests based on PP2A from ZEU Immunotec in solution or immobilized within a gel were used for OA detection in contaminated shellfish. 相似文献
96.
Hanif MA Al-Maskri AY Al-Mahruqi ZM Al-sabahi JN Al-Azkawi A Al-Maskari MY 《Natural product communications》2011,6(10):1451-1454
Three wild Omani plants, Moringa peregrina, Acacia nilotica and Rhazya stricta, were selected for the present study. Na, K and Ca contents were determined using flame photometric analysis. M. peregrina seeds (22.5 mg/g) and pods (27.7 mg/g) had higher Na contents than A. nilotica (0.33 mg/g) and R. stricta (0.30 mg/g), whereas the K and Ca contents of R. stricta were significantly higher than those of the other two plants. The protein content was lowest in R. stricta (9.8%) and highest in M peregrina seeds (21.0%). The highest total phenolic contents (TPC) were found in M. peregrina seeds (350.3 mg/g) and the lowest in A. nilotica (66.1 mg/g). The major component of M. peregrina seed oil was oleic acid (74.7%). Gas chromatographic-mass spectrometric analysis (GC-MS) revealed that octadecanal (30.9%) was the major compound in A. nilotica. The presence of various phenolics and flavonoids in M. peregrina, A. nilotica and R. stricta were confirmed by high performance liquid chromatography (HPLC). 相似文献
97.
M. Pakdemirli T. Hayat M. Yürüsoy S. Abbasbandy S. Asghar 《Nonlinear Analysis: Real World Applications》2011,12(3):1774-1785
A modified second grade non-Newtonian fluid model is considered. The model is a combination of power-law and second grade fluids in which the fluid may exhibit normal stresses, shear thinning or shear thickening behaviors. The flow of this fluid is considered over a porous plate. Equations of motion in dimensionless form are derived. When the power-law effects are small compared to second grade effects, a regular perturbation problem arises which is solved. The validity criterion for the solution is derived. When second grade effects are small compared to power-law effects, or when both effects are small, the problem becomes a boundary layer problem for which the solutions are also obtained. Perturbation solutions are contrasted with the numerical solutions. For the regular perturbation problem of small power-law effects, an excellent match is observed between the solutions if the validity criterion is met. For the boundary layer solution of vanishing second grade effects however, the agreement with the numerical data is not good. When both effects are considered small, the boundary layer solution leads to the same solution given in the case of a regular perturbation problem. 相似文献
98.
Mu Xiaojie Jiang Daqing Hayat Tasawar Alsaedi Ahmed Ahmad Bashir 《Nonlinear dynamics》2021,103(2):2081-2096
Nonlinear Dynamics - The mathematical model with time delay is often more practical because it is subject to current and past state. What remains unclear are the details, such as how time delay and... 相似文献
99.
Miaomiao Gao Daqing Jiang Tasawar Hayat Ahmed Alsaedi 《Mathematical Methods in the Applied Sciences》2021,44(1):1013-1028
In this paper, we study the dynamical behavior of a stochastic food chain chemostat model, in which the white noise is proportional to the variables. Firstly, we prove the existence and uniqueness of the global positive solution. Then by constructing suitable Lyapunov functions, we show the system has a unique ergodic stationary distribution. Furthermore, the extinction of microorganisms is discussed in two cases. In one case, both the prey and the predator species are extinct, and in the other case, the prey species is surviving and the predator species is extinct. Finally, numerical experiments are performed for supporting the theoretical results. 相似文献
100.
Muhammad Khurram Tufail Adeel Ahmed Muhammad Rafiq Muhammad Asif Nawaz Syed Shoaib Ahmad Shah Manzar Sohail Muhammad Sufyan Javed Tayyaba Najam Raed H. Althomali Mohammed M. Rahman 《Chemical record (New York, N.Y.)》2024,24(1):e202300155
In recent years, flexible and wearable electronics such as smart cards, smart fabrics, bio-sensors, soft robotics, and internet-linked electronics have impacted our lives. In order to meet the requirements of more flexible and adaptable paradigm shifts, wearable products may need to be seamlessly integrated. A great deal of effort has been made in the last two decades to develop flexible lithium-ion batteries (FLIBs). The selection of suitable flexible materials is important for the development of flexible electrolytes self-supported and supported electrodes. This review is focused on the critical discussion of the factors that evaluate the flexibility of the materials and their potential path toward achieving the FLIBs. Following this analysis, we present how to evaluate the flexibility of the battery materials and FLIBs. We describe the chemistry of carbon-based materials, covalent-organic frameworks (COFs), metal-organic frameworks (MOFs), and MXene-based materials and their flexible cell design that represented excellent electrochemical performances during bending. Furthermore, the application of state-of-the-art solid polymer and solid electrolytes to accelerate the development of FLIBs is introduced. Analyzing the contributions and developments of different countries has also been highlighted in the past decade. In addition, the prospects and potential of flexible materials and their engineering are also discussed, providing the roadmap for further developments in this fast-evolving field of FLIB research. 相似文献