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141.
Tsuyoshi Nakayama Ha Minh Hiep Satoshi Furui Yuji Yonezawa Masato Saito Yuzuru Takamura Eiichi Tamiya 《Analytical and bioanalytical chemistry》2010,396(1):457-464
DNA analysis with the polymerase chain reaction (PCR) has become a routine part of medical diagnostics, environmental inspections,
food evaluations, and biological studies. Furthermore, the development of a microscale PCR chip is an essential component
of studies aimed at integrating PCR into a micro total analysis system (μ-TAS). However, the occurrence of air bubbles in
microchannels complicates this process. In this study, we investigated a new technique based on the fluid dynamics of laminar
flow that utilizes a small amount of mineral oil at the beginning of sample injection to prevent air bubbles from occurring
in microchannels. We also further optimized the pressure, the length of the pressurizing channel and the volume of oil, thus
making our microfluidic device more useful for high-temperature PCR. Additionally, quantitative continuous-flow PCR was performed
using the optimized PCR chip in order to detect genetically modified (GM) maize. DNA was extracted from GM maize, MON 810,
and non-GM maize at several concentrations from 0% (w/v) to 100% (w/v). The DNA amplification signals were then analyzed on
the PCR chip using a laser-based system. The signal from our microfluidic PCR chip was found to increase in direct proportion
to the initial GM maize concentration. 相似文献
142.
Three-component allylation and cyanation utilizing a ketone and an N-methoxyamine are reported. The high nucleophilicity of the N-methoxyamine and high electrophilicity of the corresponding iminium ion enable the concise synthesis of α-trisubstituted amines in a single step. 相似文献
143.
Tanaka R Yuhi T Nagatani N Endo T Kerman K Takamura Y Tamiya E 《Analytical and bioanalytical chemistry》2006,385(8):1414-1420
The immunochromatographic assay is a well-known and convenient diagnostic system. In this report, the development of a novel
enhancement assay for the test strips is described. Additionally, this highly sensitive immunochromatographic assay was applied
to detect human chorionic gonadotropin hormone (HCG) as the model case. The primary antibody-conjugated gold nanoparticles
were used as the enhancer of the standard method. The primary antibodies were immobilized within a defined detection zone
(test line) on the diagnostic nitrocellulose membrane. The secondary antibodies were conjugated with colloidal gold nanoparticles.
In combination with an effective sample pretreatment, the gold-conjugated antibodies and the primary antibodies formed a sandwich
complex with the target protein. Within the test line, the sandwich complex was immobilized, and furthermore, concentrated
by the enhancer resulting in a localized surface plasmon resonance (LSPR) phenomenon and a distinct red color on the test
line. The intensity of color of the red test line (signal intensity), which correlated directly with the concentration of
the target protein in the standard or spiked samples, was assessed visually and by computer image analysis using a three-determination
analysis. Under optimum conditions, the limit of detection (LOD) for HCG assay was 1 pg/mL. When using human serum, 10 pg/mL
of HCG could be detected. We have also spiked total prostate-specific antigen (TPSA) in female serum. The LOD for TPSA was
determined as 0.2 ng/mL. With this method, the quantitative determination of the target protein could be completed in less
than 15 min. Our novel immunochromatographic strips using the enhancing method based on LSPR of gold nanoparticles are useful
as a rapid and simple screening method for the detection of important analytes for medical applications, environmental monitoring,
food control, and biosecurity.
相似文献
144.
The main objective of this paper is to establish a large deviationprinciple for heat kernel measures on loop spaces. It givesan extension of Fang and Zhang's results on loop groups. Forthe proof, we use the continuity theorem of Lyons' rough paththeory. 相似文献
145.
Yoshihisa Kurosaki Dr. Toshiya Sagisaka Tomoo Matsushima Prof. Takashi Ubukata Prof. Yasushi Yokoyama 《Chemphyschem》2020,21(13):1375-1383
A chiral and thermally irreversible photochromic fulgide derivative incorporating an (R)-binaphthol unit in its acid anhydride moiety was used for the photoswitching of the pitch length of cholesteric liquid crystals. Since the absorption maximum wavelengths of both thermally stable photoisomers are nearly in the UV region (quasi-stealth photochromism), it can be exposed to visible light without inducing photochromic reactions. Therefore, when the photoswitching molecule is added to a permanent cholesteric liquid crystal whose reflection light wavelength is in the visible region, the UV light-induced photochromic reaction of the photoswitching molecule changes the wavelength of the reflection light in the visible light region. We have succeeded in regulating the color of cholesteric liquid crystalline cells between red and blue upon UV light irradiation. Attempts to introduce this system in polymer dispersed cholesteric liquid crystals are also described. 相似文献
146.
An expression of uncertainty in calibration using stepwise or separate dilution of a stock solution.
The traditional method for linear calibration can estimate the confidence intervals of calibration lines from a set of experimental data for a single calibration line. However, the following situations, often encountered in laboratories, are out of reach of the method, since the concentrations of the standard solutions are not independent of each other: (A) a standard solution is diluted from a more concentrated one in a stepwise way (stepwise dilution); (B) every standard solution for a calibration experiment is prepared from a stock solution, but the stock solution is newly prepared for each calibration (separate dilution with the variable concentration of the stock solution). This paper puts forward a theory to calculate the confidence intervals of calibration lines in the above situations. Analyses made up of sample weighing, dilution, HPLC measurement and calibration with the linear least-squares fitting are taken as examples. The proposed theory is numerically compared to the traditional method. 相似文献
147.
Summary The optimal peak separation is defined as one from which the maximal amount of Shannon information called FUMI can be collected. The optimal peak separation depends on the peak-resolving powers of the data processing used for a chromatographic system. Data processings of different peak-resolving powers have their own optimal peak separation of different Rs. This paper demonstrates that a data processing of superior powers can collect more information from the optimal than an inferior one, although the information FUMI is calculated from their own optimals. The flow chart for the calculation of FUMI is annexed. 相似文献
148.
T Kimura E Fukui A Kageyu H Kurohara Y Kurosaki T Nakayama Y Morita K Shibusawa S Ohsawa Y Takeda 《Chemical & pharmaceutical bulletin》1989,37(2):439-441
In order to evaluate oral dosage forms of d-alpha-tocopherol acetate (VEA), d-alpha-tocopherol (VE) concentration in the plasma was examined following oral administration of three VEA preparations; lecithin-dispersed aqueous preparation, polysorbate 80 (PS-80)-solubilized aqueous solution and soybean oil solution. The lecithin-dispersed preparation gave the highest Cmax and the largest AUC0-24h, while Tmax was delayed. In the thoracic duct fistula rat, no increase in VE plasma concentration was observed after intraduodenal administration of lecithin-dispersed VEA preparation via the lymphatic route. The delayed Tmax and prolonged VE plasma concentration obtained with the lecithin-dispersed preparation in comparison with PS-80-solubilized aqueous solution could be explained by the different route of absorption. 相似文献
149.
Hasegawa C Kumazawa T Uchigasaki S Lee XP Sato K Terada M Kurosaki K 《Analytical and bioanalytical chemistry》2011,401(7):2215-2223
Dextromethorphan was extracted from human plasma samples (100 μL) using MonoTip C18 tips, which are packed with C18-bonded monolithic silica gel that is attached to the inside of the tip. The samples, which contained dextromethorphan and
trimeprazine as an internal standard (IS), were mixed with 200 μL of distilled water and 50 μL of 1 mol/L glycine–sodium hydroxide
buffer (pH 10). The mixture was extracted to the C18 phase of the tip by 20 sequential aspirating/dispensing cycles using a manual micropipettor. The analytes retained on the
C18 phase were then eluted with methanol by five sequential aspirating/dispensing cycles. The eluate was injected directly into
a gas chromatograph and detected by a mass spectrometer with selected ion monitoring in positive electron ionization mode.
An Equity-5 fused silica capillary column (30 m × 0.32 mm i.d., film thickness 0.5 μm) gave adequate separation of the dextromethorphan,
IS, and impurities. The recoveries of dextromethorphan and the IS spiked into plasma were >87.4%. The regression equation
for dextromethorphan showed excellent linearity from 2.5 to 320 ng/mL of plasma, and the limit of detection was 1.25 ng/mL
of plasma. The intraday and interday coefficients of variation were less than 10.5% and 14.7%, respectively. The accuracy
ranged from 91.9% to 107%. The validated method was successfully used to quantify the plasma concentration of dextromethorphan
in a human subject after oral administration of the drug. 相似文献
150.
We analytically link three properties of nonlinear dynamical systems, namely sensitivity to initial conditions, entropy production, and escape rate, in z-logistic maps for both positive and zero Lyapunov exponents. We unify these relations at chaos, where the Lyapunov exponent is positive, and at its onset, where it vanishes. Our result unifies, in particular, two already known cases, namely (i) the standard entropy rate in the presence of escape, valid for exponential functionality rates with strong chaos, and (ii) the Pesin-like identity with no escape, valid for the power-law behavior present at points such as the Feigenbaum one. 相似文献