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991.
提出一种基于甚高频调频广播(VHF-FM)微波段的室内人体探测方法,该方法是根据VHF-FM天线阵列接收机接收到的数据做空时相关处理得到信号子空间特征向量,并将信号子空间特征向量映射为相应的代价值进行探测.在静态无人,室内环境没发生改变时,代价值基本没有太大变化;而当有人进入,室内环境发生改变时,代价值会发生明显的变化.研究结果表明:该方法能够很好地区分室内静态无人环境和动态有人环境,且不容易受到噪声环境的影响,具有稳定、准确的探测性能.  相似文献   
992.
为克服模糊故障树分析模型计算过程专家人员需求量大,参评专家众多时,定量量化过程复杂及缺少随机性的问题,采用蒙特卡罗法建立模糊故障树分析模型,使用计算机运作生成随机数,并以船舶海上交通事故调查报告中的3个基本事故最小割集进行定量分析.结果表明,蒙特卡罗模型法结合使用计算机生成随机数可以解决模糊故障树分析模型对事故随机性分析结果不准确的问题,实现了在参评专家人员众多情形下简化计算过程的目标.最后通过案例验证了该模型法具有很强的针对性和实用性.  相似文献   
993.
一种着装人体动态热湿传递模拟方法   总被引:2,自引:0,他引:2  
针对服装热湿功能设计问题,结合改进的人体热调节模型和微元织物热湿耦合模型,实现了着装人体动态热湿传递过程的模拟。水分的蒸发凝结、纤维对湿的吸附解吸、液态水的毛细传递、人体汗水在体表积聚等现象,及其对服装热性能的作用在模型中都给予了考虑。并给出了计算流程。算例表明了模拟方法的有效性。  相似文献   
994.
We have developed and validated a fast and sensitive ultra high‐performance liquid chromatography with positive ion electrospray ionization tandem mass spectrometry method for determining N‐ butylscopolamine levels in human plasma using propranolol as an internal standard. The acquisition was set up in the multiple reaction monitoring mode with the transitions m /z 360.3 → 138.0 for N‐ butylscopolamine and m /z 260.2 → 116.1 for IS. This method uses a liquid–liquid extraction process with dichloromethane. The analyte and IS were chromatographed on a C18, 50 × 2.1 mm, 1.7 μm column through isocratic elution with acetonitrile–5 mm ammonium acetate (adjusted to pH 3.0 with formic acid). The method was linear in the 1–1000 pg/mL range for N‐ butylscopolamine and was selective, precise, accurate and robust. The validated method was successfully applied to perform a bioequivalence study of the reference (Buscopan®, from Boehringer Ingelheim) and the test sample coated‐tablet formulations (from Foundation for Popular Remedy), both containing 10 mg of N‐ butylscopolamine bromide administered as a single dose. Using 58 healthy volunteers and accounting for the high intra‐individual variability confirmed by statistical calculations (38%), the two formulations were considered bioequivalent because the rate and extent of absorption (within 80–125% interval), satisfying international requirements.  相似文献   
995.
Biomarkers involved in alcohol‐induced oxidative stress play an important role in alcoholic liver disease prevention and diagnosis. Alcohol‐induced oxidative stress in human liver L‐02 cells was used to discover the potential biomarkers. Metabolites from L‐02 cells induced by alcohol were measured by high‐performance liquid chromatography and mass spectrometry. Fourteen metabolites that allowed discrimination between control and model groups were discovered by multivariate statistical data analysis (i.e. principal components analysis, orthogonal partial least‐squares discriminate analysis). Based on the retention time, UV spectrum and LC–MS findings of the samples and compared with the authentic standards, eight biomarkers involved in alcohol‐induced oxidative stress, namely, malic acid, oxidized glutathione, γ‐glutamyl‐cysteinyl‐glycine, adenosine triphosphate, phenylalanine, adenosine monophosphate, nitrotyrosine and tryptophan, were identified. These biomarkers offered important targets for disease diagnosis and other researches.  相似文献   
996.
This study presents a validated strategy for the determination of tryptamine in the presence of its competitors, which involves the molecularly imprinted solid‐phase extraction combined with high‐performance liquid chromatography coupled with fluorimetric detection. Tryptamine‐imprinted microscale sorbent was produced from 4‐vinylbenzoic acid and ethylene glycol dimethacrylate in methanol by precipitation polymerization, and its imprinting factor was equal to 15.4 in static experiments or 18.6 in dynamic binding experiments. The method for tryptamine determination in the presence of serotonin and l ‐tryptophan was validated using a complex matrix of bovine serum albumin yielding the recoveries of tryptamine that ranged between 98.7 and 107.0%. Very low limits of detection and limits of quantification for tryptamine (19.9 and 60.3 nmol/L, respectively) allow the quantification of tryptamine in human cerebrospinal fluid in the presence of tryptophan and serotonin.  相似文献   
997.
Two novel and high-throughput enzyme-linked immunosorbent assays (ELISA) were developed for determining tonalide in human blood samples. For establishing the proposed methods, the tonalide hapten and immunogen primarily were prepared. After the immunization, the polyclonal antibody and biotinylated polyclonal antibody were obtained. The biotin-streptavidin system and polyamidoamine-gold nanoparticle conjugation were applied respectively to establish thebiotin-streptavidin-ELISA and Au-polyamidoamine-ELISA. For reducing the background interference, some factors and procedures were also discussed and optimized. Under the optimal conditions, the IC10 of biotin-streptavidin-ELISA was 0.046?µg/L and the IC10 of Au-polyamidoamine-ELISA was 0.016?µg/L. The Au-polyamidoamine-ELISA was used to determine tonalide in human blood and the recovery values and coefficients of variation were acceptable. In this study, tonalide was detected in 92.2% of the samples; the median and the maximum values were 0.62 and 1.76?µg/L, respectively. In general, due to the specificity of the antibody and novel nanoprobe design, this Au-polyamidoamine-ELISA simplified the sample preparation and provided a useful and potential way for trace determination of tonalide. The results also suggested that tonalide concentrations were not significantly relative to gender, but the high concentrations of tonalide in human blood should encourage further toxicological studies.  相似文献   
998.
In this work, we develop mathematical models describing the interactions between Human papillomavirus (HPV)-infected cells and the immune system. We start with simple models in order to capture the most important features of such interactions. Then, we proceed to consider fundamental immunological characteristics for the models. For the numerical counterpart, we develop and implement efficient numerical discretizations of our models in order to illustrate the behavior of the schemes using different initial conditions, which represent the degree of infection of the disease. Understanding such interactions is of paramount importance for the prevention and the potential eradication of the infection. One main goal of this research is to analyze how and under what circumstances the immune system succeeds in eliminating HPV-infected cells.  相似文献   
999.
Retrieving DNA from highly degraded human skeletal remains is still a challenge due to low concentration and fragmentation, which makes it difficult to extract and purify. Recent works showed that silica-based methods allow better DNA recovery and this fact may be attributed to the type of bones and the quality of the preserved tissue. However, more systematic studies are needed to evaluate the efficiency of the different silica-based extraction methods considering the type of bones. The main goal of the present study is to establish the best extraction method and the type of bone that can maximize the recovery of PCR-amplifiable DNA and the subsequent retrieval of mitochondrial and nuclear genetic information. Five individuals were selected from an archaeological site located in Catalonia–Spain dating from 5th to 11th centuries AD. For each individual, five samples from different skeletal regions were collected: petrous bone, pulp cavity and cementum of tooth, and rib and limb bones. Four extraction methods were tested, three silica-based (silica in-suspension, HE column and XS plasma column) and the classical method based on phenol–chloroform. Silica in-suspension method from petrous bone and pulp cavity showed the best results. However, the remains preservation will ultimately be the key to the molecular result success.  相似文献   
1000.
A series of broadly neutralizing antibodies called PGT have been shown to be bound directly to human immunodeficiency virus type-1 via high mannose glycans on glycoprotein gp120. Despite the sequence similarities of amino acids of the antibodies, their affinities to the glycan differ. Glycan–antibody interactions among these antibodies are systematically compared with quantum chemical fragment molecular orbital calculations and molecular dynamics simulations. The differences among structural stability of the glycan in the active site of the complexes and total interaction energies as well as binding free energies between the glycan and antibodies agree well with the experimentally shown affinities of the glycan to the antibodies. The terminal saccharide, Man D3, is structurally stable and responsible for the glycan–antibody binding through electrostatic and dispersion interactions. The structural stability of nonterminal saccharides such as Man 4 or Man C plays substantial roles in the interaction via direct hydrogen bonds. © 2019 Wiley Periodicals, Inc.  相似文献   
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