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151.
C. Jurado M. P. Gimnez M. Menndez M. Repetto 《Forensic Science International Supplement Series》1995,70(1-3)
The present paper describes a sensitive method developed in our laboratory for the simultaneous analysis of opiates (morphine, codeine and monoacetylmorphine), cocainics (cocaine and benzoylecgonine) and cannabinoids (Δ9-tetrahydrocannabinol and 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid) in hair samples. After decontaminating the sample with dichloromethane, two consecutive hydrolyses were performed in order to achieve the best conditions for extracting the three kinds of drugs from the protein matrix. First the opiate and cocainic compounds were extracted by means of a soft acidic hydrolysis with 0.1 N HCl at 50 °C overnight and organic solvent extraction at pH 9.2. The cannabinoids need a stronger basic hydrolysis with 11.8 N KOH for 10 min at laboratory temperature. After adding maleic acid, the cannabinoids were extracted with an organic solvent. The derivatization was carried out with heptafluorobutyric anhydride and hexafluoropropanol. Calibration curves were linear between 0.5–100 ng/mg of hair. Recovery and reproducibility were assured. The quantification limits ranged between 0.04–0.26 ng/mg of hair. Seventy hair samples from known drug abusers were cut into 1-cm segments and analyzed by this method. The ranges of measured concentrations (ng/mg) were 0.31–89 for cocaine, 0.1–5.76 for benzoylecgonine, 0.34–45.79 for morphine, 0.45–39.59 for codeine, 0.09–48.18 for monoacetylmorphine, 0.06–7.63 for THC and 0.06–3.87 for THC---COOH. The results of sectional analyses agreed with the self reported drug histories. The usefulness of this method is in assessing earlier drug consumption, and also at the same time obtaining a chronological profile of the consumption of these three types of drugs. 相似文献
152.
153.
Multivariate Classification of Original and Fake Perfumes by Ion Analysis and Ethanol Content
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Clêrton L. Gomes Ph.D. Ari Clecius A. de Lima M.S. Adonay R. Loiola Ph.D. Abel B. R. da Silva M.S. Manuela C. L. Cândido M.S. Ronaldo F. Nascimento Ph.D. 《Journal of forensic sciences》2016,61(4):1074-1079
The increased marketing of fake perfumes has encouraged us to investigate how to identify such products by their chemical characteristics and multivariate analysis. The aim of this study was to present an alternative approach to distinguish original from fake perfumes by means of the investigation of sodium, potassium, chloride ions, and ethanol contents by chemometric tools. For this, 50 perfumes were used (25 original and 25 counterfeit) for the analysis of ions (ion chromatography) and ethanol (gas chromatography). The results demonstrated that the fake perfume had low levels of ethanol and high levels of chloride compared to the original product. The data were treated by chemometric tools such as principal component analysis and linear discriminant analysis. This study proved that the analysis of ethanol is an effective method of distinguishing original from the fake products, and it may potentially be used to assist legal authorities in such cases. 相似文献
154.
Andrew Silke 《Terrorism and Political Violence》2016,28(3):417-434
The 1916 Rising was, in military terms, a shambolic failure. Despite the fact that Britain was locked in a gruelling struggle with Germany, the Rising was still utterly crushed within a week. How then, in the aftermath of victory against Germany, did Britain fail to win the subsequent struggle with the Irish Republican Army (IRA) between 1919 and 1921? This article assesses some of the key factors that played out in the conflict, drawing particular attention to the IRA's focus on the Royal Irish Constabulary and the consequences of this, and then later, how distorted perceptions of the proximity of success ultimately undermined British commitment. One of the most remarkable features of the conflict was the widespread belief among many on the British side (and more than a few in the Republican camp) that the IRA was on the verge of total defeat when the truce was declared in 1921. The IRA had suffered heavy casualties and were running low on weapons and ammunition. Yet, somehow the movement prevailed. This article aims to shed light on how and why that happened. 相似文献
155.
Ana Claudia Martins Ciconelle BSc MSc Renan Lucio Berbel da Silva DDS MSc Jun Ho Kim DDS MSc PhD Bruno Aragão Rocha MD Dênis Gonçalves dos Santos BSc Luis Gustavo Rocha Vianna BSc MSc Luma Gallacio Gomes Ferreira BSc Vinícius Henrique Pereira dos Santos Jeferson Orofino Costa DDS Renato Vicente BSc MSc PhD 《Journal of forensic sciences》2023,68(6):2057-2064
The objective of this study is to assess the performance of an innovative AI-powered tool for sex determination using panoramic radiographs (PR) and to explore factors affecting the performance of the convolutional neural network (CNN). The study involved 207,946 panoramic dental X-rays and their corresponding reports from 15 clinical centers in São Paulo, Brazil. The PRs were acquired with four different devices, and 58% of the patients were female. Data preprocessing included anonymizing the exams, extracting pertinent information from the reports, such as sex, age, type of dentition, and number of missing teeth, and organizing the data into a PostgreSQL database. Two neural network architectures, a standard CNN and a ResNet, were utilized for sex classification, with both undergoing hyperparameter tuning and cross-validation to ensure optimal performance. The CNN model achieved 95.02% accuracy in sex estimation, with image resolution being a significant influencing factor. The ResNet model attained over 86% accuracy in subjects older than 6 years and over 96% in those over 16 years. The algorithm performed better on female images, and the area under the curve (AUC) exceeded 96% for most age groups, except the youngest. Accuracy values were also assessed for different dentition types (deciduous, mixed, and permanent) and missing teeth. This study demonstrates the effectiveness of an AI-driven tool for sex determination using PR and emphasizes the role of image resolution, age, and sex in determining the algorithm's performance. 相似文献
156.
Allelic frequencies, forensic parameters and admixture values for eleven STR loci (F13B, TPOX, CSF1PO, F13A01, D7S820, LPL, TH01, vWA, D13S317, FESFPS, and D16S539) were determined in a sample of unrelated individuals, European descendants from Rio de Janeiro area, Brazil. 相似文献
157.
158.
Minimum postmortem interval (mPMI) can be estimated with preceding mean ambient temperature models that predict carrion taxon pre‐appearance interval. But accuracy has not been compared with using summary statistics (mean ± SD of taxon arrival/departure day, range, 95% CI). This study collected succession data from ten experimental and five control (infrequently sampled) pig carcasses over two summers (n = 2 experimental, n = 1 control per placement date). Linear and exponential preceding mean ambient temperature models for appearance and departure times were constructed for 17 taxa/developmental stages. There was minimal difference in linear or exponential model success, although arrival models were more often significant: 65% of linear arrival (r2 = 0.09–0.79) and exponential arrival models (r2 = 0.05–81.0) were significant, and 35% of linear departure (r2 = 0.0–0.71) and exponential departure models (r2 = 0.0–0.72) were significant. Performance of models and summary statistics for estimating mPMI was compared in two forensic cases. Only summary statistics produced accurate mPMI estimates. 相似文献
159.
Antinea Menéndez Garmendia B.A. Jorge A. Gómez‐Valdés M.A. Francisco Hernández B.A. Julie K. Wesp M.A. Gabriela Sánchez‐Mejorada Ph.D. M.D. 《Journal of forensic sciences》2014,59(5):1325-1329
In this work, we present a measuring methodology for long bones of the limbs (humerus, femur, and tibia) of human corpses. Measurements of cadaveric height and long bone lengths were conducted on 72 corpses (20 females and 52 males) from the School of Medicine at the National Autonomous University of Mexico. Additionally, these measurements were compared with those taken from dry bones of a subsample of individuals. Our results show marginal differences (TEM% = 0.59) between cadaveric and dry bone measurements, resulting from different osteometric technical procedures. This note outlines the measuring methodology, which will be subsequently used to create regression formulas for stature estimation. 相似文献
160.
Kevin M. Beaver Joseph L. Nedelec Christian da Silva Costa Ana Paula Poersch Mônica Celis Stelmach Micheli Cristina Freddi Jamie M. Gajos Cashen Boccio 《Journal of criminal justice》2014