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961.
This study involved the comparative analysis and discrimination of 90 electrical tape adhesives. The objectives included the evaluation of the ability of individual techniques to discriminate samples and the assessment of the ability of the techniques combined to distinguish samples. The techniques utilized were stereomicroscopy, Fourier transform infrared spectroscopy (FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). Stereomicroscopy, to assess adhesive colors of black, clear/colorless, and clear adhesives with brown tint, resulted in a discrimination of 53%. FTIR analysis yielded eight distinct groups with a discrimination of 67%. Py-GC/MS analysis resulted in 16 groups with a discrimination of 83%. These analyses confirmed and further subdivided the FTIR groups. SEM/EDS resulted in five separate groups at 17% discrimination, increasing the overall discrimination to above 85%. 相似文献
962.
The organic peroxide explosive triacetone triperoxide (TATP) is regularly encountered by law enforcement agents in various stages of its production. This study utilizes solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) to examine sulfuric acid-, hydrochloric acid-, and nitric acid-catalyzed TATP syntheses during the initial 24 h of these reactions at low temperatures (5-9°C). Additionally, aging of the reaction mixtures was examined at both low and ambient temperatures (19-21°C) for a further 9 days. For each experiment, TATP could be readily identified in the headspace above the reaction mixture 1 h subsequent to the combination of reagents; at 24 h, TATP and diacetone diperoxide (DADP) were prominent. TATP degraded more rapidly than DADP. Additionally, chlorinated acetones chloroacetone and 1,1,-dichloroacetone were identified in the headspace above the hydrochloric acid-catalyzed TATP reaction mixture. These were not present when the catalyst was sulfuric acid or nitric acid. 相似文献
963.
Abstract: A 15‐year‐old male orally consumed an unknown but fatal amount of sustained release hydromorphone. He was naïve to opioid use. No other drugs or alcohol were involved. The cause of death was acute aspiration‐related bronchopneumonia, secondary to hydromorphone ingestion; the manner of death was accidental. Hydromorphone and hydromorphone‐3‐glucuronide were quantified in postmortem fluids by tandem liquid chromatography–mass spectrometry. The hydromorphone concentrations in the peripheral blood, urine, and vitreous humor were 57, 4460, and 31 ng/mL, respectively. The hydromorphone‐3‐glucuronide concentrations in the corresponding three fluids were 459, 36,400, and 40 ng/mL. Hydromorphone‐3‐glucuronide accumulation probably did not contribute significantly to the opiate toxicity. The proposed minimum lethal hydromorphone blood concentration in the nontolerant user is in the vicinity of 60 ng/mL. 相似文献
964.
Kanamori T Kuwayama K Tsujikawa K Miyaguchi H Iwata YT Inoue H 《Journal of forensic sciences》2011,56(5):1319-1323
This article describes the synthesis and identification of urinary metabolites of 4-iodo-2,5-dimethoxyphenethylamine (2C-I), a new psychoactive drug. 2C-I hydrochloride was administered orally to male Sprague-Dawley rats, and the urinary extracts were analyzed by gas chromatography/mass spectrometry (GC/MS), then five putative 2C-I metabolites were synthesized in our laboratory. In the synthetic process of the 2C-I metabolites, iodination of the aromatic ring was successfully carried out using iodine and orthoperiodic acid as the iodination reagent, and selective debenzylation of aryl benzyl ether was accomplished by the acid hydrolysis method using trifluoroacetic acid and thioanisole. The synthesized metabolites were well separated and detected by GC/MS after valeryl derivatization. The results showed that 2C-I underwent O-demethylation, N-acetylation, and deamination, followed by oxidation to the corresponding carboxylic acid in rats. The data presented in this study will be very useful for the analysis of 2C-I and its metabolites in forensic samples. 相似文献
965.
In this study, δ13C values of six cocaine samples were identified and classified using a single quadrupole mass spectrometer and an isotope ratio mass spectrometry (IRMS) as simultaneous gas chromatography detectors. Our instrument modification is simple to use and is useful (i) when the sample is of limited size or can only be injected once, (ii) to help identify peaks in a complicated IRMS chromatogram, and (iii) to help differentiate very simple systems when impurity profiling is not possible. The EI-MS confirmed the identity of cocaine in each sample. The IRMS data distinguished 12 of the 15 possible pair-wise comparisons at the 95% CL. Three samples could not be differentiated by their δ13C ratios for cocaine. ANOVA demonstrated that the measurement variance was consistently larger than the sample variance. As the δ13C values clearly show, this technique enables the exclusion of a potential common source even when two samples have otherwise identical chemical and physical properties. 相似文献
966.
Successful DNA-based identification of mass disaster victims depends on acquiring tissues that are not highly degraded. In this study, multiple protocols for field preservation of tissues for later DNA analysis were tested. Skin and muscle samples were collected from decaying pig carcasses. Tissues were preserved using cold storage, desiccation, or room temperature storage in preservative solutions for up to 6 months. DNA quality was assessed through amplification of successively larger segments of nuclear DNA. Solution-based storage, including a DMSO/NaCl/EDTA mixture, alcohols, and RNAlater preserved DNA of the highest quality, refrigeration was intermediate, and desiccation was least effective. Tissue type and extent of decomposition significantly affected stored DNA quality. Overall, the results indicate that any tissue preservation attempt is far superior to delaying or forgoing preservation efforts, and that simple, inexpensive methods can be highly effective in preserving DNA, thus should be initiated as quickly as possible. 相似文献
967.
968.
Sarah Kerrigan Ph.D. Ashley Mott M.S. Breanna Jatzlau M.S. Francisco Ortiz M.S. Laura Perrella M.S. Sarah Martin M.S. Kelsie Bryand M.S. 《Journal of forensic sciences》2014,59(1):175-183
Designer psychostimulants are known by recreational drug users to produce a complex array of adrenergic and hallucinogenic effects. Many of these drugs are not targeted during routine toxicology testing and as a consequence, they are rarely reported. The purpose of this study was to develop a procedure for the detection of 15 psychostimulants in urine using liquid chromatography–tandem mass spectrometry (LC‐MS/MS), specifically 2,5‐dimethoxy‐4‐bromophenethylamine (2C‐B), 2,5‐dimethoxy‐4‐chlorophenethylamine (2C‐C), 2,5‐dimethoxy‐4‐methylphenethylamine (2C‐D), 2,5‐dimethoxy‐4‐ethylphenethylamine (2C‐E), 2,5‐dimethoxyphenethylamine (2C‐H), 2,5‐dimethoxy‐4‐iodophenethylamine (2C‐I), 2,5‐dimethoxy‐4‐ethylthiophenethylamine (2C‐T‐2), 2,5‐dimethoxy‐4‐isopropylthiophenethylamine (2C‐T‐4), 2,5‐dimethoxy‐4‐propylthiophenethylamine (2C‐T‐7), 2,5‐dimethoxy‐4‐bromoamphetamine (DOB), 2,5‐dimethoxy‐4‐chloroamphetamine (DOC), 2,5‐dimethoxy‐4‐ethylamphetamine (DOET), 2,5‐dimethoxy‐4‐iodoamphetamine (DOI), 2,5‐dimethoxy‐4‐methylamphetamine (DOM), and 4‐methylthioamphetamine (4‐MTA). Analytical recoveries using solid‐phase extraction were 64–92% and the limit of detection was 0.5 ng/mL for all drugs except 2C‐B (1 ng/mL). The assay was evaluated in terms of analytical recovery, precision, accuracy, linearity, matrix effect, and interferences. The technique allows for the simultaneous detection of 15 psychostimulants at sub‐ng/mL concentrations. 相似文献
969.
Marzia Vassalini M.D. Andrea Verzeletti M.D. Francesco De Ferrari M.D. 《Journal of forensic sciences》2014,59(6):1568-1574
A retrospective study was carried out on postmortem examination data of 131 sharp force‐related casualties recorded by the Brescia Institute of Forensic Medicine between 1982 and 2012. The objective was to identify relevant parameters that may be used to distinguish the manner of deaths between homicide, suicide, and accident. The following variables were considered: manner of death; demographic data; scene; type of sharp object; location and numbers of wounds; the presence of hesitation marks/defense wounds; toxicological findings; psychiatric history. There were 92 homicides, 28 suicides, and 11 accidents. Most victims were male, with an average age of 43. Injuries in isolation were present in 9.8% of homicides, in 35.7% of suicides, and in 54.5% of accidents. Most injuries involved the left anterior chest in homicides and the forearms in suicides. This study underlines the importance of a meticulous postmortem examination of injuries on the body and their relationship with other results from the death scene investigation. 相似文献
970.
Ariel I. Ahram 《Terrorism and Political Violence》2014,26(3):488-503
This article explains how and why armed, non-state actors collaborate with states to inflict massive levels of violence. Regime type and state capacity interact to provide state elites a menu of repertoires for implementing violence, some emphasizing direct state action, others emphasizing cooperation and alliance between state and armed, non-state actors. Rather than struggling in vain to build strong states to eliminate armed non-state actors and establish a monopoly over the use of force, averting genocide might necessitate recruiting and strengthening the power of indigenous, armed non-state actors. 相似文献