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231.
STREET NETWORK STRUCTURE AND CRIME RISK: AN AGENT‐BASED INVESTIGATION OF THE ENCOUNTER AND ENCLOSURE HYPOTHESES 下载免费PDF全文
Street networks shape day‐to‐day activities in complex ways, dictating where, when, and in what contexts potential victims, offenders, and crime preventers interact with one another. Identifying generalizable principles of such influence offers considerable utility to theorists, policy makers, and practitioners. Unfortunately, key difficulties associated with the observation of these interactions, and control of the settings within which they take place, limit traditional empirical approaches that aim to uncover mechanisms linking street network structure with crime risk. By drawing on parallel advances in the formal analyses of street networks and the computational modeling of crime events interactions, we present a theoretically informed and empirically validated agent‐based model of residential burglary that permits investigation of the relationship between street network structure and crime commission and prevention through guardianship. Through the use of this model, we explore the validity of competing theoretical accounts of street network permeability and crime risk—the encounter (eyes on the street) and enclosure (defensible space) hypotheses. The results of our analyses provide support for both hypotheses, but in doing so, they reveal that the relationship between street network permeability and crime is likely nonlinear. We discuss the ramifications of these findings for both criminological theory and crime prevention practice. 相似文献
232.
Quantitative Determination of Cannabinoids in Cannabis and Cannabis Products Using Ultra‐High‐Performance Supercritical Fluid Chromatography and Diode Array/Mass Spectrometric Detection 下载免费PDF全文
Mei Wang Ph.D. Yan‐Hong Wang Ph.D. Bharathi Avula Ph.D. Mohamed M. Radwan Ph.D. Amira S. Wanas Ph.D. Zlatko Mehmedic M.Sc. John van Antwerp B.Sc. Mahmoud A. ElSohly Ph.D. Ikhlas A. Khan Ph.D. 《Journal of forensic sciences》2017,62(3):602-611
Ultra‐high‐performance supercritical fluid chromatography (UHPSFC ) is an efficient analytical technique and has not been fully employed for the analysis of cannabis. Here, a novel method was developed for the analysis of 30 cannabis plant extracts and preparations using UHPSFC /PDA ‐MS . Nine of the most abundant cannabinoids, viz . CBD , ?8‐THC , THCV , ?9‐THC , CBN , CBG , THCA ‐A, CBDA , and CBGA , were quantitatively determined (RSD s < 6.9%). Unlike GC methods, no derivatization or decarboxylation was required prior to UHPSFC analysis. The UHPSFC chromatographic separation of cannabinoids displayed an inverse elution order compared to UHPLC . Combining with PDA ‐MS , this orthogonality is valuable for discrimination of cannabinoids in complex matrices. The developed method was validated, and the quantification results were compared with a standard UHPLC method. The RSD s of these two methods were within ±13.0%. Finally, chemometric analysis including principal component analysis (PCA ) and partial least squares‐discriminant analysis (PLS ‐DA ) were used to differentiate between cannabis samples. 相似文献
233.
Chengzhi Li Ph.D. Dong Ma Ph.D. Kaifei Deng B.Sc. Yijiu Chen M.Sc. Ping Huang Ph.D. Zhenyuan Wang Ph.D. 《Journal of forensic sciences》2017,62(5):1345-1350
Estimating the postmortem interval (PMI) is very important in the forensic sciences. Although many approaches have been used for estimating the PMI, accurate PMI calculations are still difficult. In this study, four Sprague Dawley (SD) rats were sacrificed by suffocation, and muscle samples were collected by dissection at various time intervals (0, 48, 96, and 144 h) after death. All samples were probed using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) to obtain molecular images and data for principal component analysis (PCA). The results showed that the peaks at m/z 1511, 1543, 1564, 1586 clearly decreased in intensity from 0 to 144 h postmortem and that the time groups were separated from each other on the PCA score plot. The prediction model showed high recognition capability (95.93%) and cross‐validation (83.72%). Our work suggests that MALDI‐TOF MS can be used to determine the PMI. 相似文献
234.
Feasibility of Canine Detection of Mass Storage Devices: A Study of Volatile Organic Compounds Emanating from Electronic Devices Using Solid Phase Microextraction 下载免费PDF全文
Lauryn E. DeGreeff Ph.D. Michelle Cerreta Ph.D. Mark Rispoli J.D. 《Journal of forensic sciences》2017,62(6):1613-1616
Detection of canines are well‐known to be valuable in the location of contraband, such as explosives or narcotics. More recently, canines have been trained and utilized in the detection of concealed mass storage devices that might contain evidence of illegal activity such as child pornography. To lay the analytical foundation for this detection work, research was carried out to determine the volatile organic compounds associated with mass storage devices (MSD) that could be used by trained canines for detection. Headspace analysis of a variety of electronic devices was performed using solid phase microextraction (SPME) with gas chromatography/mass spectrometry (GC/MS). Analyses found several volatile compounds common to SIM and SD cards, as well as USB drives, including 2‐propenenitrile, styrene, isophorone, hydroxycyclohexyl phenyl ketone, and 2‐furanmethanol, tetrahydro. Results indicated that mass storage devices do have a characteristic odor profile making detection with minimal false alerts feasible for trained canines. 相似文献
235.
Qiang Yu 《Computer Law & Security Report》2017,33(1):103-111
China's merger enforcement agency approved the Google/Motorola merger with conditions. This pattern of approval is not in full accordance with that in other jurisdictions, including the United States and the European Union, which made unconditional approvals. This contradiction attracted ample criticism; some critics believe that China's policy is designed to protect domestic industry. In investigating the Chinese merger agency's decision and the basis for its decision making, this article finds that much of the criticism is groundless and misleading because the critics have failed to incorporate all elements of the global value chain of mobile intelligent terminals into their analyses. The investigation also shows that, although the decision makers are less experienced, their decisions are based on Chinese competition law and market realities. It is important for international firms to be aware of this pattern in merger analysis. 相似文献
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237.
This study addresses the conditional nature of the effectiveness of open-street CCTV (closed circuit television) by examining the differences in the effects (1) between daytime and nighttime crime, (2) between weekday and weekend crime, (3) across specific-crime offenses, and (4) depending on CCTV site characteristics, including location type (e.g. downtown, business district, school/university, or residential area) and the site’s base rate of crime. This study used HLM (hierarchical linear modeling) with 84 repeated measures across 34 camera locations in Cincinnati, Ohio, while also accounting for overlapping camera areas. Overall, the findings provided minimal evidence of the effectiveness of CCTV in reducing crime, though some types of crime were reduced in residential areas especially, and effectiveness was clearly interdependent with an area’s base rate of crime. Finally, WDQ analyses showed that diffusion of benefits occurred much more often than displacement in cases where there was a crime reduction, post-CCTV. 相似文献
238.
Supporting the positive development of a special needs child is especially challenging when parents have separated or divorced. Invariably, there is an increased need for collaborative co‐parenting wherein information is shared and intervention plans can be implemented effectively. In this article, the evolving literature on parental gatekeeping is applied to families with special needs children, as it offers a useful model for understanding the strengths and liabilities of co‐parenting relationships. We describe some of the typical and unique gatekeeping dynamics that occur when children suffer from developmental, physical, and/or psychiatric syndromes that require specific treatment and specialized parenting skills. Examples of both restrictive and facilitative gatekeeping are described as they manifest in these families. Implications for decision making are also discussed. 相似文献
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