全文获取类型
收费全文 | 13123篇 |
免费 | 394篇 |
专业分类
各国政治 | 798篇 |
工人农民 | 366篇 |
世界政治 | 1053篇 |
外交国际关系 | 705篇 |
法律 | 7026篇 |
中国共产党 | 1篇 |
中国政治 | 64篇 |
政治理论 | 3343篇 |
综合类 | 161篇 |
出版年
2021年 | 83篇 |
2020年 | 162篇 |
2019年 | 227篇 |
2018年 | 282篇 |
2017年 | 315篇 |
2016年 | 339篇 |
2015年 | 224篇 |
2014年 | 289篇 |
2013年 | 1767篇 |
2012年 | 362篇 |
2011年 | 359篇 |
2010年 | 319篇 |
2009年 | 339篇 |
2008年 | 346篇 |
2007年 | 385篇 |
2006年 | 368篇 |
2005年 | 365篇 |
2004年 | 372篇 |
2003年 | 360篇 |
2002年 | 377篇 |
2001年 | 420篇 |
2000年 | 387篇 |
1999年 | 314篇 |
1998年 | 170篇 |
1997年 | 193篇 |
1996年 | 163篇 |
1995年 | 167篇 |
1994年 | 181篇 |
1993年 | 154篇 |
1992年 | 233篇 |
1991年 | 253篇 |
1990年 | 214篇 |
1989年 | 232篇 |
1988年 | 208篇 |
1987年 | 203篇 |
1986年 | 230篇 |
1985年 | 184篇 |
1984年 | 173篇 |
1983年 | 188篇 |
1982年 | 123篇 |
1981年 | 128篇 |
1980年 | 94篇 |
1979年 | 146篇 |
1978年 | 93篇 |
1977年 | 92篇 |
1976年 | 85篇 |
1975年 | 79篇 |
1974年 | 96篇 |
1973年 | 90篇 |
1972年 | 81篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
Distribution of blood groups by the serum Gm system was studied in Buryats and in the entire population of Buryatia without consideration for the national appurtenance and with consideration for sex. Differences in the incidence of the factors were detected. 相似文献
993.
Karch SB Stephens BG Nazareno GV 《The American journal of forensic medicine and pathology》2001,22(3):266-269
GHB can be produced either as a pre- or postmortem artifact. The authors describe two cases in which GHB was detected and discuss the problem of determining the role of GHB in each case. In both cases, NaF-preserved blood and urine were analyzed using gas chromatography. The first decedent, a known methamphetamine abuser, had GHB concentrations similar to those observed with subanesthetic doses (femoral blood, 159 microg/ml; urine, 1100 microg/ml). Myocardial fibrosis, in the pattern associated with stimulant abuse, was also evident. The second decedent had a normal heart but higher concentrations of GHB (femoral blood, 1.4 mg/ml; right heart, 1.1 mg/ml; urine, 6.0 mg/ml). Blood cocaine and MDMA levels were 420 and 730 ng/ml, respectively. Both decedents had been drinking and were in a postabsorptive state, with blood to vitreous ratios of less than 0.90. If NaF is not used as a preservative, GHB is produced as an artifact. Therefore, the mere demonstration of GHB does not prove causality or even necessarily that GHB was ingested. Blood and urine GHB concentrations in case 1 can be produced by a therapeutic dose of 100 mg, and myocardial fibrosis may have had more to do with the cause of death than GHB. The history in case 2 is consistent with the substantial GHB ingestion, but other drugs, including ethanol, were also detected. Ethanol interferes with GHB metabolism, preventing GHB breakdown, raising blood concentrations, and making respiratory arrest more likely. Combined investigational, autopsy, and toxicology data suggest that GHB was the cause of death in case 2 but not case 1. Given the recent discovery that postmortem GHB production occurs even in stored antemortem blood samples (provided they were preserved with citrate) and the earlier observations that de novo GHB production in urine does not occur, it is unwise to draw any inferences about causality unless (1) blood and urine are both analyzed and found to be elevated; (2) blood is collected in NaF-containing tubes; and (3) a detailed case history is obtained. 相似文献
994.
Baker AM Keller G Garcia D 《The American journal of forensic medicine and pathology》2001,22(3):285-287
The authors report the case of a 21-year-old man who was killed while duck hunting when a shotgun accidentally discharged, shooting him in the head. The loaded weapon, which had been lying on the ground with the safety off and the muzzle pointed toward a river a few feet away, discharged when a hunting dog stepped on the trigger. Scene investigation confirmed that the victim had been standing in the river, planting decoys, with his head approximately level with the adjacent bank. Autopsy examination and ballistic testing confirmed a range of fire consistent with the witness' statements. Examination of the weapon in question documented a light trigger pull but no mechanical defects. The authors review the epidemiology and causality of hunting accidents and discuss the various safety rules that were violated in this highly unusual case. The importance of a complete death investigation, including autopsy, when dealing with a firearm death is emphasized. 相似文献
995.
Mall G Hubig M Büttner A Kuznik J Penning R Graw M 《Forensic science international》2001,117(1-2):23-30
The determination of sex and the estimation of stature from bones play an important role in identifying unknown bodies, parts of bodies or skeletal remains. In medico-legal practice statements on the probable sex of a decomposed body or part of a body are often expected even during autopsy. The present study was, therefore, restricted to few easily accessible dimensions from bones which were prepared only by mechanically removing soft tissues, tendons and ligaments. The specimens came from the Anatomical Institutes in Munich and Cologne from the years 1994-1998 including a total of 143 individuals (64 males and 79 females). The mean age was 79 years (46-108), the mean body height 161cm (134-189). The following measurements were taken: maximum humeral length (mean: 33.4cm in males; 30.7cm in females), vertical humeral head diameter (mean: 5.0cm in males, 4.4cm in females), humeral epicondylar width (mean: 6.6cm in males; 5.8cm in females), maximum ulnar length (mean: 26.5cm in males, 23.8cm in females), proximal ulnar width (mean: 3.4cm in males, 2.9cm in females), distal ulnar width (mean: 2.2cm in males; 1.8cm in females), maximum radial length (mean: 24.6cm in males; 22.0cm in females), radial head diameter (mean: 2.6cm in males, 2.2cm in females) and distal radial width (mean: 3.6cm in males; 3.2cm in females). The differences between the means in males and females were significant (P<0.0005). A discriminant analysis was carried out with good results. A percentage of 94.93% of cases were correctly classified when all measures of the radius were applied jointly, followed by humerus (93.15%) and ulna (90.58%). Applied singly, the humeral head diameter allowed the best distinction (90.41% correctly grouped cases), followed by the radial length (89.13%), the radial head diameter (88.57%) and the humeral epicondylar width (88.49%). The linear regression analysis for quantifying the correlation between the bone lengths and the stature led to unsatifactory results with large 95%-confidence intervals for the coefficients and high standard errors of estimate. 相似文献
996.
Jayaprakash PT Srinivasan GJ Amravaneswaran MG 《Forensic science international》2001,117(1-2):121-143
Skull-photograph superimposition continues to be the most prevalent method employed for identifying a skull recovered in a criminal case as that belonging to a putative victim whose face photograph is available. The reliability of identification achieved has been shown to be 91%, indicating the possibility of a skull mismatching with a face photograph belonging to a person other than the actual deceased. This lack of reliability dampens the confidence of the expert and in turn confounds the mind of the judge. It has been shown that the variations in the shape of the facial organs are influenced by the corresponding variations in the skeletal elements of the facial skull. "Cranio-facial morphanalysis", a new anthroposcopic method proposed here for evaluating the shape correlations between a skull and a face photograph, when applied conjointly with skull-photograph superimposition is shown to increase the reliability in forensic skull identification. 相似文献
997.
Ninhydrin developed fingerprints can be enhanced by treatment with a zinc or cadmium salt. The resulting fingerprint luminescence has been attributed to the induced coplanarity of the bicyclic indanedione rings of Ruhemann's purple due to complexation with the metal ions. This paper explores whether this effect also occurs in the 1,8-diaza-9-fluorenone (DFO)-amino acid adduct (1), formed from the reaction of DFO with amino acids. Molecular modeling studies of (1) indicate a relatively small out-of-plane angle of 24 degrees. 1H NMR studies indicate (1) is asymmetric about the C2 axis in contrast to what has been previously reported. Little, if any, enhancement of luminescence was observed with Zn, Cd, Ru or Eu treated DFO developed latent fingerprints. This lack of enhancement was also borne out by solution luminescence studies. Given this lack of enhancement of luminescence, solutions of (1) and the four metal ions above were analyzed by electrospray mass spectrometry (ESMS). This indicated the formation of predominantly 1:1 complexes of (1) with both Zn and Cd, and the 2:1 complex with ruthenium. No evidence of a Eu complex was found by ESMS. 相似文献
998.
Weakley-Jones B Gerber JE Biggs G 《The American journal of forensic medicine and pathology》2001,22(2):203-206
Deaths resulting from the oral ingestion of colchicine are occasionally associated with suicides and therapeutic toxicity. However, homicidal deaths in which this drug is used are extremely rare. Two homicides in which colchicine was used are reported. 相似文献
999.
Sensitive and specific multiresidue methods for the determination of pesticides of various classes in clinical and forensic toxicology 总被引:2,自引:0,他引:2
Lacassie E Marquet P Gaulier JM Dreyfuss MF Lachâtre G 《Forensic science international》2001,121(1-2):116-125
Original and sensitive multiresidue methods are presented for the detection and quantitation, in human biological matrices, of 61 pesticides of toxicological significance in human. These methods involved rapid solid-phase extraction using new polymeric support (HLB and MCX) OASIS cartridges. Gas chromatography-mass spectrometry (GC-MS) was used for volatile (organophosphate, organochlorine, phtalimide, uracil) pesticides and liquid chromatography-ionspray-mass spectrometry (LC-MS) for thermolabile and polar pesticides (carbamates, benzimidazoles). Acquisition was performed in the selected ion monitoring (SIM) mode. Extraction recovery varied owing to the nature of pesticides, but was satisfactory for all. Limits of detection (LODs) and limits of quantitation (LOQs) ranged, respectively, from 2.5 to 20 and from 5 to 50ng/ml. An excellent linearity was observed from LOQs up to 1000ng/ml for all the pesticides studied. The proposed procedures yielded reproducible results with good inter-assay accuracy and precision. A few cases of intoxication are presented to demonstrate the diagnostic interest of these methods: in two cases were determined lethal concentrations of endosulfan and carbofuran; in four other cases, the procedures helped diagnose intoxication with, respectively, parathion-ethyl, the association of bromacil and strychnine, bifenthrin and aldicarb. 相似文献
1000.
Brady JG 《The Journal of contemporary health law and policy》2001,18(1):1-51
Despite reforms to ensure that nursing homes maintain compliance with federal quality standards, one-fourth of all homes nationwide continue to be cited for deficiencies that either caused actual harm to residents or carried the potential for death or serious injury. This pattern has not changed since the July 1995 reforms were implemented. Although the reforms equipped federal and state regulators with many alternatives and tools to help promote sustained compliance with Medicare and Medicaid standards, the way in which states and HCFA have applied them appears to have resulted in little headway against the pattern of serious and repeated noncompliance. Such performance may do little to dispel concerns over the health and safety of frail and dependent nursing home residents. 相似文献