全文获取类型
收费全文 | 2130篇 |
免费 | 18篇 |
国内免费 | 24篇 |
专业分类
安全科学 | 55篇 |
废物处理 | 69篇 |
环保管理 | 257篇 |
综合类 | 472篇 |
基础理论 | 440篇 |
环境理论 | 1篇 |
污染及防治 | 636篇 |
评价与监测 | 110篇 |
社会与环境 | 117篇 |
灾害及防治 | 15篇 |
出版年
2023年 | 21篇 |
2022年 | 19篇 |
2021年 | 31篇 |
2020年 | 23篇 |
2019年 | 28篇 |
2018年 | 52篇 |
2017年 | 56篇 |
2016年 | 65篇 |
2015年 | 73篇 |
2014年 | 80篇 |
2013年 | 91篇 |
2012年 | 88篇 |
2011年 | 138篇 |
2010年 | 118篇 |
2009年 | 135篇 |
2008年 | 121篇 |
2007年 | 125篇 |
2006年 | 89篇 |
2005年 | 64篇 |
2004年 | 91篇 |
2003年 | 57篇 |
2002年 | 76篇 |
2001年 | 71篇 |
2000年 | 40篇 |
1999年 | 19篇 |
1998年 | 22篇 |
1997年 | 28篇 |
1996年 | 22篇 |
1995年 | 33篇 |
1994年 | 26篇 |
1993年 | 8篇 |
1992年 | 19篇 |
1991年 | 27篇 |
1990年 | 14篇 |
1989年 | 19篇 |
1988年 | 7篇 |
1985年 | 5篇 |
1984年 | 8篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 6篇 |
1979年 | 11篇 |
1970年 | 10篇 |
1968年 | 5篇 |
1967年 | 5篇 |
1966年 | 5篇 |
1965年 | 8篇 |
1964年 | 5篇 |
1960年 | 6篇 |
1956年 | 5篇 |
排序方式: 共有2172条查询结果,搜索用时 15 毫秒
721.
K. ten Berg A. C. C. van Oppen P. G. J. Nikkels A. C. Gittenberger-de Groot G. B. van der Voet E. H. Brilstra D. Lindhout 《黑龙江环境通报》2005,25(2):156-158
We describe a fetus with a hypoplastic right ventricle detected by prenatal ultrasound examination. A possible causal relationship with prenatal valproate exposure is discussed. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
722.
Brigitte H. W. Faas Dineke Westra Sonja A. de Munnik Maartje van Rij Carlo Marcelis Sara Joosten Ingrid Krapels Vivian Vernimmen Malou Heijligers Marjolein H. Willemsen Nicole de Leeuw Tuula Rinne Rolph Pfundt Sanne P. Smeekens Sander P. A. Stegmann Merryn Macville Esther Sikkel Audrey Coumans Lia Wijnberger Irma Derks Josefa van Lent-Albrechts Tom Hofste Raoul Timmermans Janneke van den End Servi J. C. Stevens Ilse Feenstra 《黑龙江环境通报》2023,43(4):527-543
Objective
We performed a 1-year evaluation of a novel strategy of simultaneously analyzing single nucleotide variants (SNVs), copy number variants (CNVs) and copy-number-neutral Absence-of-Heterozygosity from Whole Exome Sequencing (WES) data for prenatal diagnosis of fetuses with ultrasound (US) anomalies and a non-causative QF-PCR result.Methods
After invasive diagnostics, whole exome parent-offspring trio-sequencing with exome-wide CNV analysis was performed in pregnancies with fetal US anomalies and a non-causative QF-PCR result (WES-CNV). On request, additional SNV-analysis, restricted to (the) requested gene panel(s) only (with the option of whole exome SNV-analysis afterward) was performed simultaneously (WES-CNV/SNV) or as rapid SNV-re-analysis, following a normal CNV analysis.Results
In total, 415 prenatal samples were included. Following a non-causative QF-PCR result, WES-CNV analysis was initially requested for 74.3% of the chorionic villus (CV) samples and 45% of the amniotic fluid (AF) samples. In case WES-CNV analysis did not reveal a causative aberration, SNV-re-analysis was requested in 41.7% of the CV samples and 17.5% of the AF samples. All initial analyses could be finished within 2 weeks after sampling. For SNV-re-analysis during pregnancy, turn-around-times (TATs) varied between one and 8 days.Conclusion
We show a highly efficient all-in-one WES-based strategy, with short TATs, and the option of rapid SNV-re-analysis after a normal CNV result. 相似文献723.
724.
J. T. J. Brons H. P. Van Geijn J. W. Wladimiroff J. J. van der Harten M. L. Kwee M. Sobotka-Plojhar N. F. Th. Arts 《黑龙江环境通报》1988,8(3):175-181
The Holt-Oram syndrome is an autosomal dominant disorder consisting of a congenital heart defect in combination with characteristic upper limb abnormalities. This report presents the ultrasonographic follow-up of two fetuses at risk for the Holt-Oram syndrome. In the first fetus, the existence of Holt-Oram syndrome was suspected at 22 weeks of gestation; a ventricular septal defect, an atrial septal defect, and a minor skeletal defect were found. In the second fetus, no structural abnormalities were discovered until the 30th week, when a small atrial septal defect was detected. In both pregnancies, it was possible to exclude early in gestation the more severe forms of the Holt-Oram syndrome. 相似文献
725.
S. Lehuger B. Gabrielle M. van Oijen D. Makowski J.-C. Germon T. Morvan C. Hnault 《Agriculture, ecosystems & environment》2009,133(3-4):208
Nitrous oxide (N2O) is the main biogenic greenhouse gas contributing to the global warming potential (GWP) of agro-ecosystems. Evaluating the impact of agriculture on climate therefore requires a capacity to predict N2O emissions in relation to environmental conditions and crop management. Biophysical models simulating the dynamics of carbon and nitrogen in agro-ecosystems have a unique potential to explore these relationships, but are fraught with high uncertainties in their parameters due to their variations over time and space. Here, we used a Bayesian approach to calibrate the parameters of the N2O submodel of the agro-ecosystem model CERES-EGC. The submodel simulates N2O emissions from the nitrification and denitrification processes, which are modelled as the product of a potential rate with three dimensionless factors related to soil water content, nitrogen content and temperature. These equations involve a total set of 15 parameters, four of which are site-specific and should be measured on site, while the other 11 are considered global, i.e. invariant over time and space. We first gathered prior information on the model parameters based on the literature review, and assigned them uniform probability distributions. A Bayesian method based on the Metropolis–Hastings algorithm was subsequently developed to update the parameter distributions against a database of seven different field-sites in France. Three parallel Markov chains were run to ensure a convergence of the algorithm. This site-specific calibration significantly reduced the spread in parameter distribution, and the uncertainty in the N2O simulations. The model’s root mean square error (RMSE) was also abated by 73% across the field sites compared to the prior parameterization. The Bayesian calibration was subsequently applied simultaneously to all data sets, to obtain better global estimates for the parameters initially deemed universal. This made it possible to reduce the RMSE by 33% on average, compared to the uncalibrated model. These global parameter values may be used to obtain more realistic estimates of N2O emissions from arable soils at regional or continental scales. 相似文献
726.
Johannes H. C. Cornelissen Ute Sass-Klaassen Lourens Poorter Koert van Geffen Richard S. P. van Logtestijn Jurgen van Hal Leo Goudzwaard Frank J. Sterck René K. W. M. Klaassen Grégoire T. Freschet Annemieke van der Wal Henk Eshuis Juan Zuo Wietse de Boer Teun Lamers Monique Weemstra Vincent Cretin Rozan Martin Jan den Ouden Matty P. Berg Rien Aerts Godefridus M. J. Mohren Mariet M. Hefting 《Ambio》2012,41(3):231-245
Dead wood provides a huge terrestrial carbon stock and a habitat to wide-ranging organisms during its decay. Our brief review highlights that, in order to understand environmental change impacts on these functions, we need to quantify the contributions of different interacting biotic and abiotic drivers to wood decomposition. LOGLIFE is a new long-term ‘common-garden’ experiment to disentangle the effects of species’ wood traits and site-related environmental drivers on wood decomposition dynamics and its associated diversity of microbial and invertebrate communities. This experiment is firmly rooted in pioneering experiments under the directorship of Terry Callaghan at Abisko Research Station, Sweden. LOGLIFE features two contrasting forest sites in the Netherlands, each hosting a similar set of coarse logs and branches of 10 tree species. LOGLIFE welcomes other researchers to test further questions concerning coarse wood decay that will also help to optimise forest management in view of carbon sequestration and biodiversity conservation. 相似文献
727.
We have determined whether derivated fetal haemoglobin (dHbF, consisting of glycated and acetylated HbF) can be used as a cell age marker for fetal red blood cells (RBCs). Cord blood was obtained between 19 and 39 weeks of gestation from 28 alloimmunised anaemic fetuses (23 RhD+ and 5 Kell) and from 20 non-anaemic fetuses and newborns (controls). Density gradient centrifugation was applied to 36 samples (20 RhD+, 15 controls and 1 Kell) to obtain fractions of increasing cell age. Blood samples were used for measurements of mean cellular volume (MCV), mean cell haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), pyruvate kinase activity (PK) and derivated fetal haemoglobin (dHbF) by cation-exchange HPLC. Reticulocytes were counted only in the whole blood samples. In all density gradient separated RBC fractions, the values for MCV, MCH and PK activity decreased and those of MCHC and dHbF increased with increasing density (equivalent to increasing cell age). The mean density was lower for RBCs of the anaemic RHD group (1.072±0.007 g/ml) than for the non-anaemic controls (1.077±0.005 g/ml) (p<0.05) The RBC density of the Kell sensitised fetus did not differ from those of the controls. In the control group, the values of the cell age markers in whole blood changed significantly with the gestational age, showing an increase of mean age of the erythrocyte population. The best linear relationship was found for dHbF (y=6.28+0.17*weeks; r=0.84; p<0.001). In the anaemic RhD+ fetuses, the RBC age markers did not change with gestational age; the dHbF percentages were lower, and the MCV, MCH, PK values and the reticulocyte counts were higher than in the controls (0.05<p<0.001). The dHbF values of the Kell sensitised fetuses were above (p<0.01) and the reticulocyte counts were below normal (p<0.05) for gestational age. For the anaemic fetuses, a significant number of the dHbF values (86%) and of the reticulocyte counts (78%) differed from the values of the controls (p<0.01). The dHbF percentages in RhD+ fetuses showed the best correlation with the Hb deficit, which is a measure for anaemia (r=−0.81, p<0.0001). We conclude that the percentage derivated HbF may indicate whether the RBC production is normal for gestational age. It may in that sense reflect stimulated or impaired erythropoiesis in alloimmunised haemolytic anaemia. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
728.
Manon Gijtenbeek Monique C. Haak Tom J. P. Huberts Johanna M. Middeldorp Frans J. C. M. Klumper Femke Slaghekke Enrico Lopriore Dick Oepkes Jeanine M. M. van Klink 《黑龙江环境通报》2020,40(7):825-830
Objective
To investigate whether perioperative fetal hemodynamic changes in twin-to-twin transfusion syndrome (TTTS) are associated with neurodevelopmental impairment (NDI) at two years.Methods
Doppler parameters of three sonograms (day before, first day after and 1 week after laser surgery for TTTS) were assessed for correlation with neurodevelopmental outcome at two years (2008-2016). NDI was defined as: cerebral palsy, deafness, blindness, and/or a Bayley-III cognitive/motor developmental test-score > 2SD below the mean.Results
Long-term outcome was assessed in 492 TTTS survivors. NDI was present in 5% (24/492). After adjustment for severe cerebral injury (present in 4%), associated with NDI were: middle cerebral artery peak systolic velocity (MCA-PSV) >1.5 multiples of the median (MoM) 1 day after surgery (odds ratio [OR] 4.96; 95% confidence interval [CI]: 1.17-21.05, P = .03), a change from normal umbilical artery pulsatility index (UA-PI) presurgery to UA-PI >p95 postsurgery (OR 4.19; 95% CI: 1.04-16.87, P = .04), a change from normal to MCA-PSV >1.5MoM (OR 4.75; 95% CI: 1.43-15.77, P = .01).Conclusion
Perioperative fetal hemodynamic changes in TTTS pregnancies treated with laser are associated with poor neurodevelopmental outcome. Prospective research on the cerebrovascular response to altered hemodynamic conditions is necessary to further understand the cerebral autoregulatory capacity of the fetus in relation to neurodevelopmental outcome. 相似文献729.