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111.
Consuelo Sánchez‐Brunete Ester Miguel José L. Tadeo 《Journal of separation science》2009,32(1):109-117
A method for the determination of 14 polybrominated diphenyl ethers (PBDEs) in sludge from wastewater treatment plants is presented. PBDEs were extracted by matrix solid‐phase dispersion assisted by sonication and determined by isotope dilution gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode, using labelled 13C‐PBDEs as internal standards. The limits of detection and quantification for the tri‐ to hepta‐BDEs were in the range of 0.05 to 0.5 ng/g dry weight and 0.15 to 1.8 ng/g dry weight, respectively, and 1.6 ng/g dry weight and 5.6 ng/g dry weight for deca‐BDE‐209. The proposed analytical method was applied to determine PBDE levels in sewage sludge samples collected from 19 water treatment plants located in the province of Madrid (Spain). In all of the examined samples, BDE‐100 and BDE‐154 were the main compounds found with a mean concentration of 3.9 and 2.0 ng/g, respectively. PBDEs were detected in all of the samples, and their total concentrations not considering BDE‐209 were between 3.9 and 23.0 ng/g dry weight. The dominant PBDE congener in sewage sludge was BDE‐209, which constituted 38.7 to 97.3% of the total, and showed concentration levels ranging from 8.1 to 717.2 ng/g dry weight. 相似文献
112.
污泥干燥预处理后与神府煤共成浆性的研究 总被引:1,自引:0,他引:1
以萘系阴离子表面活性剂为分散剂,考查了污泥干燥条件和粒径对神府煤成浆性的影响。结果表明,将污泥干燥后再制浆,明显提高了污泥煤浆的成浆浓度;升高干燥温度,有利于提高污泥煤浆的成浆浓度。干燥温度对污泥的可磨性影响较大。干燥温度越高,干燥污泥可磨性越好,球磨的污泥平均粒径越小,制得的污泥煤浆表观黏度越低;温度高于105℃,污泥的可磨性无明显差别,污泥煤浆的表观黏度亦无明显变化。污泥粒径越小,颗粒越细,一定程度上提高了煤粉的堆积效率,使污泥煤浆的表观黏度降低。 相似文献
113.
An interference-free, fast, and simple method is proposed for Pb determination in environmental solid samples combining slurry sampling and electrothermal atomic absorption spectrometry. Samples were ground to an adequate particle size and slurries were prepared by weighing from 0.05 g to 0.20 g of dry sediment, adding nitric acid, and a solution containing 0.1% Triton X-100. Ultrasonic agitation was employed for slurries homogenization. Analytical variables including acid pre-treatment conditions, particle size, slurry stability, temperature program of the graphite furnace, and type and concentration of the chemical modifier were studied. The undesirable effects of potential non-specific and spectral interferences on Pb signal were also taken into account. Continuum source and self-reversal methods for background correction were evaluated and compared. For calibration, synthetic acid solutions of Pb were employed. Calibration was linear within the range 1-30 μg L−1 and 5-30 μg L−1 when the 217.0 nm and 283.3 nm analytical lines were used. Correlation coefficients of 0.9992 and 0.9997 were obtained. Using optimized conditions, limits of detection (3σ) of 0.025 μg g−1 and 0.1 μg g−1 were achieved for the 217.0 nm and 283.3 nm analytical lines, respectively. The method was successfully applied to the determination of lead in soil, contaminated soil, municipal sludge, and sediment samples. The accuracy was assessed by the analysis of two certified reference materials: municipal sludge (QC MUNICIPAL SLUDGE A) and lake sediment (TRAP-LRM from IJS). 相似文献
114.
115.
Kalyuzhnyi S Gladchenko M Epov A Appanna V 《Applied biochemistry and biotechnology》2003,109(1-3):181-195
As a first step of treatment of landfill leachates (total chemical oxygen demand [COD]: 1.43–3.81 g/L; total nitrogen: 90–162
mg/L), performance of laboratory upflow anaerobic sludge bed reactors was investigated under mesophilic (30°C), submesophilic
(20°C), and psychrophilic (10°C) conditions. Under hydraulic retention times (HRTs) of about 0.3 d, when the average organic
loading rates (OLRs) were about 5 g of COD/(L·d), the total COD removal accounted for 81% (on average) with the effluent concentrations
close to the anaerobic biodegradability limit (0.25 g of COD/L) for mesophilic and submesophilic regimes. The psychrophilic
treatment conducted under an average HRT of 0.34 d and an average OLR of 4.22 g of ducted under an average HRT of 0.34 d and
an average OLR of 4.22 g of COD/(L·d) showed a total COD removal of 47%, giving effluents (0.75 g of COD/L) more suitable
for subsequent biologic nitrogen removal. All three anaerobic regimes used for leachate treatment were quite efficient for
elimination of heavy metals (Fe, Zn, Cu, Pb, Cd) by concomitant precipitation in the form of insoluble sulfides inside the
sludge bed. The application of aerobic/anoxic biofilter as a sole polishing step for psychrophilic anaerobic effluents was
acceptable for elimination of biodegradable COD and nitrogen approaching the current standards for direct discharge of treated
waste-water. 相似文献
116.
One sewage sludge (SLA) from Ávila region (Spain) was selected and used as raw material in order to study the influence of acid treatment on the pyrolysis behavior of sewage sludges. SLA was heat treated with acid solutions at pH 1 and pH 2 leading to SLA-1 and SLA-2, respectively. Characterization of samples has showed that acid treatment leads to metals removal and modifications in the organic matter composition of sewage sludge. Pyrolysis of three samples showed that SLA and SLA-1 have a similar pyrolysis behavior whereas SLA-2 shows a slightly extended temperature interval for pyrolysis, beginning at lower temperature and finishing at higher temperatures. 相似文献
117.
Single-stage anaerobic codigestion for mixture wastes of simulated Korean food waste and waste activated sludge 总被引:2,自引:0,他引:2
Nam Hyo Heo Soon Chul Park Jin Suk Lee Ho Kang Don Hee Park 《Applied biochemistry and biotechnology》2003,107(1-3):567-579
Korean food waste was treated with a single-stage anaerobic codigester (SSAD) using waste activated sludge (WAS) generated
from a municipal wastewater treatment plant. The stability and performance of the system was analyzed. The C/N ratio was improved
with increasing food waste fraction of feed mixture. The pH, alkalinity, and free ammonia nitrogen concentration were the
parameters used to evaluate the digester’s stability. The experimentally determined values of the parameters indicated that
there were no methane inhibitions in the digester. Digester performance was determined by measuring the total chemical oxygen
demand TCOD), volate solids (VS) removal, methane content in biogas, methane production rate (MPR), and specific methane productivity.
Methane content in biogas and MPR were significantly dependent on hydraulic retention time (HRT) and ratio of food waste to
WAS. The methane content in biogas decreased at shorter HRT or higher organic loading rate (OLR) with increased food waste
fraction. Concerning the performance of the codigester, the optimum operating condition of the SSAD was found to be at an
HRT of 10 d with a feed mixture ratio of 50% food waste and 50% WAS. A TCOD removal efficiency of 53.6% and a VS removal efficiency
of 53.7% were obtained at an OLR of 5.96 kg of TCOD/(m3·d) and 3.14 kg of VS/(m3·d), respectively. A maximum MPR of 1.15 m3 CH4/(m3·d) and an SMP of 0.37 m3 CH4/kg of VSfeed were obtained at an HRT of 10 d with a methane content of 63%. 相似文献
118.
A significant, valuable percentage of today's municipal solid wastestream consists of polymeric materials, for which almost no economicrecycling technology currently exists. This polymeric waste is incinerated,landfilled, or recycled via downgraded usage. Thermal plasma treatment is apotentially viable means of recycling these materials by converting themback into monomers or into other useful compounds. The technical, laboratoryscale, feasibility of using an induction-coupled RF plasma (ICP) heatedreactor for this purpose has been demonstrated in the presentstudy. Polyethylene powder was injected axially through the center of anICP torch. Results from the initial set of experiments, analyzed using astatistical design of experiment technique, showed that plasma plate power,central gas flow rate, probe gas flow rate, powder feed rate, and theinteraction between the quench gas flow rate and power input were the keyprocess parameters affecting the yield of ethylene in the product gasstream. The gaseous products obtained were mainly mixtures of ethylene andpropylene. The amount of propylene obtained was significantly higher thananticipated and was believed to be due to -scission reactionsoccurring at the higher plasma temperatures. 相似文献
119.
PCP with a variety of application in industrial, agricultural and domestic fields, is an inhibitor of oxidative phosphorylation, therefore, toxic to a broad spectrum of organisms and may have mutagenic properties [1]. In China, sodium pentachlorophenate (Na-PCP) has been sprayed widely since the 1960s to control the spread of snailborne schistosomiasis. Although Na-PCP has been replaced by some new molluscicides since 1990s, the persistence of PCP has resulted in the accumulation in soil … 相似文献
120.