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71.
Various methods to detect foodborne viruses including norovirus (NoV) in contaminated food have been developed. However, a practical method suitable for routine examination that can be applied for the detection of NoVs in oily, fatty, or emulsive food has not been established. In this study, we developed a new extraction and concentration method for detecting NoVs in contaminated composite meals. We spiked NoV-GI.4 or -GII.4 stool suspension into potato salad and stir-fried noodles. The food samples were suspended in homogenizing buffer and centrifuged to obtain a food emulsion. Then, anti-NoV-GI.4 or anti-NoV-GII.4 rabbit serum raised against recombinant virus-like particles or commercially available human gamma globulin and Staphylococcus aureus fixed with formalin as a source of protein A were added to the food emulsion. NoV-IgG-protein A-containing bacterial complexes were collected by centrifugation, and viral RNA was extracted. The detection limits of NoV RNA were 10–35 copies/g food for spiked NoVs in potato salad and stir-fried noodles. Human gamma globulin could also concentrate other NoV genotypes as well as other foodborne viruses, including sapovirus, hepatitis A virus, and adenovirus. This newly developed method can be used as to identify NoV contamination in composite foods and is also possibly applicable to other foodborne viruses.  相似文献   
72.
There is increasing concern about feeds prepared from food residues (FFR) from an environmental viewpoint; however, various forms of energy are consumed in the production of FFR. Environmental impacts of three scenarios were therefore investigated and compared using life cycle assessment (LCA): production of liquid FFR by sterilization with heat (LQ), production of dehydrated FFR by dehydration (DH), and disposal of food residues by incineration (IC). The functional unit was defined as 1 kg dry matter of produced feed standardized to a fixed energy content. The system boundaries included collection of food residues and production of feed from food residues. In IC, food residues are incinerated as waste, and thus the impacts of production and transportation of commercial concentrate feeds equivalent to the FFR in the other scenarios are included in the analysis. Our results suggested that the average amounts of greenhouse gas (GHG) emissions from LQ, DH, and IC were 268, 1073, and 1066 g of CO(2) equivalent, respectively. The amount of GHG emissions from LQ was remarkably small, indicating that LQ was effective for reducing the environmental impact of animal production. Although the average amount of GHG emissions from DH was nearly equal to that from IC, a large variation of GHG emissions was observed among the DH units. The energy consumption of the three scenarios followed a pattern similar to that of GHG emissions. The water consumption of the FFR-producing units was remarkably smaller than that of IC due to the large volumes of water consumed in forage crop production.  相似文献   
73.
Poly(L-lactide)(PLA)-degrading activities of a fungus, Tritirachium album, and two strains of actinomycetes,Lentzea waywayandensis and Amycolatopsis orientalis, were inducible by some proteins (poly-L-amino acid), peptides and amino acids. Extracellular PLA-degrading activity of the culture filtrates was detected when these strains grew in liquid basal medium containing 0.1% (w/v) of (poly-L-amino acids), peptides or amino acids as the enzyme inducer. In addition to PLA-degrading activity, succinyl-(L-alanyl-L-alanyl-L-alanine)-p-nitroanilide (Suc-(Ala)3-pNA)-degrading activity was observed, implying that the enzymes produced were protease-type. The enzyme activities produced varied between different strains and different inducers. Silk fibroin was the best inducer for A. orientalis and that elastin was the best inducer for L. waywayandensis and T. album.  相似文献   
74.
The distribution behavior of pyrene on humic acid (HA)-kaolin complexes, prepared by adsorbing HA on kaolin, was investigated by batch experiments. The distribution coefficient (Kd) of pyrene on the HA-kaolin complex increased with the fraction (f(oc)) of organic carbon adsorbed to the surface of the kaolin. This can be attributed to hydrophobic interactions between pyrene and the adsorbed HAs. The effects of adsorbed HAs were quantitatively evaluated by calculating the distribution coefficient (K(oc)) and affinity constant (K(oc)ads) for pyrene to the adsorbed HAs. A fluorescence quenching method was employed to determine the affinity constant (K(oc)aq) of pyrene to HAs dissolved in an aqueous solution. When the K(oc) values were compared with the K(oc)aq values, the K(oc) values were found to be 4 to 11 times larger than the K(oc)aq values. On the other hand, the K(oc)ads values were 4 to 9 times larger than the K(oc)aq values. These indicate that the affinity for pyrene is enhanced by the adsorption of HAs to kaolin. In addition, the K(oc) values increased with increasing average molecular weights of the HAs. These results demonstrate that HAs, when they are adsorbed to clay minerals, play an important role in the deposition of polycyclic aromatic hydrocarbons (PAHs) in a soil environment.  相似文献   
75.
Iguchi Y  Ichiura H  Kitaoka T  Tanaka H 《Chemosphere》2003,53(10):1193-1199
A novel paper-based material containing titanium dioxide (TiO2) photocatalyst was successfully prepared by a papermaking technique with the internal addition of inorganic fibers on which TiO2 particles were supported. Photodegradation performance of acetaldehyde gas, an indoor pollutant, and the durability of the TiO2-containing papers were investigated under UV irradiation. Ceramic fiber suspension and polydiallyldimethylammonium chloride as a cationic flocculant were mixed, followed by the addition of TiO2 suspension and anionic polyacrylamide. Subsequently, the inorganic mixture was poured into a pulp suspension, and TiO2 handsheets then prepared by a papermaking method. The tensile strength of TiO2-containing paper without a ceramic carrier decreased by more than 30% after 240-h UV irradiation (2 mW/cm2), although the strength of the TiO2 sheet with ceramic fibers remained reasonably stable. The efficiency of acetaldehyde decomposition by the TiO2 paper containing an inorganic carrier was nearly equal to that of the carrier-free TiO2 paper. Scanning electron microscopic observation suggested that most TiO2 particles were predominantly supported on the inorganic fiber matrix, and were mostly out of contact with organic pulp fibers. The TiO2 paper with an inorganic carrier demonstrated both excellent photocatalytic performance and durability, which before had been mutually incompatible for organic materials containing TiO2 photocatalyst. The two-stage mixing procedure for TiO2 sheet-making is promising for the simple manufacture of high performance paper with photocatalytic ability.  相似文献   
76.
We simulated the long range transport of dust emitted from dust storms that occurred in China by using a global three-dimensional chemical transport model. A modified dust emission flux scheme and a nonlocal diffusion scheme for determining the atmospheric eddy diffusivity in the atmospheric boundary layer were implemented to improve the chemical transport model. We examined the dust transport by comparing the model results with TOMS satellite images. The model calculated monthly total deposition of dust masses were used for comparison with the measurements collected at sampling stations in Japan, and good agreement was found. The model generally reproduced the temporal and spatial variations of dust reasonably well.  相似文献   
77.
长良川水质中溶解氧和化学耗氧量预测模型的建立   总被引:2,自引:1,他引:2  
文章介绍了GMDH(group method of data handling)方法的基本运算法则,运用改进后的GMDH方法,建立长良川溶解氧和化学耗氧量两个水质项目的长期预到模型,模型相关度可达0.96,基本满足要求,并根据模型对水质变化机理进行分析。  相似文献   
78.
To suppress the coagulation of humic acid (HA) in aqueous solutions, HA was modified with hydrophilic amines, such as glucosamine or taurine. These amines were attached to carboxyl groups in HA via amide bond formation. The degree of modification (R(m)) was estimated to be 21-38%. Infrared spectra of the modified HAs were also consistent with the presence of amide bonds. Acid-base titration showed that the average acid-dissociation constant (pK(app)) of the HA samples was increased by the modification. The Ca(2+) binding capacity of HA decreased with an increase in R(m) value. Critical pH or Ca(2+) concentration, at which HA coagulation occurs, was increased as the result of the modification. These critical points for taurine-HA were higher than those for glucosamine-HA. This is mainly due to electrostatic repulsion by sulfonate groups in taurine. These results indicate that the coagulation of HA is suppressed by modifying the molecules with glucosamine or taurine.  相似文献   
79.
80.
Serious adverse impacts on the environment and human health from e-waste recycling have occurred in the past and continue to occur in China today, due to a lack of national management strategies. China has made great efforts to face the challenges of the approaching peak increase in the domestic generation of e-waste and the illegal shipment of e-waste from other countries. This study examined recent progress and analysed the main problems associated with this issue in China. It was found that the material and the financial flows of e-waste in China had their own specific characteristics. Nearly 60% of the generated e-wastes were sold to private individual collectors and passed into informal recycling processes. More than 90% of Chinese citizens are reluctant to pay for the recycling of their e-waste. This is due to their traditional understanding that there remained value in these end-of-life products. Regulations concerning e-waste in China have been drafted but their deficiencies are obvious. The extended producer responsibilities (EPR) have been introduced but are not well defined. Eight formal facilities have been planned and are under construction or are in operation along the eastern coast of China but it will be difficult for them to compete with the informal processes for the reasons identified during the study.  相似文献   
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