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881.
高校文书档案立卷改革的探索与应用   总被引:1,自引:0,他引:1  
传统的立卷程序繁琐复杂,既浪费了人力、物力和财力,利用效果也不理想。随着社会的发展,传统的文书立卷方法已不适应档案管理现代化的需要,必须转变观念,把工作重点由“重藏轻用”转移到“简化管理、强化检索、重在利用”的新思路上来。新的规则取消了案卷,以件为单位进行整理归档,简单、易学、实用,有利于档案的保护、查找和利用。在新规则的实践过程中,档案工作者也需灵活掌握,改进工作方法。  相似文献   
882.
Photocatalytic degradation of lignin using Pt/TiO2 as the catalyst   总被引:1,自引:0,他引:1  
Ma YS  Chang CN  Chiang YP  Sung HF  Chao AC 《Chemosphere》2008,71(5):998-1004
Photocatalytic degradation of lignin was studied with the use of catalysts TiO(2) and Pt/TiO(2). The influence of several experimental parameters, i.e. pH, catalyst dosage and illumination on lignin degradation was investigated. The results showed that application of UV irradiation alone has almost no effect on the reduction of dissolved organic carbon (DOC) and American Dye Manufacture Institute value (ADMI). However, the addition of TiO(2) and Pt/TiO(2) reduced the original DOC (251 mg l(-1)) by more than 40% within 30 min of treatment and the reaction can be simulated with pseudo-first order kinetics. Rapid degradation of lignin was observed in acidic solution using either TiO(2) or Pt/TiO(2) as the catalyst compared to high pH cases. The content of Pt in the Pt/TiO(2) catalyst is 1%. In addition, too much catalyst addition has not increased the DOC and ADMI reduction proportionally. The investigation also indicated that the photocatalytic degradation rates could be enhanced 1-6 times faster after doping TiO(2) with Pt in different pH cases. A modified Nernst type model was adopted to simulate the decoloring process using TiO(2) and Pt/TiO(2) based on the profiles of oxidation reduction potential during the photocatalytic reaction. The developed equation can be used to predict the color removal efficiency of lignin wastewater by the photocatalytic process.  相似文献   
883.
Kinetic degradation processes of butyl- and phenyltins in soils   总被引:3,自引:0,他引:3  
Heroult J  Nia Y  Denaix L  Bueno M  Lespes G 《Chemosphere》2008,72(6):940-946
The degradation of organotin compounds (OTC) in agricultural and forest soils is studied in sandy soil samples. Individual experiments involving the three butyl- and the three phenyltins were carried out during 90 d in controlled conditions (darkness, 28 degrees C, aerobic conditions, 13% moisture) and with spiking concentration representative of environmental levels (20-50 micrg(Sn) kg(-1)). After the validation of first-order degradation kinetic model, mechanisms involved throughout the study were considered. Degradation pathways are proposed for butyl- and phenyltins and discussed according to literature data. The degradation of mono- (MBT, MPhT), di-organotins (DBT, DPhT) and TBT is clearly identified as a single successive loss of an organic group whereas TPhT is directly degraded to MPhT. The half-life times were dependent on their substitution degree, ranging from 24 (TPhT) to 220 (MBT) d. The less substituted the OTC is, the more persistent it is. In the range 4.3-5.7, pH does not seem to influence OTC degradation under the present operating conditions. Finally this study shows the significant persistence in soil samples in our experimental conditions for most of studied organotins and highlights the potential impact on soil quality.  相似文献   
884.
This paper reviews several models developed to support decision making in municipal solid waste management (MSWM). The concepts underlying sustainable MSWM models can be divided into two categories: one incorporates social factors into decision making methods, and the other includes public participation in the decision-making process. The public is only apprised or takes part in discussion, and has little effect on decision making in most research efforts. Few studies have considered public participation in the decision-making process, and the methods have sought to strike a compromise between concerned criteria, not between stakeholders. However, the source of the conflict arises from the stakeholders' complex web of value. Such conflict affects the feasibility of implementing any decision. The purpose of this study is to develop a sustainable decision making model for MSWM to overcome these shortcomings. The proposed model combines multicriteria decision making (MCDM) and a consensus analysis model (CAM). The CAM is built up to aid in decision-making when MCDM methods are utilized and, subsequently, a novel sustainable decision making model for MSWM is developed. The main feature of CAM is the assessment of the degree of consensus between stakeholders for particular alternatives. A case study for food waste management in Taiwan is presented to demonstrate the practicality of this model.  相似文献   
885.
拮抗菌对黄瓜枯萎病菌的室内生物活性   总被引:16,自引:0,他引:16  
测定了从沤肥浸渍液和土壤中分离并筛选得到对黄瓜枯萎病菌的室内生物活性的6个菌株,编号为94-I、94-Ⅱ、94-Ⅲ、96-Ⅰ和98-Ⅱ,测定其孢子悬浮培养16h时对黄瓜枯萎菌的抑制率分别为48.29%、0.00%、60.69%、39.28%、61.29%和72.32%,孢子和菌丝有的变畸形并产生大泡囊;平皿拮抗试验表明,其活体浓度为50%时对黄瓜枯萎病菌的抑制率最大分别为74.52%、83.27%、90.60%、88.59%、89.35%和94.30%;而其相同浓度高压蒸汽灭活后的代谢产物对黄瓜枯萎病菌的抑制率最大分别为33.215、52.22%、62.84%、46.57%、47.61%和70.34%。  相似文献   
886.
Background Since the 1970s, at least 200 hectares (ha) of farmland has been polluted by the heavy metal cadmium (Cd).Consequently, the Cd pollution has led to contaminate the rice production and caused acute social panic. According to the recent investigation results performed by the Taiwan Environmental Protection Administration (TEPA), it is indicated that most of the Cd pollution incidents in Taiwan resulted from the wastewater discharge of stearate Cd factories. To prevent the Cd pollution incidents from spreading, the TEPA has either forced these factories to close down or assisted them in improving their production processes since the 1980s. Unfortunately, accidental incidents of Cd pollution still emerge in an endless stream, despite the strict governmental controls placed on these questionable factories. Whether this pollution has resulted from undetected or hidden pollution sources stemming from two decades ago or comes from some new source, will be an outstanding issue. Therefore, this study attempts to identify the pollution sources of Cd in soil in Taiwan as well as to find the solution to the above-mentioned, outstanding issue by way of a methodology termed Material Flow Analysis (MFA). Method logy. The MFA has proved to be a useful tool on providing quantitative information of the flow of substances through an economic to an environmental system. Based upon the supply-and-demand theory of MFA, researchers have successfully conducted an overview of the use of materials in many industries, the construction industry being one of these. Therefore, this study tries to establish a set of analytical processes by way of MFA for identifying the pollution source of Cd in soil in Taiwan. In addition, the spirit of Life Cycle Analysis (LCA) technique was also employed to identify the materials, and products should be ignored as a crucial pollution source in this study. Results and Discussion According to the MFA methodology applied in this study and on the basis of related studies performed by Taiwanese governmental authorities, we arrive at the following analysis results: (1) the total amount of Cd from the economic perspective of material and product flow was approximately 441.2 tons; (2) the wastewater directly discharged into irrigation water can be concluded to be the major pollution route of Cd in farmland soil in Taiwan; (3) material plastic stabilizer (cadmium oxide, CdO), Zn-Pd compounds and Cu compounds should be the crucial pollution sources to contaminate environment through the route of wastewater in Cd flow analysis; (4) the crucial pollution sources to contaminate environment through the route of wastewater in Cd flow analysis were five factories, Coin, Jili, Taiwan Dye, Guangzheng and Mingguan, and they were all categorized as stearate Cd industries; (5) the typical source of the Cd pollution in soil in Changhua County through the pollution route of wastewater should be the metal surfacing process industries. Conclusions This study proved that MFA can be a good tool for identifying Cd flow as well as for recognizing the crux of the problem concerning incidents of Cd pollution. This study led to the conclusion that the causal relationship between farmland pollution caused by Cd and stearate Cd factories in Taiwan seemed quite close by way of MFA methodology. In addition, this study also found that the wastewater discharged from a single metal surfacing process factory will not cause remarkable farmland pollution. However, the wastewater simultaneously discharged from a group of pollution factories can result in a significant pollution incident. Recommendations and Outlook This case study is only a small contribution to the understanding of the toxic material flow related to Cd in the environment. This study recommends that Taiwanese governmental authorities should not deal with problems on an ad hoc basis, but should instead deal with Cd pollution problems overall employing control measures. Finally, the more accurate information or data we can collect, the more reliable results we can identify. Therefore, the quality and quantity of related data used in this MFA model should be closely scrutinized in order to ensure the most correct and comprehensive investigation on the toxic material flow.  相似文献   
887.
In this paper, the movement behavior of Daphnia magna was studied as a bio-indicator of organophosphorous pesticide (OP) contamination, using an on-line bio-monitoring method, the Multispecies Freshwater Biomonitor. A static test of acute toxicity test revealed the 24-h and 48-h LC(50) values (95% confidence limit) for Daphnia magna to be respectively 0.45 microg/l and 0.21 microg/l for dipterex 3.80 microg/l and 0.90 microg/l for malathion, and 1.25 microg/l and 0.38 microg/l for parathion. The behavior strength of Daphnia magna was a sensitive indicator of sublethal OP stress and resulted in significant concentration-response relationships for the three OPs. Increasing OP concentration will result in more intensive behavioral responses of Daphnia magna and shorter response time, which could be described by the Stepwise Stress Model (SSM). Therefore movement behavior can be effectively applied in early warning of environment quality by on-line bio-monitoring. The intensive changes in behavior strength of Daphnia magna over a short time follow the SSM concept and can be used as an indicator of early stress response to OP accidental contamination.  相似文献   
888.
An arsenic speciation study has been performed in PM10 samples collected on a fortnight basis in the city of Huelva (SW Spain) during 2001 and 2002. The arsenic species were extracted from the PM10 filters using a NH2OH x HCl solution and sonication, and determined by HPLC-HG-AFS. The mean bulk As concentration of the samples analyzed during 2001 and 2002 slightly exceed the mean annual 6 ng m(-3) target value proposed by the European Commission for 2013, arsenate [As(V)] being responsible for the high level of arsenic. The speciation analyses showed that As(V) was the main arsenic species found, followed by arsenite [As(III)] (mean 6.5 and 7.8 ng m(-3) for As(V), mean 1.2 and 2.1 ng m(-3) for As(III), in 2001 and 2002, respectively). The high levels of arsenic species found in PM10 in Huelva have a predominant industrial origin, such as the one from a nearby copper smelter, and do not present a seasonal pattern. The highest daily levels of arsenic species correspond to synoptic conditions in which the winds with S and SW components transport the contaminants from the main emission source. The frequent African dust outbreaks over Huelva may result in an increment of mass levels of PM10, but do not represent a significant input of arsenic in comparison to the anthropogenic source. The rural background levels of arsenic around Huelva are rather high, in comparison to other rural or urban areas in Spain, showing a relatively high atmosphere residence time of arsenic. This work shows the importance of arsenic speciation in studies of aerosol chemistry, due to the presence of arsenic species [As(III) and As(V)] with distinct toxicity.  相似文献   
889.
Phorate (O,O-diethyl S-ethylthiomethyl phosphorodithioate) dissolved in aqueous solution was almost completely decomposed by ozonation to form various species within 10 minutes of reaction time for the experimental conditions examined in this research. The generation rate of sulfate was found to be fairly independent of solution pH value. However, the formation of phosphate and carbonate was more favorable for alkaline solutions where hydroxyl free radical is the primary oxidative species. The reaction rates increased with initial gaseous ozone concentrations, indicating the reaction was mass transfer-controlled within the experimental range of this research. Combining the analytical results by various instruments, including gas chromatograph equipped with an electron ionization detector (GC-EID), high performance liquid chromatography (HPLC), ion chromatography (IC), and total organic carbon (TOC), the temporal sequence of phorate ozonation was proposed in this study. The oxidation of sulfur atoms on the phosphorus-sulfur double bond or carbon-sulfur-carbon bond by ozonation was found to occur at first to form sulfate and various intermediates.  相似文献   
890.
A multi-compartment system was used to study the importance of microorganisms for Cd desorption from soil amended with sewage sludge and simultaneous resorption of the mobilized metal by soil constituents. Using this system made it possible to study the participation of microorganisms (Arthrobacter, Trichoderma), montmorillonite, humic acids, and iron oxides in resorption of the released Cd. A filter-sterilized water extract of root-free soil of pH 6.7 (RF) or RF supplemented with glucose (RFG) were used to mobilize Cd from soil at 14 degrees C in 48 h. Cadmium found in those extracts after 48-h incubation was recognized as bioavailable. Changes in pH values and enrichment of soil extracts with organic acids and siderophores resulted from microbial growth. RFG with lower pH and a higher content of ligands mobilized, on average, 40% of Cd introduced with sewage sludge amended soil, whereas RF mobilized only 20% of it. Sequential extractions of Cd at time 0 and Cd remaining in soil showed that RFG had mobilized Cd mostly from the fraction bound with Fe and Mn oxides. Microbial biomass accounted for only up to 3.4% (w/w) of the soil constituents used in the experiments but resorbed 25% of mobilized Cd. The chemical composition of mobilizing soil extracts and the solid-to-mobilizing-extracts volume ratio had a significant effect on the amount of bioavailable Cd. The results of the study suggest that microbial metabolites were involved in Cd mobilization, while the biomass of microorganisms was involved in Cd resorption as a biosorbent.  相似文献   
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