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41.
高浓度增塑剂生产废水的处理研究   总被引:2,自引:0,他引:2  
针对增塑剂生产废水的特点,提出了隔油→中和调节→SBR生化处理→排放的处理工艺。实验结果证明,经以上工艺处理后,CODcr去除率可稳定在92%-98%,增塑剂生产废水能达标排放。  相似文献   
42.
Blends of thermoplastic starch with poly(ethylene‐co‐vinyl alcohol) copolymer (EVOH) were melt extruded with water/glycerol as plasticizer and a series of amino acid additives. The biggest factor in end‐use mechanical properties proved to be the relative humidity (RH) during storage. Plasticized starch‐EVOH blends stored at 0 and 50% RH changed significantly over time, with, for example, the tensile strength (TS) of the glycerol‐plasticized blend increasing from 4.7 to 26.3 MPa over 8 weeks when maintained at 0% RH. In contrast, the TS of this same sample stored at 75% RH remained unchanged for 8 weeks. Amino acids provided relatively minor, but significant changes in mechanical properties with time. Based on TS, elongation‐to‐break, and modulus, it may be concluded that β‐alanine, sarcosine, and L ‐proline were more effective than glycerol at maintaining strong flexible blends. Increases in crystallinity and changes in morphology with time, as described by modulated DSC were correlated to these changes in mechanical properties. Published in 2007 by John Wiley & Sons, Ltd.  相似文献   
43.
The primary use of poly(acrylonitrile) (PAN) fibers, commonly referred to as acrylic fibers, is in textile applications like clothing, furniture, carpets, and awnings. All commercially available PAN fibers are processed by solution spinning; however, alternative, more cost‐effective processes like melt spinning are still highly desired. Here, the melt spinning of PAN‐co‐poly(methyl acrylate) (PMA) plasticized with propylene carbonate (PC) at 175°C is reported. The use of methyl acrylate (MA) as comonomer and PC as an external plasticizer renders the approach a combination of internal and external plasticization. Various mixtures of PAN and PC used in this work were examined by rheology, subjected to melt spinning, followed by discontinuous and continuous washing, respectively. The best fibers were derived from a PAN‐co‐PMA copolymer containing 8.1 mol‐% of MA having a number‐average molecular weight M n of 34 000 g/mol, spun in the presence of 22.5 wt.‐% of PC. The resulting fibers were analyzed by scanning electron microscopy and wide‐angle X‐ray scattering (WAXS), and were subjected to mechanical testing.  相似文献   
44.
PVC材料与产品对环境影响及其废物管理   总被引:2,自引:1,他引:1  
分析了PVC材料的生产过程、添加剂的使用情况以及PVC材料与产品的生命周期期间可能导致的各种环境问题,并提出了一些可行措施来减少PVC材料与产品对人体健康和环境的影响,并对各类方法进行了分析,对PVC材料与产品的生产和过程和PVC废物的管理提出了可行方法.  相似文献   
45.
甘油单醚类化合物对纤维素膜的增塑作用   总被引:2,自引:0,他引:2  
肖超渤  张曦 《应用化学》1997,14(2):13-15
报道甘油单丁醚、单己醚、单庚醚和单辛醚4种化合物的合成,并用作再生纤维素膜的增塑剂.实验结果表明这4种甘油单醚类化合物对纤维素膜具有较好的增塑作用,随增塑剂单醚碳原子数的增加,增塑效果降低,但增塑剂与纤维素分子间相互作用增强.经甘油单己醚、单庚醚和单辛醚增塑的再生纤维素膜其耐水洗性明显高于甘油增塑的膜.  相似文献   
46.
为探究食品级PVC保鲜膜中增塑剂向猪肉中迁移的行为,建立了新鲜猪肉中9种增塑剂同时检测的固相萃取-气相色谱检测方法,并运用建立的方法对市售食品级PVC保鲜膜中增塑剂含量以及其向猪肉中的迁移行为进行分析。结果表明:方法的最低检出限(LOD,S/N=3)为0.020~0.036mg/kg,能够满足分析需要。市售食品级PVC保鲜膜中检测到邻苯二甲酸二(2-乙基己基)酯(di(2-ethylhexyl)phthalate,DEHP)和己二酸二(2-乙基)己酯(di(2-ethylhexyl)adipate,DEHA)两种增塑剂,并以这两种增塑剂为实验对象进行迁移实验。迁移实验中,接触温度、时间、猪肉的脂肪含量对迁移量均有影响:在一定范围内,接触温度越高、时间越长、脂肪含量越高,迁移量越大;对于薄的包装材料,选择与食品接触的那一面进行单侧迁移实验与实际情况更接近。  相似文献   
47.
端羟基聚叠氮缩水甘油醚(GAP)聚氨酯力学性能的研究   总被引:2,自引:0,他引:2  
采用一步法合成端羟基聚叠氮缩水甘油醚(GAP)聚氨酯。DSC,DTA和静态力学性能测试结果表明:该粘合剂和硝酸酯增塑剂1,2,4-丁三醇三硝酸酯(BTTN)具有良好的溶混性;随硝酸酯含量的增加,聚氨酯胶片的分解峰温下降。同时观察到胶片的弹性模量和抗拉强度随交联剂含量的增加而增加,但断裂延伸率随之下降。固体填料HMX和GAP粘合剂之间的界面相互作用小,从而导致推进剂抗拉强度和延伸率明显降低。  相似文献   
48.
An NH -ISFET sensor based on PVC membrane technology with improved long-term stability has been developed. As a new approach, the plasticizer (tetra-n-undecyl) 3,3′,4,4′ -benzhydroltetracarboxylate (ETH2112) was used in membrane preparation. Its lipophilic nature provides a restricted diffusion of the membrane components to the external solution and improves membrane adhesion to the gate area of the ISFET. The good performance of this plasticizer was confirmed by comparison with usual plasticizers applied in standard ISE technology. Moreover, the durability and stability of the sensor were enhanced by the application of a graphite-epoxy layer as an internal reference between the gate area and the PVC membrane. This composite layer permits the reduction of the optical sensitivity and improves the adherence of the PVC membrane to the ISFET surface. Furthermore, this composite layer acts as a plug, preventing the entrance of water upon the encapsulant-chip interface, thus protecting electrical connections from moisture. As a result, an NH -ISFET with a long-term stability of three months and a sensitivity of −58.7 ± 2.3 mV decade−1 in a linear range of 10−5 −0.1 mol dm−3 has been developed. The application of this sensor to a continuous-flow system has confirmed the feasibility of the technological approach proposed.  相似文献   
49.
Extruded parts of non‐sterilized and β‐irradiated (25 and 50 kGy) plasticized poly(vinyl chloride) (PVC) used for disposable medical devices have been studied to investigate the effect of sterilization on surface chemical composition. The polymer surfaces were analysed using angle‐resolved x‐ray photoelectron spectroscopy. The inner surface of the blood tubing lines showed a fairly smooth surface both before and after sterilization, so a laterally homogeneous surface can be assumed for XPS analysis. The XPS survey spectra exhibited no signals besides carbon, chlorine, oxygen and calcium. Detailed analysis of the regions showed the C 1s, Cl 2p and O 1s signals to be multi‐component, presenting signals of the PVC, the plasticizer and the other additives. Binding energies remained constant irrespective of β‐radiation dosage, but the amount of chlorine component at 198.4 ± 0.1 eV (associated with modified PVC) decreased with sterilization dosage. Angle‐resolved XPS revealed that this component is located at the outermost surface of the polymer. It can be hypothesized that the production processes themselves (extrusion and/or injection molded) already induce modifications of the polymer surface and also lead to surface segregation of the plasticizer. During the subsequent thermal sterilization of the polymer dehydrochlorination continues but, because of the very short time required by the β‐irradiation technology to sterilize devices, the atmospheric oxygen is unable to diffuse into the irradiated material, thus inhibiting further side‐degradation of the materials, such as thermo‐oxidative degradation. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
50.
气相色谱-串联质谱法测定土壤中的邻苯二甲酸酯   总被引:4,自引:0,他引:4  
Li H  Tian F  Ren X  Wang X 《色谱》2011,29(6):563-566
建立了土壤中6种邻苯二甲酸酯的气相色谱-串联质谱(GC-MS/MS)分析方法。土壤样品用超声提取,以二氯甲烷-丙酮(1:1, v/v)混合溶液为提取溶剂,提取液经Florisil小柱净化后,经HP-5MS色谱柱(30 m×0.25 mm×0.25 μm)分离,利用MS/MS的多反应监测(MRM)模式进行定性和定量。结果表明本方法可对样品中的邻苯二甲酸酯进行分析,在10~1000 μg/L质量浓度范围内,线性关系良好,相关系数为0.9973~0.9976;6种邻苯二甲酸酯的相对标准偏差(RSD)不大于14.3%, 2 μg/kg和10 μg/kg两个加标水平的回收率为72.9%~106.2%; 6种目标化合物的检出限为0.1~0.5 μg/kg。该方法快速准确、背景干扰较少、分析灵敏度较高,适用于土壤样品中邻苯二甲酸酯的分析。  相似文献   
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