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排序方式: 共有197条查询结果,搜索用时 15 毫秒
61.
The cryostability of frozen concentrated orange juices (FCOJ) produced by an enzymatic process (enzymatic juice) and a squeezing process (squeezed juice) was investigated. The results showed that after thawing the enzymatic juice was superior in colour stability and cloud stability to the squeezed juice. The influence of glass transition temperature and viscosity of juices on the cryostability was examined and the data showed that some physico-chemical changes/reactions in juices during storage were controlled by diffusion. The composition of carbohydrates in juices was determined by high performance liquid chromatography (HPLC). Results obtained showed that the dominant solutes (low molecular weight compounds) of FCOJ governed the glass transition temperature of juices while the smaller fractions (high molecular weight carbohydrates) of the total solids of FCOJ had significant effects on the viscosity of FCOJ.  相似文献   
62.
This study considered the removal efficiency of turbidity and organic content from high-turbidity storm water of tropical storm Nari, using polyaluminum chloride (PACl) as a coagulant. The resulting floc size and compactness (fractal dimension) were determined using a small-angle light scattering technique. The response surface method, and the Box-Behnken design, was adopted to examine how the hydrogen ion concentration (pH), turbidity, and alkalinity of the suspension, the PACl dosage, and the dosed amount of humic acid affect the removal efficiency. Flocs with a looser interior structure more efficiently removed turbidity and humic acid. An acidic suspension and moderate PACl dosage and alkalinity level favor the production of loose flocs. Optimal conditions for generating large flocs includé pH neutrality and high PACl dosage. Producing both large and loose flocs depends on a compromise. The removal of turbidity/humic acid from high-turbidity storm water does not proceed by a charge neutralization mechanism.  相似文献   
63.
We investigated the drug and fatty acid binding capacity of Pluronic-based microemulsions through simple turbidity experiments. Pluronic-based oil-in-water microemulsions of various compositions were synthesized and titrated to turbidity with concentrated amitriptyline, an antidepressant drug. The BASF Pluronic grid was used to select two series of Pluronic surfactants: (1) those having the same number of ethylene oxide (EO) groups, with an increasing number of propylene oxide (PO) groups and (2) those having the same number of propylene oxide groups with an increasing number of ethylene oxide groups. We observed that the binding of sodium caprylate fatty acid and amitriptyline drug increases with increasing hydrophobicity (i.e., increasing number of PO groups). This is attributed to the greater number of binding sites for the sodium caprylate, which results in more charge on the microemulsion, subsequently leading to increased drug binding. We also determined that when the number of PO groups was held fixed and the number of EO groups was increased, there is no direct correlation to the binding behavior of fatty acid and drug. This is due to the fact that the hydrophilic groups (EO) do not play a direct role in the binding of fatty acid molecules. In fact, when there are a significantly large number of EO groups present, they can act to inhibit binding of fatty acid and hence, drug, to the microemulsion.
Dinesh O. Shah (Corresponding author)Email:
  相似文献   
64.
表面散射浊度测量研究   总被引:5,自引:0,他引:5  
本文在理论上计算了球形粒子对光的单次散射及多重散射解 ,证明了通过检测 90°方向散射光强度来获得样品浊度方案的优越性。随着样品浊度的增加 ,当考虑样品的多重光散射后 ,90°方向散射光强与浊度的线性度下降。设计了表面散射浊度在线测量系统 ,当 Formazin标准液在 0~ 1 0 0 0 NTU范围内时 ,获得了散射光强与浊度的线性度优于± 3% ,测量结果表明用表面散射法来测量浊度具有测量范围宽、线性好的优点。  相似文献   
65.
Qin X  Gao F  Chen G 《Water research》2012,46(4):1133-1144
A multi-sensor water quality monitoring system incorporating an UV/Vis spectrometer and a turbidimeter was used to monitor the Chemical Oxygen Demand (COD), Total Suspended Solids (TSS) and Oil & Grease (O&G) concentrations of the effluents from the Chinese restaurant on campus and an electrocoagulation-electroflotation (EC-EF) pilot plant. In order to handle the noise and information unbalance in the fused UV/Vis spectra and turbidity measurements during the calibration model building, an improved boosting method, Boosting-Iterative Predictor Weighting-Partial Least Squares (Boosting-IPW-PLS), was developed in the present study. The Boosting-IPW-PLS method incorporates IPW into boosting scheme to suppress the quality-irrelevant variables by assigning small weights, and builds up the models for the wastewater quality predictions based on the weighted variables. The monitoring system was tested in the field with satisfactory results, underlying the potential of this technique for the online monitoring of water quality.  相似文献   
66.
An evaluation procedure for flocculation of coal preparation plant tailings   总被引:1,自引:0,他引:1  
Sabah E  Cengiz I 《Water research》2004,38(6):1542-1549
In solid-liquid separation of coal preparation plant tailings by flocculation, in addition to the type and amount of flocculants, the composition of waste materials including clay minerals must be determined in order to devise an effective and economic sedimentation system. In this study, the characterization of organic and inorganic impurities was made with the help of mineralogical data and instrumental analysis techniques. The effects of polymer type (medium and low anionic, cationic and nonionic), polymer dosage and suspension pH on flocculation mechanism of tailings particles (-0.18 mm) in the Tun?bilek Coal Preparation Plant tailings of Tun?bilek (Turkey) were investigated. Medium anionic polymer accelerated the settling rate of particles. An optimum settling rate (300 mm/min) was reached at a dosage rate of 34.19 g/ton-solids (2.0 mg/l), 51.28 g/ton-solids (3.0 mg/l), 102.56 g/ton-solids (6.0 mg/l) and 119.66 g/ton-solids (7.0mg/l) for medium anionic, low charged anionic, nonionic and cationic polymers, respectively. The lowest turbidity values at low polymer dosages were obtained by the cationic polymer at around 25.64 g/ton-solids (1.5 mg/l) polymer dosages; however, the low anionic and nonionic polymers produced lower turbidity values at higher dosages (>25.64 g/ton-solids). At optimum dosages of the polymer, the settling rate decreased at low and high pHs indicating that the natural pH (pH 8.3) of the suspension is the most appropriate pH for the settling rate. On the other hand, the water clarity values at natural pHs were high for all of the polymers.  相似文献   
67.
Divakaran R  Pillai VN 《Water research》2004,38(8):2135-2143
Flocculation of kaolinite using chitosan alone as flocculant has been reported to be difficult. Detailed investigations in our laboratory have shown that kaolinite can be easily removed from aqueous suspensions by flocculation and settling using chitosan, provided the suspension medium contains traces of dissolved humic substances. The flocculation is also extremely sensitive to the pH of the suspension. Removal of suspended titanium dioxide particles in water by flocculation using chitosan in presence of humic acids is also reported for the first time. A plausible mechanism explaining these observations is proposed in this paper.  相似文献   
68.
综述了几种常见的临界聚沉浓度(CCC)测试方法及其理论模型。  相似文献   
69.
高琴  冯燕 《中国纤检》2012,(17):60-62
介绍了目前常用的羽绒羽毛检测标准,包括中国GB/T10288-2003、日本JISL1903:2011、国际羽绒羽毛局IDFB测试规则2010版、欧盟BSEN方法,并详细比较分析了这些方法的差异性,对规范和统一检测技术具有指导作用。  相似文献   
70.
The feasibility of utilizing infrared spectroscopy for the prediction of haze formation in white wines resulting from heat and colloidal stability tests was investigated. One-hundred eleven white wines, representing multiple regions and varieties from the 2008 California vintage, were collected and analyzed. The near and mid-infrared spectra were measured and heat and colloidal (ethanol addition) stability tests were performed on the same wines. Partial-least squares regression analysis was then used to construct models predictive of the resulting nepholometric turbidity to the acquired spectra. Preliminary models obtained following application of spectral pretreatments today considered as “classical” (e.g., derivatives, standard normal variate, vector normalization, constant offset elimination) lacked robustness; two alternative algorithms designed to remove spectral information unrelated to the turbidity were then employed (orthogonal signal correction; direct orthogonal signal correction). While OSC pretreatment did not result in more robust models, DOSC considerably enhanced the goodness of the PLS model constructed to predict the ethanol test turbidity. Predictive modeling of the short-NIR spectra, following DOSC preprocessing, allowed the prediction of colloidal stability on an unknown test set with an R2 = 0.80 and a RMSEP = 10.12 using three latent variables. When the data set was restricted to Chardonnay wines alone, the predictive ability improved, with R2 = 0.85 and RMSEP = 8.90.  相似文献   
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