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41.
Peter?S.?Piispanen Marcus?Persson Per?Claesson Torbj?rn?NorinEmail author 《Journal of surfactants and detergents》2004,7(2):147-159
Several novel and some previously known, mostly sugar-based, surfactants have been synthesized and some of their surface properties
have been characterized and compared with those of commercial nonylphenol ethoxylates. The surfactant solubility in water,
ethanol, and dodecane was studied. The properties of these compounds as emulsification agents in systems composed of the surfactant
with water/isopropyl myristate, water/rapeseed oil, and water/dodecane are presented. The aqueous solubility of the surfactants
follows the general trend expected from their hydrophilic-lipophilic balance according to Griffin (HLBG), but it is also clear
that the nature of the headgroup and the structure of the nonpolar part affect the solubility in a manner not aptured in the
standard HLBG concept. An ester or amine group as the connecting unit between the hydrophile and the hydrophobe produces a
more water-soluble surfactant than the corresponding amide derivative. Some effective emulsifiers were found. For instance,
the surfactants with a dehydroabietic nonpolar group appear to be promosing emulsifiers. Most sugar-based surfactants were
able to form macroemulsions of up to around 2 wt/vol% of oil. The stability of many of these amulsions was very high, extending
for months. 相似文献
42.
Foams used in buoyancy applications must resist penetration by water at significant depths of immersion. The behavior of water blown rigid polyurethane foam at different water pressures from 0 to 3 MPa are studied in this work. The effects of different surfactants on the cell structure and hydraulic resistance of the foams are examined. The foams have densities in the range of 145 to 160 kg/m3. With increasing applied hydraulic pressure, it is found that the foams have very small buoyancy losses at low pressures but beyond a threshold pressure, buoyancy losses increase rapidly. The threshold pressures of the foams increase with decrease in cell window area. A cell window is the lamella of the foam material that separates two adjacent cells. The cell sizes of the foam are found to correlate with the size of the air bubbles entrained during initial mixing. Surfactants, which reduce the surface tension of the polyol to the greatest extent, are found to give the finest initial bubbles, smaller cells, and foams with the highest hydraulic resistance. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2821–2829, 2004 相似文献
43.
Hyun‐Ah Kang Gyu‐Jong Jeon Moo‐Yeal Lee Ji‐Won Yang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2002,77(2):205-210
A series of alginate‐derived polymeric surfactants (APSs) with a linear alkyl group (C8, C12, C16) was synthesized by oxidation followed by reductive amination of 2,3‐dialdehydic alginate. The products were characterized by measuring IR spectra, NMR spectra, surface tension and critical micelle concentration (cmc). They were also tested for the solubilization of azobenzene and adsorption of heavy metal. In the case of 40% CHO‐C8 APSs, the lowest interfacial tension value (31.5 m Nm?1) was obtained at the cmc value of 1.35 g dm?3. The dissolving capacity of 40% CHO‐C8 APS towards azobenzene was 27 times greater than that of alginate. The overall cobalt (Co2+) removal efficiency by adsorption using APSs was high compared with that of sodium alginate at pH 3, 5 and 7. Equilibrium aspects of cobalt adsorption onto 10% CHO‐APSs were studied, and the results show that APSs had high equilibrium capacities for cobalt uptake, 115.5 mgg?1. © 2002 Society of Chemical Industry 相似文献
44.
A series of novel nonionic functional polyurethane surfactants were synthesized by the polycondensation of 2,4‐toluene diisocyanate with poly(propylene oxide) (weight‐average molecular weight = 400, 1000, or 2000) and monoallyl‐end‐capped poly(ethylene oxide). The chemical structure of the polyurethane surfactants was determined by Fourier transform infrared and 1H‐NMR, and the effects of the concentration, salt, rest time, and temperature on the surface tension were investigated. These polymeric surfactants exhibited excellent surface activity. Sample III, which was synthesized with monoallyl‐end‐capped poly(ethylene oxide) (number‐average molecular weight = 1000), poly(propylene oxide) (number‐average molecular weight = 2000), and tolylene diisocyanate, could reduce the surface tension to 37.6 mN/m at a concentration of 0.06 mol/L at 25°C. All polyurethane surfactants synthesized in this study had low critical micelle concentrations (ca. 10?4 to 10?5 mol/L) and could reduce the surface tension even at very low concentration levels. Moreover, the surface tension decreased with an increase in the temperature or the concentration of the polyurethane surfactants. The addition of salt resulted in a decrease in the surface tension, and it took some time for the polyurethane surfactants to reach a constant surface tension value. UV spectra were found to be very useful for determining the critical micelle concentration. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2956–2962, 2006 相似文献
45.
E. D. Goddard 《Journal of the American Oil Chemists' Society》1994,71(1):1-16
The field of polymer/surfactant interaction is reviewed in this work. Results from two investigative methods,viz., dialysis and surface tension, are discussed, illustrating the main behavioral patterns and outlining the principles of the
interactions. Next, aspects of the interaction phenomena that appear to have relevance to detergent formulation are presented.
These include solution rheology, solubility control and surface conditioning. Lastly, the importance of surface activity of
the polymer itself is stressed, culminating in a discussion of the properties of hydrophobically modified water-soluble polymers
(“polymeric surfactants”), both alone and in the presence of conventional surfactants.
Based on the Samuel Rosen Memorial Award lecture, given at the AOCS Annual Meeting, Anaheim, CA, April 1993. 相似文献
46.
十二烷基苯磺酸钠水溶液聚集性质的研究 总被引:8,自引:0,他引:8
用滴体积法测出十二烷基苯磺酸钠(SDBS)稀水溶液的表面张力;然后求出其临界胶束浓度(CMC)。同时通过溶液的电导率、吸收光谱以及荧光光谱测定求出其CMC。这样测出的CMC值为1.2~1.6×10-3mol/L,与文献值相符。也研究了部分水解的聚丙烯酰胺(PHPAM)对SDBS聚集性质的影响;发现SDBS的CMC值随PHPAM的加人而减少并且PHPAM水溶液的粘度随SDBS的存在而急剧降低(类似盐效应)。这些方法与性质对强化采油(EOR)是重要的。 相似文献
47.
48.
Particle-liquid mass transfer in a co-current three-phase fluidized bed of glass beads, water and air was studied with two measurement techniques. Both techniques measured the weight loss of a few particles coated with benzoic acid in a bed of inert glass beads. The effects of liquid and gas velocities, gas distribution and surface active agents on particle-liquid mass transfer in a three-phase fluidized bed were thus determined. In the absence of surface active agents in the liquid, particle-liquid mass transfer rates in a three-phase fluidized bed were up to 30% higher than in the corresponding liquid fluidized bed. When surface active agents were added to the liquid, the particle-liquid mass transfer rate was increased by up to about 100% in the three-phase fluidized bed, relative to the liquid fluidized bed. The particle-liquid mass transfer coefficient was found to be inversely proportional to the liquid hold-up in the three-phase fluidized bed. 相似文献
49.
A correlation for the estimation of critical micellization concentrations and temperatures of polyols in aqueous solutions 总被引:1,自引:0,他引:1
Paschalis Alexandridis Josef F. Holzwarth T. Alan Hatton 《Journal of the American Oil Chemists' Society》1995,72(7):823-826
An empirical correlation is presented for the estimation of critical micellization concentrations (CMC) and critical micellization
temperatures (CMT) for poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) copolymers in aqueous solutions. The CMC and CMT are expressed as a function of the polyol molecular
weight, composition, and temperature (for CMC determination) or concentration (in the case of CMT). The correlation was developed
from experimental CMT data for a set of 12 polyols that covered a wide range of molecular weights (2900–14600) and poly(ethylene
oxide) contents (30–80 wt%) and is based on a simple expression for the standard free energy of micellization. Such a correlation
should be useful to practitioners of the field as it allows easy prediction of CMC and CMT for a wide range of polyols with
a minimal number of input parameters. 相似文献
50.
Gemini surfactants were synthesized by reaction of long-chain N-alkyl glucamines with epoxy resins. Analogous to the synthesis of gemini surfactns from long-chain N-alkyl glucamines and α, ω-diepoxides (1), the reaction in methanol at 70°C could be used to convert the starting materials
selectively and almost quantitatively. N-Octyl glucamine, N-decyl glucamine, and N-dodecyl glucamine were combined with several epoxy resins, mainly technical glycidyl ethers of diols. Syntheses involving
equimolar amounts of amine resulted in quantitative conversion of the epoxy resins, and epoxide and products could be isolated
quantitatively by removing the solvent. Gemini surfactants having hydrophobic or hydrophilic spacers were preparared according
to their structures and the hydrophilic properties of the epoxy resin. Surface tensions were measured, and foaming propertiers
were examined to characterize surface-active properties of these surfactants. The more hydrophilic products were of particularly
high surface activity. Tensiometric studies showed a reduction of surface tension to 30–34 mN/m and critical micelle concentrations
in the range of 2–35 mg/L. Comparison of gemini surfactants from long-chain N-alkyl glucamines and diepoxides of α,ω-diolefins (chain lengths: C8, C9, C10, and C14) with those based on epoxy resins showed similar or lower surface activities using hydrophobic epoxy resins and much better
surface-active properties using hydrophilic epoxy resins (e.g., based on glycerol). This, together with the easier availability,
makes the epoxy resin-based products interesting surfactants. Products having very good surface-active properties are available,
especially using glycidyl ether of aliphatic diols or glycerol. 相似文献