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61.
Shingo Hadano Kenjiro Onimura Hiromori Tsutsumi Hirohito Yamasaki Tsutomu Oishi 《应用聚合物科学杂志》2003,90(8):2059-2065
Chemical‐modified pulps were synthesized from four types of waste pulps (Pulp1–4) and succinic anhydride (SAn) or maleic anhydride (MAn). The solubility of the modified pulps was evaluated in common organic solvents, and their thermal properties were investigated by DSC measurement. The solubility of the modified pulps increased with an increasing degree of substitution (DS). However, no Tg or Tm of these modified pulps was confirmed. Pulps and modified pulps were graft‐polymerized with ε‐caprolactone (CL) in bulk and in DMAc/LiCl. Although the solubility of the graft copolymers was similar to modified pulps, some graft copolymers showed a Tg by the introduction of CL units. In the bulk, graft copolymers obtained from modified pulps and nonmodified pulps showed a Tg of about 75°C and no Tg, respectively. In DMAc/LiCl, the obtained graft copolymers from both modified and nonmodified pulps exhibited a Tg of 95–110°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2059–2065, 2003 相似文献
62.
Isao Mochida Kazuhiro Tamaru Yozo Korai Hiroshi Fujitsu Kenjiro Takeshita 《Carbon》1983,21(6):535-541
The modifying activities of hydrogenated pyrene (HP) and its oxidized derivatives were examined in co-carbonization with solvent refined coal, solvent treated coal, a fusible and a non-fusible coal. The present additives all showed a significant activity, with HP oxidized at 150°C exhibiting the highest activity. The activity of the additive is discussed from its structural indices and coke yield in relation to its dissolving and hydrogen donating abilities. The modifying susceptivility of the carbonizing substance is rated in the order described above, being correlated with its single carbonization properties, such as fusibility and potential for anisotropic development. A consecutive treatment of partial hydrogenation and oxidation is emphasized as a useful technique for producing active additive and an excellent coking substance from the pitch material. 相似文献
63.
The carbonization of four kinds of solvent-refined-coal (SRC) pitches was investigated in order to determine the properties required for the formation of needle coke. Although the pitches were free from Ql materials, two of them gave needle cokes, whereas the other two gave mosaic cokes. The BS fractions of all pitches formed needle cokes, and all Bl fractions were infusible and isotropic. A combination of suitable BS and Bl fractions gave a needle coke, whereas another mixture formed a mosaic coke, indicating that the BS and the Bl fractions can be compatible to yield a needle coke. Cocarbonization of the BS fractions from other pitch sources with the Bl from the SRC pitches was further studied to evaluate the compatibility, which has been discussed from the structural viewpoint. Trials to improve the properties were proposed, based on the structural information. 相似文献
64.
Shingo Hadano Seiji Maehara Kenjiro Onimura Hirohito Yamasaki Hiromori Tsutsumi Tutomu Oishi 《应用聚合物科学杂志》2004,92(4):2658-2664
Benzylated waste pulps (PBzs) were synthesized from treated waste pulp (Pulp), and benzyl chloride with phase transfer catalyst (PTC), and graft copolymers (PBz‐g‐LA) were synthesized from PBzs and L‐lactic acid (LA). Thermal properties, solubility, crystallinity, and biodegradability of the obtained PBzs and graft copolymers were investigated. PBzs with the degree of substitution (DS) higher than 1.5 showed Tg and Tm in DSC measurement. All PBz‐g‐LA exhibited no Tm. However, the graft copolymers obtained from lower DS PBzs having no Tg, exhibited Tg. The solubility of PBzs enhanced with increasing DS, and the crystallinity of PBzs reduced with increasing DS because of hydrophobicity and steric effect of benzyl groups. The solubility of graft copolymers was similar to that of original PBzs. Biodegradation tests for PBzs, Pulp, and graft copolymers were performed using cellulase in 0.1 M acetate buffer solution (pH 5.5) at 37°C. All samples showed biodegradability though the biodegradation rate decreased with increasing DS of PBz. In PBz‐g‐LA, the initial biodegradation rate was faster than that of original PBz because of hydrolysis of LA units. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2658–2664, 2004 相似文献
65.
Tsutomu Oishi Hirohito Yamasaki Kenjiro Onimura Toshiyuki Fukushima Seiji Morihashi 《应用聚合物科学杂志》2004,92(4):2552-2557
Fumaramate bearing a phosphoryl choline group, isopropyl‐2‐[2′‐(trimethylammonium) ethyl phosphoryl] ethyl fumaramate (IPTPFA), was radically copolymerized with 2‐hydroxyethylmethacrylate (HEMA) in the presence of various crosslinking agents, water, and 2,2′‐azobis(isobutyronitrile) to obtain hydrogel membranes. The obtained hydrogel membranes adsorbed bovine serum albumin (BSA) much less than those of poly(HEMA), and the values of water content (H) were higher than those of poly(HEMA). The values of tensile strength and tensile elongation of the hydrogel were 68.4 g/mm2 and 239%, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2552–2557, 2004 相似文献
66.
In this study, we developed new worm wheel mechanisms with passive rollers as their teeth and confirmed useful functions of these worm wheels with passive rollers to transmit power from worm gears with higher energy efficiency than ordinary worm wheels. By using passive rollers as their teeth, the developed worm wheels could realize high-power transmission efficiency with rolling frictional resistance instead of sliding frictional resistance. A worm wheel with conical passive rollers and one with disk-shaped passive rollers was fabricated as prototypes and examined in experiments. Smooth back-drivability of the worm wheels with passive rollers, which is difficult to realize with conventional worm wheels, was also demonstrated in the experiments. These serial experiments revealed that the developed worm wheel mechanism with passive rollers can replace conventional worm wheels with the same number of teeth and module in ordinary power transmission mechanisms with worm gearing and realize higher energy efficiency and smooth back-drivability. These features can be very useful to realize safe and soft actuators for automation systems in a human environment. 相似文献
67.
Yoshiharu Shimomura Kenjiro Sugio Michio Kiritani 《Computational Materials Science》1999,14(1-4):97-102
Kiritani found that vacancy clusters of large number density form in f.c.c. thin metal of 100 nm thickness deformed to their fracture. In the present work, a computer simulation of deformation of thin metal is carried out to investigate how vacancies of high concentration generate during a deformation of thin specimens of Al and Cu. A crystal of 4000 atoms whose size is (10a0 × 10a0 × 10a0) is elongated to z-axes. Two modes of simulation are carried out. In the mode 1, surface which are normal to x-axes and y-axes are kept free. In the mode 2, the periodic boundary condition is applied for all surfaces. The mode 2 is equivalent to the deformation of bulk metal. In the simulation of mode 1, the tilting of 1 1 0 atom row initiates on the surface. A tilting of rows to the same direction expands on a (1 1 1) plane and arrives to other side of surface. Dislocations do not form during the tilting. The tilting of atom rows occurs due to easy movement of atoms on surface responding to stress. In highly deformed thin metal, the tilting of atom rows occurs on multi-layers of parallel planes. Subsequently a tilted row split into two rows. A new row initiates by moving an atom on surface to the interstitial position. A transportation of atoms from the normal row to the new row occurs during deformation, which contributes to the reduction of thickness. Vacancies of high concentration are not generated in the case of the mode 1 deformation. In the simulation of the mode 2, the formation of domain in which atom rows tilt to the same direction occurs. At the domain boundary ordered array of atom rows becomes disordered in an instant and grows to a small crack of vacancy cluster. The formation process of vacancy clusters which were observed in deformed thin metal is due to the combination of the processes of the modes 1 and 2. 相似文献
68.
Maher M. Al-Dabbas Khaled Al-Ismail Kanefumi Kitahara Naoya Chishaki Fumio Hashinaga Toshihiko Suganuma Kenjiro Tadera 《Food chemistry》2007,104(2):734-739
The DPPH radical-scavenging activity of 25 inorganic salts, two buffer systems, and crude water extract of aerial parts of Varthemia (Varthemia iphionoides) before and after resins purification were investigated. Eight of the 25 inorganic salts tested quenched the DPPH radical colour. Na2S2O3 and FeCl2 showed markedly high DPPH colour-quenching activity, with inhibition of 65.3% and 47.7% respectively, at a concentration of 10 μg/ml. Four salts slightly increased the intensity of DPPH radical colour. The rest of tested salts, acetate buffer, and phosphate buffer at a concentration less than 0.1 mM did not affect DPPH radical colour. The DPPH radical-scavenging activity of BHT and catechol was considerably affected by the concentration of phosphate buffer (pH 7.0), and by acetate buffer (pH 5.0) at concentrations more than 0.01 mM in the case of BHT only. The DPPH radical-scavenging activity of a crude water extract of aerial parts of Varthemia iphionoides was much higher than that of an extract desalted by cation-exchange resin, indicating that iron ions apparently elevated the DPPH radical-scavenging activity of the extract. Therefore, desalting of plant extracts is important in order to obtain the true value of DPPH radical-scavenging activity. 相似文献
69.
Masashi Ikegami Jun Suzuki Kenjiro Teshima Masahide Kawaraya Tsutomu Miyasaka 《Solar Energy Materials & Solar Cells》2009,93(6-7):836-839
Large-area integrated modules of flexible plastic type dye-sensitized solar cell (DSC) have been fabricated based on polyethylene naphthalate (PEN) film for practical applications such as ubiquitous power sources. From the view point of improving durability, composition of organic solvent-based electrolytes has been investigated. As a result, a plastic DSC module using LiI-free electrolyte maintained its energy conversion efficiency of 2% over 220 h under the accelerated condition of 55 °C and 95% relative humidity. 相似文献
70.
Takenori?SuzukiEmail author Chunqing?He Victor?Shantarovich Kenjiro?Kondo Yasuo?Ito Lin?Ma Masaru?Matsuo 《Materials Research Innovations》2003,7(1):31-36
Relaxation behaviors of polyethylene, polypropylene, and polycarbonate have been studied by positron annihilation lifetime
spectroscopy (PALS). In PALS positron sources made of radioisotopes are used to inject positrons into polymer as a micro probe.
The injected positron probes can induce radiation effect, which plays an important role in detecting the polymer relaxation
behavior through electrons trapped in shallow potentials at low temperature. Monitoring the intensity (I3) of ortho-positronium (o-Ps), transitions of γ and δ relaxation can be measured by PALS as a secondary effect. In this experiment,
the change of I3 below Tg is connected with the number of the trapped electrons, which can be excited from the shallow potential by the thermal
motion of polymer structures and visible light irradiation. In the PALS measurements of non-irradiated PP samples, relaxation
of methyl groups was observed as low as 50 K, which can be assigned as the δ relaxation. Relaxations of β and γ were also
observed for the non-irradiated PP samples between 100–370 K. However for the 3 MGy γ-ray irradiated PP samples, only β relaxation
was observed because the large radiation dose caused a large number of scissions of –CH3 groups from main chains and the characteristics changed. For the irradiated samples, radiation hardening was observed.
Electronic Publication 相似文献