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排序方式: 共有205条查询结果,搜索用时 15 毫秒
91.
本文主要介绍了利用PLC对我厂纯水系统中水箱液位控制的改造,对其控制的原理、方式等内容进行了阐述。 相似文献
92.
Summary The problem of impurity diffusion accompanying segregation phase nucleation on dislocations has been studied using the approximation
of the local equilibrium with respect to the impurity distribution between the volume solution and dislocation regions. It
has been shown that the known experimental data on diffusion and solubility of some interstitial impurities in cold-worked
b.c.c. and f.c.c. metals and alloys can be described in the framework of the dislocation trap model. The characteristics of
the impurity segregation regions near dislocations have been obtained from the treatment of the diffusion and solubility data
for the systems. On the basis of the crystallographic and thermodynamic considerations the possibility of the existence of
such segregation phase regions along dislocations in the systems in question has been shown. 相似文献
93.
以不同比例浓盐酸与30%过氧化氢混合溶液治疗了256例着色型氟斑牙患者,有效率为98.71%、中度95.15%、重度92.35%。 相似文献
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96.
In part 2 of this report related parameters of the rice bran (as a sorbent of heavy metals) such as exchange capacity, distribution coefficients and isotherms, etc. were studied. The obtained results show that selectivity of the bran towards heavy metals such as Cu(II), Cd(II), Fe(III), Ni(II), Zn(II) and Pb(II) is very high. Also, distribution coefficients between aqueous solution and bran are more than 104 so that all cations are completely adsorbed by the bran in relatively low concentrations. The principal advantages of this sorbent are as follows: high efficiency, very high exchanging speed, cheapness (in comparison with conventional resins), performance in batch and continuous conditions and producing no environmental pollution. The only disadvantage of the bran is low exchanging capacity for some elements (but for lead it is comparable to classical resins); however, it is able to eliminate heavy metals in mg/L level and above. On the other hand, due to low cost of bran and high cost of recovery of ion exchangers there is no necessity to recover the bran. Reproducibility of the proposed method in removal of heavy metals is excellent and the relative standard deviations for eight repeated removals for all cations with the exception of iron are less than 1%. 相似文献
97.
Masayuki Yamane 《Journal of Sol-Gel Science and Technology》2006,40(2-3):273-279
Two unique commercial applications of the sol-gel process in Japan are presented. One application involves alkoxide-derived
nanometer-sized silica particles used in the final polishing of silicon wafers for the fabrication of integrated circuits.
The particles are cocoon-like in shape and have almost replaced conventional abrasives because of the advantages over spherical
particles of similar size in terms of obtaining high polishing efficiency for good surface finish. The other application concerns
the treatment of paper with an alkoxide solution for water repellent and oil resistance properties, which leads to new products
for disposable tableware or cooking ware for microwave oven use. 相似文献
98.
《Comptes Rendus Chimie》2016,19(4):511-516
Algerian's municipal sewage treatment plants generate around 106 m3 of sewage sludge annually. Recently, rapid expansion of wastewater treatment plants without equal attention to the treatment of the produced sludge has generated increasing concerns. While the sludge is usually incinerated or used as an agricultural fertilizer and may contain numerous nutrients, there may also be harmful substances that complicate sludge management. Hence the removal of pollutants from the sludge is necessary before further usage. This paper discusses the characteristics of potable water treatment sludge containing a high aluminum content. Furthermore, an electrokinetic treatment is proposed to remove aluminum from this sludge by varying the type of solution contained in the cathode compartment and modifying the treatment time to optimize the efficiency of the process. Successful results were achieved where 60% of aluminum was collected on the cathode side with a consumed energy around of 1000–2000 kWh kg−1 of sludge weight. 相似文献
99.
Jing Guo Yanqiu Zhang Fan Yang Bhekie B. Mamba Jun Ma Lu Shao Shaomin Liu 《Angewandte Chemie (International ed. in English)》2023,62(23):e202302931
Two-dimensional graphene oxide (GO) membranes are gaining popularity as a promising means to address global water scarcity. However, current GO membranes fail to sufficiently exclude angstrom-sized ions from solution. Herein, a de novo “posterior” interfacial polymerization (p-IP) strategy is reported to construct a tailor-made polyamide (PA) network in situ in an ultrathin GO membrane to strengthen size exclusion while imparting a positively charged membrane surface to repel metal ions. The electrostatic repulsion toward metal ions, coupled with the reinforced size exclusion, synergistically drives the high-efficiency metal ion separation through the synthesized positively charged GO framework (PC-GOF) membrane. This dual-mechanism-driven PC-GOF membrane exhibits superior metal ion rejection, anti-fouling ability, good operational stability, and ultra-high permeance (five times that of pristine GO membranes), enabling a sound step towards a sustainable water-energy-food nexus. 相似文献
100.