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quantization of channel capacity has significant value in information theory, and its concept is described in this paper. It is proved that channel capacity of quantum and classical communication theory has similar properties according to related definition. Channel capacity of optical communication is analyzed and studied. Then, the channel capacities with different parameters are calculated and exhibited. The relationship among the channel capacity C, average thermal photon numbers 〈M〉and average signal photon numbers K are displayed. As a result, by choosing the parameters reasonably, the signal communication efficiency is improved.

The circuit that a high-voltage pulse is sharpened by an opening switch and a closing switch is designed. The electric exploding wire switch (EEOS) is adopted as the opening switch to steepen pulse primarily. When the EEOS explodes, the voltage passes through the gas switch which is used as the closing switch， and then is sharpened to high-voltage pulse on the terminal load. This high-voltage and high-current circuit is simulated by steps with the software PSPICE. The experimental results show that the rising time of the pulse steepened twice is nearly 1ns, and the peak voltage is greater than 200kV on condition that the preliminary voltage is 35kV. The results obtained from the simulation and the experiment are identical on the whole. As a result, this circuit has great prospects in the pulse mediation system.

Using 219 F2 individuals developed by crossing the genetic standard line TM-1 and the multiple dominant marker line T586 in Gossypium hirsutum L., a genetic linkage map with 19 linkage groups was constructed based on simple sequence repeat (SSR) markers. Compared with our tetraploid backboned molecular genetic map from a(TM-1 × Hai 7124) × TM-1 BC1 population, 17 of the 19 linkage groups were combined and anchored to 12 chromosomes (sub-genomes). Of these groups, four morphological marker genes in T586 had been mapped into the molecular linkage map. Meanwhile, three quantitative trait loci for lint percentage were tagged and mapped separately on the A03 linkage group and chromosome 6. (Managing editor: Li-Hui Zhao)

Twenty bacterial artificial chromosome (BAC) clones that could produce bright signals and no or very low fluorescence in situ hybridization (FISH) background were identified from Gossypium arboreum cv. JLZM, and G. hirsutum accession (acc.) TM-1 and 0-613-2R. Combining with 45S and 5S rDNA, a 22-probe cocktail that could identify all 13 G. arboreum chromosomes simultaneously was developed. According to their homology with tetraploid cotton, the G. arboreum chromosomes were designated as A1–A13, and a standard karyotype analysis of G. arboreum was presented. These results demonstrated an application for multiple BAC–FISH in cotton cytogenetic studies and a technique to overcome the problem of simultaneous chromosome recognition in mitotic cotton cells.

In this paper, an error probability analysis is performed for the differential frequency hopping (DFH) communication system in a frequency-nonselective, slowly fading channel with partial-band noise jamming. Each transmitted hop is assumed to fade independently according to a Rician process. The partial-band noise jamming is modeled as a Gaussian process. Thermal noise is neglected in the analysis. In the DFH receiver, the noncoherent square-law energy detector is combined with the Viterbi decoder to determine a soft-decision estimate of the transmitted data. The DFH bit error probability is obtained via Union-Chernoff bounds. Results show that the inherent dependence of adjacent transmitted frequencies provides good partial-band jamming rejection capability for DFH systems

Based on two major QTLs that control high fiber strength which originated from an elite fiber germ-plasm line 7235 (Gossypium hiusutum L.), the efficiency of molecular marker-assisted selection (MAS) was investigated using two populations from pedigree selection and modified backcrossing pyramiding developed for the breeding purpose. Simian 3 (SM3), a widely planted variety in the Yangtze River Valley, and 7235 were used as parents to develop the two populations. In the two major QTLs for fiber strength from 7235, QTLfs-1 could explain more than 30% of the phenotypic variation (PV) in the (7235 x TM-1) F2 population. QTLfs-2 was at first identified in another super quality fiber line HS427-10 from (HS427-10 x TM-1) F2 population with 12.5% of PV explanation,which was further also identified in 7235 line but was non-allelic with QTLfs-1. The result of molecular marker-assisted selection for fiber strength showed that the genetic effect of the QTLfs-1 was stable under different environmental conditions, and its molecular marker-assisted selection showed significant selective efficiency among breeding populations with different genetic backgrounds. QTLfs-2 also showed high selective efficiency in advanced generation populations though its effect was a little lower than the former. When QTLfs-1 was selected simultaneously with 2 molecular markers with known genetic distance, the selection efficiency for the fiber strength was greatly increased. The pyramiding for two QTLs that control high fiber strength by MAS greatly improved the selection efficiency for cotton fiber strength. This report provides a successful example of MAS pyramiding for QTL for favorable traits in breeding programs.