剖析黑客Sniffer

对黑客的一种重要攻击手段Sniffer进行了分析。介绍了Sniffer的基本概念和工作原理 ;对Linux下黑客Sniffer(linsniffer)作了剖析 。

论唐代乐府诗的流传形式与影响

本文从接受学的角度,把唐代乐府诗置于整个唐前乐府流传的大背景下,从两个不同层面考察、清理、分析了唐代乐府诗的流传形式与影响。文章认为,历代的编者或选家在对待乐府诗上存在一个较为突出的倾向:宗奉汉魏,重视六朝而轻视唐代。这种倾向随着相关典籍的流传而产生广泛持久的影响,从而在一定程度上阻碍了唐代乐府诗的研究进程。

Analysis of complicated structure seismic wave fields

In western China seismic wave fields are very complicated and have low signal to noise ratio.In this paper,we focus on complex wave field research by forward modeling and indicate that density should not be ignored in wave field simulation if the subsurface physical properties are quite different.We use the acoustic wave equation with density in the staggered finite-difference method to simulate the wave fields.For this purpose a complicated geologic structural model with rugged surfaces,near-surface low-velocity layers,and high-velocity outcropping layers was designed.Based on the instantaneous wave field distribution,we analyzed the mechanism forming complex wave fields.The influence of low velocity layers on the wave field is very strong.A strong waveguide occurs between the top and base of a low velocity layer,producing multiples which penetrate into the earth and form strong complex wave fields in addition to reflections from subsurface interfaces.For verifying the correctness of the simulated wave fields,prestack depth migration was performed using different algorithms from the forward modeling.The structure revealed by the stacked migration profile is same as the known structure.

浅谈sniffer的原理与防范

本文主要了sniffer的基本工作原理，然后根据其工作特点提出在LAN内人工和自动的sniffer检测方法，并且给出了实验检测结果。最后，简要地给出sniffer的防范方法。

Screening and Application of Oilseed Rape Varieties with High Yield and High Harvest Index

28 oilseed rape Pol CMS three-line hybrid combinations diallel-crossed were compared in the yield and harvest index and analyzed on the correlation between the experimental yields and harvest indexes in this study. The correlation coeffcient was only 0.365 4, lower than a signifcant level, which indicated that there was no signifcant positive （or negative） correlation between the economic yields and the harvest indexes in oilseed rape. Among them, 8 hybrid combinations including 7 with a harvest index〉0.30 and one with a harvest index〈0.27 increased signifcantly in the yields compared with the control, and then were screened for production experiment. Under different cultivation methods, all the 8 combinations had a stable harvest index, and the combinations with higher harvest indexes also had a stable performance in yields. An oilseed rape variety Fengyou 737 with higher yield and harvest index selected through a further screening was grown with the harvest indexhigher than 0.33 whether transplanted or directly seeded in Yangtze River Basin Demonstration Area, demonstrating stable high yields as well as good ecological adaptability. The combination of yield and harvest index in the study is conducive to breeding a new oilseed rape variety with stable yields and good tolerance to close planting.

Iterative Block DFE for Underwater Acoustic Single Carrier System

Abstract： In order to gain a better performance and reduce the computational complexity of the filter design in the underwater acoustic single car rier system, a new Iterative Block DFE （IBDFE） is proposed, which operates iteratively on blocks of the received signal, and fully implements its filtering operations by Discrete Fourier Trans forms （DFTs）. Two design methods are consid ered for IBDFE： one is HDIBDFE, and the oth er is SDIBDFE. In this paper, the first one is a dopted. In this scheme,

A Wavelength Tunable DBR Laser Integrated with an Electro-Absorption Modulator by a Combined Method of SAG and QWI

We report a wavelength tunable electro-absorption modulated DBR laser based on a combined method of SAG and QWI. The threshold current is 37mA and the output power at 100mA gain current is 3.5mW. When coupled to a single-mode fiber with a coupling efficiency of 15% ,more than a 20dB extinction ratio is observed over the change of EAM bias from 0 to -2V. The 4.4nm continuous wavelength tuning range covers 6 channels on a 100GHz grid for WDM telecommunications.

Localization and the Chinese Overseas： Acculturation, Assimilation, Hybridization, Creolization, and Identification

Based on materials on the localized Chinese overseas, including the Melaka Babas, who are mostly Malay-speaking Chinese, this article reflects on the use of such terms as acculturation and assimilation, as well as hybridization and creolization, in relation to highly localized Chinese. All these concepts are seen as different ways of describing cultural formation in transcultural context. In particular, the relevance of using creolization to refer to the kind of creative process of cultural formation beyond its original usage in the Caribbean is discussed. This results in the identification of fragmented creolization as in the case of the Caribbean and a rooted creolization as in the case of the Babas. The author shall first discuss the issues of assimilation and integration, followed by hybridization and creolization. This is followed by the discussion on localization of Chinese overseas and identity. The concluding section provides some remarks on the concepts reviewed, and three main categories of acculturated Chinese are identified, namely, Chinese who are linguistically assimilated but still observe major Chinese traditions, Chinese who are so acculturated to the mainstream society that they hardly practice Chinese traditions, and Chinese who are both highly localized and highly mixed “racially”.

A Concise Joint Transmit/Receive Antenna Selection Algorithm

For reducing the computational complexity of the problem of joint transmit and receive antenna selection in Multiple-Input-Multiple-Output (MIMO) systems, we present a concise joint transmit/receive antenna selection algorithm. Using a novel partition of the channel matrix, we drive a concise formula. This formula enables us to augment the channel matrix in such a way that the computational complexity of the greedy Joint Transmit/Receive Antenna Selection (JTRAS) algorithm is reduced by a factor of 4n L , where n L is the number of selected antennas. A decoupled version of the proposed algorithm is also proposed to further improve the efficiency of the JTRAS algorithm, with some capacity degradation as a tradeoff. The computational complexity and the performance of the proposed approaches are evaluated mathematically and verified by computer simulations. The results have shown that the proposed joint antenna selection algorithm maintains the capacity perormance of the JTRAS algorithm while its computational complexity is only 1/4n L of that of the JTRAS algorithm. The decoupled version of the proposed algorithm further reduces the computational complexity of the joint antenna selection and has better performance than other decoupling-based algorithms when the selected antenna subset is small as compared to the total number of antennas.

Preliminary evaluation of five elephant grass cultivars harvested at different time for sugar production

Five elephant grass cultivars, Pennisetum purpureum, cv. Huanan （Huanan）, P. purpureum, cv. N51 （N51）, P. purpureum, cv. Sumu No. 2 （Sumu-2）, （ Penniseturn americanum x P. purpureum ） x P. purpureum cv. Guimu No. 1 （Guimu-1） and P. americanum cv. Tift23A x P. purpureum cv. Tilt NS1 （Hybrid Pennisetum）, at three harvest stages were studied. With dilute sulfuric acid pretreatment followed by enzymatic hydrolysis, it is found that cel- lulose conversion of the five elephant grass cultivars harvested in August and September is higher than that har- vested in October. The cellulose conversion for elephant grass cultivars harvested in August and September follows an order of Hybrid Pennisetum 〉 Sumu-2 〉 Huanan 〉 Guimu-1 〉 N51. This may be explained by the fact that lignification is gradually strengthened with time, inhibiting degradation of cellulose and hemicellulose. Moreover, cellulose conversions of Hybrid Pennisetum, Sumu-2 and Huanan harvested in August and September are higher based on hierarchical clustering results.

The Optimal Time for Harvesting the Seeds of Gui 39722, the Female Parent of a Maize Hybrid Guidan 0810

To determine the optimal time for harvesting the seeds of Gui 39722, which is the female parent of a newly-developed maize hybrid Guidan 0810, the cobs of Gui 39722 were harvested 31 （the first stage）, 34 （the second stage）, 37 （the third stage）, 40 （the fourth stage）, 43 （the fifth stage） and 46 （the sixth stage） d after pollination and oven dried at 38 ~C to constant weight. Then, the 1 000-ker- nel weight, germination rate and the agronomic traits of three-leaf seedlings were measured and compared. The results showed that the seeds of Gui 39722 harvest- ed 43 d after pollination （the fifth stage） had the greatest germination rate, seedling height, vigor index, root dry weight, shoot dry weight and germination potential, and high 1 000-kernel weight （very close to the highest level）, root length, number of roots per seedling and root-shoot ratio. Therefore, 43 d after pollination was the op- timal time for harvesting the seeds of Gui 39722, when the effective accumulated temperature after pollination reached 780.7 ℃ and the ear leaf dried. The seeds harvested at this stage had the highest yield and the best quality. Field sampling revealed that 89.00% to 95.00% （with an average of 91.15%） of the seedlings of six stages of seeds grew well.

Linear and Nonlinear Optical Absorptions of a Donor Impurity in Spherical Quantum Dots

An investigation of the optical properties of a hydrogenic donor in spherical parabolic quantum dots hasbeen performed by using the matrix diagonalization method.The optical absorption coefficient between the ground(L=0) and the first excited state (L=1) have been examined based on the computed energies and wave functions.The results are presented as a function of the incident photon energy for the different values of the confinement strength.These results show the effects of the quantum size and the impurity on the optical absorption coefficient of a donorimpurity quantum dot.

On the direct use of recovered scrap copper and saving copper with aluminum in the Chinese cable industry

The copper consumption by the Chinese cable industry amounted to 354×104 t in 2006, taking over 70 % of the total copper consumption in China in that year. At present, making copper rod directly from recovered scrap copper and saving copper with aluminum have become topics of general interests in the Chinese cable industry. The quality of the copper conductors in the industry is declining, resulting in sharp decrease in the rate of qualified wire and cable products. More and more copper wires are drawn from the rods made directly from scrap copper. The manufacturers know well some of the wires or rods are unqualified products though, they continue to use or produce products not complying with standards in order to make profits. Now the consumption of copper-clad-aluminum and copper-clad-steel is growing gradually. In 2006, the consumption of copper-clad-aluminum in China amounted to ca. 5×104 t. But in some applications, neither the common understanding between buyer and supplier nor the results of feasibility study are achieved in the product orientation and technical/economic feasibility in terms of saving copper with aluminum. This paper presents the status-quo, problems arisen and suggestions in terms of making copper rod directly from recovered scrap copper and saving copper with aluminum, in a view to promote these two topics of general interests to go toward a virtuous circle.

BACKSIDE EFFECT OF BISTATIC AIRBORNE CLUTTER CHARACTERISTICS AND ITS APPLICATIONS IN GMTI

An interesting clutter characteristic of bistatic radars is presented, which is named as backside effect. In such an effect, the range-dependent ground clutter spectrum can be easily aligned, and Space-Time Adaptive Processing (STAP) is to be more applicable and effective for the Ground Moving Target Indication (GMTI) in bistatic systems. The backside effect is proved by the numerical calculation method and explained in point of the geometry. At last a new spectrum aligning method is induced, i.e., ADC and Rotation (ADCR), which can gain a further performance improvement on GMTI.

8-Weighted-Type Fractional Fourier Transform Based Three-Branch Transmission Method

To improve the bit error rate(BER) performance of multiple input multiple output(MIMO) systems with low complexity, a three-branch transmission scheme employing 8-weighted-type fractional Fourier transform(8-WFRFT) module is proposed. In the proposed scheme, the original signal is first decomposed into eight sub-signals and then merged into three component signals by the same carrier pattern. The three signals have mathematical constraint relations among themselves that can counteract the channel fading. They are simultaneously transmitted via three independent antennas after delay regulating. At the receiver, an inverse 8-WFRFT module is employed to obtain the estimated original signal by processing the received signal. Then, the bit error rate(BER) performance, transmitting power, transmission rate, power spectrum and computational complexity of the proposed scheme are analysed in detail. Numerical results show that the proposed scheme has a superior performance compared to STBC based three-antenna transmission scheme, in terms of BER performance.

Infrared emissivity of transition elements doped ZnO

Infrared emissivity was studied in Zno.99Mo.olO （M is Mn, Fe or Ni） and Znl_xCoxO （x=0.01, 0.02, 0.03 and 0.04） powders synthesized by solid-state reaction at various temperatures. XRD patterns confirm the wurtzite structure of the prepared samples. No peaks of other phases arising from impurities are detected in Mn- and Co-doped ZnO, hut the peaks of ZnFe204 and NiO are observed in Zno.99Feo.010 and Zno.99Nio.o10. The SEM observations indicate that with larger grain sizes than those of Zn0.99Feo.010 and Zno.99Ni0.010, Co-doped ZnO exhibits smooth grain surfaces. The infrared absorption spectra show that infrared absorptions related to oxygen in Zn0.99M0.010 are much stronger than those in Co-doped ZnO. Co ions are dissolved into the ZnO lattice with Co2＋ state from XPS spectra analysis. The infrared emissivity results imply that the emissivity of Zno.99Ni0.010 is the highest （0.829） and that of Zno.99C00.010 is the lowest （0.784） at 1 200 ℃. The emissivity of Zno.99Co0.010 decreases to the minimum （0.752） at 1 150 ℃ and then increases with growing calcination temperature. As the Co doping content grows, the emissivity of Co-doped ZnO calcined at 1 200 ℃ falls to 0.758 in the molar fraction of 3% and then ascends.

Design and fabrication of Panda-type erbium-doped polarization-maintaining fibres

To obtain the stable operation of erbium-doped fibre laser, the simple and ideal technology is adopted by use of the erbium doped polarization maintaining fibre （EDPMF）. The design criteria of the Panda-type EDPMF are presented, which take into account the cutoff wavelength, mode field diameter, modal birefringence and background loss. Four groups of optimum structural paramcter combinations are determined in terms of the design criteria. Two kinds of the Panda-type EDPMFs are selected to be fabricated. The fabrication process and the parameter control of the Panda-type EDPMFs are presented in detail. Their refractive index profiles, birefringence and absorption spectra are experimentally investigated. The absorption coefficient of the EDPMF, whose core is co-doped with Bi, Ga, A1 and Ge, is about 57.9dB/m at 1.53μm. Co-doping Bi, Ga and A1 can greatly increase the erbium concentration in the silica-based fibre. The high birefringence is obtained for the Panda-type EDPMF. The group birefringence of the EDPMF, whose outer cladding diameter is 125 μm, is about 4.8 × 10%^-4.

Ammonia Removal from Wastewater through Combination of Absorption Process in the Membrane Contactor and Advance Oxydation Process in Hybride Plasma-Ozone Reactor

Wastewater containing high concentrations of ammonia can be harmful to aquatic life and degrade the water quality. Wastewater containing ammonia is usually removed by conventional methods such as aeration in towers, biological treatment and adsorption of the ammonium ion to the zeolite surface. However, these methods are less effective and relatively expensive. Therefore there is a need for alternative technologies that can improve the efficiency of ammonia removal from wastewater. This study aims to obtain the process of ammonia removal through a combination of absorption in the membrane contactor and the advance oxidation process in the hybrid plasma-ozone reactor. Wastewater containing ammonia used in the study was a synthetic wastewater with a concentration of about 800 ppm. In the experiment, the wastewater fi＇om the reservoir was firstly passed into the membrane contactor on the shell side, and then mixed with ozone from the ozonator befbre entering the plasma reactor, and finally was circulated back to the reservoir. Meanwhile, the absorbent solution was sent to the lumen fiber in membrane contactor. Experimental results showed that the ammonia removal efficiency increases with increasing in circulation rate and temperature of the wastewater. The highest efficiency of ammonia removal obtained from the experimental results was 77%.

Inclusion behavior of oxybutynin with hydroxypropyl-β-cyclodextrin

Inclusion behavior of oxybutynin （OBN） with hydroxypropyl-β-cyclodextrin （HP-β-CD） was investigated by ultraviolet absorption spectrum and fluorescence spectrum. A reliable determination of the complex stoichiometry was provided by the continuous variation technique. Alcohol was added to further investigate the mechanism of the inclusion behavior. Thermodynamic constants AG, AH and AS for inclusion interaction of OBN and HP-β-CD were determined. The results show that host-guest complex with molar ratio of 1：1 is formed, and inclusion stability constant between OBN and HP-β-CD is 54.9 L/mol determined by ultraviolet spectrum and 11.1 L/mol determined by fluorescence spectrum. OBN has weak binding ability with HP-β-CD in aqueous solution （stability constant 〈102 L/mol） and addition of alcohol leads to a decrease of stability constant, which indicates that the hydrophobic force contributes to the inclusion process. AG, AH and AS are all less than zero, which indicates that the inclusion process is a spontaneous and exothermic process.

Violence against Women with Breast Neoplasms

The aim of this study is to assess the occurrence and type of violence suffered by women with breast cancer in the High Complexity Care Unit of a municipality in the South of Minas and patients in a support group of the University of the South of Minas Gerais. For that aim, a descriptive-exploratory methodology was applied through the quantitative method. Data were collected through a semi-structured form applied in individual interviews over a period of three months. We interviewed 57 patients and among those, 20 women （35.08%） reported having experienced some form of violence at some stage of their life, and the most frequently mentioned was the psychological violence followed by physical aggression. Although it was possible to identify that violence against affected these women, complaints against the aggressor were not affected.