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Secondary atmospheric pollutions may result from wet flue gas desulfurization (WFGD) systems caused by the reduction of Hg2+to Hg0and lead to a damping of the co-benefit mercury removal efficiency by WFGD systems. The effects of the operating conditions, which included the pH, temperature, and oxygen concentrations, on Hg0re-emission inhibition efficiency by DTCR from WFGD liquors was carried out. The established data reflected an outstanding performance on the Hg0re-emission inhibition from the simulated WFGD liquors by adding DTCR. Our data suggested that a concentration of 0.0005% (v/v) was enough for Hg0re-emission inhibition in the simulated WFGD liquors. The results also indicated that the Hg0re-emission inhibition efficiency by adding DTCR decreased as the operational temperatures increased and the Hg0re-emission inhibition efficiency increased as pH values and the oxygen concentration in the flue gas increased. The present findings could be valuable for industrial application of DTCR as a precipitant for stabilizing dissolved Hg2+to prevent re-emission of Hg0in WFGD solutions.

Hg2+captured by wet flue gas desulfurization (WFGD) systems can easily be reduced by reducing substances such as S(IV) (SO32-or HSO3-) and results in emissions of elemental mercury (Hg0). The re-emission of Hg0would lead to a damping of the total mercury removal efficiency by WFGD systems. The effects of the operating conditions, which included the pH, temperature, Cl-concentrations and oxygen concentrations, on Hg0re-emission from WFGD liquors was carried out. The experimental results indicated that the Hg0re-emission rate from WFGD liquors increased as the operational temperatures and pH values increased. The Hg0re-emission rates decreased as the O2concentration of flue gas and Cl-concentration of WFGD liquors increased. So the Hg0re-emission from WFGD system can be reduced or slowed by decreasing the temperature and pH, or by using forced oxidation. The present findings could be valuable for industrial application of characterizing and optimizing mercury control in WFGD systems.

The removal of elemental mercury (Hg0) with the reactive species produced by gas phase surface discharge plasma was studied. The effects of several operational parameters, such as applied voltage, inlet Hg0 concentration and gas humidity, were investigated. The removal of Hg0 was significantly promoted by an increase in the applied voltage of the reactor system. Hg0 oxidation efficiency decreases with increasing inlet Hg0 concentration. Furthermore, with the addition of H2O, Hg0 oxidation is remarkably restrained.

Oxidation of gas phase elemental mercury (Hg0) in the simulated flue gas by DBD plasma under atmospheric pressure and ambient temperature (298 K) was conducted. Experimental results indicated that the oxidative efficiency of Hg0 increased with O2 content, the residence time of flue gas in reactor and the applied voltage. The oxidation efficiency of Hg0 reached over 96% under the applied voltage of 11 kV and the residence time of 0.24 s when the O2 content in flue gas was 20%, and the corresponding energy efficiency was at about 14.1 μg kJ-1. It was noted that the oxidation efficiency of Hg0 could still reach 80% when the O2 content in flue gas was only 4% (near the actual O2 content in flue gas of coal-fired boilers). The experimental results indicated that DBD plasma was one of the efficient technologies for purification of Hg0 vapor industrial flue gas.

According to the statistics data and planning material from the authority, the power source structure of China is analyzed and the clean power prospect is forecasted, which aim to explore occurring to CO2emissions reduction in the power industry. Based on The national greenhouse gas list guide published by Inter-governmental Panel on Climate Change (IPCC) in 2006, the trend of clean energy reduction CO2is predicted. In recent years, the clean energy power is developing quickly, while the share of thermal power gradually declines. By the end of 2010, the percent of thermal power in the total installed capacity is 73.44%, while the hydropower, and wind power and nuclear power accounts for 26.53%. The contribution of thermal power to generated energy is 80.76%, while the clean power is 19.22%. The capacity of thermal power unit with above 300 MW is predominate, accounting for 80%. In 2020, the installed capacity of hydroelectric power, wind power and nuclear power will reach 402 million kW, 150 million kW and 70 million kW, respectively. The corresponding annual energy production of three kinds of clean energy can reach 1.75 trillion kW•h, 314.55 billion kW•h, and 554.68 billion kW•h, which can reduce CO2emissions 1534, 276, 486 million tons, respectively. It is estimated that a total of 2.296 billion tons CO2emissions will be reduced in 2020.

Resolving NMR signals which are separated in frequency on the order of their line widths requires obtaining the time domain free induction decay for a maximum time tmax = πT2 , where T2 is the transverse relaxation time of the given signals. Unfortunately, samples acquired beyond ∼1.26T2 contribute more noise than signal to the data; and samples in the range of about (0.75-1.26)× T2 have a negligible effect on the signal-to-noise ratio (SNR). Therefore, one must sacrifice SNR to reach evolution times of πT2 . One can preserve resolution in a shorter total experimental time by selecting a reduced set of samples from the Nyquist grid according to an exponential probability density which is on the order of the T2 of the signals. This practice is widely termed nonuniform sampling (NUS). We derive analytic theory for the enhancement of the intrinsic SNR of NUS time domain data compared with uniformly sampled data when the total experimental times are equivalent. This theory is general for any tmax and exponential weighting and is further carefully validated with simulations. Enhancements of SNR in the time domain on the order of twofold are routinely available when tmax ∼ πT2 and are reflected in the subsequent maximum entropy reconstructed spectra. SNR enhancement by NUS is demonstrated to be helpful in enabling the acquisition of HMQC spectra of dilute bile salts in which high resolution in the indirect carbon dimension is required.

The new high-efficiency video coding (HEVC) standard is becoming popular owing to its excellent rate-distortion performance especially for emerging high-resolution applications. In HEVC more flexible coding options and partitioning types are provided for prediction units (PUs) and consequently motion estimation (ME) is more involved than previous video-coding standards. The existing fast ME algorithms, including the test zone search provided in the HEVC reference software, cannot generate high-quality video with reasonable computational complexity. A new fast integer-pixel ME algorithm for HEVC is presented. Starting with the initial motion vector obtained by the advanced motion vector prediction, the proposed directional search extends three search paths from the initial motion vector and considers the highly probable horizontal or vertical movement. Compared to the test zone search, the proposed method saves, on average, 60% time in integer-pixel ME with negligible rate-distortion degradation.

Lunar laser ranging has made significant contributions to the study of gravitational physics and the Earth-Moon system. The best results for fundamental gravitational experiments have been achieved using lunar laser ranging data accumulated so far. However, corner cube retroreflector arrays placed on the Moon currently set a limit on the laser-ranging precision, which is approximately several centimeters for a single photon received. To achieve millimeter precision, next generation of lunar laser ranging using a single hollow retroreflector with a large aperture has been proposed. We developed a prototype hollow retroreflector with a 100-mm aperture using silicate bonding together with a new fabrication method. Dihedral angle offsets of 0.5'', 0.8'' and 1.9'' were realized, which partly come close to meeting the requirements (offset of 0.6'' for each dihedral angle) for lunar laser ranging. Fluctuation of the wavefront is approximately 1.038λ at 633 nm. A thermal cycle test ranging from −40°C to +75°C was carried out for 18.5 periods (approximately 5 d). After this test, the dihedral angle offsets were measured to be 0.39'', 1.00'' and 2.06''. The results indicate the potential application of our method for manufacturing a hollow retroreflector with a large aperture to realize lunar laser ranging.

A multi-beam adaptive antenna is investigated by considering the adaptive beam forming performance for time-variant channels on the focus of mobile to base station or reverse link. This antenna is constructed by Fresnel zone phase-correcting plane (FZP) focusing element and uniformly spaced feeds array. An estimator for the beamforming weight vector in the presence of angle spreads is derived using a code filtering approach. Owing to the time-varying nature of the channels, a recursive method for computing and tracking the above optimal weight vector solution that is easy to implement is applied. The effects of angle spread, maximum Doppler frequency, and forgetting factor are studied. Simulation results showed that this type of adaptive antenna is capable of performing adaptive beam forming for time-variant channels effectively.

The three concatenated coding schemes of the inner-outer type, the parallel type and the consecutive type to improve the current forward error correction (FEC) coding technologies are proposed for dense wavelength-division multiplexing (DWDM) systems, after introducing the development trend of DWDM optical communication systems. The concatenated code is theoretically analyzed. The theoretical analyses and simulation results show that inner-outer concatenated code has a greater redundancy and the decoding of parallel concatenated code is too complex. However, consecutive concatenated code is superior coding scheme with advantages such as better error correction performance, moderate redundancy and easy implementation, therefore it could be better used in high-speed and long-haul DWDM systems.

This paper investigated the fire-retardant mechanism of the nano-LDHs in the intumescent system by the temperature programmed oxidation (TPO). Researches were also conducted to explore the function of the nano-LDHs in the composite fire-retardant agents in air and nitrogen atmosphere, respectively. The results indicated that the nano-LDHs species were responsible for the catalytic oxidation of the rich-carbon compound in oxygen atmosphere. In addition, the nano-LDHs species and their calcinated products at high temperature could increase the carbonaceous residue-shield of the carbon-rich materials, improve the quality and the graphitization degree of the formed char-layer, and accelerate the intumescence and expansion of the melting carbon-rich materials to a certain degree under the oxygen-free condition, leading to the carbonization and expansion of the intumescent layer.

The structures of the novel super forward error correction (Super-FEC) code type based on the concatenated code for high-speed long-haul optical communication systems are studied in this paper. The Reed–Solomon (RS) (255, 239) + Bose–Chaudhuri–Hocguenghem (BCH) (1023, 963) concatenated code is presented after the characteristics of the concatenated code and the two Super-FEC code type presented in ITU-T G.975.1 have theoretically been analyzed, the simulation result shows that this novel code type, compared with the RS (255, 239) + convolutional-self-orthogonal-code (CSOC) (k0/n0 = 6/7, J = 8) code in ITU-T G.975.1, has a lower redundancy and better error-correction capabilities, and its net coding gain (NCG) at the third iteration is 0.57 dB more than that of RS (255, 239) + CSOC (k0/n0 = 6/7, J = 8) code in ITU-T G.975.1 at the third iteration for the bit error rate (BER) of 10−12. Therefore, the novel code type can better be used in long-haul, larger capacity and higher bit-rate optical communication systems. Furthermore, the design and implementation of the novel concatenated code type are also discussed.

Herein, we present a novel strategy based on a "turn-on" fluorescence system made up of metal-organic frameworks Fe-MIL-88 and H2O2 for detecting biothiols in human serum. The nonfluorescent Fe-MIL-88 gives weak fluorescence in the presence of H2O2. Interestingly, it was found that biothiols such as glutathione (GSH), cysteine (Cys) or homocysteine (Hcy) could induce fluorescence turn-on of the Fe-MIL-88/H2O2 system. Under optimal conditions, the relative fluorescence intensity exhibited a good linear relationship in the range from 50 nM-10 μM for GSH (r = 0.994), 50 nM-10 μM for Cys (r = 0.990), and 50 nM-10 μM (r = 0.992) for Hcy; the detection limits of GSH, Cys and Hcy were 30 nM, 40 nM, and 40 nM respectively. Mechanism investigation reveals that biothiols could associate with Fe-MIL-88 via hydrogen bonding and electrostatic interaction followed by redox reaction between biothiols and Fe(3+) present in the Fe-MIL-88, Fe(3+) was thus reduced to Fe(2+), and then Fe(2+) could efficiently catalyze the decomposition of H2O2 to yield ˙OH radicals through the Fenton reaction. Besides, biothiols were able to reduce H2O2 to produce ˙OH radicals directly. Thus the Fe-MIL-88 as well as biothiols could cooperatively contribute to the activation of H2O2 to generate higher amounts of ˙OH radicals, which in turn oxidize the free ligand terephthalic acid (BDC) outside or within the Fe-MIL-88 structure to strongly fluorescent hydroxylated terephthalic acid (OHBDC), thereby turning on the fluorescence.

To investigate the effects of serotonin (5-HTIA) receptors in the hippocampal dentate gyrus (DG) on active avoidance learning in rats.Totally 36 SD rats were randomly divided into control group, antagonist group and agonist group(n = 12). Active avoidance learning ability of rats was assessed by the shuttle box. The extracellular concentrations of 5-HT in the DG during active avoidance conditioned reflex were measured by microdialysis and high performance liquid chromatography (HPLC) techniques. Then the antagonist (WAY-100635) or agonist (8-OH-DPAT) of the 5-HT1A receptors were microinjected into the DG region, and the active avoidance learning was measured.(1) During the active avoidance learning, the concentration of 5-HT in the hippocampal DG was significantly increased in the extinction but not establishment in the conditioned reflex, which reached 164.90% ± 26.07% (P0.05) of basal level. (2) The microinjection of WAY-100635 (an antagonist of 5-HT1A receptor) into the DG did not significantly affect the active avoidance learning. (3) The microinjection of 8-OH-DPAT(an agonist of 5-HT1A receptor) into the DG significantly facilitated the establishment process and inhibited the extinction process during active avoidance conditioned reflex.The data suggest that activation of 5-HT1A receptors in hipocampal DG may facilitate active avoidance learning and memory in rats.

Because of the noninvasive, locally selective potential of thermal energy, considerable effort has been focused on the use of an external, alternating magnetic field for conversion of magnetic work to heat with iron oxide nanoparticles. However, proper regulation of thermal energy remains a challenge because of the lack of feedback from the local temperature change to the external power supply. Here, we show development of smart magnetic nanoparticles composed of Fe and Si with intrinsically tunable heat generation capability. They were engineered to possess an adjustable magnetic transition temperature through tuning the exchange between Fe atoms by incorporation of silicon atoms. They show relatively high magnetic moment. Moreover, their biocompatibility was established in several cell lines. The nanoparticles were also combined with a thermosensitive polymer, which had the capability to release of molecules with a magnetic stimulus, thereby providing a platform for locally controlled, drug release.

This article presents a general evaluation of handoff dwell time distribution based on geometric analysis methods. Considering the geometric characteristic of the deployed sector pattern, and the distribution of the users' position and the moving direction in the given sector, the general formulas of the probability density function of sector handoff dwell time are derived. Some numerical results are also presented for illustration.

Background Masson pine (Pinus massoniana) is one of the most important timber species with adaptable, fast growing, versatile advantages in southern China. Despite considerable research efforts, the cellular and molecular mechanisms of A1 toxicity and resistance in P. massoniana are still poorly understood. The effects of Al on uptake and translocation of Al and other minerals, cell division and nucleolus in P. massoniana were investigated. Results The results indicated that Al accumulated mainly in the roots, and small amounts were transported to aboveground organs. In the presence of Al, the contents of Mg and Fe in stems increased and decreased in roots. Accumulation of Mn in the organs was inhibited significantly. Evidence from cellular experiments showed that Al had an inhibitory effect on the root growth at all concentrations (10−5 – 10−2 M) used. Chromosome fragments, chromosome bridges, C-mitosis and chromosome stickiness were induced during mitosis in the root tip cells. Al induced the formation of abnormal microtubule (MT) arrays, consisting of discontinuous wavy MTs or short MT fragments at the cell periphery. MT organization and function of the mitotic spindle and phragmoplast were severely disturbed. The nucleolus did not disaggregate normally and still remained its characteristic structure during metaphase. Nucleolar particles containing argyrophilic proteins were accumulated and leached out from the nucleus to the cytoplasm. Evidence confirmed that these proteins contained nucleophosmin (B23), nucleolin (C23) and fibrillarin. Western immunoblot analysis revealed that the contents of three nucleolar proteins increased significantly. Conclusion Based on the information provided in this article, it is concluded that root tips of plants are the most sensitive organ to environmental stresses and the accumulation of Al ions primarily is in roots of P. massoniana, and small amounts of Al are transported to aboveground. Root apical meristems play a key role in the immediate reaction to stress factors by activating signal cascades to the other plant organs. Al induces a series of the cellular toxic changes concerning with cell division and nucleolus. The data presented above can be also used as valuable and early markers in cellular changes induced by metals for the evaluation of metal contamination.

To study the retinal ultrastructure of streptozocin (STZ)-induced diabetic rats and the intervention effect of Lycium Barbarum Polysaccharides (LBP).The STZ-induced diabetic SD rat model was established. LBP was given to those in the treatment group by gastrogavage. Changes of body weight, blood glucose, and retinal ultrastructure at 24-week were observed.Early retinal changes covered mitochondrion changes, cell degeneration and apoptosis of retinal neurons and neuroglia cells in the diabetic rats. No change of body weight or blood glucose was observed between the LBP group and the diabetic model group (P0.05). The ultrastructural changes were obviously relieved by LBP, and limited to the inner nuclear layer.LBP could obviously relieve pathological changes of mitochondrion, hinder neural cell apoptosis. Its effect might not be achieved by lowering blood glucose. It was expected to be used in preventing and treating early diabetic retinal neuropathy.

To investigate the distribution, bioconcentration, metabolism, and biomarker responses of macrolide antibiotic roxithromycin (ROX) in fish, crucian carp (Carassius auratus) were exposed to various concentrations of ROX (4, 20, and 100μgL(-1)) for 20d. The ROX content in different tissues was quantified using UPLC/MS/MS. The liver exhibited the highest ROX concentration followed by the bile, gills, and muscle tissues. After 15d of exposure to different concentrations of ROX, the bioconcentration factors were 2.15-38.0 in the liver, 0.950-20.7 in the bile, 0.0506-19.7 in the gill, and 0.0439-13.8 in the muscle; these results were comparable to the estimated BCF values. The metabolites formed in the bile were identified based on metabolic identification in human bile. Additionally, the biomarkers, including acetylcholinesterase in the brain, as well as 7-ethoxyresorufin O-deethylase and superoxide dismutase in the liver changed significantly after 5, 10, 15, and 20d of exposure (P0.05). Our results suggest that ROX can accumulate and be metabolized in fish; therefore, interactions between ROX or its metabolites and the biological systems may induce biochemical disturbances in fish.

Resolving NMR signals which are separated in frequency on the order of their line widths requires obtaining the time domain free induction decay for a maximum time tmax = πT2 , where T2 is the transverse relaxation time of the given signals. Unfortunately, samples acquired beyond ∼1.26T2 contribute more noise than signal to the data; and samples in the range of about (0.75-1.26)× T2 have a negligible effect on the signal-to-noise ratio (SNR). Therefore, one must sacrifice SNR to reach evolution times of πT2 . One can preserve resolution in a shorter total experimental time by selecting a reduced set of samples from the Nyquist grid according to an exponential probability density which is on the order of the T2 of the signals. This practice is widely termed nonuniform sampling (NUS). We derive analytic theory for the enhancement of the intrinsic SNR of NUS time domain data compared with uniformly sampled data when the total experimental times are equivalent. This theory is general for any tmax and exponential weighting and is further carefully validated with simulations. Enhancements of SNR in the time domain on the order of twofold are routinely available when tmax ∼ πT2 and are reflected in the subsequent maximum entropy reconstructed spectra. SNR enhancement by NUS is demonstrated to be helpful in enabling the acquisition of HMQC spectra of dilute bile salts in which high resolution in the indirect carbon dimension is required.

In this paper, we utilize rough set theory as a tool to deal with the problem of null-value estimation in an incomplete information system, a rating mechanism in collaborative filtering technology is introduced into this paper for the weakness of null value estimation based on similar relational algorithm (SIM-EM), such as no sparse degree process and low accuracy, and an improved null value estimation method, which based on SIM-EM is proposed from the perspective of similarity. The null value data is predicted and filled through the similarity of objects, otherwise a dual feature weight method is proposed according to the attribute's feature in rough set, which improves the accuracy in similarity calculation, the improved algorithm is good at dealing with sparse rough set, and the accuracy and the mean absolute error is better than the original method.

The conclusion draws from traditional power supplying capability evaluation method can not reflect the actual supplying capability of gridby quantitative index, so evaluating the overall power supplying capability by means of fuzzy method has its advantage. Fuzzy analysis method has been employed to create a city gridpower supplying evaluating model in respect of the reality of power supplying condition of KunMing network, in which weighting is assigned by effect value of data reflected by information entropy to avoid the influence of subjective elements in weighting assigning. Seven elements which reflect the power supplying capability of KunMing grid objectively and comprehensively have been chose to construct corresponding membership degree function curve according to their different reflecting dimensionalities of power supplying capability, then the membership degree value of each elements is deduced. Each of the seven evaluating elements is judged to obtain quantitative fuzzy evaluating results, and then these 7 elements are combined to judge the power supplying capability synthetically to derive the fuzzy evaluating result of power supplying capability of KunMing network.

This paper uses the evaluation for listed companies' disclosure level by Shenzhen Stock Exchange as the agency variable of financial accounting information quality, including listed firms in Shenzhen Stock Exchange from 2002 to 2006 as our sample, empirically tests the relation between the quality of financial accounting information and economic performance, and the paper also tests if financial accounting information affects economic performance through corporate governance system channel. Empirical results show high-quality financial accounting information does improve economic performance and corporate governance is one of the channels, regardless of Tobin's Q or return on assets or ratio of net operating cash flow to assets as the agency variable of economic performance. But we don't empirically test if there are other channels through which financial accounting information can promote economic performance, this may be one direction We want to research about in future. Therefore higher-quality financial accounting information is of great significance for economic performance.

The classical four-state component model haven't accord to practical situation because the equipment repairing technique based on condition of component developed quickly, and this paper put forwarded an advanced four state component model. That model redefined abnormal state and maintainable state, combined repair state based on condition of component and schedule repair state to repair state and then confirmed the conversion relationship and the parameter to each state. This paper put forwarded combining components and dividing subzone method to simplify the main electrical scheme to be a simple directional network, applied advanced four state component model in that network to calculate the subzone's reliability parameter. Applied the least path searching method to search the least path matrix for the network and predigested the method by matrix multiplication, enumerated each fault state of that network by analytical method, worked out the reliability index of that network by VC++. And the reliability index of network is the reliability index of main electrical scheme in ChuXiong plusmn800 kV rectifier station. At last this paper analyzed the result of main electrical scheme's reliability and it proved the method's validity which used in this paper.

As one of the most important equipments to guarantee power gird operating safely and stably, the fault diagnosis of transformer has most important sense. Since the general diagnosis methods such as DGA and attributes' reduction of rough set haven't enough precision for transformer's fault diagnosis, Extenics and rough set theory are brought into diagnosing the fault of transformer. Using attribute predigesting method in rough set theory to classify the attribute term which needed by each fault diagnosis. Then building matter element model for transformer's fault diagnosis. Using DGA testing datum to be attribute set and the transformer's standard fault model to be the decision set for transformer's fault diagnosis. Utilize association function from Extenics to count each fault degree. Define the fault accepting rule to get transformer's fault. Use this method to diagnose one fault transformer and the diagnosis result matched case of fact fault. Apply this method to diagnose 76 DGA testing data and the right ratio of diagnostic result is better than IEC method.

In this paper, the three ameliorated new coding schemes of the Super-FEC (Forward Error Correction) concatenatedcodes (namely, the inner-outer concatenated-code, the parallel concatenated-code and the successive concatenated-code with interleaving) are proposed after the development trend of high-rate optical transmission systems and the defects of the FEC codes in the current optical transmission systems have been analyzed. The system simulation of the inner-outer concatenated-codes is implemented and the schemes of encoding/decoding the parallel concatenated-codes are proposed. Furthermore, the two successive concatenated-codes with interleaving of the RS(255,239)+RS(255,239) code and the RS(255,239)+RS(255,223) code are simulated, and the analyses for the simulation results show that the two successive concatenated-codes with interleaving, compared with the classic RS (255,239) code and other codes, are a superior code type with the advantages of the better correction error, moderate redundancy and easy realization. And their net coding gains (NCG) are respectively 1.5dB, 2.5dB more than that of the classic RS(255,239) code at the BER (Bit Error Rate) of 10 -12 . At last, based on the ITU-T G.709, the frame format of the new concatenated-code on applying in high-rate optical transmission systems is proposed and designed, this lays a firm foundation in order to design its hardware in future and pioneers a direction in its physical application.

A novel super forward error correction (super-FEC) coding scheme (viz: the BTC code pattern of BCH(64,57) times BCH(64,57)) based on the block turbo code (BTC) in long-haul optical transmission systems is proposed in this paper. The BTC of Bose-Chaudhur-Hocguenghem (BCH)(64,57)timesBCH(64,57) has been constructed, simulated and analyzed. The simulation results and the performance analyses show that the net coding gain (NCG) of BCH(64,57)timesBCH(64,57) code at the sixth iteration is 0.35 dB more than that of Reed-Solomon (RS)(255,239) + convolutional self orthogonal code (CSOC) (k0/n0=6/7, J=8) code in ITU-T G.975.1 at the third iteration for a BER of 10-12 and the novel BTC has the advantageous characteristics such as the shorter component code and the rapid encoding/decoding speed, these advantages reduce not only the complexity for implementing the software/hardware but also the time delay for the encoding/decoding. Therefore, the novel BTC coding scheme can be used in large capacity, high-speed and ultra long-haul optical transmission systems. At last, the design and implementation of the novel BTC are also discussed

In this paper, a modified UTD model to predict the propagation channel parameters in indoor scenarios is presented. The model is based on the blueprint of the rooms for a transmitter and receiver located at the same room. It employs two plane views reference to the transmitter and the receiver, respectively and a new criteria adopting vector's dot product to construct the visibility graph. To verify the model, comparisons between the simulation results and measurements available in literature are given. The numerical results show that the modified ray tracing model will be applied in complex indoor propagation environment and find all propagation paths from a transmitter to a receiver in a high degree of accuracy without redundant computation time