The asymptotic behavior of a class of nonlinear delay difference equation wax studied . Some sufficient conditions are obtained for permanence and global attractivity . The results can be applied to a claxs of nonline...The asymptotic behavior of a class of nonlinear delay difference equation wax studied . Some sufficient conditions are obtained for permanence and global attractivity . The results can be applied to a claxs of nonlinear delay difference equations and to the delay discrete Logistic model and some known results are included.展开更多
Using patho-morphological method and transplantation bio-assay, the in vivo invasiveness of leukemia cells is three transplantable mouse T cell leukemia models was comparatively studied. The results showed that the in...Using patho-morphological method and transplantation bio-assay, the in vivo invasiveness of leukemia cells is three transplantable mouse T cell leukemia models was comparatively studied. The results showed that the invasion to the liver was consistent, but that to other organs was obviously different. L615 and L7212 leukemia cells preferred to the bone marrow and spleen than to the peritoneum while L7811 leukemia cells were just the opposite. Transplantation bio-assay demonstrated that leukemia cells were present in the bone marrow of L615 mice as early as 6 hours after leukemic cell inoculation, but no leukemia cells was detected in bone marrow of L7811 mice 2 days after inoculation. In the terminal phase, L615 mice bone marrow became filled with leukemia cells, but L7811 mice bone marrow contained only a few leukemia cells. The difference of invasiveness of leukemia cells among organs is probably related to "homing" receptor. The same type of leukemia cells may possess multiple "homing" receptor.展开更多
An Ha-ras oncogene was isolated from a cell line of gastric carcinoma called BGE-823 in order to elucidate genetic control and the influence of DNA sequences. The oncogene was cloned and identified as a single nucleot...An Ha-ras oncogene was isolated from a cell line of gastric carcinoma called BGE-823 in order to elucidate genetic control and the influence of DNA sequences. The oncogene was cloned and identified as a single nucleotide substitution of thymine for guanine in the 12th codon through the sequencing of its first axon. We compared the differences of expression and regulation between the transformed Ha-ras cells and untransformed parent cells. Data indicated that the expression of Ha-ras in the transformed cells was five-fold higher than in the untransformed cells and that the Ha-ras gene in the former was hypersensitive toward DNase I. In addition, a nuclear protein of 35 kilodaltons bound strongly to the 2.5 Kb fragment located upstream of the 6.6 Kb Ha-ras gene and contained a CC rich region. These results suggest that there might be another mechanism of activation for the ras gene besides point mutation.展开更多
A new method for image segmentation based on pulse neural network is proposed. Every neuron in the network represents one pixel in the image and the network is locally connected. Each group of the neurons that corresp...A new method for image segmentation based on pulse neural network is proposed. Every neuron in the network represents one pixel in the image and the network is locally connected. Each group of the neurons that correspond to each object synchronizes while different groups of the neurons oscillate at different period. Applying this period difference, different objects are divided. In addition to simulation, an analysis of the mechanism of the method is presented in this paper.展开更多
Teicoplanin is one of the macrocyclic glycopeptide antibiotics, which is active against Gram-positive bacteria, and has attracted a lot of attention in the field of chiral separation recently. In this work, the partit...Teicoplanin is one of the macrocyclic glycopeptide antibiotics, which is active against Gram-positive bacteria, and has attracted a lot of attention in the field of chiral separation recently. In this work, the partition coefficients and extraction ratio of teicoplanin in three different solvent systems were studied: conventional extraction, reactive extraction and reverse micelle extraction. With conventional solvent extraction, n-butanol demonstrated high partition coefficient for teicoplanin, but low extraction ratio because of its high solubility in water. Reactive extraction of teicoplanin showed the highest partition coefficient with almost 100% recovery in organic phase when tri-n-octylmethyl ammonium chloride (TOMAC) was used as extractant and pH value was above 5.0. A reverse micelle system, consisted of isooctane +10mmol-L-1 TOMAC +1% n-octanol, also offered high separation factor for teicoplanin. The results are beneficial for the design of teicoplanin separation and purification process.展开更多
Durable press finishing of cotton fabrics with polycarboxylic acid increases fabric wrinkle-resistance at the expense of its mechanical strength. Severe tensile strength loss is the major disadvantage for wrinkle resi...Durable press finishing of cotton fabrics with polycarboxylic acid increases fabric wrinkle-resistance at the expense of its mechanical strength. Severe tensile strength loss is the major disadvantage for wrinkle resistant cotton fabrics.Tensile strength loss of cotton fabric crosslinked by a polycarboxylic acid can be attributed to depolymerization and crosslink of cellulose molecules. Measurement of the molecular weight of cotton fabric before and after crosslinked by polycarboxylic acids can offer a possibility of direct understanding of the depolymerization. In this research, amultiple angle laser light scattering photometer was used todetermine the absolute molecular weight of cotton fabric treated with BTCA at different pH and then hydrolyzed with 0. 5 M NaOH solution at 50℃ for 144 h. The results indicate that average molecular weights of cotton fabric treated with polycarboxylic acids at different pH are almost the same.展开更多
The similarities and differences of ASTM and China GB standard are studied in three aspects:measure instrument,terminology and applicable field.They are similar on the measuring apparatus and GB has less measurements,...The similarities and differences of ASTM and China GB standard are studied in three aspects:measure instrument,terminology and applicable field.They are similar on the measuring apparatus and GB has less measurements,such as girth,length and width measurements than ASTM and it lack across chest width,back width,total crotch length and shoulder slope which are important measurements in pattern making.ASTM classifies its standards according to the customers' size,gender and age.So we think GB standard could make some modifications from these fields to satisfy the users.展开更多
Objective: To investigate the potential of superparamagnetic iron oxide particles (SPIO) in MR imaging for the differentiation between hyperplastic and metastatic lymph node. Methods: Animal models of malignant lymph ...Objective: To investigate the potential of superparamagnetic iron oxide particles (SPIO) in MR imaging for the differentiation between hyperplastic and metastatic lymph node. Methods: Animal models of malignant lymph node metastasis were established in 6 New-Zealand rabbits by a unilateral intra-muscular injection of VX2 carcinoma cells, and models of hyperplastic lymph nodes were induced in another 6 rabbits by a unilateral intra-muscular injection of egg yolk emulsion. MR images of the lymph nodes were obtained before and 12 h after interstitial injection of SPIO. Image results were analyzed and compared with pathological findings. Results: On unenhanced images, the signal intensity of hyperplastic and metastatic lymph nodes did not differ significantly. After administration of SPIO, the signal intensity of both hyperplastic and metastatic lymph nodes remained unchanged on T1-weighted SE images. On T2-weighted SE images, the signal intensity of hyperplastic lymph nodes decreased heterogeneously, while that of all metastatic ones remained unchanged. On T2-weighted GRE images, the signal intensity of hyperplastic lymph nodes decreased significantly and homogeneously, while that of 4 metastatic ones remained unchanged and that of the rest 2 decreased heterogeneously. Conclusion: SPIO-enhanced MR imaging may enable the differentiation between the hyperplastic and metastatic lymph nodes.展开更多
Objectives To explore the basic heart functional state and cardiac reserve function of patients with different types of unstable angina pectoris (UAP) and observe the relations between the heart function and severity ...Objectives To explore the basic heart functional state and cardiac reserve function of patients with different types of unstable angina pectoris (UAP) and observe the relations between the heart function and severity of coronary arterial disease. Methods 70 cases with UAP were enrolled including 25 patients with angina decubitus (AD), 23 patients with mixed angina (MA) , and 22 patients with accelerated effort angina (AEA). All patients underwent a series of examination such as UCG, ECT, hemodynamics and volume-loading test. The patients were divided into three groups in light of the results of the hemodynamic examination: ① diastolic dysfunction group ② systolic dysfunction group ③ normal heart function group. We assessed the basic heart function and cardiac reserve function of patients with different types of UAP and also observed the relations between coronary arteriography and heart function. Results ① Under basic conditions, patients with angina decubitus suffered from the systolic (36%) or diastolic dysfunction (48%). 43 percent of the patients with mixed angina had systolic dysfunction and other 43 percent of them had normal cardiac function. However, patients with accelerated effort angina (AEA) were characterized by diastolic dysfunction (31%) or normal heart function (60%). ② In hemodynamic examination, the pulmonary capillary wedge pressure of positive patients rose, at the same time cardiac index fell to the extreme instantaneously after loading in volume-loading test and then they restored to the basic level until 60 minutes. However, both PCWP and CI of the negative patients reach the peak momentarily after loading. They returned to the basic level within 30 minutes. ③ coronary arteriography show: there are 41% of patient with three-vessel disease, 50% with two-vessel disease, 9% single vessel disease and left main narrowing 22. 7% in AEA. There are separately 76%, 24%, 0% and 36% in AD; and 26.1% , 43.4% , 21.7% , 43.4% in MA. ④ Constituent ratio of the AEA and MA were separately compared with AD, AEA/AD: P < 0.05(P = 0.031); MA/AD: P < 0.01 (P = 0.000313). Conclusions Most of patients with the above three types of unstable angina pectoris suffered from the basic heart dysfunction and cardiac reserve dysfunction which might participate in the occurrence and development of unstable angina pectoris. In angiography, there are the most three-vessel diseases in AD that are, therefore, the most severe UAP.展开更多
Is there any difference between the abilities of differentiation and redifferentiation of tissues of wheat spike in the process of culture in vitro when it is at different developmental stages So far no reports about ...Is there any difference between the abilities of differentiation and redifferentiation of tissues of wheat spike in the process of culture in vitro when it is at different developmental stages So far no reports about this have been found in the literature.展开更多
The copper phthalocyanine (CuPc) as a dye and photoconductive material plays an important role in bionics. The different crystal forms of CuPc have distinct properties. In this article XPS results of α, β, γ, X-CuP...The copper phthalocyanine (CuPc) as a dye and photoconductive material plays an important role in bionics. The different crystal forms of CuPc have distinct properties. In this article XPS results of α, β, γ, X-CuPc have been reported. The character of shake-up satellite peaks and valence band spectra in these CuPc compounds was also examined. It was found that the difference of X-CuPc with other crystal forms of CuPc is obvious. XPS study on different crystal forms of CuPc has not been reported previously.展开更多
Cytochrome P-450 is widely distributed in different species of animals. As a terminal oxidase ot the microsomal monooxygenase system, cytochrome P-450 is the key element of the enzyme system. Because of its broad subs...Cytochrome P-450 is widely distributed in different species of animals. As a terminal oxidase ot the microsomal monooxygenase system, cytochrome P-450 is the key element of the enzyme system. Because of its broad substrate specificity, it is involved in the biotransformation of many xenobiotic and endogenous compounds which are important in envitonmental protection, pharmacology and carcinogenicity. Microsomal P-450 is also a展开更多
A prominent feature for modern biological research is to make full use of different apparatus and techniques, such as spectrometry, chromatography, mass spectrometry and so on, which are hitherto chiefly used in the f...A prominent feature for modern biological research is to make full use of different apparatus and techniques, such as spectrometry, chromatography, mass spectrometry and so on, which are hitherto chiefly used in the fields of chemistry and physics. Gasliquid chromatography, as a new method for analytical chemistry, was invented by展开更多
The general difference schemes for the first boundary problem of the fully nonlinear pseudo-hyperbolic systemsf(x, t, u,u_x,u_(xx),u_t,u_(tt),u_(xt),u_(xxt))=0are considered in the rectangular domain Q_T={0≤x≤1, 0≤...The general difference schemes for the first boundary problem of the fully nonlinear pseudo-hyperbolic systemsf(x, t, u,u_x,u_(xx),u_t,u_(tt),u_(xt),u_(xxt))=0are considered in the rectangular domain Q_T={0≤x≤1, 0≤t≤T}, where u(x,t)and f(x, t, u,p_1, p_2, r_1,r_2,q_1,q_2) are two m-dimensional vector functions with m≥1 for(x, t)∈Q_T and u,p_1,p_2,r_1,r_2,q_1,q_2∈R. The existence and the estimates of solutionsfor the finite difference system are established by the fixed point technique. The absolute andrelative stability and convergence of difference schemes are justified by means of a series of a prioriestimates. In the present study, the existence of unique smooth solution of the original problemis assumed. The similar results for nonlinear and quasilinear pseudo-hyperbolic systems are alsoobtained.展开更多
Ⅰ. JNTRODUCTION Each ommatidium in the diptera compound eye contains 8 retinular cells. The first subsystem consists of 6 large retinular cells in periphery. Six different peripheral retinular cells from the 6 neighb...Ⅰ. JNTRODUCTION Each ommatidium in the diptera compound eye contains 8 retinular cells. The first subsystem consists of 6 large retinular cells in periphery. Six different peripheral retinular cells from the 6 neighbouring ommatidia receive visual information and transmit it into a single neuro-ommatidium (cartridge) of the first optic ganglion. The other two retinular cells are located at the centre of the ommatidium from the second subsystem, which receives visual information and sends it directy to the second optic ganglion.展开更多
The laser-induced damage behavior of narrow-band interference filters was investigated with a Nd:YAG laser at 1064 nm under single-pulse mode and free-running laser mode. The absorption measurement of such coatings ha...The laser-induced damage behavior of narrow-band interference filters was investigated with a Nd:YAG laser at 1064 nm under single-pulse mode and free-running laser mode. The absorption measurement of such coatings has been performed by surface thermal lensing (STL) technique. The relationship between damage morphology and absorption under the two different laser modes was studied in detail. The explanation was given by the standing-wave distribution theory.展开更多
Experimental research of simultaneous tunable chromatic dispersion (CD) and adaptive polarization mode dispersion (PMD) compensations in optical fiber communication system was reported. Two different nonlinearly chirp...Experimental research of simultaneous tunable chromatic dispersion (CD) and adaptive polarization mode dispersion (PMD) compensations in optical fiber communication system was reported. Two different nonlinearly chirped fiber Bragg gratings fabricated through the equivalent chirp technology were adopted in the experiment. One of the gratings was used as CD compensator, with a tunable dispersion range from 300 to 600 ps/nm. The other made of photosensitive polarization maintaining fiber was used as a tunable delay line of PMD compensator, which provided a varying amount of differential group delay (DGD) from 40 to 110 ps. Our experiment was operated at 10-Gb/s non-return-to-zero (NRZ) system and the results showed that the eye pattern recovery is excellent after both PMD and CD are compensated. Especially, the power penalty at a bit error rate (BER) of 10-9 is about 1 dB.展开更多
基金Foundation items: the National Natural Science Foundation of China (10171040)the Natural Science Foundation of Gansu Province of China (ZS011-A25-007-Z)+1 种基金 the Foundation for University Key Teacher by Ministry of Education of China the Teaching and Re
文摘The asymptotic behavior of a class of nonlinear delay difference equation wax studied . Some sufficient conditions are obtained for permanence and global attractivity . The results can be applied to a claxs of nonlinear delay difference equations and to the delay discrete Logistic model and some known results are included.
文摘Using patho-morphological method and transplantation bio-assay, the in vivo invasiveness of leukemia cells is three transplantable mouse T cell leukemia models was comparatively studied. The results showed that the invasion to the liver was consistent, but that to other organs was obviously different. L615 and L7212 leukemia cells preferred to the bone marrow and spleen than to the peritoneum while L7811 leukemia cells were just the opposite. Transplantation bio-assay demonstrated that leukemia cells were present in the bone marrow of L615 mice as early as 6 hours after leukemic cell inoculation, but no leukemia cells was detected in bone marrow of L7811 mice 2 days after inoculation. In the terminal phase, L615 mice bone marrow became filled with leukemia cells, but L7811 mice bone marrow contained only a few leukemia cells. The difference of invasiveness of leukemia cells among organs is probably related to "homing" receptor. The same type of leukemia cells may possess multiple "homing" receptor.
文摘An Ha-ras oncogene was isolated from a cell line of gastric carcinoma called BGE-823 in order to elucidate genetic control and the influence of DNA sequences. The oncogene was cloned and identified as a single nucleotide substitution of thymine for guanine in the 12th codon through the sequencing of its first axon. We compared the differences of expression and regulation between the transformed Ha-ras cells and untransformed parent cells. Data indicated that the expression of Ha-ras in the transformed cells was five-fold higher than in the untransformed cells and that the Ha-ras gene in the former was hypersensitive toward DNase I. In addition, a nuclear protein of 35 kilodaltons bound strongly to the 2.5 Kb fragment located upstream of the 6.6 Kb Ha-ras gene and contained a CC rich region. These results suggest that there might be another mechanism of activation for the ras gene besides point mutation.
文摘A new method for image segmentation based on pulse neural network is proposed. Every neuron in the network represents one pixel in the image and the network is locally connected. Each group of the neurons that correspond to each object synchronizes while different groups of the neurons oscillate at different period. Applying this period difference, different objects are divided. In addition to simulation, an analysis of the mechanism of the method is presented in this paper.
文摘Teicoplanin is one of the macrocyclic glycopeptide antibiotics, which is active against Gram-positive bacteria, and has attracted a lot of attention in the field of chiral separation recently. In this work, the partition coefficients and extraction ratio of teicoplanin in three different solvent systems were studied: conventional extraction, reactive extraction and reverse micelle extraction. With conventional solvent extraction, n-butanol demonstrated high partition coefficient for teicoplanin, but low extraction ratio because of its high solubility in water. Reactive extraction of teicoplanin showed the highest partition coefficient with almost 100% recovery in organic phase when tri-n-octylmethyl ammonium chloride (TOMAC) was used as extractant and pH value was above 5.0. A reverse micelle system, consisted of isooctane +10mmol-L-1 TOMAC +1% n-octanol, also offered high separation factor for teicoplanin. The results are beneficial for the design of teicoplanin separation and purification process.
基金The Project-sponsored by SRF for ROCS, SEM and EYTP of MOE
文摘Durable press finishing of cotton fabrics with polycarboxylic acid increases fabric wrinkle-resistance at the expense of its mechanical strength. Severe tensile strength loss is the major disadvantage for wrinkle resistant cotton fabrics.Tensile strength loss of cotton fabric crosslinked by a polycarboxylic acid can be attributed to depolymerization and crosslink of cellulose molecules. Measurement of the molecular weight of cotton fabric before and after crosslinked by polycarboxylic acids can offer a possibility of direct understanding of the depolymerization. In this research, amultiple angle laser light scattering photometer was used todetermine the absolute molecular weight of cotton fabric treated with BTCA at different pH and then hydrolyzed with 0. 5 M NaOH solution at 50℃ for 144 h. The results indicate that average molecular weights of cotton fabric treated with polycarboxylic acids at different pH are almost the same.
文摘The similarities and differences of ASTM and China GB standard are studied in three aspects:measure instrument,terminology and applicable field.They are similar on the measuring apparatus and GB has less measurements,such as girth,length and width measurements than ASTM and it lack across chest width,back width,total crotch length and shoulder slope which are important measurements in pattern making.ASTM classifies its standards according to the customers' size,gender and age.So we think GB standard could make some modifications from these fields to satisfy the users.
文摘Objective: To investigate the potential of superparamagnetic iron oxide particles (SPIO) in MR imaging for the differentiation between hyperplastic and metastatic lymph node. Methods: Animal models of malignant lymph node metastasis were established in 6 New-Zealand rabbits by a unilateral intra-muscular injection of VX2 carcinoma cells, and models of hyperplastic lymph nodes were induced in another 6 rabbits by a unilateral intra-muscular injection of egg yolk emulsion. MR images of the lymph nodes were obtained before and 12 h after interstitial injection of SPIO. Image results were analyzed and compared with pathological findings. Results: On unenhanced images, the signal intensity of hyperplastic and metastatic lymph nodes did not differ significantly. After administration of SPIO, the signal intensity of both hyperplastic and metastatic lymph nodes remained unchanged on T1-weighted SE images. On T2-weighted SE images, the signal intensity of hyperplastic lymph nodes decreased heterogeneously, while that of all metastatic ones remained unchanged. On T2-weighted GRE images, the signal intensity of hyperplastic lymph nodes decreased significantly and homogeneously, while that of 4 metastatic ones remained unchanged and that of the rest 2 decreased heterogeneously. Conclusion: SPIO-enhanced MR imaging may enable the differentiation between the hyperplastic and metastatic lymph nodes.
文摘Objectives To explore the basic heart functional state and cardiac reserve function of patients with different types of unstable angina pectoris (UAP) and observe the relations between the heart function and severity of coronary arterial disease. Methods 70 cases with UAP were enrolled including 25 patients with angina decubitus (AD), 23 patients with mixed angina (MA) , and 22 patients with accelerated effort angina (AEA). All patients underwent a series of examination such as UCG, ECT, hemodynamics and volume-loading test. The patients were divided into three groups in light of the results of the hemodynamic examination: ① diastolic dysfunction group ② systolic dysfunction group ③ normal heart function group. We assessed the basic heart function and cardiac reserve function of patients with different types of UAP and also observed the relations between coronary arteriography and heart function. Results ① Under basic conditions, patients with angina decubitus suffered from the systolic (36%) or diastolic dysfunction (48%). 43 percent of the patients with mixed angina had systolic dysfunction and other 43 percent of them had normal cardiac function. However, patients with accelerated effort angina (AEA) were characterized by diastolic dysfunction (31%) or normal heart function (60%). ② In hemodynamic examination, the pulmonary capillary wedge pressure of positive patients rose, at the same time cardiac index fell to the extreme instantaneously after loading in volume-loading test and then they restored to the basic level until 60 minutes. However, both PCWP and CI of the negative patients reach the peak momentarily after loading. They returned to the basic level within 30 minutes. ③ coronary arteriography show: there are 41% of patient with three-vessel disease, 50% with two-vessel disease, 9% single vessel disease and left main narrowing 22. 7% in AEA. There are separately 76%, 24%, 0% and 36% in AD; and 26.1% , 43.4% , 21.7% , 43.4% in MA. ④ Constituent ratio of the AEA and MA were separately compared with AD, AEA/AD: P < 0.05(P = 0.031); MA/AD: P < 0.01 (P = 0.000313). Conclusions Most of patients with the above three types of unstable angina pectoris suffered from the basic heart dysfunction and cardiac reserve dysfunction which might participate in the occurrence and development of unstable angina pectoris. In angiography, there are the most three-vessel diseases in AD that are, therefore, the most severe UAP.
文摘Is there any difference between the abilities of differentiation and redifferentiation of tissues of wheat spike in the process of culture in vitro when it is at different developmental stages So far no reports about this have been found in the literature.
文摘The copper phthalocyanine (CuPc) as a dye and photoconductive material plays an important role in bionics. The different crystal forms of CuPc have distinct properties. In this article XPS results of α, β, γ, X-CuPc have been reported. The character of shake-up satellite peaks and valence band spectra in these CuPc compounds was also examined. It was found that the difference of X-CuPc with other crystal forms of CuPc is obvious. XPS study on different crystal forms of CuPc has not been reported previously.
文摘Cytochrome P-450 is widely distributed in different species of animals. As a terminal oxidase ot the microsomal monooxygenase system, cytochrome P-450 is the key element of the enzyme system. Because of its broad substrate specificity, it is involved in the biotransformation of many xenobiotic and endogenous compounds which are important in envitonmental protection, pharmacology and carcinogenicity. Microsomal P-450 is also a
文摘A prominent feature for modern biological research is to make full use of different apparatus and techniques, such as spectrometry, chromatography, mass spectrometry and so on, which are hitherto chiefly used in the fields of chemistry and physics. Gasliquid chromatography, as a new method for analytical chemistry, was invented by
文摘The general difference schemes for the first boundary problem of the fully nonlinear pseudo-hyperbolic systemsf(x, t, u,u_x,u_(xx),u_t,u_(tt),u_(xt),u_(xxt))=0are considered in the rectangular domain Q_T={0≤x≤1, 0≤t≤T}, where u(x,t)and f(x, t, u,p_1, p_2, r_1,r_2,q_1,q_2) are two m-dimensional vector functions with m≥1 for(x, t)∈Q_T and u,p_1,p_2,r_1,r_2,q_1,q_2∈R. The existence and the estimates of solutionsfor the finite difference system are established by the fixed point technique. The absolute andrelative stability and convergence of difference schemes are justified by means of a series of a prioriestimates. In the present study, the existence of unique smooth solution of the original problemis assumed. The similar results for nonlinear and quasilinear pseudo-hyperbolic systems are alsoobtained.
文摘Ⅰ. JNTRODUCTION Each ommatidium in the diptera compound eye contains 8 retinular cells. The first subsystem consists of 6 large retinular cells in periphery. Six different peripheral retinular cells from the 6 neighbouring ommatidia receive visual information and transmit it into a single neuro-ommatidium (cartridge) of the first optic ganglion. The other two retinular cells are located at the centre of the ommatidium from the second subsystem, which receives visual information and sends it directy to the second optic ganglion.
基金This work was supported by the National "863" Project of China. W. Gao's e-mail address is wdgao@mail.siom. ac.cn.
文摘The laser-induced damage behavior of narrow-band interference filters was investigated with a Nd:YAG laser at 1064 nm under single-pulse mode and free-running laser mode. The absorption measurement of such coatings has been performed by surface thermal lensing (STL) technique. The relationship between damage morphology and absorption under the two different laser modes was studied in detail. The explanation was given by the standing-wave distribution theory.
基金This work was supported by the National "863" Project of China (No. 2001AA122041) the National Natural Science Foundation of China (No. 60378011).
文摘Experimental research of simultaneous tunable chromatic dispersion (CD) and adaptive polarization mode dispersion (PMD) compensations in optical fiber communication system was reported. Two different nonlinearly chirped fiber Bragg gratings fabricated through the equivalent chirp technology were adopted in the experiment. One of the gratings was used as CD compensator, with a tunable dispersion range from 300 to 600 ps/nm. The other made of photosensitive polarization maintaining fiber was used as a tunable delay line of PMD compensator, which provided a varying amount of differential group delay (DGD) from 40 to 110 ps. Our experiment was operated at 10-Gb/s non-return-to-zero (NRZ) system and the results showed that the eye pattern recovery is excellent after both PMD and CD are compensated. Especially, the power penalty at a bit error rate (BER) of 10-9 is about 1 dB.
