We introduce the notion of the contraction integrated semigroups and give the Lumber-Phillips characterization of the generator, and also the charaterazied generators of isometric integrated semigroups. For their appl...We introduce the notion of the contraction integrated semigroups and give the Lumber-Phillips characterization of the generator, and also the charaterazied generators of isometric integrated semigroups. For their application, a necessary and sufficient condition for q-matrices Q generating a contraction integrated semigroup is given, and a necessary and sufficient condition for a transition function to be a Feller-Reuter-Riley transition function is also given in terms of its q-matrix.展开更多
In this paper we give the (L^p(ω~p),L^q(ω~q)) boundedness for a class of multilinear operators, which is similar to the higher-order commutator for the rough fractional integral.In our results the kernel function is...In this paper we give the (L^p(ω~p),L^q(ω~q)) boundedness for a class of multilinear operators, which is similar to the higher-order commutator for the rough fractional integral.In our results the kernel function is merely assumed on a size condition.展开更多
Background Human rickettsioses are worldwide zoonoses and it is not easy to differentiate them from other infectious diseases because of their atypical manifestation. In recent years the number of patients with fever ...Background Human rickettsioses are worldwide zoonoses and it is not easy to differentiate them from other infectious diseases because of their atypical manifestation. In recent years the number of patients with fever of unknown causes from Hongta District CDC, Yuxi city of Yunnan Province has been increasing significantly in the summer. Diagnosis of scrub typhus was made by local clinicians. In order to ascertain the disease, we undertook a laboratory investigation for such patients from August 18 to 26, 2005. Methods Active surveillance was conducted by Hongta District CDC Yuxi city of Yunnan Province from 2002 to 2004 and basic data were obtained from cases confirmed according to clinical definitions. Average incidences and town-level incidences were calculated during the study periods. Blood samples were analyzed by PCR and serological test. Based on the groEL gene sequences a paired general outer primers （Gro-1 and Gro-2） targeting typhus, spotted fever as well as scrub typhus and two paired inner primers （SF1, SR2 and TF1, TR2） for typhus together with spotted fever and scrub typhus, respectively, were designed to perform a multiplex-nested PCR. Serological assay was carried out by indirect immunofluorescence assay with 7 different rickettsial antigens, i.e., R.mossori, R.sibirica, R.conorii, O.tsutsugamushi, B.quintana, B.henselae and Coxilella burnetii phase Ⅱ Ag. Results Epidemiological surveillance showed that from 2002 to 2004, the average incidences of the scrub typhus or scrub typhus with murine typhus were 222.1/10^5, 204.3/10^5 and 109.6/10^5, respectively. Of 13 blood samples taken during acute stage of illness, 6 showed the amplified products for scrub typhus and the sequenced products showed 100%, 99%, 99%, 99%, 99%, 99% similarity to O.tsutsugamushi Karp but they shared the same deduced amino acid sequences, which indicated 100% identity with the heat shock protein of the O.tsutsugamushi Karp strain. Five yielded PCR products for murine typhus and their corresponding nucleotide sequenc展开更多
Multi-component seismic exploration technology, combining reflected PP- and converted PS-waves, is an effective tool for solving complicated oil and gas exploration problems. The improvement of converted wave resoluti...Multi-component seismic exploration technology, combining reflected PP- and converted PS-waves, is an effective tool for solving complicated oil and gas exploration problems. The improvement of converted wave resolution is one of the key problems. The main factor affecting converted wave resolution is the absorption of seismic waves in overlying strata. In order to remove the effect of absorption on converted waves, inverse Q filtering is used to improve the resolution. In this paper, we present a method to estimate the S-wave Q values from prestack converted wave gathers. Furthermore, we extend a stable and effective poststack inverse Q filtering method to prestack data which uses wave field continuation along the ray path to compensate for attenuation in prestack common shot PP- and PS-waves. The results of theoretical modeling prove that the method of estimating the S-wave Q values has high precision. The results from synthetic and real data prove that the stable inverse Q filtering method can effectively improve the resolution of prestack PP- and PS-waves.展开更多
Considering the main thermal forcing factor, which is critical for the development of synoptic systems, the concept of the moist ageostrophic vector Q is introduced. A formula of the moist ageostrophic Q and the ageos...Considering the main thermal forcing factor, which is critical for the development of synoptic systems, the concept of the moist ageostrophic vector Q is introduced. A formula of the moist ageostrophic Q and the ageostrophic diabatic equation, in which the divergence of the moist ageostrophic Q is taken as a single forcing term, is derived. Meanwhile, the moist ageostrophic Q is applied to diagnose a torrential rain process in North China. The results suggest that the moist ageostrophic Q can clearly reveal the system development during the torrential rain process; the corresponding relationship between the divergence of the moist ageostrophic Q and the rainfall area is better than that of the vertical velocity (w) and the divergence of the dry Q; the 6-h rainfall region can be correctly drawn according to the negative area of the divergence of the moist ageostrophic Q, and its precipitation is positively correlated to the magnitude of the divergence of the moist ageostrophic Q. The research provides valuable information for improving short-term weather forecast.展开更多
文摘We introduce the notion of the contraction integrated semigroups and give the Lumber-Phillips characterization of the generator, and also the charaterazied generators of isometric integrated semigroups. For their application, a necessary and sufficient condition for q-matrices Q generating a contraction integrated semigroup is given, and a necessary and sufficient condition for a transition function to be a Feller-Reuter-Riley transition function is also given in terms of its q-matrix.
基金This research is supported by the NNSF (Grant:19971010)National 973 Project of China.
文摘In this paper we give the (L^p(ω~p),L^q(ω~q)) boundedness for a class of multilinear operators, which is similar to the higher-order commutator for the rough fractional integral.In our results the kernel function is merely assumed on a size condition.
基金the grant from the National Key Technologies R&D Program(No.2003BA712A02)
文摘Background Human rickettsioses are worldwide zoonoses and it is not easy to differentiate them from other infectious diseases because of their atypical manifestation. In recent years the number of patients with fever of unknown causes from Hongta District CDC, Yuxi city of Yunnan Province has been increasing significantly in the summer. Diagnosis of scrub typhus was made by local clinicians. In order to ascertain the disease, we undertook a laboratory investigation for such patients from August 18 to 26, 2005. Methods Active surveillance was conducted by Hongta District CDC Yuxi city of Yunnan Province from 2002 to 2004 and basic data were obtained from cases confirmed according to clinical definitions. Average incidences and town-level incidences were calculated during the study periods. Blood samples were analyzed by PCR and serological test. Based on the groEL gene sequences a paired general outer primers （Gro-1 and Gro-2） targeting typhus, spotted fever as well as scrub typhus and two paired inner primers （SF1, SR2 and TF1, TR2） for typhus together with spotted fever and scrub typhus, respectively, were designed to perform a multiplex-nested PCR. Serological assay was carried out by indirect immunofluorescence assay with 7 different rickettsial antigens, i.e., R.mossori, R.sibirica, R.conorii, O.tsutsugamushi, B.quintana, B.henselae and Coxilella burnetii phase Ⅱ Ag. Results Epidemiological surveillance showed that from 2002 to 2004, the average incidences of the scrub typhus or scrub typhus with murine typhus were 222.1/10^5, 204.3/10^5 and 109.6/10^5, respectively. Of 13 blood samples taken during acute stage of illness, 6 showed the amplified products for scrub typhus and the sequenced products showed 100%, 99%, 99%, 99%, 99%, 99% similarity to O.tsutsugamushi Karp but they shared the same deduced amino acid sequences, which indicated 100% identity with the heat shock protein of the O.tsutsugamushi Karp strain. Five yielded PCR products for murine typhus and their corresponding nucleotide sequenc
基金supported by the 863 Program(Grant No.2007AA06Z218)
文摘Multi-component seismic exploration technology, combining reflected PP- and converted PS-waves, is an effective tool for solving complicated oil and gas exploration problems. The improvement of converted wave resolution is one of the key problems. The main factor affecting converted wave resolution is the absorption of seismic waves in overlying strata. In order to remove the effect of absorption on converted waves, inverse Q filtering is used to improve the resolution. In this paper, we present a method to estimate the S-wave Q values from prestack converted wave gathers. Furthermore, we extend a stable and effective poststack inverse Q filtering method to prestack data which uses wave field continuation along the ray path to compensate for attenuation in prestack common shot PP- and PS-waves. The results of theoretical modeling prove that the method of estimating the S-wave Q values has high precision. The results from synthetic and real data prove that the stable inverse Q filtering method can effectively improve the resolution of prestack PP- and PS-waves.
基金supported by the National Natural Science Foundation of China under Grant Nos.40205008 and 401350201.
文摘Considering the main thermal forcing factor, which is critical for the development of synoptic systems, the concept of the moist ageostrophic vector Q is introduced. A formula of the moist ageostrophic Q and the ageostrophic diabatic equation, in which the divergence of the moist ageostrophic Q is taken as a single forcing term, is derived. Meanwhile, the moist ageostrophic Q is applied to diagnose a torrential rain process in North China. The results suggest that the moist ageostrophic Q can clearly reveal the system development during the torrential rain process; the corresponding relationship between the divergence of the moist ageostrophic Q and the rainfall area is better than that of the vertical velocity (w) and the divergence of the dry Q; the 6-h rainfall region can be correctly drawn according to the negative area of the divergence of the moist ageostrophic Q, and its precipitation is positively correlated to the magnitude of the divergence of the moist ageostrophic Q. The research provides valuable information for improving short-term weather forecast.
