The intensified monsoon increases summer rainfall and creates wet conditions in the Asian summer monsoon region during the early Holocene. Along with millennial-scale changes of the monsoon intensity, it is still uncl...The intensified monsoon increases summer rainfall and creates wet conditions in the Asian summer monsoon region during the early Holocene. Along with millennial-scale changes of the monsoon intensity, it is still unclear whether the boundary of the monsoon region changes according to monsoon variability. Investigations into the early Holocene environment in monsoon marginal zones are crucial for understanding the monsoon boundary changes. Zhuye Lake is located at the northwest edge of the Asian summer monsoon, the northern Qilian Mountains, which are less affected by modern summer monsoon water vapor. Previous studies have reached different conclusions regarding the early Holocene climatic and environmental changes based on different dating methods（^14C and OSL（optically stimulated luminescence）） and materials（shells, carbonate, pollen concentrates and bulk organic carbon）. In this study, we synthesized 102 ^14C dates and 35 OSL dates from ten Holocene sedimentary sections and ten paleo-shorelines in the lake basin. A comparison between ages from different dating methods and materials generally shows that carbon reservoir effects are relatively slight in Zhuye Lake while the disordered chronologies are mainly related to the erosion processes and reworking effects. In addition, proxy data, including lithology, pollen, total organic carbon and carbonate, were collected from different sites of Zhuye Lake. According to the new synthesis, the early Holocene environment was relatively humid, associated with high runoff and lake water levels. The result indicates that the monsoon boundary moves to the north during the period of the intensified monsoon. A typical arid-area lake was formed during the mid-Holocene when carbonate accumulation and high organic matter contents were the main features of this period. The lake retreated strongly during the late Holocene, showing a drought trend. Overall, the lake evolution is generally consistent with the Holocene Asian summer monsoon change, showing the monsoon influence to monsoon marginal zones.展开更多
AIM: To assess the safety and feasibility of peroral esophageal myotomy(POEM) in patients with achalasia.METHODS: From January 2012 to March 2014, 50 patients(28 men, 22 women; mean age: 42.8 years, range: 14-70 years...AIM: To assess the safety and feasibility of peroral esophageal myotomy(POEM) in patients with achalasia.METHODS: From January 2012 to March 2014, 50 patients(28 men, 22 women; mean age: 42.8 years, range: 14-70 years) underwent POEM. Pre- and postoperative symptoms were quantified using the Eckardt scoring system. Barium swallow and esophagogastroscopy were performed before and after POEM, respectively. Esophageal motility was evaluated in all patients, both preoperatively and one month after POEM treatment, using a high-resolution manometry system. Manometry data, Eckardt scores, lower esophageal sphincter pressure and barium swallow results were used to evaluate the effect of the procedure.RESULTS: POEM was successfully completed for all patients. The mean procedure time was 55.4 ± 17.3 min and the mean total length of myotomy of the circular esophagus was 10.5 ± 2.6 cm. No specific complications occurred, with the exception of two patients that developed as ymptomatic pneumomediastinum and subcutaneous emphysema. Clinical improvement in symptoms was achieved in all patients. Approximately 77.5% of patients experienced weight gain 6 mo after POEM, with an average of 4.78 kg(range: 2-15 kg). The lower esophageal sphincter resting pressure, four second integrated relaxation pressure and Eckardt scores were all significantly reduced after POEM(Ps < 0.05). A small segment of proximal esophageal peristalsis appeared postoperatively in two patients, but without normal esophageal peristalsis. The average diameter of the esophageal lumen decreased significantly from 4.39 to 3.09 cm(P < 0.01). CONCLUSION: POEM can relieve achalasia symptoms, improve gastroesophageal junction relaxation and restore esophageal body motility function, but not normal esophageal peristalsis.展开更多
The polymerization of amphiphilic self assemblies is a promising method to synthesize nano structured materials with novel properties. These materials have many attractive features for their application in biomedica...The polymerization of amphiphilic self assemblies is a promising method to synthesize nano structured materials with novel properties. These materials have many attractive features for their application in biomedical area and materials science, such as catalysis, separation, surface modification, and therapeutics areas. A general review on the polymerization of lipids and surfactant self assemblies to amphiphilic self assemblies is given in this paper with 49 references. The polymerization and the subsequently resulted structure of lipids in different morphologies are summarized. The polymerization of polymerizable surfactants(surfmers) in emulsion and liquid crystalline phases are also discussed. The potential application of new nano porous materials is briefly described.展开更多
The measuring of VFT phase voltage in three-phase enclosed GIS is more complex and difficult than in single-phase ones. There are 3 capacitive sensors in the measuring system, the outputs of which are with a linear re...The measuring of VFT phase voltage in three-phase enclosed GIS is more complex and difficult than in single-phase ones. There are 3 capacitive sensors in the measuring system, the outputs of which are with a linear relation to the three phase voltages. This linear relation is presented with a factorial matrix. Because each capacitive sensor is coupled with the electric field of three phases (A, B, and C), the electric coupling coefficients are introduced. In order to determine the matrix of electric coupling coefficients, the numerical calculation method can be used. From the discussion on two types of three-phase enclosed GIS bus, i.e. standard arrangement and biased arrangement, the dominant electric coupling coefficients are named, which can be simply and approximately calculated by an analytic expression. Finally, as an example, the waveforms of VFT phase voltage generated on a three-phase enclosed GIS bus model are displayed. When a capacitive sensor is located at the ’shortest point’ of phase A (or B, or C), the VFT phase voltage V A (or V B, or V C) can almost be measured by that capacitive sensor alone.展开更多
A New View on Sino-U. S. Relations Sino-U. S. relations seem to have emerged into a more positive light in recent years. China and the United States have sustained a strong relationship since 9/11, for the simple reas...A New View on Sino-U. S. Relations Sino-U. S. relations seem to have emerged into a more positive light in recent years. China and the United States have sustained a strong relationship since 9/11, for the simple reason that international relations at present require展开更多
This paper introduces the design of an IC, which is capable of cross-converting between various DTV(digital television) standards, up to the HDTV (high definition television) resolution. A multi-phase FIR-based filter...This paper introduces the design of an IC, which is capable of cross-converting between various DTV(digital television) standards, up to the HDTV (high definition television) resolution. A multi-phase FIR-based filtering algorithm is developed to perform the video scaling task. A dedicated fast SDRAM interface is designed, providing an economical high-density storage for frame buffer. Film material pre-processing and frame/field rate up-conversion are implemented in the memory control block. All the programmable parameters, such as the filter properties, can be set dynamically at run-time through an I2C interface, making the IC a very flexible system. This design has been verified through an FPGA emulation system.展开更多
Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the u...Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the use of different methods to cross link block copolymer self assemblies in the presence of a selective solvent and to stabilize the structures is reviewed. In addition, the cross linking reaction kinetics of block copolymer amphiphilic self assemblies is briefly discussed.展开更多
Two new steroidal bitter principles, taccolanolide O, P have been isolated from Tacca subflaellata and their structures were established by spectroscopic methods.
基金supported by the National Natural Science Foundation of China (41371009)the Fundamental Research Fund for the Central Universities (lzujbky-2013-127)
文摘The intensified monsoon increases summer rainfall and creates wet conditions in the Asian summer monsoon region during the early Holocene. Along with millennial-scale changes of the monsoon intensity, it is still unclear whether the boundary of the monsoon region changes according to monsoon variability. Investigations into the early Holocene environment in monsoon marginal zones are crucial for understanding the monsoon boundary changes. Zhuye Lake is located at the northwest edge of the Asian summer monsoon, the northern Qilian Mountains, which are less affected by modern summer monsoon water vapor. Previous studies have reached different conclusions regarding the early Holocene climatic and environmental changes based on different dating methods（^14C and OSL（optically stimulated luminescence）） and materials（shells, carbonate, pollen concentrates and bulk organic carbon）. In this study, we synthesized 102 ^14C dates and 35 OSL dates from ten Holocene sedimentary sections and ten paleo-shorelines in the lake basin. A comparison between ages from different dating methods and materials generally shows that carbon reservoir effects are relatively slight in Zhuye Lake while the disordered chronologies are mainly related to the erosion processes and reworking effects. In addition, proxy data, including lithology, pollen, total organic carbon and carbonate, were collected from different sites of Zhuye Lake. According to the new synthesis, the early Holocene environment was relatively humid, associated with high runoff and lake water levels. The result indicates that the monsoon boundary moves to the north during the period of the intensified monsoon. A typical arid-area lake was formed during the mid-Holocene when carbonate accumulation and high organic matter contents were the main features of this period. The lake retreated strongly during the late Holocene, showing a drought trend. Overall, the lake evolution is generally consistent with the Holocene Asian summer monsoon change, showing the monsoon influence to monsoon marginal zones.
文摘AIM: To assess the safety and feasibility of peroral esophageal myotomy(POEM) in patients with achalasia.METHODS: From January 2012 to March 2014, 50 patients(28 men, 22 women; mean age: 42.8 years, range: 14-70 years) underwent POEM. Pre- and postoperative symptoms were quantified using the Eckardt scoring system. Barium swallow and esophagogastroscopy were performed before and after POEM, respectively. Esophageal motility was evaluated in all patients, both preoperatively and one month after POEM treatment, using a high-resolution manometry system. Manometry data, Eckardt scores, lower esophageal sphincter pressure and barium swallow results were used to evaluate the effect of the procedure.RESULTS: POEM was successfully completed for all patients. The mean procedure time was 55.4 ± 17.3 min and the mean total length of myotomy of the circular esophagus was 10.5 ± 2.6 cm. No specific complications occurred, with the exception of two patients that developed as ymptomatic pneumomediastinum and subcutaneous emphysema. Clinical improvement in symptoms was achieved in all patients. Approximately 77.5% of patients experienced weight gain 6 mo after POEM, with an average of 4.78 kg(range: 2-15 kg). The lower esophageal sphincter resting pressure, four second integrated relaxation pressure and Eckardt scores were all significantly reduced after POEM(Ps < 0.05). A small segment of proximal esophageal peristalsis appeared postoperatively in two patients, but without normal esophageal peristalsis. The average diameter of the esophageal lumen decreased significantly from 4.39 to 3.09 cm(P < 0.01). CONCLUSION: POEM can relieve achalasia symptoms, improve gastroesophageal junction relaxation and restore esophageal body motility function, but not normal esophageal peristalsis.
基金Supported by National Natural Science Foundation(No.0 5 1730 0 3) Beijing Science and Technology New Star Program(No.H0 10 4 10 0 10 112 ) and Im portant Natural Science Foundation of Beijing(No.2 0 310 0 1) .
文摘The polymerization of amphiphilic self assemblies is a promising method to synthesize nano structured materials with novel properties. These materials have many attractive features for their application in biomedical area and materials science, such as catalysis, separation, surface modification, and therapeutics areas. A general review on the polymerization of lipids and surfactant self assemblies to amphiphilic self assemblies is given in this paper with 49 references. The polymerization and the subsequently resulted structure of lipids in different morphologies are summarized. The polymerization of polymerizable surfactants(surfmers) in emulsion and liquid crystalline phases are also discussed. The potential application of new nano porous materials is briefly described.
文摘The measuring of VFT phase voltage in three-phase enclosed GIS is more complex and difficult than in single-phase ones. There are 3 capacitive sensors in the measuring system, the outputs of which are with a linear relation to the three phase voltages. This linear relation is presented with a factorial matrix. Because each capacitive sensor is coupled with the electric field of three phases (A, B, and C), the electric coupling coefficients are introduced. In order to determine the matrix of electric coupling coefficients, the numerical calculation method can be used. From the discussion on two types of three-phase enclosed GIS bus, i.e. standard arrangement and biased arrangement, the dominant electric coupling coefficients are named, which can be simply and approximately calculated by an analytic expression. Finally, as an example, the waveforms of VFT phase voltage generated on a three-phase enclosed GIS bus model are displayed. When a capacitive sensor is located at the ’shortest point’ of phase A (or B, or C), the VFT phase voltage V A (or V B, or V C) can almost be measured by that capacitive sensor alone.
文摘A New View on Sino-U. S. Relations Sino-U. S. relations seem to have emerged into a more positive light in recent years. China and the United States have sustained a strong relationship since 9/11, for the simple reason that international relations at present require
文摘This paper introduces the design of an IC, which is capable of cross-converting between various DTV(digital television) standards, up to the HDTV (high definition television) resolution. A multi-phase FIR-based filtering algorithm is developed to perform the video scaling task. A dedicated fast SDRAM interface is designed, providing an economical high-density storage for frame buffer. Film material pre-processing and frame/field rate up-conversion are implemented in the memory control block. All the programmable parameters, such as the filter properties, can be set dynamically at run-time through an I2C interface, making the IC a very flexible system. This design has been verified through an FPGA emulation system.
基金Supported by National Natural Science Foundation of China(No.0 5 1730 0 3) Beijing Science and Technology New StarProgram(No.H0 10 4 10 0 10 112 ) and Important Natural Science Foundation of Beijing(No.2 0 310 0 1) .
文摘Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the use of different methods to cross link block copolymer self assemblies in the presence of a selective solvent and to stabilize the structures is reviewed. In addition, the cross linking reaction kinetics of block copolymer amphiphilic self assemblies is briefly discussed.
文摘Two new steroidal bitter principles, taccolanolide O, P have been isolated from Tacca subflaellata and their structures were established by spectroscopic methods.
