[Objectives]To observe the effect of Jianpi Xiaowei Decoction on gastric function and quality of life in elderly patients with chronic atrophic gastritis(CAG)of liver-stomach heat stagnation type.[Methods]Seventy-two ...[Objectives]To observe the effect of Jianpi Xiaowei Decoction on gastric function and quality of life in elderly patients with chronic atrophic gastritis(CAG)of liver-stomach heat stagnation type.[Methods]Seventy-two elderly patients with CAG of liver-stomach stagnation-heat type were randomly divided into study group and control group.The two groups were treated with Jianpi Xiaowei Decoction and Rabeprazole Enteric-coated Tablets respectively.The curative effect of TCM syndromes,serum pepsinogen I and II(PG-I and PG-II),gastrin-17(G-17)and quality of life(SF-36 table)scores of gastric function indicators before and after treatment were observed.[Results]After treatment,the total effective rate of the study group was 97.22%(35/36),which was significantly higher than that of the control group 77.78%(28/36)(P<0.05).Before treatment,there was no significant difference in the levels of gastric function indicators between the two groups(P>0.05).After treatment,the indicators of the study group were significantly lower than those of the control group(t=12.239,6.010,5.928,10.420,P<0.05).Before treatment,there was no significant difference in SF-36 scores between the two groups(P>0.05).After treatment,the SF-36 scores in the study group were significantly lower than those in the control group(t=3.520,10.335,11.300,9.693,P<0.05).[Conclusions]Jianpi Xiaowei Decoction can achieve significant curative effect in the treatment of CAG with liver and stomach stagnation heat type in the elderly,and can significantly improve the key gastrointestinal hormone levels and quality of life of elderly patients.It is worthy of promotion in the same clinical cases.展开更多
Gastroesophageal reflux disease (GERD) is a high-incidence digestive system disease. Western medicine mainly uses drugs such as proton pump inhibitors to inhibit gastric acid secretion, but some patients are accompani...Gastroesophageal reflux disease (GERD) is a high-incidence digestive system disease. Western medicine mainly uses drugs such as proton pump inhibitors to inhibit gastric acid secretion, but some patients are accompanied by symptoms such as non-acid reflux and gas reflux, which cannot effectively treat the disease. It is necessary to actively explore other treatment schemes. Traditional Chinese medicine (TCM) has a long history of research on gastroesophageal reflux disease, which emphasizes the treatment based on syndrome differentiation as a whole. Through the treatment of various and multi-component TCM prescriptions, the patient’s body condition can be adjusted, and the treatment effect on gastroesophageal reflux disease is reliable, which has obvious therapeutic advantages. To further clarify the treatment of gastroesophageal reflux disease, this study reviewed and analyzed the research progress of the treatment of liver disease with modified prescriptions, and the report is as follows.展开更多
In this article,we derive the Lp-boundedness of the variation operators associated with the heat semigroup which is generated by the high order Schrodinger type operator(—Δ)^2+V%2 in R%n(n≥5)with V being a nonnegat...In this article,we derive the Lp-boundedness of the variation operators associated with the heat semigroup which is generated by the high order Schrodinger type operator(—Δ)^2+V%2 in R%n(n≥5)with V being a nonnegative potential satisfying the reverse Holder inequality.Furt her more,we prove the boundedness of the variation operators on associated Morrey spaces.In the proof of the main results,we always make use of the variation inequalities associated with the hea t semigroup genera ted by the biharmonic operator(-Δ)2.展开更多
The electromotive force (EMF) changes in type K heavy gauge sheathed thermocouple cables was investigated. To cope with this discrepancy owing to EMF steep reduction and understand the difference between type K heavy ...The electromotive force (EMF) changes in type K heavy gauge sheathed thermocouple cables was investigated. To cope with this discrepancy owing to EMF steep reduction and understand the difference between type K heavy gauge sheathed thermocouple cables and small ones, the affects of EMF from sheath pipe, drawing times, annealing temperature, annealing time and annealing way were mainly studied and appropriately analyzed. The results show the change in the thermal EMF is related with the residual stress and crystal defects, which are imparted by cold work during manufacture. The affects of cold work can be removed by annealing. Finally, a feasible way of fabricating heavy gauge sheathed thermocouples was suggested according to practical situation.展开更多
Objective:To observe the clinical efficacy of Chuanxiong Hualiu Mixture in the treatment of blood stasis and phlegm stagnation type of ovarian cyst and the effects on physical and chemical indicators.Methods: A total ...Objective:To observe the clinical efficacy of Chuanxiong Hualiu Mixture in the treatment of blood stasis and phlegm stagnation type of ovarian cyst and the effects on physical and chemical indicators.Methods: A total of 80 patients with blood stasis and phlegm stagnation type of ovarian cyst were randomly divided into two groups, research group (n=40) took Chuanxiong Hualiu Mixture, control group (n=40) took Guizhi Fuling Capsule, 3 months was a course of treatment, and the curative effect was compared between two groups.Results:(1) The overall response rate of Chuanxiong Hualiu mixture group after 3 months of treatment was 82.5%, that of Guizhi Fuling Capsule group was 62.5%, the overall response rate of Chuanxiong Hualiu mixture group was higher than that of control group, and the difference was statistically significant;(2) before and after treatment, sex hormone and hemorheology index E2 of both groups decreased significantly, whole blood viscosity, whole blood reduced viscosity and plasma viscosity decreased significantly, the results were statistically significant, but there was no difference between two groups;(3) rank sum test of TCM symptom efficacy between two groups before and after treatment showed that the overall response rate of Chuanxiong Hualiu mixture group was 95%, the overall response rate of Guizhi Fuling Capsule group was 85%, the overall response rate of research group was better than that of control group, and the difference was statistically significant.Conclusion:Chuanxiong Hualiu mixture has good curative effect for the treatment of ovarian cyst, it can effectively improve the patients' blood stasis and phlegm stagnation constitution, and its mechanism of action is associated with lowering estrogen levels and improving hemorrheology.展开更多
Creep lives of high Cr ferritic heat resisting steel weldments decrease due to Type Ⅳ fracture, which occurs as a result of formation and growth of creep voids and cracks on grain boundaries in fine-grained heat affe...Creep lives of high Cr ferritic heat resisting steel weldments decrease due to Type Ⅳ fracture, which occurs as a result of formation and growth of creep voids and cracks on grain boundaries in fine-grained heat affected zone (HAZ). Because boron is considered to suppress the coarsening of grain boundary precipitates and growth of creep voids, we have investigated the effect of boron addition on the creep properties of 9Cr steel weldments. Four kinds of 9Cr3WSCoVNb steels with boron content varying from 4.7×10-5 to 1.8×10-4 and with nitrogen as low as 2.0×10-5 were prepared. The steel plates were welded by gas tungsten arc welding and crept at 923K. It was found that the microstructures of HAZ were quite different from those of conventional high Cr steels such as P91 and P92, namely the fine-grained HAZ did not exist in the present steel weldments. Boron addition also has the effect to suppress coarsening of grain boundary carbides in HAZ during creep. As a result of these phenomena, the welded joints of present steels showed no Type Ⅳ fractures and much better creep lives than those of conventional steels.展开更多
In the nanoscale beam,two effects become domineering.One is the non-Fourier effect in heat conduction and the other is the coupling effect between temperature and strain rate.In the present study,a generalized solutio...In the nanoscale beam,two effects become domineering.One is the non-Fourier effect in heat conduction and the other is the coupling effect between temperature and strain rate.In the present study,a generalized solution for the generalized thermoelastic vibration of gold nano-beam resonator induced by ramp type heating is developed.The solution takes into account the above two effects.State-space and Laplace transform methods are used to determine the lateral vibration,the temperature,the displacement,the stress and the strain energy of the beam.The effects of the relaxation time and the ramping time parameters have been studied.展开更多
A mild, cascade type methodology was developed for the synthesis of polyphenolic ethers by the palladium-catalyzed cross coupling of phenols and halo compounds under microwave heating. In most cases, reactions run in ...A mild, cascade type methodology was developed for the synthesis of polyphenolic ethers by the palladium-catalyzed cross coupling of phenols and halo compounds under microwave heating. In most cases, reactions run in neat conditions and in some cases, IPA/water mixture, and 1,4-dioxane were employed as solvents to furnish the products. By applying this new method, we were able to synthesize and purify a good number of polyether compounds with complete spectral data.展开更多
Objective:To compare the efficacy of traditional Chinese medicine (TCM),western medicine and integrative medicine in treating type 2 diabetes mellitus (T2DM) in a rat model.Methods:The T2DM rat model was established w...Objective:To compare the efficacy of traditional Chinese medicine (TCM),western medicine and integrative medicine in treating type 2 diabetes mellitus (T2DM) in a rat model.Methods:The T2DM rat model was established with a high-fat diet (HFD) for 35 days and a single injection of streptozotocin (STZ,30 mg/kg).The T2DM-induced rats were divided into three groups,and treated with Yiqi Yangyin Huatan (YQYYHT) granules (3.84 g/kg per day),pioglitazone (1.35 mg/kg per day) or YQYYHT granules + pioglitazone (3.84 g/kg per day+1.35 mg/kg per day) respectively for 14 days.Clinical features and behavioral changes,as well as T2DM indicators,were recorded to evaluate therapeutics effects in each treatment group.Results:The T2DM rat model expressed insulin resistance (IR),with features similar to qi-yin deficiency and phlegm stasis syndrome,including decreased cyclic adenosine monophosphate/cyclic guanosine monophosphate (cAMP/cGMP) ratio,decreased levels of Na+-K+-ATPase,superoxide dismutase (SOD) and high density lipoprotein-cholesterol (HDL-C),and increased levels of serum triglyceride (TG),total cholesterol (TC) and low density lipoprotein (LDL-C).All three treatment groups showed significant decreases in fasting blood glucose (FBG) and fasting insulin (Fins),and improvement of TCM syndrome to different degrees.Importantly,YQYYHT improved the most of the indicators of T2DM,followed by integrative medicine and pioglitazone alone.Conclusion:Compared with western medicine or integrative medicine,prescription of TCM based on syndrome differentiation may offer more advantages in the prevention and treatment of T2DM.展开更多
Separate type heat pipe heat exchangers are often used for large-scale heat exchanging. The arrangement of such a heat exchanger conveniently allows heat input to and output from the heat exchanger at remote locations...Separate type heat pipe heat exchangers are often used for large-scale heat exchanging. The arrangement of such a heat exchanger conveniently allows heat input to and output from the heat exchanger at remote locations. The traditional method of designing an ordinary HPHE (heat pipe heat exchanger) is commonly applied in the separate type exchanger design, but the calculations have to be carried out separately, which makes it very complicated. In this work, the ε-NTU (effectiveness-Number of Transfer Units) method was applied for optimization analysis of single- or multi-level separate type heat pipe heat exchangers. An optimizing formula for single-level separate type heat pipe heat exchangers was obtained. The optimizing principles of effec- tiveness-NTU and heat transfer rate by the equal distribution method for multi-level separate type heat pipe heat exchanger are presented. The design of separate type heat pipe heat exchangers by the optimizing method is more convenient and faster than by the traditional method.展开更多
The refrigerant mixture of ethanol aqueous was applied to the parallel type pulsating heat pipe (PHP). The operation characteristics of the PHP were analyzed by means of experiment and nonlinear chaotic theory. Moreov...The refrigerant mixture of ethanol aqueous was applied to the parallel type pulsating heat pipe (PHP). The operation characteristics of the PHP were analyzed by means of experiment and nonlinear chaotic theory. Moreover, the relationship between the running state and attractor was described. The results indicate that starting power, stable running power and dry burning transition power are about 64.08 W, 148.68 W and 234.0 W respectively. The cycle and amplitude of PHP initially decrease and then increase with the increasing power. However, the data are welldistributed in a certain range. The running state is in agreement with the attractors, and the changing process for attractors is as follows: the attractors first disperse in the whole phase space, then present mass status, and finally show band distribution.展开更多
A modelling study is performed to compare the plasma flow and heat transfer characteristics of low-power arc-heated thrusters (arcjets) for three different propellants: hydrogen, nitrogen and argon. The all-speed S...A modelling study is performed to compare the plasma flow and heat transfer characteristics of low-power arc-heated thrusters (arcjets) for three different propellants: hydrogen, nitrogen and argon. The all-speed SIMPLE algorithm is employed to solve the governing equations, which take into account the effects of compressibility, Lorentz force and Joule heating, as well as the temperature- and pressure-dependence of the gas properties. The temperature, velocity and Mach number distributions calculated within the thruster nozzle obtained with different propellant gases are compared for the same thruster structure, dimensions, inlet-gas stagnant pressure and arc currents. The temperature distributions in the solid region of the anode-nozzle wall are also given. It is found that the flow and energy conversion processes in the thruster nozzle show many similar features for all three propellants. For example, the propellant is heated mainly in the near-cathode and constrictor region, with the highest plasma temperature appearing near the cathode tip; the flow transition from the subsonic to supersonic regime occurs within the constrictor region; the highest axial velocity appears inside the nozzle; and most of the input propellant flows towards the thruster exit through the cooler gas region near the anode-nozzle wall. However, since the properties of hydrogen, nitrogen and argon, especially their molecular weights, specific enthMpies and thermal conductivities, are different, there are appreciable differences in arcjet performance. For example, compared to the other two propellants, the hydrogen arcjet thruster shows a higher plasma temperature in the arc region, and higher axial velocity but lower temperature at the thruster exit. Correspondingly, the hydrogen arcjet thruster has the highest specific impulse and arc voltage for the same inlet stagnant pressure and arc current. The predictions of the modelling are compared favourably with available experimental results.展开更多
This article deals with a nonlocal heat system subject to null Dirichlet bound- ary conditions, where the coupling nonlocal sources consist of mixed type asymmetric non- linearities. We at first give the criterion for...This article deals with a nonlocal heat system subject to null Dirichlet bound- ary conditions, where the coupling nonlocal sources consist of mixed type asymmetric non- linearities. We at first give the criterion for simultaneous blow-up of solutions, and then establish the uniform blow-up profiles of solutions near the blow-up time. It is observed that not only the simultaneous blow-up rates of the two components u and v are asymmet- ric, but also the blow-up rates of the same component u (or v) may be in different levels under different dominations.展开更多
This article obtains an explicit expression of the heat kernels on H-type groups and then follow the estimate of heat kernels to deduce the Hardy's uncertainty principle on the nilpotent Lie groups.
As an important component of tokamaks,the divertor is mainly responsible for extracting heat and helium ash,and the targets of the divertor need to withstand high heat flux of 10 MW m-2 for steady-state operation.In t...As an important component of tokamaks,the divertor is mainly responsible for extracting heat and helium ash,and the targets of the divertor need to withstand high heat flux of 10 MW m-2 for steady-state operation.In this study,we proposed a new strategy,using microchannel cooling technology to remove high heat load on the targets of the divertor.The results demonstrated that the microchannel-based W/Cu flat-type mock-up successfully withstood the thermal fatigue test of 1000 cycles at 10 MW m^(-2)with cooling water of 26 l min^(-1),30°C(inlet),0.8 MPa(inlet),15 s power on and 15 s dwell time;the maximum temperature on the heat-loaded surface(W surface)of the mock-up was 493°C,which is much lower than the recrystallization temperature of W(1200°C).Moreover,no occurrence of macrocrack and‘hot spot’at the W surface,as well as no detachment of W/Cu tiles were observed during the thermal fatigue testing.These results indicate that microchannel cooling technology is an efflcient method for removing the heat load of the divertor at a low flow rate.The present study offers a promising solution to replace the monoblock design for the EAST divertor.展开更多
正确认识不同区域能量和水分循环特征是研究局地地气相互作用及准确预测区域天气,气候变化的关键.为了研究属于干旱/半干旱气候的青藏高原(TP)和湿润/半湿润气候的长江流域(YRR)之间地表能量和水分交换的异同,本文对比分析了两个区域8...正确认识不同区域能量和水分循环特征是研究局地地气相互作用及准确预测区域天气,气候变化的关键.为了研究属于干旱/半干旱气候的青藏高原(TP)和湿润/半湿润气候的长江流域(YRR)之间地表能量和水分交换的异同,本文对比分析了两个区域8个不同地表类型(包括高山荒漠,高山草地,(平原)城市和(平原)草地等)观测站点的地表辐射和能量通量数据.结果显示:(1)TP由于高原大气层稀薄且空气洁净,年平均入射短波辐射为251.3W m^(-2),是YRR的1.7倍.加之高原地表反照率高导致反射辐射(59.6 W m^(-2))是YRR的2.87倍.入射及出射的长波辐射为231.5和338.0 W m^(-2),分别为YRR的0.64和0.83.而两个区域的净辐射差异不大;(2)草地站更多的潜热释放使得地表总加热效率高于城市和高山荒漠,TP和YRR的草地站的年平均潜热分别为35.0和38.8 W m^(-2),而植被稀疏且土壤干燥的高山荒漠地区感热最大,年平均感热为42.1 W m^(-2);其次是城市下垫面,其年平均感热为37.7 W m^(-2).研究结果揭示了不同气候背景下典型下垫面地气相互作用特征,为地气相互作用过程深入分析奠定了基础.展开更多
The non-Fourier effect in heat conduction and the coupling effect between temperature and strain rate, became the most significant effects in the nano-scale beam. In the present study, a generalized solution for the g...The non-Fourier effect in heat conduction and the coupling effect between temperature and strain rate, became the most significant effects in the nano-scale beam. In the present study, a generalized solution for the generalized thermoelastic vibration of a bounded nano-beam resonator induced by ramp type of heating is developed and the solutions take into account the above two effects. The Laplace transforms and direct method are used to determine the lateral vibration, the temperature, the displacement, the stress and the energy of the beam. The effects of the relaxation time and the ramping time parameters have been studied with some comparisons.展开更多
Based on thermal value theory, the aim of this paper is to deduce the theoretical formulas for evaluating the energy effective utilization degree in technological pyrological processes exemplified by metallurgical hea...Based on thermal value theory, the aim of this paper is to deduce the theoretical formulas for evaluating the energy effective utilization degree in technological pyrological processes exemplified by metallurgical heating furnaces. Heat transfer models for continuous heating furnaces, batch-type heating furnaces, and regenerative heating furnaces are established, respectively. By analyzing the movement path of injected infinitesimal heat attached on steel or gas, thermal value equations of continuous, batch-type, and regenerative heating furnaces are derived. Then the influences of such factors as hot charging, gas preheating and intake time of heat on energy effective utilization degree are discussed by thermal value equations. The results show that thermal value rises with hot charging and air preheating for continuous heating furnaces, with shorter intake time when heat is attached on steel or longer intake time when heat is attached on gas for batch-type heating furnaces and that with more heat supply at early heating stage or less at late stage for regenerative heating furnaces.展开更多
基金Supported by National Natural Science Foundation of China (82374546)The Ninth Batch of Suzhou Gusu Health Key Talents Project (GSWS2023015).
文摘[Objectives]To observe the effect of Jianpi Xiaowei Decoction on gastric function and quality of life in elderly patients with chronic atrophic gastritis(CAG)of liver-stomach heat stagnation type.[Methods]Seventy-two elderly patients with CAG of liver-stomach stagnation-heat type were randomly divided into study group and control group.The two groups were treated with Jianpi Xiaowei Decoction and Rabeprazole Enteric-coated Tablets respectively.The curative effect of TCM syndromes,serum pepsinogen I and II(PG-I and PG-II),gastrin-17(G-17)and quality of life(SF-36 table)scores of gastric function indicators before and after treatment were observed.[Results]After treatment,the total effective rate of the study group was 97.22%(35/36),which was significantly higher than that of the control group 77.78%(28/36)(P<0.05).Before treatment,there was no significant difference in the levels of gastric function indicators between the two groups(P>0.05).After treatment,the indicators of the study group were significantly lower than those of the control group(t=12.239,6.010,5.928,10.420,P<0.05).Before treatment,there was no significant difference in SF-36 scores between the two groups(P>0.05).After treatment,the SF-36 scores in the study group were significantly lower than those in the control group(t=3.520,10.335,11.300,9.693,P<0.05).[Conclusions]Jianpi Xiaowei Decoction can achieve significant curative effect in the treatment of CAG with liver and stomach stagnation heat type in the elderly,and can significantly improve the key gastrointestinal hormone levels and quality of life of elderly patients.It is worthy of promotion in the same clinical cases.
文摘Gastroesophageal reflux disease (GERD) is a high-incidence digestive system disease. Western medicine mainly uses drugs such as proton pump inhibitors to inhibit gastric acid secretion, but some patients are accompanied by symptoms such as non-acid reflux and gas reflux, which cannot effectively treat the disease. It is necessary to actively explore other treatment schemes. Traditional Chinese medicine (TCM) has a long history of research on gastroesophageal reflux disease, which emphasizes the treatment based on syndrome differentiation as a whole. Through the treatment of various and multi-component TCM prescriptions, the patient’s body condition can be adjusted, and the treatment effect on gastroesophageal reflux disease is reliable, which has obvious therapeutic advantages. To further clarify the treatment of gastroesophageal reflux disease, this study reviewed and analyzed the research progress of the treatment of liver disease with modified prescriptions, and the report is as follows.
基金supported by the National Natural Science Foundation of China(11701453)Fundamental Research Funds for the Central Universities(31020180QD05)+2 种基金The second author was supported by the National Natural Science Foundation of China(11971431,11401525)the Natural Science Foundation of Zhejiang Province(LY18A010006)and the first Class Discipline of Zhejiang-A(Zhejiang Gongshang University-Statistics).
文摘In this article,we derive the Lp-boundedness of the variation operators associated with the heat semigroup which is generated by the high order Schrodinger type operator(—Δ)^2+V%2 in R%n(n≥5)with V being a nonnegative potential satisfying the reverse Holder inequality.Furt her more,we prove the boundedness of the variation operators on associated Morrey spaces.In the proof of the main results,we always make use of the variation inequalities associated with the hea t semigroup genera ted by the biharmonic operator(-Δ)2.
文摘The electromotive force (EMF) changes in type K heavy gauge sheathed thermocouple cables was investigated. To cope with this discrepancy owing to EMF steep reduction and understand the difference between type K heavy gauge sheathed thermocouple cables and small ones, the affects of EMF from sheath pipe, drawing times, annealing temperature, annealing time and annealing way were mainly studied and appropriately analyzed. The results show the change in the thermal EMF is related with the residual stress and crystal defects, which are imparted by cold work during manufacture. The affects of cold work can be removed by annealing. Finally, a feasible way of fabricating heavy gauge sheathed thermocouples was suggested according to practical situation.
文摘Objective:To observe the clinical efficacy of Chuanxiong Hualiu Mixture in the treatment of blood stasis and phlegm stagnation type of ovarian cyst and the effects on physical and chemical indicators.Methods: A total of 80 patients with blood stasis and phlegm stagnation type of ovarian cyst were randomly divided into two groups, research group (n=40) took Chuanxiong Hualiu Mixture, control group (n=40) took Guizhi Fuling Capsule, 3 months was a course of treatment, and the curative effect was compared between two groups.Results:(1) The overall response rate of Chuanxiong Hualiu mixture group after 3 months of treatment was 82.5%, that of Guizhi Fuling Capsule group was 62.5%, the overall response rate of Chuanxiong Hualiu mixture group was higher than that of control group, and the difference was statistically significant;(2) before and after treatment, sex hormone and hemorheology index E2 of both groups decreased significantly, whole blood viscosity, whole blood reduced viscosity and plasma viscosity decreased significantly, the results were statistically significant, but there was no difference between two groups;(3) rank sum test of TCM symptom efficacy between two groups before and after treatment showed that the overall response rate of Chuanxiong Hualiu mixture group was 95%, the overall response rate of Guizhi Fuling Capsule group was 85%, the overall response rate of research group was better than that of control group, and the difference was statistically significant.Conclusion:Chuanxiong Hualiu mixture has good curative effect for the treatment of ovarian cyst, it can effectively improve the patients' blood stasis and phlegm stagnation constitution, and its mechanism of action is associated with lowering estrogen levels and improving hemorrheology.
文摘Creep lives of high Cr ferritic heat resisting steel weldments decrease due to Type Ⅳ fracture, which occurs as a result of formation and growth of creep voids and cracks on grain boundaries in fine-grained heat affected zone (HAZ). Because boron is considered to suppress the coarsening of grain boundary precipitates and growth of creep voids, we have investigated the effect of boron addition on the creep properties of 9Cr steel weldments. Four kinds of 9Cr3WSCoVNb steels with boron content varying from 4.7×10-5 to 1.8×10-4 and with nitrogen as low as 2.0×10-5 were prepared. The steel plates were welded by gas tungsten arc welding and crept at 923K. It was found that the microstructures of HAZ were quite different from those of conventional high Cr steels such as P91 and P92, namely the fine-grained HAZ did not exist in the present steel weldments. Boron addition also has the effect to suppress coarsening of grain boundary carbides in HAZ during creep. As a result of these phenomena, the welded joints of present steels showed no Type Ⅳ fractures and much better creep lives than those of conventional steels.
文摘In the nanoscale beam,two effects become domineering.One is the non-Fourier effect in heat conduction and the other is the coupling effect between temperature and strain rate.In the present study,a generalized solution for the generalized thermoelastic vibration of gold nano-beam resonator induced by ramp type heating is developed.The solution takes into account the above two effects.State-space and Laplace transform methods are used to determine the lateral vibration,the temperature,the displacement,the stress and the strain energy of the beam.The effects of the relaxation time and the ramping time parameters have been studied.
文摘A mild, cascade type methodology was developed for the synthesis of polyphenolic ethers by the palladium-catalyzed cross coupling of phenols and halo compounds under microwave heating. In most cases, reactions run in neat conditions and in some cases, IPA/water mixture, and 1,4-dioxane were employed as solvents to furnish the products. By applying this new method, we were able to synthesize and purify a good number of polyether compounds with complete spectral data.
基金the National Natural Science Foundation of China,China (Grant 81373541).
文摘Objective:To compare the efficacy of traditional Chinese medicine (TCM),western medicine and integrative medicine in treating type 2 diabetes mellitus (T2DM) in a rat model.Methods:The T2DM rat model was established with a high-fat diet (HFD) for 35 days and a single injection of streptozotocin (STZ,30 mg/kg).The T2DM-induced rats were divided into three groups,and treated with Yiqi Yangyin Huatan (YQYYHT) granules (3.84 g/kg per day),pioglitazone (1.35 mg/kg per day) or YQYYHT granules + pioglitazone (3.84 g/kg per day+1.35 mg/kg per day) respectively for 14 days.Clinical features and behavioral changes,as well as T2DM indicators,were recorded to evaluate therapeutics effects in each treatment group.Results:The T2DM rat model expressed insulin resistance (IR),with features similar to qi-yin deficiency and phlegm stasis syndrome,including decreased cyclic adenosine monophosphate/cyclic guanosine monophosphate (cAMP/cGMP) ratio,decreased levels of Na+-K+-ATPase,superoxide dismutase (SOD) and high density lipoprotein-cholesterol (HDL-C),and increased levels of serum triglyceride (TG),total cholesterol (TC) and low density lipoprotein (LDL-C).All three treatment groups showed significant decreases in fasting blood glucose (FBG) and fasting insulin (Fins),and improvement of TCM syndrome to different degrees.Importantly,YQYYHT improved the most of the indicators of T2DM,followed by integrative medicine and pioglitazone alone.Conclusion:Compared with western medicine or integrative medicine,prescription of TCM based on syndrome differentiation may offer more advantages in the prevention and treatment of T2DM.
基金the Strategic Project of the Chinese Academy of Sciences[grant number XDA19070402]the National Natural Science Foundation of China[grant number 41790473].
文摘Separate type heat pipe heat exchangers are often used for large-scale heat exchanging. The arrangement of such a heat exchanger conveniently allows heat input to and output from the heat exchanger at remote locations. The traditional method of designing an ordinary HPHE (heat pipe heat exchanger) is commonly applied in the separate type exchanger design, but the calculations have to be carried out separately, which makes it very complicated. In this work, the ε-NTU (effectiveness-Number of Transfer Units) method was applied for optimization analysis of single- or multi-level separate type heat pipe heat exchangers. An optimizing formula for single-level separate type heat pipe heat exchangers was obtained. The optimizing principles of effec- tiveness-NTU and heat transfer rate by the equal distribution method for multi-level separate type heat pipe heat exchanger are presented. The design of separate type heat pipe heat exchangers by the optimizing method is more convenient and faster than by the traditional method.
基金Supported by Tianjin Science and Technology Development Strategy Research Program(No.06YFGZGX18300)
文摘The refrigerant mixture of ethanol aqueous was applied to the parallel type pulsating heat pipe (PHP). The operation characteristics of the PHP were analyzed by means of experiment and nonlinear chaotic theory. Moreover, the relationship between the running state and attractor was described. The results indicate that starting power, stable running power and dry burning transition power are about 64.08 W, 148.68 W and 234.0 W respectively. The cycle and amplitude of PHP initially decrease and then increase with the increasing power. However, the data are welldistributed in a certain range. The running state is in agreement with the attractors, and the changing process for attractors is as follows: the attractors first disperse in the whole phase space, then present mass status, and finally show band distribution.
基金supported by National Natural Science Foundation of China (Nos.50836007, 10921062)
文摘A modelling study is performed to compare the plasma flow and heat transfer characteristics of low-power arc-heated thrusters (arcjets) for three different propellants: hydrogen, nitrogen and argon. The all-speed SIMPLE algorithm is employed to solve the governing equations, which take into account the effects of compressibility, Lorentz force and Joule heating, as well as the temperature- and pressure-dependence of the gas properties. The temperature, velocity and Mach number distributions calculated within the thruster nozzle obtained with different propellant gases are compared for the same thruster structure, dimensions, inlet-gas stagnant pressure and arc currents. The temperature distributions in the solid region of the anode-nozzle wall are also given. It is found that the flow and energy conversion processes in the thruster nozzle show many similar features for all three propellants. For example, the propellant is heated mainly in the near-cathode and constrictor region, with the highest plasma temperature appearing near the cathode tip; the flow transition from the subsonic to supersonic regime occurs within the constrictor region; the highest axial velocity appears inside the nozzle; and most of the input propellant flows towards the thruster exit through the cooler gas region near the anode-nozzle wall. However, since the properties of hydrogen, nitrogen and argon, especially their molecular weights, specific enthMpies and thermal conductivities, are different, there are appreciable differences in arcjet performance. For example, compared to the other two propellants, the hydrogen arcjet thruster shows a higher plasma temperature in the arc region, and higher axial velocity but lower temperature at the thruster exit. Correspondingly, the hydrogen arcjet thruster has the highest specific impulse and arc voltage for the same inlet stagnant pressure and arc current. The predictions of the modelling are compared favourably with available experimental results.
基金Supported by the National Natural Science Foundation of China (10771024,11171048)the Education Department Program of Liaoning Province (L2010068)
文摘This article deals with a nonlocal heat system subject to null Dirichlet bound- ary conditions, where the coupling nonlocal sources consist of mixed type asymmetric non- linearities. We at first give the criterion for simultaneous blow-up of solutions, and then establish the uniform blow-up profiles of solutions near the blow-up time. It is observed that not only the simultaneous blow-up rates of the two components u and v are asymmet- ric, but also the blow-up rates of the same component u (or v) may be in different levels under different dominations.
基金supported by National Science Foundation of China (10571044)
文摘This article obtains an explicit expression of the heat kernels on H-type groups and then follow the estimate of heat kernels to deduce the Hardy's uncertainty principle on the nilpotent Lie groups.
基金financial support from the National MCF Energy R&D Program(No.2018YFE0312300)National Natural Science Foundation of China(No.51706100)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20180477)Fundamental Research Funds for the Central Universities(No.30918011205)。
文摘As an important component of tokamaks,the divertor is mainly responsible for extracting heat and helium ash,and the targets of the divertor need to withstand high heat flux of 10 MW m-2 for steady-state operation.In this study,we proposed a new strategy,using microchannel cooling technology to remove high heat load on the targets of the divertor.The results demonstrated that the microchannel-based W/Cu flat-type mock-up successfully withstood the thermal fatigue test of 1000 cycles at 10 MW m^(-2)with cooling water of 26 l min^(-1),30°C(inlet),0.8 MPa(inlet),15 s power on and 15 s dwell time;the maximum temperature on the heat-loaded surface(W surface)of the mock-up was 493°C,which is much lower than the recrystallization temperature of W(1200°C).Moreover,no occurrence of macrocrack and‘hot spot’at the W surface,as well as no detachment of W/Cu tiles were observed during the thermal fatigue testing.These results indicate that microchannel cooling technology is an efflcient method for removing the heat load of the divertor at a low flow rate.The present study offers a promising solution to replace the monoblock design for the EAST divertor.
基金supported by the National Natural Science Foundation of China,under the project entitled“The study of land-atmosphere water and heat flux interaction over the complex terrain of the north and south slopes of the Qomolangma region"[grant number 42230610]a Ministry of Science and Technology of China project called“Landatmosphere interaction and its climate effect of the Second Tibetan Plateau Scientific Expedition and Research Program"[grant number 2019QzKK0103]the Youth Innovation Promotion Association of the Chinese Academy of Sciences[2022069].
文摘正确认识不同区域能量和水分循环特征是研究局地地气相互作用及准确预测区域天气,气候变化的关键.为了研究属于干旱/半干旱气候的青藏高原(TP)和湿润/半湿润气候的长江流域(YRR)之间地表能量和水分交换的异同,本文对比分析了两个区域8个不同地表类型(包括高山荒漠,高山草地,(平原)城市和(平原)草地等)观测站点的地表辐射和能量通量数据.结果显示:(1)TP由于高原大气层稀薄且空气洁净,年平均入射短波辐射为251.3W m^(-2),是YRR的1.7倍.加之高原地表反照率高导致反射辐射(59.6 W m^(-2))是YRR的2.87倍.入射及出射的长波辐射为231.5和338.0 W m^(-2),分别为YRR的0.64和0.83.而两个区域的净辐射差异不大;(2)草地站更多的潜热释放使得地表总加热效率高于城市和高山荒漠,TP和YRR的草地站的年平均潜热分别为35.0和38.8 W m^(-2),而植被稀疏且土壤干燥的高山荒漠地区感热最大,年平均感热为42.1 W m^(-2);其次是城市下垫面,其年平均感热为37.7 W m^(-2).研究结果揭示了不同气候背景下典型下垫面地气相互作用特征,为地气相互作用过程深入分析奠定了基础.
文摘The non-Fourier effect in heat conduction and the coupling effect between temperature and strain rate, became the most significant effects in the nano-scale beam. In the present study, a generalized solution for the generalized thermoelastic vibration of a bounded nano-beam resonator induced by ramp type of heating is developed and the solutions take into account the above two effects. The Laplace transforms and direct method are used to determine the lateral vibration, the temperature, the displacement, the stress and the energy of the beam. The effects of the relaxation time and the ramping time parameters have been studied with some comparisons.
文摘Based on thermal value theory, the aim of this paper is to deduce the theoretical formulas for evaluating the energy effective utilization degree in technological pyrological processes exemplified by metallurgical heating furnaces. Heat transfer models for continuous heating furnaces, batch-type heating furnaces, and regenerative heating furnaces are established, respectively. By analyzing the movement path of injected infinitesimal heat attached on steel or gas, thermal value equations of continuous, batch-type, and regenerative heating furnaces are derived. Then the influences of such factors as hot charging, gas preheating and intake time of heat on energy effective utilization degree are discussed by thermal value equations. The results show that thermal value rises with hot charging and air preheating for continuous heating furnaces, with shorter intake time when heat is attached on steel or longer intake time when heat is attached on gas for batch-type heating furnaces and that with more heat supply at early heating stage or less at late stage for regenerative heating furnaces.