The polymer binder selection is one of the very important aspects for the powder injection molding. However,even nowadays the binder selection is still mainly performed by try and error method. Six commercial or inten...The polymer binder selection is one of the very important aspects for the powder injection molding. However,even nowadays the binder selection is still mainly performed by try and error method. Six commercial or intensive studied binder fo rmulas were analyzed according to state diagram and chemical characteristics of ingredients in each binder formula. In addition,the interactions between the bi nder components and additives were also taken into account. Based on the analysi s,the optimum binder formula was selected and some selection criterions were pu t forward for the binder and additives.展开更多
Ti-Mo getters have been fabricated via metal injection molding (MIM) using three kinds of Ti powders with different mean particle sizes of 46 μm,35 μm and 26 μm,respectively. The surface morphology,porosity,and hyd...Ti-Mo getters have been fabricated via metal injection molding (MIM) using three kinds of Ti powders with different mean particle sizes of 46 μm,35 μm and 26 μm,respectively. The surface morphology,porosity,and hydrogen sorption properties of Ti-Mo getters formed by MIM using paraffin wax as a principal binder constituent were examined. It has been proven that the powder injection molding is a viable forming technique for porous Ti-Mo getters. The particle size of Ti powders and the powder loading influence...展开更多
By technological experiments on bottom pulverized coal injection in a 10 t converter,the metallurgical reaction of continuous coal-oxygen injected into molten steel was studied.An assumption of direct burning of coal ...By technological experiments on bottom pulverized coal injection in a 10 t converter,the metallurgical reaction of continuous coal-oxygen injected into molten steel was studied.An assumption of direct burning of coal in molten steel is proposed and the result that low carbon steel can also be produced with coal injection is explained.The formulae for decarburization of melting bath were given.The apparent desulphurization rate constant is measured and activation energy of dephosphorization calculated.The influence of coal injection on nitrogen pick-up is studied too.展开更多
A sequential injection analysis (SIA) system for the determination of total calcium in blood has been implemented. The assay principle is based on the arsenazo III method, in which the indicator’s complex with calciu...A sequential injection analysis (SIA) system for the determination of total calcium in blood has been implemented. The assay principle is based on the arsenazo III method, in which the indicator’s complex with calcium forms a blue-purple colour. The absorbance peak height at 650 nm was proportional to the calcium content in samples. A linear range was obtained from 2.5 - 15 mg?dL–1 (r2 = 0.999), with a detection limit of 0.430 mg?dL–1 (3σ). Magnesium, glucose, hae-moglobin, and bilirubin at 123, 1,000, 50, and 0.5 mg?dL–1, respectively, were not found to interfere with the proposed system significantly (recovery 99.1% - 104.4%). The sampling frequency was 30 h–1, in which the carry-over effect was negligible (0.69%). The proposed SIA system was successfully applied to the determination of calcium from serum samples (r2 = 0.970;n = 30).展开更多
To tackle the challenge of producing highly filled polymer composites using the traditional injection molding technique,which is characterized by the fairly high melt viscosity that makes mold filling difficult,the au...To tackle the challenge of producing highly filled polymer composites using the traditional injection molding technique,which is characterized by the fairly high melt viscosity that makes mold filling difficult,the authors propose a solution based on dynamic covalent chemistry.As demonstrated by the proof-of-concept experiments,the 4-arm starshaped polycaprolactone(PCL)oligomers and microcrystalline cel-lulose(MCC)are crosslinked by the reversible Diels-Alder(DA)bonds.The flowability of the compounds greatly decreases due to the dissociation of the intercomponent DA bonds at the retro-reaction tempera-ture,and the networked architecture is reconstructed during cooling as a result of the forward DA reaction.Consequently,the high-loading MCC fillers are well distributed in the matrix and covalently bonded to the nearby PCL,forming a striking contrast to the control in which linear PCL acts as the matrix.The DA bonds crosslinked biodegradable PCL composites exhibit decent mechanical strength(20.7 MPa)even at the MCC fraction of 65 wt%,which is superior to those(5-12.2 MPa)of the highly filled PCL composites(with filler contents of 50-63.8 wt%)reported so far.The proposed approach has sufficient expansibility for the fabrication of the highly filled polymer composites constructed by other types of matrix and fillers.展开更多
Objective: To assess the efficacy of Lishen injection (LSI) in treating coronary heart disease (CHD). Methods: The effect of LSI on serum estradiol (E2) testosterone (T) and E2/T ratio in 30 postmenopausal patients wi...Objective: To assess the efficacy of Lishen injection (LSI) in treating coronary heart disease (CHD). Methods: The effect of LSI on serum estradiol (E2) testosterone (T) and E2/T ratio in 30 postmenopausal patients with CHD of Kidney Deficiency (KD) were observed. Results: (1 ) Serum E2 and the E2/Tratio were lower (P ＜ 0. 01 ) in the group of Kidney Yang Deficiency type (KYaDT) and higher (P ＜ 0. 01 ) in the group of Kidney Yin Deficiency type (KYiDT) as compared with normal control. (2) After treatment with LSI the levels of serum E2 and the E2/T ratio were elevated in the KYaDT group (P ＜ 0. 01 ) and lowered in the KYiDT group (P ＜ 0. 01 ). Both approached the normal level (P ＞ 0. 05 ). (3) The levels of T in both groupswere unaffected (P ＞0. 05) before and after treatment. Conclusion: The imbalance of Kidney-Yin and KidneyYang is correlated to the disturbance of sex hormones and LSI could not only regulate the Kidney-Yin and Kidney-Yang, improve the symptoms of KD, but also reverse the disturbance of sex hormone. With a good bidirectional regulatory effect on E2, it is beneficial on balance of sex hormones of both sexes in the inner environment of human body.展开更多
压水堆(pressurized water reactor,PWR)核电站一次侧运行水化学的优化控制是减少辐射剂量,防止关键设备腐蚀损伤,保持燃料性能的最经济、最有效的途径之一,其本质是通过水化学与设备材料的交互作用改善材料表面氧化膜的特性.综述了PWR...压水堆(pressurized water reactor,PWR)核电站一次侧运行水化学的优化控制是减少辐射剂量,防止关键设备腐蚀损伤,保持燃料性能的最经济、最有效的途径之一,其本质是通过水化学与设备材料的交互作用改善材料表面氧化膜的特性.综述了PWR核电站一次侧主冷却剂水化学与设备材料腐蚀损伤关系的研究现状及问题,介绍了近年来在PWR一次侧注Zn水化学(Zn-injected water chemistry,ZWC)方面的应用基础研究进展.展开更多
文摘The polymer binder selection is one of the very important aspects for the powder injection molding. However,even nowadays the binder selection is still mainly performed by try and error method. Six commercial or intensive studied binder fo rmulas were analyzed according to state diagram and chemical characteristics of ingredients in each binder formula. In addition,the interactions between the bi nder components and additives were also taken into account. Based on the analysi s,the optimum binder formula was selected and some selection criterions were pu t forward for the binder and additives.
文摘Ti-Mo getters have been fabricated via metal injection molding (MIM) using three kinds of Ti powders with different mean particle sizes of 46 μm,35 μm and 26 μm,respectively. The surface morphology,porosity,and hydrogen sorption properties of Ti-Mo getters formed by MIM using paraffin wax as a principal binder constituent were examined. It has been proven that the powder injection molding is a viable forming technique for porous Ti-Mo getters. The particle size of Ti powders and the powder loading influence...
文摘By technological experiments on bottom pulverized coal injection in a 10 t converter,the metallurgical reaction of continuous coal-oxygen injected into molten steel was studied.An assumption of direct burning of coal in molten steel is proposed and the result that low carbon steel can also be produced with coal injection is explained.The formulae for decarburization of melting bath were given.The apparent desulphurization rate constant is measured and activation energy of dephosphorization calculated.The influence of coal injection on nitrogen pick-up is studied too.
文摘A sequential injection analysis (SIA) system for the determination of total calcium in blood has been implemented. The assay principle is based on the arsenazo III method, in which the indicator’s complex with calcium forms a blue-purple colour. The absorbance peak height at 650 nm was proportional to the calcium content in samples. A linear range was obtained from 2.5 - 15 mg?dL–1 (r2 = 0.999), with a detection limit of 0.430 mg?dL–1 (3σ). Magnesium, glucose, hae-moglobin, and bilirubin at 123, 1,000, 50, and 0.5 mg?dL–1, respectively, were not found to interfere with the proposed system significantly (recovery 99.1% - 104.4%). The sampling frequency was 30 h–1, in which the carry-over effect was negligible (0.69%). The proposed SIA system was successfully applied to the determination of calcium from serum samples (r2 = 0.970;n = 30).
基金the support of the National Natural Science Foundation of China(Grants:52033011,51973237,and 52173092)Natural Science Foundation of Guangdong Province(Grants:2019B1515120038,2020A1515011276,2021A1515010417)+1 种基金Science and Technology Planning Project of Guangzhou City(Grant:202201011568)Fundamental Research Funds for the Central Universities,Sun Yatsen University(Grant:23yxqntd002).
文摘To tackle the challenge of producing highly filled polymer composites using the traditional injection molding technique,which is characterized by the fairly high melt viscosity that makes mold filling difficult,the authors propose a solution based on dynamic covalent chemistry.As demonstrated by the proof-of-concept experiments,the 4-arm starshaped polycaprolactone(PCL)oligomers and microcrystalline cel-lulose(MCC)are crosslinked by the reversible Diels-Alder(DA)bonds.The flowability of the compounds greatly decreases due to the dissociation of the intercomponent DA bonds at the retro-reaction tempera-ture,and the networked architecture is reconstructed during cooling as a result of the forward DA reaction.Consequently,the high-loading MCC fillers are well distributed in the matrix and covalently bonded to the nearby PCL,forming a striking contrast to the control in which linear PCL acts as the matrix.The DA bonds crosslinked biodegradable PCL composites exhibit decent mechanical strength(20.7 MPa)even at the MCC fraction of 65 wt%,which is superior to those(5-12.2 MPa)of the highly filled PCL composites(with filler contents of 50-63.8 wt%)reported so far.The proposed approach has sufficient expansibility for the fabrication of the highly filled polymer composites constructed by other types of matrix and fillers.
文摘Objective: To assess the efficacy of Lishen injection (LSI) in treating coronary heart disease (CHD). Methods: The effect of LSI on serum estradiol (E2) testosterone (T) and E2/T ratio in 30 postmenopausal patients with CHD of Kidney Deficiency (KD) were observed. Results: (1 ) Serum E2 and the E2/Tratio were lower (P ＜ 0. 01 ) in the group of Kidney Yang Deficiency type (KYaDT) and higher (P ＜ 0. 01 ) in the group of Kidney Yin Deficiency type (KYiDT) as compared with normal control. (2) After treatment with LSI the levels of serum E2 and the E2/T ratio were elevated in the KYaDT group (P ＜ 0. 01 ) and lowered in the KYiDT group (P ＜ 0. 01 ). Both approached the normal level (P ＞ 0. 05 ). (3) The levels of T in both groupswere unaffected (P ＞0. 05) before and after treatment. Conclusion: The imbalance of Kidney-Yin and KidneyYang is correlated to the disturbance of sex hormones and LSI could not only regulate the Kidney-Yin and Kidney-Yang, improve the symptoms of KD, but also reverse the disturbance of sex hormone. With a good bidirectional regulatory effect on E2, it is beneficial on balance of sex hormones of both sexes in the inner environment of human body.
文摘压水堆(pressurized water reactor,PWR)核电站一次侧运行水化学的优化控制是减少辐射剂量,防止关键设备腐蚀损伤,保持燃料性能的最经济、最有效的途径之一,其本质是通过水化学与设备材料的交互作用改善材料表面氧化膜的特性.综述了PWR核电站一次侧主冷却剂水化学与设备材料腐蚀损伤关系的研究现状及问题,介绍了近年来在PWR一次侧注Zn水化学(Zn-injected water chemistry,ZWC)方面的应用基础研究进展.
