A pH predictive model based on acid–base equilibria and ion equilibria was proposed to calculate the pH value of the overhead condensing system of crude distillation unit. The pH model could be used to predict the ap...A pH predictive model based on acid–base equilibria and ion equilibria was proposed to calculate the pH value of the overhead condensing system of crude distillation unit. The pH model could be used to predict the appropriate amounts of neutralizers by measuring the Cl-ion concentration of the overhead knockout drum. The pH values of various neutralized streams were estimated by this model. The results showed that the predicted pH values were in good agreement with the experimental ones. The trend of the corrosion inhibition efficiency decreases in the following order: ethylenediamine > N,Ndimethylethanolamine> triethylamine > 3-methoxypropylamine > morpholine. The difficulty in the accurate control of corrosion was solved, and a good instruction was provided for mitigating corrosion in refinery.展开更多
The potential—pH diagrams of the Cr-H2O system at temperatures of 298, 323, 373 and 423 K were established through thermodynamic calculation with coupling of experimental results. The potential—pH diagram at 298 K a...The potential—pH diagrams of the Cr-H2O system at temperatures of 298, 323, 373 and 423 K were established through thermodynamic calculation with coupling of experimental results. The potential—pH diagram at 298 K agrees well with the previously reported results. Based on the potential—pH diagrams of the Cr-H2O and Fe-H2O systems, IR spectra and XRD pattern, the existence forms of iron in the potassium chromate were analyzed, and the methods of iron removal were investigated. The results show that the existence forms of iron in the potassium chromate are potassium ferrate. These results are instructive and helpful to the hydrometallurgical processing of chromite ore.展开更多
A novel pH-sensitive nanoparticle drug delivery system (DDS) derived fl om natural polysaccharide pullulan for doxorubicin (DOX) release was prepared.Pullulan was functionalized by successive carboxymethylization and ...A novel pH-sensitive nanoparticle drug delivery system (DDS) derived fl om natural polysaccharide pullulan for doxorubicin (DOX) release was prepared.Pullulan was functionalized by successive carboxymethylization and amidation to introduce hydrazide groups.DOX was then grafted onto pullulan backbone through the pH-sensitive hydrazone bond to form a pullulan/DOX conjugate.This conjugate self-assembled to form nano-sized particles in aqueous solution as a result of the hydrophobic interaction of the DOX.Trans...展开更多
吸收塔内浆液的pH是影响燃煤电厂湿法脱硫系统效率的重要参数。燃煤电厂的湿法脱硫系统具有大滞后、非线性、强耦合等特征,因而其吸收塔浆液的pH很难实现精准控制。利用门控循环单元(gated recurrent unit,GRU)神经网络在处理时间序列...吸收塔内浆液的pH是影响燃煤电厂湿法脱硫系统效率的重要参数。燃煤电厂的湿法脱硫系统具有大滞后、非线性、强耦合等特征,因而其吸收塔浆液的pH很难实现精准控制。利用门控循环单元(gated recurrent unit,GRU)神经网络在处理时间序列数据的优越性,对吸收塔内的浆液pH进行预测建模,通过将燃煤电厂采集的影响浆液pH的变量数据作为模型的输入,对模型进行训练处理,获得吸收塔内浆液pH的预测模型。将预测模型应用于辽宁省华能营口电厂600 MW机组湿法脱硫智能控制系统中吸收塔内浆液pH的预测。结果表明相比于反向传播(back propagation,BP)神经网络模型、径向基函数(radial basis function,RBF)神经网络、循环神经网络(recurrent neural network,RNN)和长短期记忆(long and short term memory,LSTM)神经网络,该模型精确度更高,实用性更强。展开更多
This study reveals the successful design of the data acquisition system for pH sensors.The data acquisition system includes an instrumentation amplifier,a low pass filter and a calculation program.The instrumentation ...This study reveals the successful design of the data acquisition system for pH sensors.The data acquisition system includes an instrumentation amplifier,a low pass filter and a calculation program.The instrumentation amplifier used as the readout circuit has many advantages,including high input impedance,high gain,low output impedance,high CMRR and high bandwidth.The low pass filter is employed to cancel the circuit noise.The calculation program uses the two-point calibration method to calculate the sample concentration.Furthermore,this study employs Boolean function to cancel error signals.As indicated by experimental results,the readout circuit obtains the sensing signal and the calculation program calculates the pH value.Hence,this study successfully fabricates an effective data acquisition system for pH sensors.展开更多
The application of Bluetooth on the pH sensor was accomplished.Based on the experimental results,Bluetooth technology was used to measure pH values without limiting the distance.Moreover,Biuetooth technology provides ...The application of Bluetooth on the pH sensor was accomplished.Based on the experimental results,Bluetooth technology was used to measure pH values without limiting the distance.Moreover,Biuetooth technology provides low power, low cost and small volume,therefore,it can increase the practicability of the system.In this investigation,the pH value was detected by the SnO_2/ITO glass-based pH sensor.During the signal progress,the detected signal was transferred to the microchip PIC18.After that,the microchip was able to communicate with PC by the Bluetooth.Moreover,the microchip can diagnose the sensing signal and sends the warning signal by alert function.In addition,the part of PC has the ability to record the information,builds the database for analyzing the pH values,and provides a better long-distance monitoring system.展开更多
The mix of cellular pumps, channels, transporters, and isoenzymes is genetically inherited. However, the environment has the ability to impact the cellular pumps, channels, transporters, and isoenzymes to some degree....The mix of cellular pumps, channels, transporters, and isoenzymes is genetically inherited. However, the environment has the ability to impact the cellular pumps, channels, transporters, and isoenzymes to some degree. Cellular pumps, channels, transporters and isoenzymes help control cellular pH and vice versa. Therefore possibly the pH in the nervous system is more variable than previously believed. If so, that could explain some of the changes we see in the nervous system.展开更多
In this study,the multi-sensing system based on the tin oxide pH electrode for the ion-determination was presented. With the advantages of the real-time supervisory control apparatus,the measured values could be displ...In this study,the multi-sensing system based on the tin oxide pH electrode for the ion-determination was presented. With the advantages of the real-time supervisory control apparatus,the measured values could be displayed on the liquid crystal display (LCD) immediately.In this study,the basic sensor was the tin oxide pH electrode,which was fabricated by radio frequency (r.f.) sputtering system on the indium tin oxide (ITO)/glass substrate.Moreover,the major blocks of the system consist of the tin oxide electrode-based ion selective electrodes (ISEs),an analog front-ended readout circuit,a microcontroller with built-in analog to digital (A/D) converter.In addition,by the embedded system design,the measurement results can be transmitted to a portable system or computer through the Universal Serial Bus (USB) and Universal Asynchronous Receiver Transmitter (UART) interface immediately.According to the experimental results,the multi-sensing system has high performance and reliability for pH,K^+,and Na^+ detection.展开更多
基金supported by the PetroChina Company Limited (20151191)
文摘A pH predictive model based on acid–base equilibria and ion equilibria was proposed to calculate the pH value of the overhead condensing system of crude distillation unit. The pH model could be used to predict the appropriate amounts of neutralizers by measuring the Cl-ion concentration of the overhead knockout drum. The pH values of various neutralized streams were estimated by this model. The results showed that the predicted pH values were in good agreement with the experimental ones. The trend of the corrosion inhibition efficiency decreases in the following order: ethylenediamine > N,Ndimethylethanolamine> triethylamine > 3-methoxypropylamine > morpholine. The difficulty in the accurate control of corrosion was solved, and a good instruction was provided for mitigating corrosion in refinery.
基金Project(2007CB613501) supported by the National Basic Research Program of ChinaProject(2006BAC02A05) supported by the National Science and Technology Pillar Program of ChinaProject(50904058) supported by the National Natural Science Foundation of China
文摘The potential—pH diagrams of the Cr-H2O system at temperatures of 298, 323, 373 and 423 K were established through thermodynamic calculation with coupling of experimental results. The potential—pH diagram at 298 K agrees well with the previously reported results. Based on the potential—pH diagrams of the Cr-H2O and Fe-H2O systems, IR spectra and XRD pattern, the existence forms of iron in the potassium chromate were analyzed, and the methods of iron removal were investigated. The results show that the existence forms of iron in the potassium chromate are potassium ferrate. These results are instructive and helpful to the hydrometallurgical processing of chromite ore.
基金the National Basic Research program of China (No.2005CB623903).
文摘A novel pH-sensitive nanoparticle drug delivery system (DDS) derived fl om natural polysaccharide pullulan for doxorubicin (DOX) release was prepared.Pullulan was functionalized by successive carboxymethylization and amidation to introduce hydrazide groups.DOX was then grafted onto pullulan backbone through the pH-sensitive hydrazone bond to form a pullulan/DOX conjugate.This conjugate self-assembled to form nano-sized particles in aqueous solution as a result of the hydrophobic interaction of the DOX.Trans...
文摘吸收塔内浆液的pH是影响燃煤电厂湿法脱硫系统效率的重要参数。燃煤电厂的湿法脱硫系统具有大滞后、非线性、强耦合等特征,因而其吸收塔浆液的pH很难实现精准控制。利用门控循环单元(gated recurrent unit,GRU)神经网络在处理时间序列数据的优越性,对吸收塔内的浆液pH进行预测建模,通过将燃煤电厂采集的影响浆液pH的变量数据作为模型的输入,对模型进行训练处理,获得吸收塔内浆液pH的预测模型。将预测模型应用于辽宁省华能营口电厂600 MW机组湿法脱硫智能控制系统中吸收塔内浆液pH的预测。结果表明相比于反向传播(back propagation,BP)神经网络模型、径向基函数(radial basis function,RBF)神经网络、循环神经网络(recurrent neural network,RNN)和长短期记忆(long and short term memory,LSTM)神经网络,该模型精确度更高,实用性更强。
文摘This study reveals the successful design of the data acquisition system for pH sensors.The data acquisition system includes an instrumentation amplifier,a low pass filter and a calculation program.The instrumentation amplifier used as the readout circuit has many advantages,including high input impedance,high gain,low output impedance,high CMRR and high bandwidth.The low pass filter is employed to cancel the circuit noise.The calculation program uses the two-point calibration method to calculate the sample concentration.Furthermore,this study employs Boolean function to cancel error signals.As indicated by experimental results,the readout circuit obtains the sensing signal and the calculation program calculates the pH value.Hence,this study successfully fabricates an effective data acquisition system for pH sensors.
文摘The application of Bluetooth on the pH sensor was accomplished.Based on the experimental results,Bluetooth technology was used to measure pH values without limiting the distance.Moreover,Biuetooth technology provides low power, low cost and small volume,therefore,it can increase the practicability of the system.In this investigation,the pH value was detected by the SnO_2/ITO glass-based pH sensor.During the signal progress,the detected signal was transferred to the microchip PIC18.After that,the microchip was able to communicate with PC by the Bluetooth.Moreover,the microchip can diagnose the sensing signal and sends the warning signal by alert function.In addition,the part of PC has the ability to record the information,builds the database for analyzing the pH values,and provides a better long-distance monitoring system.
文摘The mix of cellular pumps, channels, transporters, and isoenzymes is genetically inherited. However, the environment has the ability to impact the cellular pumps, channels, transporters, and isoenzymes to some degree. Cellular pumps, channels, transporters and isoenzymes help control cellular pH and vice versa. Therefore possibly the pH in the nervous system is more variable than previously believed. If so, that could explain some of the changes we see in the nervous system.
文摘In this study,the multi-sensing system based on the tin oxide pH electrode for the ion-determination was presented. With the advantages of the real-time supervisory control apparatus,the measured values could be displayed on the liquid crystal display (LCD) immediately.In this study,the basic sensor was the tin oxide pH electrode,which was fabricated by radio frequency (r.f.) sputtering system on the indium tin oxide (ITO)/glass substrate.Moreover,the major blocks of the system consist of the tin oxide electrode-based ion selective electrodes (ISEs),an analog front-ended readout circuit,a microcontroller with built-in analog to digital (A/D) converter.In addition,by the embedded system design,the measurement results can be transmitted to a portable system or computer through the Universal Serial Bus (USB) and Universal Asynchronous Receiver Transmitter (UART) interface immediately.According to the experimental results,the multi-sensing system has high performance and reliability for pH,K^+,and Na^+ detection.
