A simple method for determining the inverse current of cyclic voltammetry in the processes of steady-state or quasi-steady-state was presented. The experimental result verified the theoretical relation or inverse and ...A simple method for determining the inverse current of cyclic voltammetry in the processes of steady-state or quasi-steady-state was presented. The experimental result verified the theoretical relation or inverse and forward current at microelectrode. Their ratio is proportional to the square root of scan rate.展开更多
Germ cells are the precursors of the sperm and oocytes and hence are critical for survival of the species. In mammals, they are specified during fetal life, migrate to the developing gonads and then undergo a critical...Germ cells are the precursors of the sperm and oocytes and hence are critical for survival of the species. In mammals, they are specified during fetal life, migrate to the developing gonads and then undergo a critical period during which they are instructed, by the soma, to adopt the appropriate sexual fate. In a fetal ovary, germ cells enter meiosis and commit to oogenesis, whereas in a fetal testis, they avoid entry into meiosis and instead undergo mitotic arrest and mature toward spermatogenesis. Here, we discuss what we know so far about the regulation of sex-specific differentiation of germ cells, considering extrinsic molecular cues produced by somatic cells, as well as critical intrinsic changes within the germ cells. This review focuses almost exclusively on our understanding of these events in the mouse model.展开更多
Proper matching of forestry machinery is important when raising mechanization levels for forestry production. In the matching process, forestry machinery needs not only expertise, but also improved methods for solving...Proper matching of forestry machinery is important when raising mechanization levels for forestry production. In the matching process, forestry machinery needs not only expertise, but also improved methods for solving problems. I propose combination of case-based reasoning （CBR） and rule-based reasoning （RBR） by calculating the similarity of quantitative parameters of various forestry machines in an analytical and hierarchical process. I calculated the similarity of machin-ery used in forest industries to enable better selection and matching of equipment. I propose a weight-value adjusting method based on sums of squares of deviations in which the individual parameter weights were modified in the process of application. During the process of system design, I put forward a design method knowledge base and generated a dynamic web reasoning framework to integrate the processes of forest industry machinery selection and weight-value adjustment. This enables expansion of the scope of the complete system and enhancement of the reasoning efficiency. I demonstrate the validity and practicability of this method using a practical example.展开更多
Having been developed in the way of concept extension, Marxism appears to be nowadays as the concrete-universal theory, in which originally imperfect transition program from abstract-universal to concrete-universal co...Having been developed in the way of concept extension, Marxism appears to be nowadays as the concrete-universal theory, in which originally imperfect transition program from abstract-universal to concrete-universal concepts of logic and sense is realized on materialistic foundation. This very program that was brought about in Karl Marx＇s ＂Capital＂ has not been sufficiently expressed in classical or contemporary philosophy. The base of this new Marxist philosophical form is not constructed by the terms of matter, movement, and development overall, but by the conception of the general naturally determined universal process of infinite movement from lower to superior forms of matter. We are aware of four of them： physical, chemical, biological, and social matter. Representing the eternal world as the progressive whole, modern materialism makes nature and proper place of each fundamental science understandable and helps to clarify the location and development future trends of the Man in the world.展开更多
Multi-photon polymerization is a well-established,yet actively developing,additive manufacturing technique for 3D printing on the micro/nanoscale.Like all additive manufacturing techniques,determining the process para...Multi-photon polymerization is a well-established,yet actively developing,additive manufacturing technique for 3D printing on the micro/nanoscale.Like all additive manufacturing techniques,determining the process parameters necessary to achieve dimensional accuracy for a structure 3D printed using this method is not always straightforward and can require time-consuming experimentation.In this work,an active machine learning based framework is presented for determining optimal process parameters for the recently developed,high-speed,layer-by-layer continuous projection 3D printing process.The proposed active learning framework uses Bayesian optimization to inform optimal experimentation in order to adaptively collect the most informative data for effective training of a Gaussian-process-regression-based machine learning model.This model then serves as a surrogate for the manufacturing process:predicting optimal process parameters for achieving a target geometry,e.g,the 2D geometry of each printed layer.Three representative 2D shapes at three different scales are used as test cases.In each case,the active learning framework improves the geometric accuracy,with drastic reductions of the errors to within the measurement accuracy in just four iterations of the Bayesian optimization using only a few hundred of total training data.The case studies indicate that the active learning framework developed in this work can be broadly applied to other additive manufacturing processes to increase accuracy with significantly reduced experimental data collection effortforoptimization.展开更多
The equilibrium and kinetic characteristics of the adsorption of erythromycin to Sepabeads SP825 were determined.The equilibrium data in a batch system was well described by a Langmuir isotherm.The separation performa...The equilibrium and kinetic characteristics of the adsorption of erythromycin to Sepabeads SP825 were determined.The equilibrium data in a batch system was well described by a Langmuir isotherm.The separation performance was investigated in a fixed-bed system with respect to the adsorption superficial velocity,ionic strength and pH.A mathematical model was used to simulate the mass transfer mechanism,taking film mass transfer,pore diffusion and axial dispersion into account.The model predictions were consistent with the experi-mental data and were consequently used to determine the mass transfer coefficients.展开更多
文摘A simple method for determining the inverse current of cyclic voltammetry in the processes of steady-state or quasi-steady-state was presented. The experimental result verified the theoretical relation or inverse and forward current at microelectrode. Their ratio is proportional to the square root of scan rate.
文摘Germ cells are the precursors of the sperm and oocytes and hence are critical for survival of the species. In mammals, they are specified during fetal life, migrate to the developing gonads and then undergo a critical period during which they are instructed, by the soma, to adopt the appropriate sexual fate. In a fetal ovary, germ cells enter meiosis and commit to oogenesis, whereas in a fetal testis, they avoid entry into meiosis and instead undergo mitotic arrest and mature toward spermatogenesis. Here, we discuss what we know so far about the regulation of sex-specific differentiation of germ cells, considering extrinsic molecular cues produced by somatic cells, as well as critical intrinsic changes within the germ cells. This review focuses almost exclusively on our understanding of these events in the mouse model.
基金financially supported by the Fundamental Research Funds for the Central Universities Nos.DL12EB01-03the planning subject of "the Twelfth Five-Year-Plan" in National Science and Technology Nos.2012AA102003-2Heilongjiang Natural Science Fund in China Nos.F201116
文摘Proper matching of forestry machinery is important when raising mechanization levels for forestry production. In the matching process, forestry machinery needs not only expertise, but also improved methods for solving problems. I propose combination of case-based reasoning （CBR） and rule-based reasoning （RBR） by calculating the similarity of quantitative parameters of various forestry machines in an analytical and hierarchical process. I calculated the similarity of machin-ery used in forest industries to enable better selection and matching of equipment. I propose a weight-value adjusting method based on sums of squares of deviations in which the individual parameter weights were modified in the process of application. During the process of system design, I put forward a design method knowledge base and generated a dynamic web reasoning framework to integrate the processes of forest industry machinery selection and weight-value adjustment. This enables expansion of the scope of the complete system and enhancement of the reasoning efficiency. I demonstrate the validity and practicability of this method using a practical example.
文摘Having been developed in the way of concept extension, Marxism appears to be nowadays as the concrete-universal theory, in which originally imperfect transition program from abstract-universal to concrete-universal concepts of logic and sense is realized on materialistic foundation. This very program that was brought about in Karl Marx＇s ＂Capital＂ has not been sufficiently expressed in classical or contemporary philosophy. The base of this new Marxist philosophical form is not constructed by the terms of matter, movement, and development overall, but by the conception of the general naturally determined universal process of infinite movement from lower to superior forms of matter. We are aware of four of them： physical, chemical, biological, and social matter. Representing the eternal world as the progressive whole, modern materialism makes nature and proper place of each fundamental science understandable and helps to clarify the location and development future trends of the Man in the world.
基金supported by the National Science Foundation(NSF)through grant numbers CMMI-2135585 and CMMI-2229143J.EJ.acknowledges the National Science Foundation for support under the Graduate Research Fellowship Program(GRFP)under grant number DGE-1842166.
文摘Multi-photon polymerization is a well-established,yet actively developing,additive manufacturing technique for 3D printing on the micro/nanoscale.Like all additive manufacturing techniques,determining the process parameters necessary to achieve dimensional accuracy for a structure 3D printed using this method is not always straightforward and can require time-consuming experimentation.In this work,an active machine learning based framework is presented for determining optimal process parameters for the recently developed,high-speed,layer-by-layer continuous projection 3D printing process.The proposed active learning framework uses Bayesian optimization to inform optimal experimentation in order to adaptively collect the most informative data for effective training of a Gaussian-process-regression-based machine learning model.This model then serves as a surrogate for the manufacturing process:predicting optimal process parameters for achieving a target geometry,e.g,the 2D geometry of each printed layer.Three representative 2D shapes at three different scales are used as test cases.In each case,the active learning framework improves the geometric accuracy,with drastic reductions of the errors to within the measurement accuracy in just four iterations of the Bayesian optimization using only a few hundred of total training data.The case studies indicate that the active learning framework developed in this work can be broadly applied to other additive manufacturing processes to increase accuracy with significantly reduced experimental data collection effortforoptimization.
文摘The equilibrium and kinetic characteristics of the adsorption of erythromycin to Sepabeads SP825 were determined.The equilibrium data in a batch system was well described by a Langmuir isotherm.The separation performance was investigated in a fixed-bed system with respect to the adsorption superficial velocity,ionic strength and pH.A mathematical model was used to simulate the mass transfer mechanism,taking film mass transfer,pore diffusion and axial dispersion into account.The model predictions were consistent with the experi-mental data and were consequently used to determine the mass transfer coefficients.
