Long-term load and flexural failure experiments are carried out on two prestressed concrete(PC) simply supported box girders. In the long-term load experiment, girder-1(G1) is in an elastic state, while girder-2(G2) i...Long-term load and flexural failure experiments are carried out on two prestressed concrete(PC) simply supported box girders. In the long-term load experiment, girder-1(G1) is in an elastic state, while girder-2(G2) is in a cracking state. To investigate the influence of cracking on the flexural behaviors of PC simply supported box beams, the experiment results are analyzed from many aspects, such as load–deflection, load–strain, and failure mode. Experiment results show the following: 1) the shrinkage and creep of concrete have considerable influences on the long-term deflection and strain of the two girders; 2) in the flexural failure experiment, the cracks and ultimate loads of the two girders are close. The rigidity degeneration of G2 is significantly faster than that of G1, and thus G2 shows nonlinear characteristics earlier; 3) to prove the validity and rationality of the current code, the cracking load and ultimate load of the two girders are calculated according to the current code.展开更多
An international consortium of scientists studying gamma-ray bursts (GRBs) as part of the POLAR (GRB polarimeter) experiment has revealed that high-energy photon emissions from black holes are neither completely chaot...An international consortium of scientists studying gamma-ray bursts (GRBs) as part of the POLAR (GRB polarimeter) experiment has revealed that high-energy photon emissions from black holes are neither completely chaotic nor completely organized, but a mixture.展开更多
The xanthan fermentation data in the stationary phase was analyzed using the black box and the metabolic network models. The data consistency is checked through the elemental balance in the black box model. In the met...The xanthan fermentation data in the stationary phase was analyzed using the black box and the metabolic network models. The data consistency is checked through the elemental balance in the black box model. In the metabolic network model, the metabolic flux distribution in the cell is calculated using the metabolic flux analysis method, then the maintenance coefficients is calculated.展开更多
The paper proves that due to the existence of electromagnetic interaction, the experiments of LIGO cannot detect gravitational waves. This is also the reason why Weber’s experiments of gravitational waves failed. In ...The paper proves that due to the existence of electromagnetic interaction, the experiments of LIGO cannot detect gravitational waves. This is also the reason why Weber’s experiments of gravitational waves failed. In fact, the formulas of general relativity that gravitational waves affect distances are only suitable for particles in vacuum. LIGO experiments are carried out on the earth. The laser interferometers are fixed on the steel pipes on the earth’s surface in the balanced state of electromagnetic force. Electromagnetic force is 10<sup>40</sup> times greater than gravity. Gravitational waves are too weak to overcome electromagnetic force and change the length of steel pipes. Without considering this factor, the design principle of LIGO experiment has serious problem. The experiments to detect gravitational waves should move to space to avoid the influence of electromagnetic interaction. Besides, LIGO experiments have the following problems. 1) No explosion source of gravitational waves is really founded. 2) The argument that the Einstein’s theory of gravity is verified is a vicious circle and invalid in logic. 3) The results of experiments cause sharp contradiction for the energy currents of gravitational waves. The difference reaches to 10<sup>24</sup> times and is unacceptable. 4) The method of numerical relativity causes great errors due to the existence of singularities. The errors are enlarged by the effect of butterfly due to the non-linearity of Einstein’s equation of gravity. 5) The so-called change of length 10<sup>-18</sup> m between two glasses of interferometers detected in the experiment exceeds the ability of current technique. This kind of precise has entered micro-scalar. The uncertain principle of quantum mechanics makes it impossible. The signs appeared in LIGO experiments are not caused by distance change. 6) LIGO experiments have not detected gravitational waves. What detected may be the signs of disturbances coming from the middle region between two laser interferometers.展开更多
Reliability-based design optimization (RBDO) is intrinsically a double-loop procedure since it involves an overall optimization and an iterative reliability assessment at each search point. Due to the double-loop pr...Reliability-based design optimization (RBDO) is intrinsically a double-loop procedure since it involves an overall optimization and an iterative reliability assessment at each search point. Due to the double-loop procedure, the computational expense of RBDO is normally very high. Current RBDO research focuses on problems with explicitly expressed performance functions and readily available gradients. This paper addresses a more challenging type of RBDO problem in which the performance functions are computation intensive. These computation intensive functions are often considered as a "black-box" and their gradients are not available or not reliable. On the basis of the reliable design space (RDS) concept proposed earlier by the authors, this paper proposes a Reliable Space Pursuing (RSP) approach, in which RDS is first identified and then gradually refined while optimization is performed. It fundamentally avoids the nested optimization and probabilistic assessment loop. Three well known RBDO problems from the literature are used for testing and demonstrating the effectiveness of the proposed RSP method.展开更多
Concept of black box, condition of modeling and control methods were introduced. Taking high purity silica brick as an example, the silica brick featured with high purity, low porosity, low true density and high stren...Concept of black box, condition of modeling and control methods were introduced. Taking high purity silica brick as an example, the silica brick featured with high purity, low porosity, low true density and high strength was developed through problem analysis, test design, modeling and optimization. Using information technology to upgrade refractories industry was discussed.展开更多
In this paper, Black Box approach is presented for behavioral modeling of a non linear power amplifier with memory effects. Large signal parameters of a Motorola LDMOS power amplifier driven by a WCDMA signal were ext...In this paper, Black Box approach is presented for behavioral modeling of a non linear power amplifier with memory effects. Large signal parameters of a Motorola LDMOS power amplifier driven by a WCDMA signal were extracted while taking into considerations the power amplifier’s bandwidth. The proposed model was validated based on the simulated data. Some validation results are presented both in the time and frequency domains, using WCDMA signal.展开更多
Objective:Adverse surgical events are a major cause of morbidity,mortality,and disability worldw ide.The cause of many such events can be attributed to interruptions in the operating room(OR),muli-tasking by surgeons,...Objective:Adverse surgical events are a major cause of morbidity,mortality,and disability worldw ide.The cause of many such events can be attributed to interruptions in the operating room(OR),muli-tasking by surgeons,etc.The objective of this study was to observe the types and frequency of intra-operative wor kflow interruptions in our ORs.Method:This ccoss-sectional study was conducted from March Do April of 2023.An observational approach using an audio-video recording device was employed to record OR flow disr uptions.One elective OR and one emergency OR under the Department of General Surgery were selected for the study.All open and laparoscopic surger ies conducted in the selected ORs were included.An Internet Protocol camera'was installed in the selec ted ORS with a view of the entire room,including the anesthesia station.Audio-video recording was started after the first indsion and stopped after closure of the surgical site.Result:Of the 51 cases that were studied,45(88.2%)were elective,and 18(35.3%)were laparoscopic cases.They could be classified into 8 types of open procedures and 4 types of lapar oscopic procedures.The mean maximum headcount inside the OR was 15.5土3.6 and doors opened on average of 15.8土6.0 times during a procedure.Other interruptions were surgeons attending phone calls(24,47.1%),leaving the sterile area(21,41.2%),technical disturbances(32,62.7%),anesthetic interruptions(18,35.3%),and faulty instruments(29,56.9%)Elective procedures had a signifcandy higher average number of in-terruptions per operating hour than emergency procedures(175±8.6vs.7.1±2.9,p<0.01).Condusion:Preventable factors such as faulty instruments,anesthetic interruption,and attending phone calls by the surgeon are commonly observed in ORs.They need to be addressed by timely surgical audits or the adoption of continued sureillance methods that can help take measures to minimize their occurrence.展开更多
On the basis of analyzing the connotation and function of black box of science and technology,this article expounds the necessity of cultivating modern and new farmers in China at present,and points out that with ince...On the basis of analyzing the connotation and function of black box of science and technology,this article expounds the necessity of cultivating modern and new farmers in China at present,and points out that with incessant progress of science and technology,the modern agriculture based on black box of science and technology will continue to grow,which requires a large number of new farmers who can learn and improve black box of agricultural science and technology.Finally,the recommendations are put forward for cultivation of new farmers:improving farmers' training system;enhancing rural financial support,so that the farmers benefit from black box of science and technology;strengthening the cultivation of the practical ability,and promoting farmers' management capacity;strengthening the cultivation of innovative ability,and nurturing innovative farmers.展开更多
Based on the“three box”exergy analysis model,a black box-gray box hierarchical exergy analysis and evaluation method is put forward in this paper,which is applied to evaluate the power generation technology of diffe...Based on the“three box”exergy analysis model,a black box-gray box hierarchical exergy analysis and evaluation method is put forward in this paper,which is applied to evaluate the power generation technology of differential pressure produced by natural gas expansion.By using the exergy analysis theory,the black box-gray box hierarchical exergy analysis models of three differential pressure power generation technologies are established respectively.Firstly,the“black box”analysis models of main energy consuming equipment are established,and then the“gray box”analysis model of the total system is established.Based on the calculation results of exergy analysis indexes,the weak energy consumption equipment in the whole power generation process is accurately located.Taking a gas field in southwest China as an example,the comprehensive energy consumption evaluation of the three power generation technologies is carried out,and the technology with the best energy consumption condition among the three technologies is determined.Finally,the rationalization improvement measures are put forward from improving the air tightness,replacing the deflector and reducing the flow loss.展开更多
Notable for the completeness with which it surrenders formally and artistically to the textual dictates of Twitter, Jennifer Egan's 2012 short science fiction Black Box is one of the most triumphant and fully-fledged...Notable for the completeness with which it surrenders formally and artistically to the textual dictates of Twitter, Jennifer Egan's 2012 short science fiction Black Box is one of the most triumphant and fully-fledged fictions written in the form of new media. This paper explores the Twitter narrative employed in Black Box, pointing out that the serialized tweeting format of the story released via computer, mobile phone, or other electronic equipments brings readers immediate reading experience, allowing readers to sense the same feelings as the protagonist does. Through the experimental serialization of"Twitter" narrative, Egan expresses her concerns and worries about the security of the American security as well as the whole world in the post-"9.11" period and at the same time she embraces the virtues and pleasures of traditional storytelling delivered through a wholly new digital format. This paper concludes that Black Box is perhaps one of the boldest experiments of narrative form and is direct exploration into the contemporary image culture.展开更多
Like many other people ~*with nowhere better to go^1,thewoman everyone called Old Betty came to the library almost everyday.Prim^2 Miss Tonsitt sometimes had to get the caretaker^3 to e-ject^4 old people from the libr...Like many other people ~*with nowhere better to go^1,thewoman everyone called Old Betty came to the library almost everyday.Prim^2 Miss Tonsitt sometimes had to get the caretaker^3 to e-ject^4 old people from the library if their sleeping,eating or talkingbecame too objectionable^5,but Old Betty never gave any trouble.Still quite sprightly^6 despite her age, ~*though subiect to展开更多
With the advancement of technology in recent years, effective fault diagnosis became a necessity to verify the performance and ensure the quality of complex systems. In this paper, an original verification methodology...With the advancement of technology in recent years, effective fault diagnosis became a necessity to verify the performance and ensure the quality of complex systems. In this paper, an original verification methodology for complex consumer electronic devices is presented. Verification of the system which consists of hardware (integrated circuit) and corresponding software within a flat panel TV set is in the focus. Proposed methodology provides reliable functional failure detection using the concept of black box testing. Further, the approach is fully automated, improving the reliability and speed of failure detection. The methodology effectiveness has been experimentally evaluated and the analysis results have been reported.展开更多
The multiplicity distribution (P(nch)) of charged particles produced in a high energy collision is a key quantity to understand the mechanism of multiparticle production. This paper describes the novel application of ...The multiplicity distribution (P(nch)) of charged particles produced in a high energy collision is a key quantity to understand the mechanism of multiparticle production. This paper describes the novel application of an artificial neural network (ANN) black-box modeling approach based on the cascade correlation (CC) algorithm formulated to calculate and predict multiplicity distribution of proton-proton (antiproton) (PP and PP ) inelastic interactions full phase space at a wide range of center-mass of energy . In addition, the formulated cascade correlation neural network (CCNN) model is used to empirically calculate the average multiplicity distribution nch> as a function of . The CCNN model was designed based on available experimental data for = 30.4 GeV, 44.5 GeV, 52.6 GeV, 62.2 GeV, 200 GeV, 300 GeV, 540 GeV, 900 GeV, 1000 GeV, 1800 GeV, and 7 TeV. Our obtained empirical results for P(nch), as well as nch> for (PP and PP) collisions are compared with the corresponding theoretical ones which obtained from other models. This comparison shows a good agreement with the available experimental data (up to 7 TeV) and other theoretical ones. At full large hadron collider (LHC) energy ( = 14 TeV) we have predicted P(nch) and nch> which also, show a good agreement with different theoretical models.展开更多
A complementarity hypothesis concerning outsider and insider perspectives of a gargantuan black hole is proposed. The two thought experiments presented herein are followed by a brief discussion of a new interpretation...A complementarity hypothesis concerning outsider and insider perspectives of a gargantuan black hole is proposed. The two thought experiments presented herein are followed by a brief discussion of a new interpretation of black hole interior “space-and-time-reversal”. Specifically, it is proposed that the “singularity” space of the black hole interior is time-like and the expansion time of the black hole interior is space-like. The resemblance of this new insider interpretation to our own expanding and redshifting big bang universe is compelling.展开更多
基金Project(51551801)supported by the National Natural Science Foundation of ChinaProject(14JJ4062)supported by Natural Science Foundation of Hunan Province,China
文摘Long-term load and flexural failure experiments are carried out on two prestressed concrete(PC) simply supported box girders. In the long-term load experiment, girder-1(G1) is in an elastic state, while girder-2(G2) is in a cracking state. To investigate the influence of cracking on the flexural behaviors of PC simply supported box beams, the experiment results are analyzed from many aspects, such as load–deflection, load–strain, and failure mode. Experiment results show the following: 1) the shrinkage and creep of concrete have considerable influences on the long-term deflection and strain of the two girders; 2) in the flexural failure experiment, the cracks and ultimate loads of the two girders are close. The rigidity degeneration of G2 is significantly faster than that of G1, and thus G2 shows nonlinear characteristics earlier; 3) to prove the validity and rationality of the current code, the cracking load and ultimate load of the two girders are calculated according to the current code.
文摘An international consortium of scientists studying gamma-ray bursts (GRBs) as part of the POLAR (GRB polarimeter) experiment has revealed that high-energy photon emissions from black holes are neither completely chaotic nor completely organized, but a mixture.
基金Supported by the National Natural Science Foundation of China(No.29776035).
文摘The xanthan fermentation data in the stationary phase was analyzed using the black box and the metabolic network models. The data consistency is checked through the elemental balance in the black box model. In the metabolic network model, the metabolic flux distribution in the cell is calculated using the metabolic flux analysis method, then the maintenance coefficients is calculated.
文摘The paper proves that due to the existence of electromagnetic interaction, the experiments of LIGO cannot detect gravitational waves. This is also the reason why Weber’s experiments of gravitational waves failed. In fact, the formulas of general relativity that gravitational waves affect distances are only suitable for particles in vacuum. LIGO experiments are carried out on the earth. The laser interferometers are fixed on the steel pipes on the earth’s surface in the balanced state of electromagnetic force. Electromagnetic force is 10<sup>40</sup> times greater than gravity. Gravitational waves are too weak to overcome electromagnetic force and change the length of steel pipes. Without considering this factor, the design principle of LIGO experiment has serious problem. The experiments to detect gravitational waves should move to space to avoid the influence of electromagnetic interaction. Besides, LIGO experiments have the following problems. 1) No explosion source of gravitational waves is really founded. 2) The argument that the Einstein’s theory of gravity is verified is a vicious circle and invalid in logic. 3) The results of experiments cause sharp contradiction for the energy currents of gravitational waves. The difference reaches to 10<sup>24</sup> times and is unacceptable. 4) The method of numerical relativity causes great errors due to the existence of singularities. The errors are enlarged by the effect of butterfly due to the non-linearity of Einstein’s equation of gravity. 5) The so-called change of length 10<sup>-18</sup> m between two glasses of interferometers detected in the experiment exceeds the ability of current technique. This kind of precise has entered micro-scalar. The uncertain principle of quantum mechanics makes it impossible. The signs appeared in LIGO experiments are not caused by distance change. 6) LIGO experiments have not detected gravitational waves. What detected may be the signs of disturbances coming from the middle region between two laser interferometers.
基金supported by Natural Science and Engineering Research Council (NSERC) of Canada
文摘Reliability-based design optimization (RBDO) is intrinsically a double-loop procedure since it involves an overall optimization and an iterative reliability assessment at each search point. Due to the double-loop procedure, the computational expense of RBDO is normally very high. Current RBDO research focuses on problems with explicitly expressed performance functions and readily available gradients. This paper addresses a more challenging type of RBDO problem in which the performance functions are computation intensive. These computation intensive functions are often considered as a "black-box" and their gradients are not available or not reliable. On the basis of the reliable design space (RDS) concept proposed earlier by the authors, this paper proposes a Reliable Space Pursuing (RSP) approach, in which RDS is first identified and then gradually refined while optimization is performed. It fundamentally avoids the nested optimization and probabilistic assessment loop. Three well known RBDO problems from the literature are used for testing and demonstrating the effectiveness of the proposed RSP method.
基金This paper is funded by National 11th " Five-Year-Plan" Major Supporting Projects for Scientific and Technology. Its item name is "Green Manufacturing Processes and Equipment" with subject number of 2006BAF02A26.
文摘Concept of black box, condition of modeling and control methods were introduced. Taking high purity silica brick as an example, the silica brick featured with high purity, low porosity, low true density and high strength was developed through problem analysis, test design, modeling and optimization. Using information technology to upgrade refractories industry was discussed.
文摘In this paper, Black Box approach is presented for behavioral modeling of a non linear power amplifier with memory effects. Large signal parameters of a Motorola LDMOS power amplifier driven by a WCDMA signal were extracted while taking into considerations the power amplifier’s bandwidth. The proposed model was validated based on the simulated data. Some validation results are presented both in the time and frequency domains, using WCDMA signal.
文摘Objective:Adverse surgical events are a major cause of morbidity,mortality,and disability worldw ide.The cause of many such events can be attributed to interruptions in the operating room(OR),muli-tasking by surgeons,etc.The objective of this study was to observe the types and frequency of intra-operative wor kflow interruptions in our ORs.Method:This ccoss-sectional study was conducted from March Do April of 2023.An observational approach using an audio-video recording device was employed to record OR flow disr uptions.One elective OR and one emergency OR under the Department of General Surgery were selected for the study.All open and laparoscopic surger ies conducted in the selected ORs were included.An Internet Protocol camera'was installed in the selec ted ORS with a view of the entire room,including the anesthesia station.Audio-video recording was started after the first indsion and stopped after closure of the surgical site.Result:Of the 51 cases that were studied,45(88.2%)were elective,and 18(35.3%)were laparoscopic cases.They could be classified into 8 types of open procedures and 4 types of lapar oscopic procedures.The mean maximum headcount inside the OR was 15.5土3.6 and doors opened on average of 15.8土6.0 times during a procedure.Other interruptions were surgeons attending phone calls(24,47.1%),leaving the sterile area(21,41.2%),technical disturbances(32,62.7%),anesthetic interruptions(18,35.3%),and faulty instruments(29,56.9%)Elective procedures had a signifcandy higher average number of in-terruptions per operating hour than emergency procedures(175±8.6vs.7.1±2.9,p<0.01).Condusion:Preventable factors such as faulty instruments,anesthetic interruption,and attending phone calls by the surgeon are commonly observed in ORs.They need to be addressed by timely surgical audits or the adoption of continued sureillance methods that can help take measures to minimize their occurrence.
文摘On the basis of analyzing the connotation and function of black box of science and technology,this article expounds the necessity of cultivating modern and new farmers in China at present,and points out that with incessant progress of science and technology,the modern agriculture based on black box of science and technology will continue to grow,which requires a large number of new farmers who can learn and improve black box of agricultural science and technology.Finally,the recommendations are put forward for cultivation of new farmers:improving farmers' training system;enhancing rural financial support,so that the farmers benefit from black box of science and technology;strengthening the cultivation of the practical ability,and promoting farmers' management capacity;strengthening the cultivation of innovative ability,and nurturing innovative farmers.
基金financially supported by the National Natural Science Foundation of China(52074089 and 51534004)Natural Science Foundation of Heilongjiang Province of China(LH2019E019)。
文摘Based on the“three box”exergy analysis model,a black box-gray box hierarchical exergy analysis and evaluation method is put forward in this paper,which is applied to evaluate the power generation technology of differential pressure produced by natural gas expansion.By using the exergy analysis theory,the black box-gray box hierarchical exergy analysis models of three differential pressure power generation technologies are established respectively.Firstly,the“black box”analysis models of main energy consuming equipment are established,and then the“gray box”analysis model of the total system is established.Based on the calculation results of exergy analysis indexes,the weak energy consumption equipment in the whole power generation process is accurately located.Taking a gas field in southwest China as an example,the comprehensive energy consumption evaluation of the three power generation technologies is carried out,and the technology with the best energy consumption condition among the three technologies is determined.Finally,the rationalization improvement measures are put forward from improving the air tightness,replacing the deflector and reducing the flow loss.
文摘Notable for the completeness with which it surrenders formally and artistically to the textual dictates of Twitter, Jennifer Egan's 2012 short science fiction Black Box is one of the most triumphant and fully-fledged fictions written in the form of new media. This paper explores the Twitter narrative employed in Black Box, pointing out that the serialized tweeting format of the story released via computer, mobile phone, or other electronic equipments brings readers immediate reading experience, allowing readers to sense the same feelings as the protagonist does. Through the experimental serialization of"Twitter" narrative, Egan expresses her concerns and worries about the security of the American security as well as the whole world in the post-"9.11" period and at the same time she embraces the virtues and pleasures of traditional storytelling delivered through a wholly new digital format. This paper concludes that Black Box is perhaps one of the boldest experiments of narrative form and is direct exploration into the contemporary image culture.
文摘Like many other people ~*with nowhere better to go^1,thewoman everyone called Old Betty came to the library almost everyday.Prim^2 Miss Tonsitt sometimes had to get the caretaker^3 to e-ject^4 old people from the library if their sleeping,eating or talkingbecame too objectionable^5,but Old Betty never gave any trouble.Still quite sprightly^6 despite her age, ~*though subiect to
文摘With the advancement of technology in recent years, effective fault diagnosis became a necessity to verify the performance and ensure the quality of complex systems. In this paper, an original verification methodology for complex consumer electronic devices is presented. Verification of the system which consists of hardware (integrated circuit) and corresponding software within a flat panel TV set is in the focus. Proposed methodology provides reliable functional failure detection using the concept of black box testing. Further, the approach is fully automated, improving the reliability and speed of failure detection. The methodology effectiveness has been experimentally evaluated and the analysis results have been reported.
文摘The multiplicity distribution (P(nch)) of charged particles produced in a high energy collision is a key quantity to understand the mechanism of multiparticle production. This paper describes the novel application of an artificial neural network (ANN) black-box modeling approach based on the cascade correlation (CC) algorithm formulated to calculate and predict multiplicity distribution of proton-proton (antiproton) (PP and PP ) inelastic interactions full phase space at a wide range of center-mass of energy . In addition, the formulated cascade correlation neural network (CCNN) model is used to empirically calculate the average multiplicity distribution nch> as a function of . The CCNN model was designed based on available experimental data for = 30.4 GeV, 44.5 GeV, 52.6 GeV, 62.2 GeV, 200 GeV, 300 GeV, 540 GeV, 900 GeV, 1000 GeV, 1800 GeV, and 7 TeV. Our obtained empirical results for P(nch), as well as nch> for (PP and PP) collisions are compared with the corresponding theoretical ones which obtained from other models. This comparison shows a good agreement with the available experimental data (up to 7 TeV) and other theoretical ones. At full large hadron collider (LHC) energy ( = 14 TeV) we have predicted P(nch) and nch> which also, show a good agreement with different theoretical models.
文摘A complementarity hypothesis concerning outsider and insider perspectives of a gargantuan black hole is proposed. The two thought experiments presented herein are followed by a brief discussion of a new interpretation of black hole interior “space-and-time-reversal”. Specifically, it is proposed that the “singularity” space of the black hole interior is time-like and the expansion time of the black hole interior is space-like. The resemblance of this new insider interpretation to our own expanding and redshifting big bang universe is compelling.