Laser anti-drone technology is entering the sequence of actual combat,and it is necessary to consider the vulnerability of typical functional parts of UAVs.Since the concept of"vulnerability"was proposed,a v...Laser anti-drone technology is entering the sequence of actual combat,and it is necessary to consider the vulnerability of typical functional parts of UAVs.Since the concept of"vulnerability"was proposed,a variety of analysis programs for battlefield targets to traditional weapons have been developed,but a comprehensive assessment methodology for targets'vulnerability to laser is still missing.Based on the shotline method,this paper proposes a method that equates laser beam to shotline array,an efficient vulnerability analysis program of target to laser is established by this method,and the program includes the circuit board and the wire into the vulnerability analysis category,which improves the precision of the vulnerability analysis.Taking the UAV engine part as the target of vulnerability analysis,combine with the"life-death unit method"to calculate the laser penetration rate of various materials of the UAV,and the influence of laser weapon system parameters and striking orientation on the killing probability is quantified after introducing the penetration rate into the vulnerability analysis program.The quantitative analysis method proposed in this paper has certain general expansibility,which can provide a fresh idea for the vulnerability analysis of other targets to laser.展开更多
When D:ξ→η is a linear ordinary differential (OD) or partial differential (PD) operator, a “direct problem” is to find the generating compatibility conditions (CC) in the form of an operator D<sub>1:</su...When D:ξ→η is a linear ordinary differential (OD) or partial differential (PD) operator, a “direct problem” is to find the generating compatibility conditions (CC) in the form of an operator D<sub>1:</sub>η→ξ such that Dξ = η implies D<sub>1</sub>η = 0. When D is involutive, the procedure provides successive first-order involutive operators D<sub>1</sub>,...,D<sub>n </sub>when the ground manifold has dimension n. Conversely, when D<sub>1</sub> is given, a much more difficult “inverse problem” is to look for an operator D:ξ→η having the generating CC D<sub>1</sub>η = 0. If this is possible, that is when the differential module defined by D<sub>1</sub> is “torsion-free”, that is when there does not exist any observable quantity which is a sum of derivatives of η that could be a solution of an autonomous OD or PD equation for itself, one shall say that the operator D<sub>1</sub> is parametrized by D. The parametrization is said to be “minimum” if the differential module defined by D does not contain a free differential submodule. The systematic use of the adjoint of a differential operator provides a constructive test with five steps using double differential duality. We prove and illustrate through many explicit examples the fact that a control system is controllable if and only if it can be parametrized. Accordingly, the controllability of any OD or PD control system is a “built in” property not depending on the choice of the input and output variables among the system variables. In the OD case and when D<sub>1</sub> is formally surjective, controllability just amounts to the formal injectivity of ad(D<sub>1</sub>), even in the variable coefficients case, a result still not acknowledged by the control community. Among other applications, the parametrization of the Cauchy stress operator in arbitrary dimension n has attracted many famous scientists (G. B. Airy in 1863 for n = 2, J. C. Maxwell in 1870, E. Beltrami in 1892 for n = 3, and A. Einstein in 1915 for n = 4). We prove that all these works are already explicitly using the self-adjoint Einstein operator, which cannot be parametrized and the comparison needs no comment. As a byproduct, they are all based on a confusion between the so-called div operator D<sub>2</sub> induced from the Bianchi operator and the Cauchy operator, adjoint of the Killing operator D which is parametrizing the Riemann operator D<sub>1</sub> for an arbitrary n. This purely mathematical result deeply questions the origin and existence of gravitational waves, both with the mathematical foundations of general relativity. As a matter of fact, this new framework provides a totally open domain of applications for computer algebra as the quoted test can be studied by means of Pommaret bases and related recent packages.展开更多
As cyber threats keep changing and business environments adapt, a comprehensive approach to disaster recovery involves more than just defensive measures. This research delves deep into the strategies required to respo...As cyber threats keep changing and business environments adapt, a comprehensive approach to disaster recovery involves more than just defensive measures. This research delves deep into the strategies required to respond to threats and anticipate and mitigate them proactively. Beginning with understanding the critical need for a layered defense and the intricacies of the attacker’s journey, the research offers insights into specialized defense techniques, emphasizing the importance of timely and strategic responses during incidents. Risk management is brought to the forefront, underscoring businesses’ need to adopt mature risk assessment practices and understand the potential risk impact areas. Additionally, the value of threat intelligence is explored, shedding light on the importance of active engagement within sharing communities and the vigilant observation of adversary motivations. “Beyond Defense: Proactive Approaches to Disaster Recovery and Threat Intelligence in Modern Enterprises” is a comprehensive guide for organizations aiming to fortify their cybersecurity posture, marrying best practices in proactive and reactive measures in the ever-challenging digital realm.展开更多
Objective: To study multi-directional derivation of cord blood mononuclear cells to CD3AK, LAK and CIK cells as well as changes of killing activity to gastric cancer cell strain in vitro. Methods: CD3mAb and IL-2 we...Objective: To study multi-directional derivation of cord blood mononuclear cells to CD3AK, LAK and CIK cells as well as changes of killing activity to gastric cancer cell strain in vitro. Methods: CD3mAb and IL-2 were used to induce CD3AK cells, and IL-2 was used to induce LAK cells; IFN-γ was used in the beginning, then IL-1, CD3mAb and IL-2 were used to induce CIK cells after 24 h for observing amplification and analyzing their relationship. The phenotypes of the cultured CIK cells were analyzed by flow cytometry. Subsequently, by using MGC-803 gastric cancer cell strain as target cells, the killing activity of CD3AK, LAK and CIK cells was evaluated by using MTT method. Results: The amplification activity of CD3AK and CIK cells was all far higher than LAK cells (P〈0.05). The amplification activity had no obvious difference between CIK cells and CD3AK cells at prophase, but that was far higher in CIK cells than CD3AK cells at about 20^th day (P〈0.05). The flow cytometry revealed that the amount of CD3^+ CD56^+ cells, major effector cells after CIK cells being cultured was significantly increased (P〈0.05), moreover, the amount of CD8^+ cells was significantly increased as well (P〈0.05). The killing activities of CD3AK and CIK cells to the MGC-803 gastric cancer cell strain were all significantly higher than LAK cells, while the killing activity of CIK cells was stronger than CD3AK cells (P〈0.05). Conclusion: CIK cells have stronger amplification activity and killing activity, and can be taken as more effective killing cells applied to the tumor adoptive immunotherapy.展开更多
Let E be a vector bundle over a compact Riemannian manifold M. We construct a natural metric on the bundle space E and discuss the relationship between the killing vector fields of E and M. Then we give a proof of the...Let E be a vector bundle over a compact Riemannian manifold M. We construct a natural metric on the bundle space E and discuss the relationship between the killing vector fields of E and M. Then we give a proof of the Bott-Baum-Cheeger Theorem for vector bundle E.展开更多
本文从生态翻译学视域对文艺作品To Kill a Mockingbird中文译本进行美学方面的研究,以生态翻译学及翻译美学两大理论为框架,从词语、句子两个层面出发,对李育超和高红梅两位译者的译本进行深入全面的分析。本文旨在通过对To Kill a Moc...本文从生态翻译学视域对文艺作品To Kill a Mockingbird中文译本进行美学方面的研究,以生态翻译学及翻译美学两大理论为框架,从词语、句子两个层面出发,对李育超和高红梅两位译者的译本进行深入全面的分析。本文旨在通过对To Kill a Mockingbird一书中的经典实例进行分析,阐释这两种译本内两种语言交换过程中的美学问题。展开更多
A prescribed performance neural controller to guarantee tracking quality is addressed for the near space kinetic kill vehicle (NSKKV) to meet the state constraints caused by side window detection. Different from the t...A prescribed performance neural controller to guarantee tracking quality is addressed for the near space kinetic kill vehicle (NSKKV) to meet the state constraints caused by side window detection. Different from the traditional prescribed performance control in which the shape of the performance function is constant, this paper exploits new performance functions which can change the shape of their function according to different symbols of initial errors and can ensure the error convergence with a small overshoot. The neural backstepping control and the minimal learning parameters (MLP) technology are employed for exploring a prescribed performance controller (PPC) that provides robust tracking attitude reference trajectories. The highlight is that the transient performance of tracking errors is satisfactory and the computational load of neural approximation is low. The pseudo rate (PSR) modulator is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the thruster. Numerical simulations show that the proposed method can achieve state constraints, pseudo-linear operation and high accuracy.展开更多
AIM: To study the selective killing of human umbilical vein endothelial cells (HUVECs) by a double suicide gene under the regulation of a kinase domain insert containing receptor (KDR) promoter and mediated by an...AIM: To study the selective killing of human umbilical vein endothelial cells (HUVECs) by a double suicide gene under the regulation of a kinase domain insert containing receptor (KDR) promoter and mediated by an adenoviral gene vector. METHODS: Human KDR promoter was cloned by polymerase chain reaction (PCR), and two recombinant adenoviral plasmids pAdKDR-CdgIyTK, pAdCMV-CDglyTK were constructed according to a two-step transformation protocol. These two newly constructed plasmids were then transfected into 293 packaging cells to grow adenovirus, which were further multiplied and purified. HUVECs and LoVo cells were infected with either of the two resultant recombinant adenoviruses (AdKDR-CDglyTK and AdCMV-CDglyTK) respectively, and the infection rates were estimated by detection of green fluorescent protein (GFP) expression. Infected cells were cultured in culture media containing different concentrations of 5-fiuoroo/tosine (5-FC) and ganciclovir (GCV), and the killing effects were measured. RESULTS: The two recombinant adenoviral plasmids pAdKDR-CdglyTK, pAdCMV-CDglyTK were successfully constructed and transfected into 293 cells. The resultant recombinant adenoviruses infected cells caused similar infection rates; and the infected cells exhibited different sensitivity to the prodrugs: HUVECs infected with AdCMV-CDglyTK and LoVo cells infected with AdCMVo CDglyTK were highly sensitive to the prodrugs, and HUVECs infected with AdKDR-CDglyTK were similarly sensitive but significantly more sensitive than the LoVo cells infected with AdKDR-CdglyTK (P 〈 0.001). CONCLUSION: Selective killing of HUVECs may be achieved by gene transfer of double suicide gene under the regulation of the KDR promoter. This finding may provide an optional way to target gene therapy of malignant tumors by abrogation of tumor blood vessels.展开更多
AIM:To investigate the stress-induced apoptosis of natural killer(NK)cells and the changes in their killing activity in mouse livers.METHODS:A restraint stress model was established in mice.Flow cytometry was employed...AIM:To investigate the stress-induced apoptosis of natural killer(NK)cells and the changes in their killing activity in mouse livers.METHODS:A restraint stress model was established in mice.Flow cytometry was employed to measure the percentage of NK cells and the changes in their absolute number in mouse liver.The cytotoxicity of hepatic and splenic NK cells was assessed against YAC-1 target cells via a 4 h 51Cr-release assay.RESULTS:The restraint stress stimulation induced the apoptosis of NK cells in the liver and the spleen,which decreased the cell number.The number and percentage of NK cells in the spleen decreased.However,the number of NK cells in the liver decreased,whereas the percentage of NK cells was significantly increased.The apoptosis of NK cells increased gradually with prolonged stress time,and the macrophage-1(Mac-1)+NK cells were more susceptible to apoptosis than Mac-1-NK cells.Large numbers of Mac-1-NK cells in the liver,which are more resistant to stress-induced apoptosis,were observed than the Mac-1-NK cells in the spleen.The stress stimulation diminished the killing activity of NK cells in the spleen was significantly decreased,but the retention of numerous Mac-1-NK cells in the liver maintained the killing ability.CONCLUSION:Significant stress-induced apoptosis was observed among Mac-1+NK cells,but not Mac-1-NK cells in the mouse liver.Stress stimulation markedly decreased the killing activity of NK cells in the spleen but remained unchanged in the liver.展开更多
Objective: To study the enhancement of the immune functions and autologous tumor killing (ATK) activity by kappa selenocarrageenan (KSC) in mice bearing sarcoma 180. Methods: To measure the effects of KSC and/or Cy...Objective: To study the enhancement of the immune functions and autologous tumor killing (ATK) activity by kappa selenocarrageenan (KSC) in mice bearing sarcoma 180. Methods: To measure the effects of KSC and/or Cyclophosphamide (Cy) on natural killer (NK) activity, lymphokine activated killer (LAK) activity, the produc tion of interleukin 2 (IL 2), ATK activity and the growth of sarcoma 180 (S 180 ). Results: KSC promoted NK activity, LAK activity and ATK activity in vivo , increased IL 2 production at 40 mg/kg/d×9d. It also enhanced the antitumor action of Cy (20 mg/kg/d×9d) and offset the inhibition of Cy on immunocopetent cells. The ATK activity in splenocytes of S 180 bearing mice could be induced and increased by recombinant interleukin 2 (rIL 2) in vitro . Conclusion: KSC has an up regulating effect on the immune functions and ATK activity in tumor bearing mice. It can be used as a biological response modifier (BRM) in cancer biotherapy.展开更多
In the novel of To Kill a Mockingbird,the theme of family education in America has been discussed through the whole story.This paper will compare the differences of family education between Americans and Chinese based...In the novel of To Kill a Mockingbird,the theme of family education in America has been discussed through the whole story.This paper will compare the differences of family education between Americans and Chinese based on this novel and analyze the reasons and the influences as well.The conclusion is that there is no better or worse family education model,in fact,the key is to find out the most suitable model for the benefit of children according to their different situations.展开更多
To Kill a Mockingbird is the masterpiece of Harper Lee,who created an important black man named Tom Robinson in it.Although hard-working and kind-hearted,Tom Robinson becomes a victim of racial discrimination with the...To Kill a Mockingbird is the masterpiece of Harper Lee,who created an important black man named Tom Robinson in it.Although hard-working and kind-hearted,Tom Robinson becomes a victim of racial discrimination with the tragic death.He is the epitome of the era and the tragedy of the individual.Based on the rape trial in To Kill a Mockingbird,this paper analyzes the injustice and inequality for black people in the white-dominated society from the perspective of racism,interpreting the tragic fate of Tom Robinson under the racial discrimination.展开更多
The new four-dimensional geometry whose Killing vectors span the Poincaré algebra is presented and its structure is analyzed.The new geometry can be regarded as the Poincaré-invariant solution of the degener...The new four-dimensional geometry whose Killing vectors span the Poincaré algebra is presented and its structure is analyzed.The new geometry can be regarded as the Poincaré-invariant solution of the degenerate extension of the vacuum Einstein field equations with a negative cosmological constant and provides a static cosmological spacetime with a Lobachevsky space.The motion of free particles in the spacetime is discussed.展开更多
In this paper we classify spatially homogeneous rotating space-times according to their teleparallel Killing vector fields using direct integration technique.It turns out that the dimension of the teleparallel Killing...In this paper we classify spatially homogeneous rotating space-times according to their teleparallel Killing vector fields using direct integration technique.It turns out that the dimension of the teleparallel Killing vector fields is 5 or 10.In the case of 10 teleparallel Killing vector fields the space-time becomes Minkowski and all the torsion components are zero.Teleparallel Killing vector fields in this case are exactly the same as in general relativity.In the cases of 5 teleparallel Killing vector fields we get two more conservation laws in the teleparallel theory of gravitation.Here we also discuss some well-known examples of spatially homogeneous rotating space-times according to their teleparallel Killing vector fields.展开更多
In this paper we classify Kantowski-Sachs and Bianchi type Ⅲ space-times according to their teleparallel Killing vector fields using direct integration technique. It turns out that the dimension of the telepaxallel K...In this paper we classify Kantowski-Sachs and Bianchi type Ⅲ space-times according to their teleparallel Killing vector fields using direct integration technique. It turns out that the dimension of the telepaxallel Killing vector fields are 4 or 6, which are the same in numbers as in general relativity. In case of 4 the teleparallel Killing vector fields are multiple of the corresponding Killing vector fields in general relativity by some function of t. In the case of 6 Killing vector fields the metric functions become constants and the Killing vector fields in this case are exactly the same as in general relativity. Here we also discuss the Lie algebra in each case.展开更多
In this paper, Killing vectors of spherically spacetimes have been evaluated in the context of teleparallel theory of gravitation. Further, we investigate the Killing vectors of the Friedmann metrics. It is found that...In this paper, Killing vectors of spherically spacetimes have been evaluated in the context of teleparallel theory of gravitation. Further, we investigate the Killing vectors of the Friedmann metrics. It is found that for static spherically spacetimes the number of Killing vectors turns out to be seven while for the Friedmann models, we obtain six teleparallel Killing vectors. The results are then compared with those of General Relativity. We conclude that both of these descriptions of gravity do not provide the consistent results in general. However, these results may coincide under certain conditions for a particular spacetime.展开更多
In an age when criminal psychology was still new, Edgar Allan Poe revolutionized the world with his tales of insightful penetration into the criminal mind. "The Tell-Tale Heart" (2007) is one such tale. Behind the...In an age when criminal psychology was still new, Edgar Allan Poe revolutionized the world with his tales of insightful penetration into the criminal mind. "The Tell-Tale Heart" (2007) is one such tale. Behind the mask of the narrator lies the dangerous, diabolical, and premeditated crime of the sadist. Most critics neglected to highlight the sadistic complex which manifests itself with outstanding clarity in the character Poe presents. Instead, they chose to focus on other aspects of his character, namely, his disturbed mental state. Yet, to dismiss a perversion such as sadism is to lose sight of Poe's legitimate merits as a criminal psychologist. This study highlights this point Through an interdisciplinary approach between criminology and literature, the study examines Poe's work from the criminological tradition represented by such figures as Richard von Krafft-Ebing, Paul De River, Carol Anne Davis, Karl Berg, Peter Vronsky, Julie Harrower, Curt R. Bartol, and others. The study is based upon criminological insights derived from and supported by actual case histories, and thus, is extremely important in bridging the gap between literature and criminology展开更多
基金National Natural Science Foundation of China(Grant Nos.62005276,62175234)the Scientific and Technological Development Program of Jilin,China(Grant No.20230508111RC)to provide fund for this research。
文摘Laser anti-drone technology is entering the sequence of actual combat,and it is necessary to consider the vulnerability of typical functional parts of UAVs.Since the concept of"vulnerability"was proposed,a variety of analysis programs for battlefield targets to traditional weapons have been developed,but a comprehensive assessment methodology for targets'vulnerability to laser is still missing.Based on the shotline method,this paper proposes a method that equates laser beam to shotline array,an efficient vulnerability analysis program of target to laser is established by this method,and the program includes the circuit board and the wire into the vulnerability analysis category,which improves the precision of the vulnerability analysis.Taking the UAV engine part as the target of vulnerability analysis,combine with the"life-death unit method"to calculate the laser penetration rate of various materials of the UAV,and the influence of laser weapon system parameters and striking orientation on the killing probability is quantified after introducing the penetration rate into the vulnerability analysis program.The quantitative analysis method proposed in this paper has certain general expansibility,which can provide a fresh idea for the vulnerability analysis of other targets to laser.
文摘When D:ξ→η is a linear ordinary differential (OD) or partial differential (PD) operator, a “direct problem” is to find the generating compatibility conditions (CC) in the form of an operator D<sub>1:</sub>η→ξ such that Dξ = η implies D<sub>1</sub>η = 0. When D is involutive, the procedure provides successive first-order involutive operators D<sub>1</sub>,...,D<sub>n </sub>when the ground manifold has dimension n. Conversely, when D<sub>1</sub> is given, a much more difficult “inverse problem” is to look for an operator D:ξ→η having the generating CC D<sub>1</sub>η = 0. If this is possible, that is when the differential module defined by D<sub>1</sub> is “torsion-free”, that is when there does not exist any observable quantity which is a sum of derivatives of η that could be a solution of an autonomous OD or PD equation for itself, one shall say that the operator D<sub>1</sub> is parametrized by D. The parametrization is said to be “minimum” if the differential module defined by D does not contain a free differential submodule. The systematic use of the adjoint of a differential operator provides a constructive test with five steps using double differential duality. We prove and illustrate through many explicit examples the fact that a control system is controllable if and only if it can be parametrized. Accordingly, the controllability of any OD or PD control system is a “built in” property not depending on the choice of the input and output variables among the system variables. In the OD case and when D<sub>1</sub> is formally surjective, controllability just amounts to the formal injectivity of ad(D<sub>1</sub>), even in the variable coefficients case, a result still not acknowledged by the control community. Among other applications, the parametrization of the Cauchy stress operator in arbitrary dimension n has attracted many famous scientists (G. B. Airy in 1863 for n = 2, J. C. Maxwell in 1870, E. Beltrami in 1892 for n = 3, and A. Einstein in 1915 for n = 4). We prove that all these works are already explicitly using the self-adjoint Einstein operator, which cannot be parametrized and the comparison needs no comment. As a byproduct, they are all based on a confusion between the so-called div operator D<sub>2</sub> induced from the Bianchi operator and the Cauchy operator, adjoint of the Killing operator D which is parametrizing the Riemann operator D<sub>1</sub> for an arbitrary n. This purely mathematical result deeply questions the origin and existence of gravitational waves, both with the mathematical foundations of general relativity. As a matter of fact, this new framework provides a totally open domain of applications for computer algebra as the quoted test can be studied by means of Pommaret bases and related recent packages.
文摘As cyber threats keep changing and business environments adapt, a comprehensive approach to disaster recovery involves more than just defensive measures. This research delves deep into the strategies required to respond to threats and anticipate and mitigate them proactively. Beginning with understanding the critical need for a layered defense and the intricacies of the attacker’s journey, the research offers insights into specialized defense techniques, emphasizing the importance of timely and strategic responses during incidents. Risk management is brought to the forefront, underscoring businesses’ need to adopt mature risk assessment practices and understand the potential risk impact areas. Additionally, the value of threat intelligence is explored, shedding light on the importance of active engagement within sharing communities and the vigilant observation of adversary motivations. “Beyond Defense: Proactive Approaches to Disaster Recovery and Threat Intelligence in Modern Enterprises” is a comprehensive guide for organizations aiming to fortify their cybersecurity posture, marrying best practices in proactive and reactive measures in the ever-challenging digital realm.
文摘Objective: To study multi-directional derivation of cord blood mononuclear cells to CD3AK, LAK and CIK cells as well as changes of killing activity to gastric cancer cell strain in vitro. Methods: CD3mAb and IL-2 were used to induce CD3AK cells, and IL-2 was used to induce LAK cells; IFN-γ was used in the beginning, then IL-1, CD3mAb and IL-2 were used to induce CIK cells after 24 h for observing amplification and analyzing their relationship. The phenotypes of the cultured CIK cells were analyzed by flow cytometry. Subsequently, by using MGC-803 gastric cancer cell strain as target cells, the killing activity of CD3AK, LAK and CIK cells was evaluated by using MTT method. Results: The amplification activity of CD3AK and CIK cells was all far higher than LAK cells (P〈0.05). The amplification activity had no obvious difference between CIK cells and CD3AK cells at prophase, but that was far higher in CIK cells than CD3AK cells at about 20^th day (P〈0.05). The flow cytometry revealed that the amount of CD3^+ CD56^+ cells, major effector cells after CIK cells being cultured was significantly increased (P〈0.05), moreover, the amount of CD8^+ cells was significantly increased as well (P〈0.05). The killing activities of CD3AK and CIK cells to the MGC-803 gastric cancer cell strain were all significantly higher than LAK cells, while the killing activity of CIK cells was stronger than CD3AK cells (P〈0.05). Conclusion: CIK cells have stronger amplification activity and killing activity, and can be taken as more effective killing cells applied to the tumor adoptive immunotherapy.
文摘Let E be a vector bundle over a compact Riemannian manifold M. We construct a natural metric on the bundle space E and discuss the relationship between the killing vector fields of E and M. Then we give a proof of the Bott-Baum-Cheeger Theorem for vector bundle E.
文摘本文从生态翻译学视域对文艺作品To Kill a Mockingbird中文译本进行美学方面的研究,以生态翻译学及翻译美学两大理论为框架,从词语、句子两个层面出发,对李育超和高红梅两位译者的译本进行深入全面的分析。本文旨在通过对To Kill a Mockingbird一书中的经典实例进行分析,阐释这两种译本内两种语言交换过程中的美学问题。
基金supported by the National Natural Science Foundation of China(61773398 61703421)
文摘A prescribed performance neural controller to guarantee tracking quality is addressed for the near space kinetic kill vehicle (NSKKV) to meet the state constraints caused by side window detection. Different from the traditional prescribed performance control in which the shape of the performance function is constant, this paper exploits new performance functions which can change the shape of their function according to different symbols of initial errors and can ensure the error convergence with a small overshoot. The neural backstepping control and the minimal learning parameters (MLP) technology are employed for exploring a prescribed performance controller (PPC) that provides robust tracking attitude reference trajectories. The highlight is that the transient performance of tracking errors is satisfactory and the computational load of neural approximation is low. The pseudo rate (PSR) modulator is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the thruster. Numerical simulations show that the proposed method can achieve state constraints, pseudo-linear operation and high accuracy.
基金Supported by the Natural Science Foundation of Guangdong Province,No.013072the 863 Program Funds,No.2001AA 217171
文摘AIM: To study the selective killing of human umbilical vein endothelial cells (HUVECs) by a double suicide gene under the regulation of a kinase domain insert containing receptor (KDR) promoter and mediated by an adenoviral gene vector. METHODS: Human KDR promoter was cloned by polymerase chain reaction (PCR), and two recombinant adenoviral plasmids pAdKDR-CdgIyTK, pAdCMV-CDglyTK were constructed according to a two-step transformation protocol. These two newly constructed plasmids were then transfected into 293 packaging cells to grow adenovirus, which were further multiplied and purified. HUVECs and LoVo cells were infected with either of the two resultant recombinant adenoviruses (AdKDR-CDglyTK and AdCMV-CDglyTK) respectively, and the infection rates were estimated by detection of green fluorescent protein (GFP) expression. Infected cells were cultured in culture media containing different concentrations of 5-fiuoroo/tosine (5-FC) and ganciclovir (GCV), and the killing effects were measured. RESULTS: The two recombinant adenoviral plasmids pAdKDR-CdglyTK, pAdCMV-CDglyTK were successfully constructed and transfected into 293 cells. The resultant recombinant adenoviruses infected cells caused similar infection rates; and the infected cells exhibited different sensitivity to the prodrugs: HUVECs infected with AdCMV-CDglyTK and LoVo cells infected with AdCMVo CDglyTK were highly sensitive to the prodrugs, and HUVECs infected with AdKDR-CDglyTK were similarly sensitive but significantly more sensitive than the LoVo cells infected with AdKDR-CdglyTK (P 〈 0.001). CONCLUSION: Selective killing of HUVECs may be achieved by gene transfer of double suicide gene under the regulation of the KDR promoter. This finding may provide an optional way to target gene therapy of malignant tumors by abrogation of tumor blood vessels.
基金Supported by The National Natural Science Foundation of China,No.30671899,No.30540012
文摘AIM:To investigate the stress-induced apoptosis of natural killer(NK)cells and the changes in their killing activity in mouse livers.METHODS:A restraint stress model was established in mice.Flow cytometry was employed to measure the percentage of NK cells and the changes in their absolute number in mouse liver.The cytotoxicity of hepatic and splenic NK cells was assessed against YAC-1 target cells via a 4 h 51Cr-release assay.RESULTS:The restraint stress stimulation induced the apoptosis of NK cells in the liver and the spleen,which decreased the cell number.The number and percentage of NK cells in the spleen decreased.However,the number of NK cells in the liver decreased,whereas the percentage of NK cells was significantly increased.The apoptosis of NK cells increased gradually with prolonged stress time,and the macrophage-1(Mac-1)+NK cells were more susceptible to apoptosis than Mac-1-NK cells.Large numbers of Mac-1-NK cells in the liver,which are more resistant to stress-induced apoptosis,were observed than the Mac-1-NK cells in the spleen.The stress stimulation diminished the killing activity of NK cells in the spleen was significantly decreased,but the retention of numerous Mac-1-NK cells in the liver maintained the killing ability.CONCLUSION:Significant stress-induced apoptosis was observed among Mac-1+NK cells,but not Mac-1-NK cells in the mouse liver.Stress stimulation markedly decreased the killing activity of NK cells in the spleen but remained unchanged in the liver.
文摘Objective: To study the enhancement of the immune functions and autologous tumor killing (ATK) activity by kappa selenocarrageenan (KSC) in mice bearing sarcoma 180. Methods: To measure the effects of KSC and/or Cyclophosphamide (Cy) on natural killer (NK) activity, lymphokine activated killer (LAK) activity, the produc tion of interleukin 2 (IL 2), ATK activity and the growth of sarcoma 180 (S 180 ). Results: KSC promoted NK activity, LAK activity and ATK activity in vivo , increased IL 2 production at 40 mg/kg/d×9d. It also enhanced the antitumor action of Cy (20 mg/kg/d×9d) and offset the inhibition of Cy on immunocopetent cells. The ATK activity in splenocytes of S 180 bearing mice could be induced and increased by recombinant interleukin 2 (rIL 2) in vitro . Conclusion: KSC has an up regulating effect on the immune functions and ATK activity in tumor bearing mice. It can be used as a biological response modifier (BRM) in cancer biotherapy.
文摘In the novel of To Kill a Mockingbird,the theme of family education in America has been discussed through the whole story.This paper will compare the differences of family education between Americans and Chinese based on this novel and analyze the reasons and the influences as well.The conclusion is that there is no better or worse family education model,in fact,the key is to find out the most suitable model for the benefit of children according to their different situations.
文摘To Kill a Mockingbird is the masterpiece of Harper Lee,who created an important black man named Tom Robinson in it.Although hard-working and kind-hearted,Tom Robinson becomes a victim of racial discrimination with the tragic death.He is the epitome of the era and the tragedy of the individual.Based on the rape trial in To Kill a Mockingbird,this paper analyzes the injustice and inequality for black people in the white-dominated society from the perspective of racism,interpreting the tragic fate of Tom Robinson under the racial discrimination.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10775140,10705048,10731080,10975141,11175245,11075206the Fundamental Research Funds for the Central Universities under Grant No.105116.
文摘The new four-dimensional geometry whose Killing vectors span the Poincaré algebra is presented and its structure is analyzed.The new geometry can be regarded as the Poincaré-invariant solution of the degenerate extension of the vacuum Einstein field equations with a negative cosmological constant and provides a static cosmological spacetime with a Lobachevsky space.The motion of free particles in the spacetime is discussed.
文摘In this paper we classify spatially homogeneous rotating space-times according to their teleparallel Killing vector fields using direct integration technique.It turns out that the dimension of the teleparallel Killing vector fields is 5 or 10.In the case of 10 teleparallel Killing vector fields the space-time becomes Minkowski and all the torsion components are zero.Teleparallel Killing vector fields in this case are exactly the same as in general relativity.In the cases of 5 teleparallel Killing vector fields we get two more conservation laws in the teleparallel theory of gravitation.Here we also discuss some well-known examples of spatially homogeneous rotating space-times according to their teleparallel Killing vector fields.
文摘In this paper we classify Kantowski-Sachs and Bianchi type Ⅲ space-times according to their teleparallel Killing vector fields using direct integration technique. It turns out that the dimension of the telepaxallel Killing vector fields are 4 or 6, which are the same in numbers as in general relativity. In case of 4 the teleparallel Killing vector fields are multiple of the corresponding Killing vector fields in general relativity by some function of t. In the case of 6 Killing vector fields the metric functions become constants and the Killing vector fields in this case are exactly the same as in general relativity. Here we also discuss the Lie algebra in each case.
文摘In this paper, Killing vectors of spherically spacetimes have been evaluated in the context of teleparallel theory of gravitation. Further, we investigate the Killing vectors of the Friedmann metrics. It is found that for static spherically spacetimes the number of Killing vectors turns out to be seven while for the Friedmann models, we obtain six teleparallel Killing vectors. The results are then compared with those of General Relativity. We conclude that both of these descriptions of gravity do not provide the consistent results in general. However, these results may coincide under certain conditions for a particular spacetime.
文摘In an age when criminal psychology was still new, Edgar Allan Poe revolutionized the world with his tales of insightful penetration into the criminal mind. "The Tell-Tale Heart" (2007) is one such tale. Behind the mask of the narrator lies the dangerous, diabolical, and premeditated crime of the sadist. Most critics neglected to highlight the sadistic complex which manifests itself with outstanding clarity in the character Poe presents. Instead, they chose to focus on other aspects of his character, namely, his disturbed mental state. Yet, to dismiss a perversion such as sadism is to lose sight of Poe's legitimate merits as a criminal psychologist. This study highlights this point Through an interdisciplinary approach between criminology and literature, the study examines Poe's work from the criminological tradition represented by such figures as Richard von Krafft-Ebing, Paul De River, Carol Anne Davis, Karl Berg, Peter Vronsky, Julie Harrower, Curt R. Bartol, and others. The study is based upon criminological insights derived from and supported by actual case histories, and thus, is extremely important in bridging the gap between literature and criminology