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Quantum Unruh Effect on Radiation of Black Holes
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作者 Tianxi Zhang 《Journal of Modern Physics》 2024年第6期938-949,共12页
The quantum Unruh effect on radiation of a gravitational object including a black hole is analyzed and calculated. It is surprisingly found that the well-known Hawking radiation of a black hole is not physical. Applyi... The quantum Unruh effect on radiation of a gravitational object including a black hole is analyzed and calculated. It is surprisingly found that the well-known Hawking radiation of a black hole is not physical. Applying the Stephan-Boltzmann law with the use of the Unruh radiation temperature at the surface of a black hole to calculate the power of radiation of the black hole is conceptually unphysical. This is because the Unruh radiation temperature results from the gravitational field of the object rather than from the thermal motion of matter of the object, so that the Stephan-Boltzmann law is not applicable. This paper shows that the emission power of Unruh radiation from a gravitational object should be calculated in terms of the rate of increase of the total Unruh radiation energy outside the object. The result obtained from this study indicates that a gravitational object can emit Unruh radiation when the variation of its mass and radius satisfies an inequality of dM/M > 1.25dR/R. For a black hole, the emission of Unruh radiation does not occur unless it can loose its mass (dM < 0). The emission power of Unruh radiation is only an extremely tiny part of the rate of mass-energy loss if the black hole is not extremely micro-sized. This study turns down our traditional understanding of the Hawking radiation and thermodynamics of black holes. 展开更多
关键词 black Hole GRAVITATION Quantum field Theory blackbody Radiation
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Black Hole Singularities and Planetary Formation
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作者 Louise Riofrio 《Journal of Applied Mathematics and Physics》 2024年第4期1079-1088,共10页
The goal of this research is to explore the effects of black hole singularities. Methodology is to start with large objects like galaxies and continue to smaller objects within our solar neighbourhood. High-redshift o... The goal of this research is to explore the effects of black hole singularities. Methodology is to start with large objects like galaxies and continue to smaller objects within our solar neighbourhood. High-redshift observations from the James Webb Space Telescope reveal that distant galaxies and their central black holes formed shortly after the Big Bang. An innovation about the speed of light explains how supermassive black holes could have formed primordially. Predictions of Hawking radiation include the possibility of black holes contributing to the energy of stars such as the Sun. Black holes have also been suggested as a source of radiation and magnetic fields in giant planets. Observations of Enceladus raise the possibility that this moon and other objects near Saturn’s Rings contain small singularities. Extrapolations of this methodology indicate that black holes could exist within solar system bodies including planets. Extended discussion describes how their presence could explain mysteries of internal heat, planetary magnetic fields, and processes of solar system formation. 展开更多
关键词 black Holes GALAXIES Magnetic fields Planets Planetary Formation Speed of Light
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Electrically Tunable Energy Bandgap in Dual-Gated Ultra-Thin Black Phosphorus Field Effect Transistors 被引量:1
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作者 Shi-Li Yan Zhi-Jian Xie +2 位作者 Jian-Hao Chen Takashi Taniguchi Kenji Watanabe 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第4期87-91,共5页
The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is o... The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is of great importance not only to device physics but also to technological applications. Here we demonstrate a widely tunable bandgap of few-layer black phosphorus (BP) by the application of vertical electric field in dual-gated BP field-effect transistors. A total bandgap reduction of 124 meV is observed when the electrical displacement field is increased from 0.10 V/nm to 0.83 V/nm. Our results suggest appealing potential for few-layer BP as a tunable bandgap material in infrared optoelectronies, thermoelectric power generation and thermal imaging. 展开更多
关键词 Electrically Tunable Energy Bandgap in Dual-Gated Ultra-Thin black Phosphorus field Effect Transistors FET BP
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Resonant frequencies of massless scalar field in rotating black-brane spacetime
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作者 荆继良 潘启沅 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第6期1985-1989,共5页
This paper investigates the resonant frequencies of the massless scalar field in the near extremal Kerr-like black-brane spacetime. It is shown that the different angular quantum number will present different resonant... This paper investigates the resonant frequencies of the massless scalar field in the near extremal Kerr-like black-brane spacetime. It is shown that the different angular quantum number will present different resonant frequencies. It is also shown that the real part of the resonant frequencies increases as the compact dimensions parameter μi increases, but the magnitude of the imaginary part decreases as μi increases. 展开更多
关键词 resonant frequency black brane scalar field
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Implications for Discovery of Strong Radial Magnetic Field at the Galactic Center—Challenge to Black Hole Models 被引量:1
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作者 Qiuhe Peng Zheng Li 《Journal of Modern Physics》 2019年第12期1416-1423,共8页
The black hole model will be excluded by a very strong radial magnetic field near the Galactic Center which has been detected in 2013. Following it, the explosion mechanism, for both supernova and the hot big bang of ... The black hole model will be excluded by a very strong radial magnetic field near the Galactic Center which has been detected in 2013. Following it, the explosion mechanism, for both supernova and the hot big bang of the Universe, driven by magnetic monopoles is proposed in this paper. 展开更多
关键词 black Hole Model Strong RADIAL MAGNETIC field MAGNETIC MONOPOLES
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Black Holes in the Light of Field Theory and Quantum Mechanics
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作者 Ahmad Tarhini Khalil Abou-Saleh 《Journal of High Energy Physics, Gravitation and Cosmology》 2019年第3期612-622,共11页
The black hole is a region in space where things may fall into it but nothing can come out. We present a study of the physics of a black hole using a quantum field theory frame based on the WZW model in a suitable mat... The black hole is a region in space where things may fall into it but nothing can come out. We present a study of the physics of a black hole using a quantum field theory frame based on the WZW model in a suitable mathematical frame. Based on the Schwarzschild metric, we show the different regions of our universe with the present singularities. Then we introduce the calculation of a black hole mass using the perturbation theory. We further discuss Hawking radiation and its quantum mechanical implications. At some limits, the space time can represent a black hole with a singularity hidden by the horizon. 展开更多
关键词 black HOLES field Theory SCHWARZSCHILD Solution Hawking Radiation
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Entropy of quantum field in toroidal black hole without brick wall 被引量:1
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作者 王波波 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第2期467-472,共6页
In this paper the entropy of a toroidal black hole due to a scalar field is investigated by using the DLM scheme. The entropy is renormalized to the standard Bekenstein-Hawking formula with a one-loop correction arisi... In this paper the entropy of a toroidal black hole due to a scalar field is investigated by using the DLM scheme. The entropy is renormalized to the standard Bekenstein-Hawking formula with a one-loop correction arising from the higher curvature terms of the gravitational action. For the scalar field, the renormalized Newton constant and two renormalized coupling constants in the toroidal black hole are the same as those in the Reissner-Nordstrom black hole except for other one. 展开更多
关键词 black hole entropy renormalization brick-wall model scalar field
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秸秆还田对东北黑土水分特征及物理性质的影响 被引量:3
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作者 郑洪兵 罗洋 +8 位作者 隋鹏祥 李瑞平 王浩 任英 袁野 周思琪 田圣陶 刘武仁 郑金玉 《干旱地区农业研究》 CSCD 北大核心 2024年第1期226-236,共11页
为明确秸秆还田对东北黑土水分特征及物理性质的影响,设置秸秆覆盖还田(FG)、秸秆翻埋还田(FM)和秸秆不还田翻耕(FD)3个处理,测定土壤含水量、水分特征曲线、容重、硬度、土壤三相比及结构稳定性等参数。结果表明:(1)秸秆覆盖还田可显... 为明确秸秆还田对东北黑土水分特征及物理性质的影响,设置秸秆覆盖还田(FG)、秸秆翻埋还田(FM)和秸秆不还田翻耕(FD)3个处理,测定土壤含水量、水分特征曲线、容重、硬度、土壤三相比及结构稳定性等参数。结果表明:(1)秸秆覆盖还田可显著提高春季耕层(0~30 cm)土壤含水量,较秸秆不还田翻耕处理增幅为11.17%~150.84%;不同处理耕层土壤在水吸力中吸力段土壤含水量变化曲线平滑,秸秆覆盖还田处理具有较高的土壤持水性。(2)秸秆还田能显著提高土壤水分有效性,与秸秆不还田翻耕处理相比,秸秆覆盖还田处理0~10 cm土层土壤田间持水量提高4.85%~11.03%,土壤凋萎系数提高10.85%~18.00%;秸秆翻埋还田处理0~10 cm土层土壤重力水增加9.65%~80.73%。秸秆翻埋还田提升了土壤供水能力,土壤比水容量较秸秆不还田翻耕处理增加4.8%~10.0%。(3)与秸秆不还田翻耕处理相比,秸秆还田降低了收获后土壤紧实度,降低幅度为0.18~0.31 MPa;秸秆覆盖还田增加表层土壤容重,降低土壤孔隙度,促进三相结构趋于合理,显著增加土壤结构稳定性。(4)皮尔森相关分析表明,三相比R值与结构距离(r=0.73*)、土壤容重(r=0.70*)相关性显著,在一定范围内三相比R值的增加有利于改善并促进土壤结构稳定。综上可知,东北黑土农田实施秸秆还田是提高春季土壤含水量、增强土壤持水性、提升土壤供水能力、调节土壤紧实性、调控土壤三相比、改善土壤结构和提高土壤宜耕性的有效措施。 展开更多
关键词 秸秆还田 黑土 水分特征 土壤结构 三相比R值
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Complex frequencies of a massless scalar field in loop quantum black hole spacetime
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作者 陈菊华 王永久 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第3期48-53,共6页
Recently, considerable progress has been made in understanding the early universe by loop quantum cosmology. Modesto et al. investigated the loop quantum black hole (LQBH)using improved semiclassical analysis and th... Recently, considerable progress has been made in understanding the early universe by loop quantum cosmology. Modesto et al. investigated the loop quantum black hole (LQBH)using improved semiclassical analysis and they found that the LQBH has two horizons, an event horizon and a Cauchy horizon, just like the Reissner-NordstrSm black hole. This paper focuses on the dynamical evolution of a massless scalar wave in the LQBH background. By investigating the relation between the complex frequencies of the massless scalar field and the LQBH parameters using the numerical method, we find that the polymeric parameter P makes the massless scalar field decay more quickly and makes the ground scalar wave oscillate slowly. However, the polymeric parameter P causes the frequency of the high harmonic massless scalar wave to shift according to its value. We also find that the loop quantum gravity area gap parameter a0 causes the massless scalar field to decay more slowly and makes the period of the massless scalar field wave become longer. In the complex ω plane, the frequency curves move counterclockwise when the polymeric parameter P increases and this spiral effect is more obvious for a higher harmonic scalar wave. 展开更多
关键词 complex frequencies massless scalar field loop quantum black hole spacetime
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橄榄黑斑病病原菌的分离鉴定及防治药剂筛选 被引量:1
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作者 邵雪花 杨永璐 +5 位作者 赖多 刘传滨 李祝成 庄庆礼 秦健 肖维强 《核农学报》 CAS CSCD 北大核心 2024年第1期68-75,共8页
为明确引起潮州市橄榄黑斑病的病原菌种类,筛选有效防治药剂,对发病果实采用组织分离法进行了病原菌的分离与纯化,并结合形态学和分子生物学技术对病原菌进行鉴定。鉴定结果表明,引起橄榄黑斑病的病原菌为链格孢菌(Alternaria alternata... 为明确引起潮州市橄榄黑斑病的病原菌种类,筛选有效防治药剂,对发病果实采用组织分离法进行了病原菌的分离与纯化,并结合形态学和分子生物学技术对病原菌进行鉴定。鉴定结果表明,引起橄榄黑斑病的病原菌为链格孢菌(Alternaria alternata)。通过菌丝生长速率法测定了14种杀菌剂对病原菌的抑菌效果,结果表明14种杀菌剂对链格孢菌均有抑制作用,其中3%中生菌素可湿性粉剂、80%克菌丹水分散粒剂、8%氟硅唑微乳剂和40%苯甲·嘧菌酯悬浮剂的抑菌效果较好,EC_(50)分别为1.267、1.207、1.100、0.944 mg·L^(-1)。田间防效测定结果表明,40%苯甲·嘧菌酯悬浮剂、8%氟硅唑微乳剂的防治效果显著,防效为68.58%、65.44%;而30%王铜、2%春雷霉素的防效较差,仅为10%左右。综上,推荐将8%氟硅唑微乳剂和40%苯甲·嘧菌酯悬浮剂2种药剂作为防控橄榄黑斑病的首选药剂。本研究可为橄榄黑斑病高效杀菌剂的筛选提供数据参考,并为其防控工作提供科学依据。 展开更多
关键词 橄榄 黑斑病 链格孢菌 药剂筛选 田间防效
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玉米秸秆堆腐还田对黑土区土壤性状的影响 被引量:1
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作者 原韬 安琦 +4 位作者 牛彦波 孟利强 吴皓琼 樊川 曹亚彬 《中国农学通报》 2024年第5期47-52,共6页
本研究针对东北地区秋冬季节气候寒冷特点和秸秆堆腐还田的实际操作需求,开展秸秆堆腐还田试验。在秋季玉米收获之后进行田间堆腐试验,期间连续监测环境温度、降水、秸秆堆温度、秸秆失重率等指标。离田玉米秸秆经过腐熟后作为肥料还田... 本研究针对东北地区秋冬季节气候寒冷特点和秸秆堆腐还田的实际操作需求,开展秸秆堆腐还田试验。在秋季玉米收获之后进行田间堆腐试验,期间连续监测环境温度、降水、秸秆堆温度、秸秆失重率等指标。离田玉米秸秆经过腐熟后作为肥料还田,连续施用3年,检测土壤有机质、碱解氮、速效磷、速效钾、土壤孔隙度、土壤容重等指标。在基本农田和棚室保护地进行为期2年的应用试验。结果表明:120 d秸秆失重率达到31.53%。施用腐熟秸秆3年,土壤有机质提高了4.06~6.31 g/kg、土壤中碱解氮提高了15.08~27.35 mg/kg、速效磷提高了18.11~21.95 mg/kg、速效钾提高63.97~89.93 mg/kg;土壤容重降低了0.10~0.14 g/cm^(3)、土壤田间持水量提高了7.51%~9.24%(V/V)、土壤孔隙度提高了3.69%~5.27%(V/V),且差异显著(P≤0.05)。基本农田和棚室保护地应用试验中,速效养分与有机质有所增长,土壤容重与田间持水量变化显著。逐年施用腐熟秸秆对于提高土壤有机质含量、速效养分具有显著作用。同时,施用腐熟秸秆能够降低土壤容重,提高土壤孔隙度与田间持水量,改善土壤板结问题。腐熟秸秆在改良与保育黑土性质方面具有良好的作用。 展开更多
关键词 玉米秸秆 堆腐 北方寒地 还田 黑土保护 土壤性状
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Quantum Unruh Effect on Singularities of Black Holes
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作者 Tianxi Zhang 《Journal of Modern Physics》 2023年第11期1526-1536,共11页
It is generally believed that matter inside or once entering a black hole will gravitationally fall into the center and form a size-less singularity, where the density goes to infinity and the spacetime breaks down wi... It is generally believed that matter inside or once entering a black hole will gravitationally fall into the center and form a size-less singularity, where the density goes to infinity and the spacetime breaks down with infinite curvature or gravitation. In accordance to the Unruh effect, one of the most surprizing predictions of quantum field theory, however, it is found from this study that such singularity cannot be actually formed because it violates the law of energy conservation. The total Unruh radiation energy of the size-less singularity is shown to be infinite, much greater than that the collapsing matter can generate. All the energies of the collapsing matter including the gravitational potential energy, deducted, are far below the Unruh radiation energy, increased, for the collapsing matter to form the singularity. The collapsing matter actually formed is shown to be not a size-less singular point but a small sphere with a finite radius, which is found to be dependent of the mass of the singularity sphere, approximately proportional to the square root of the mass. The radius of the singularity sphere cannot be zero, unless the mass also approaches to zero. The result obtained from this study not only provides us a quantum solution to the problem of black hole singularity, but also leads to profound implications to the spacetime and cosmology. The Unruh effect excludes a black hole to form a size-less singularity, which has a finite mass but infinite density, curvature, and Unruh radiation energy. A point-like or size-less singularity can only be massless and naked. 展开更多
关键词 black Hole SINGULARITY GRAVITATION Quantum field Theory blackbody Radiation
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The Singularities of Gravitational Fields of Static Thin Loop and Double Spheres Reveal the Impossibility of Singularity Black Holes 被引量:2
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作者 Xiaochun Mei 《Journal of Modern Physics》 2013年第7期974-982,共9页
In the classical Newtonian mechanics, the gravity fields of static thin loop and double spheres are two simple but foundational problems. However, in the Einstein’s theory of gravity, they are not simple. In fact, we... In the classical Newtonian mechanics, the gravity fields of static thin loop and double spheres are two simple but foundational problems. However, in the Einstein’s theory of gravity, they are not simple. In fact, we do not know their solutions up to now. Based on the coordinate transformations of the Kerr and the Kerr-Newman solutions of the Einstein’s equation of gravity field with axial symmetry, the gravity fields of static thin loop and double spheres are obtained. The results indicate that, no matter how much the mass and density are, there are singularities at the central point of thin loop and the contact point of double spheres. What is more, the singularities are completely exposed in vacuum. Space near the surfaces of thin loop and spheres are highly curved, although the gravity fields are very weak. These results are inconsistent with practical experience and completely impossible. By reasonable analogy, black holes with singularity in cosmology and astrophysics are something illusive. Caused by the mathematical description of curved space-time, they do not exist in real world actually. If there are black holes in the universe, they can only be the types of the Newtonian black holes without singularities, rather than the Einstein’s singularity black holes. In order to escape the puzzle of singularity thoroughly, the description of gravity should return to the traditional form of dynamics in flat space. The renormalization of gravity and the unified description of four basic interactions may be possible only based on the frame of flat space-time. Otherwise, theses problems can not be solved forever. Physicists should have a clear understanding about this problem. 展开更多
关键词 General Relativity The Einstein’s Equation of Gravity field Axially Symmetrical Solutions SINGULARITY Kerr METRIC Kerr-Newman METRIC GRAVITATIONAL field of Static Thin LOOP GRAVITATIONAL field of Double SPHERES black Hole Quasar MECO
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秸秆还田对东北地区黑土地质构和玉米产量的影响研究
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作者 安鹤峰 《农业科技与装备》 2024年第3期28-29,共2页
为明确秸秆还田对东北地区黑土地的土壤质构和玉米产量的影响,以长期定位试验为基础,总结秸秆还田后的土壤容重、紧实度和持水量等指标变化及秸秆还田对玉米产量的影响,旨在为进一步提高玉米产量提供参考。
关键词 秸秆还田 玉米产量 土壤质构 黑土地
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秸秆还田配施氮肥对黑土玉米田土壤CO_(2)排放与碳平衡的影响
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作者 齐智娟 徐敬文 +3 位作者 张忠学 宋芳 李铁成 孙嘉璐 《农业机械学报》 EI CAS CSCD 北大核心 2024年第6期284-293,共10页
为探寻不同秸秆还田方式配施氮肥对黑土玉米田土壤CO_(2)排放与碳平衡的影响,于2023年开展大田试验,设置秸秆离田(S0,对照)、秸秆覆盖还田(S1)、秸秆旋耕还田(S2)3种秸秆还田方式,同时设置常规施加氮肥(N,250kg/hm^(2))与不施加氮肥(W,0... 为探寻不同秸秆还田方式配施氮肥对黑土玉米田土壤CO_(2)排放与碳平衡的影响,于2023年开展大田试验,设置秸秆离田(S0,对照)、秸秆覆盖还田(S1)、秸秆旋耕还田(S2)3种秸秆还田方式,同时设置常规施加氮肥(N,250kg/hm^(2))与不施加氮肥(W,0kg/hm^(2),对照)2种施氮模式,共计6个处理。测定不同处理下玉米生育期土壤CO_(2)排放通量以及玉米收获后土壤有机碳(SOC)、可溶性有机碳(DOC)、微生物量碳(MBC)含量,探究土壤CO_(2)累积排放量与SOC、DOC、MBC含量的关系,并分析黑土玉米田生态系统碳平衡状况。结果表明:各处理中土壤CO_(2)累积排放量从大到小依次为S2N、S1N、S0N、S2W、S1W、S0W,其中S2N处理土壤CO_(2)累积排放量较S0W处理显著增加70.31%(P<0.05)。在相同施氮模式下,秸秆还田能够有效增加SOC、DOC、MBC含量,且土壤CO_(2)累积排放量与SOC、DOC、MBC含量呈正相关关系。不同秸秆还田方式配施氮肥下,S1N处理玉米产量最高,为13534.4kg/hm^(2),作物碳排放速率最低,为0.122kg/kg。不同秸秆还田方式配施氮肥下黑土玉米田生态系统碳平衡值均为正值,表现为较强的碳“汇”,其中S1N处理碳平衡值和土壤固碳潜力最大,较其他处理分别增加13.12%~94.05%、3.49%~25.32%。综上所述,在本试验条件下,秸秆覆盖还田+常规施氮(S1N处理)可以实现黑土玉米田土壤固碳减排和作物增产目的。 展开更多
关键词 玉米田 黑土 秸秆还田 氮肥 CO_(2)排放 碳平衡
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漳州市漳浦县农村黑臭水体现状研究
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作者 范蕊 陈融斌 +5 位作者 陈政强 柏皓 杨睿 杨骁成 罗文鸿 李元跃 《安徽农业科学》 CAS 2024年第10期85-88,共4页
通过遥感识别、现场检测与取样分析相结合的方法,调查漳浦县38处疑似农村黑臭水体,结果表明:漳浦县现有4处农村黑臭水体,分别为前亭镇洛运村2处、前亭镇过港村1处、旧镇镇郭厝村1处;漳浦县黑臭水体主要污染来源为生活污水,占比33.32%;... 通过遥感识别、现场检测与取样分析相结合的方法,调查漳浦县38处疑似农村黑臭水体,结果表明:漳浦县现有4处农村黑臭水体,分别为前亭镇洛运村2处、前亭镇过港村1处、旧镇镇郭厝村1处;漳浦县黑臭水体主要污染来源为生活污水,占比33.32%;黑臭水体类型为沟渠和塘,其中黑臭沟渠占75%,黑臭塘占25%。漳浦县农村黑臭水体存在的问题:农村水污染增多;农村环保设施不健全;农村水污染源治理不彻底;基层环保专业力量欠缺。针对漳浦县农村黑臭水体存在的问题提出相应的治理对策。 展开更多
关键词 农村黑臭水体 现场调查 成因分析 漳浦县
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秸秆还田对黑土中磷素吸附特性及释放风险研究
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作者 温芳悦 张羽 +1 位作者 陈尚才 王玉军 《中国环境科学》 EI CAS CSCD 北大核心 2024年第8期4475-4483,共9页
通过分析秸秆离田免耕(MG)、秸秆覆盖还田(FG)、秸秆深翻还田(SF)对土壤理化性质及土壤磷素的吸附特性的影响,研究由于土壤理化性质的改变对于磷吸附特性的影响,并进一步分析磷素在土壤中的释放风险.结果表明,秸秆还田后,土壤有机质、... 通过分析秸秆离田免耕(MG)、秸秆覆盖还田(FG)、秸秆深翻还田(SF)对土壤理化性质及土壤磷素的吸附特性的影响,研究由于土壤理化性质的改变对于磷吸附特性的影响,并进一步分析磷素在土壤中的释放风险.结果表明,秸秆还田后,土壤有机质、有效磷含量增大,土壤容重降低.与秸秆离田免耕相比,秸秆覆盖还田后土壤磷的吸附量减少20.1%,秸秆深翻还田后的土壤磷的吸附量减少35.0%.3种不同耕作模式下黑土中DPS(磷饱和度)分别为MG:0.3%,FG:4.0%,SF:10.2%,PSI(磷吸持指数)分别为MG:41.14,FG:40.04,SF:36.09(mg P/(100g))/(μmol/L),ERI(磷释放风险指数)分别为MG:0.7%,FG:9.9%,SF:28.3%.综上所述,秸秆覆盖还田及秸秆深翻还田均可显著增加土壤有机质,降低土壤对磷的吸附能力,提高土壤磷的有效性,但同时也提高了土壤磷吸附饱和度,易引起磷素流失的风险. 展开更多
关键词 黑土 秸秆还田 磷吸附 释放风险
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节水灌溉下秸秆还田形式对黑土区稻田N_(2)O排放与产量的影响
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作者 薛里 张忠学 +4 位作者 齐智娟 韩羽 徐丹 张作合 周欣 《农业机械学报》 EI CAS CSCD 北大核心 2024年第4期280-289,共10页
为探寻不同灌溉模式下秸秆还田形式对黑土区稻田N_(2)O排放与产量的影响,于2023年进行大田试验,设置常规灌溉(F)与控制灌溉(C)两种灌溉模式,同时设置秸秆还田(S)、秸秆炭化为生物炭还田(B)、秸秆过牛腹为有机肥还田(O)3种还田形式,以及... 为探寻不同灌溉模式下秸秆还田形式对黑土区稻田N_(2)O排放与产量的影响,于2023年进行大田试验,设置常规灌溉(F)与控制灌溉(C)两种灌溉模式,同时设置秸秆还田(S)、秸秆炭化为生物炭还田(B)、秸秆过牛腹为有机肥还田(O)3种还田形式,以及秸秆不还田(N)作为对照组,共计8个处理。分析不同灌溉模式下秸秆还田形式对稻田N_(2)O排放通量与水稻产量的影响,测定了水稻各生育期稻田土壤铵态氮含量、硝态氮含量、微生物氮含量、pH值,并分析了N_(2)O排放总量和水稻产量与土壤环境因子之间的关系。结果表明:除返青期外,与秸秆不还田处理相比,秸秆还田与有机肥还田处理土壤铵态氮含量、硝态氮含量、微生物氮含量均表现为增加。相同秸秆还田形式下,控制灌溉模式下各处理生育期内土壤平均铵态氮含量、硝态氮含量较常规灌溉模式高36.23%~60.82%、14.16%~19.61%。同时,秸秆还田与生物炭还田能提高稻田土壤pH值。相同灌溉模式下,与秸秆不还田处理相比较,秸秆还田与有机肥还田处理N_(2)O排放总量分别增加14.44%~24.09%、8.22%~14.44%,生物炭还田处理N_(2)O排放总量降低14.31%~23.90%。生物炭还田与有机肥还田各处理水稻产量提高3.28%~13.07%,其中控制灌溉模式下生物炭还田处理产量最高。综上所述,控制灌溉下生物炭还田可以实现节水、增产、减排的目的。 展开更多
关键词 水稻产量 N_(2)O排放 黑土区稻田 灌溉模式 秸秆还田形式
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面向神经辐射场的水印算法
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作者 陈立峰 刘佳 +2 位作者 董炜娜 孙文权 潘晓中 《计算机应用研究》 CSCD 北大核心 2024年第7期2184-2188,共5页
针对隐式表示的3D模型的版权保护问题,提出了一种面向神经辐射场(NeRF)的水印算法。该算法通过嵌入网络对训练集中的图像嵌入水印,再利用NeRF模型进行3D模型建模。版权验证方通过给定一个秘密视角作为神经辐射场的输入,生成新视角下的... 针对隐式表示的3D模型的版权保护问题,提出了一种面向神经辐射场(NeRF)的水印算法。该算法通过嵌入网络对训练集中的图像嵌入水印,再利用NeRF模型进行3D模型建模。版权验证方通过给定一个秘密视角作为神经辐射场的输入,生成新视角下的图像作为后门图像,接着利用神经网络的过参数化方法设计一个水印提取器,获取该视角下嵌入的水印图像。在黑盒场景下,一旦怀疑3D模型被未经授权地使用,验证方则可以通过秘密视角提取水印以验证网络版权。实验结果表明,所提算法提取水印不仅具有良好的视觉效果,而且对不同类型的噪声攻击具有较好的抵抗能力。 展开更多
关键词 神经辐射场 3D水印 鲁棒性 黑盒水印
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论电影《1917》“一镜到底”断点处影像意义
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作者 张金玲 蒋志敏 《湖南工业大学学报(社会科学版)》 2024年第4期95-101,共7页
2020年上映的反战影片《1917》导演萨姆•门德斯,运用“一镜到底”的技术手段,完成了将近两小时的战争叙事。他用三次黑场过渡的方式在连续不断的画面中形成断点,从而以断点来带动叙事节奏,推动情节发展,并在黑场过渡所形成的间离效果中... 2020年上映的反战影片《1917》导演萨姆•门德斯,运用“一镜到底”的技术手段,完成了将近两小时的战争叙事。他用三次黑场过渡的方式在连续不断的画面中形成断点,从而以断点来带动叙事节奏,推动情节发展,并在黑场过渡所形成的间离效果中完成他者意义表达。萨姆•门德斯没有把“一镜到底”的影像意义局限于时间真实性与空间客观性,其在影片的断点处完成了时间凝缩与空间转换,以巧妙的影像表现手法完成了情节意义的表达,实现了技术手段与艺术技巧的高度融合。 展开更多
关键词 《1917》 一镜到底 黑场过渡 断点 影像意义
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