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1.
Small ; 20(40): e2401439, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38845528

RESUMEN

Solid-state sodium metal batteries have been extensively investigated because of their potential to improve safety, cost-effectiveness, and energy density. The development of such batteries urgently required a solid-state electrolyte with fast Na-ion conduction and favorable interfacial compatibility. Herein, the progress on developing the NaB3H8 solid-state electrolytes is reported, which show a liquid-like ionic conductivity of 0.05 S cm-1 at 56 °C with an activation energy of 0.35 eV after an order-disorder phase transformation, matching or surpassing the best single-anion hydridoborate conductors investigated up to now. The steady polarization voltage and significantly decreased resistance are achieved in the symmetric Na/NaB3H8/Na cell, indicating the great electrochemical stability and favorable interfacial contact with the Na metal of NaB3H8. Furthermore, a Na/NaB3H8/TiS2 battery, the first high-rate (up to 1 C) solid-state sodium metal battery using the single-anion hydridoborate electrolyte, is demonstrated, which exhibits superior rate capability (168.2 mAh g-1 at 0.1 C and 141.2 mAh g-1 at 1 C) and long-term cycling stability (70.9% capacity retention at 1 C after 300 cycles) at 30 °C. This work may present a new possibility to solve the interfacial limitations and find a new group of solid-state electrolytes for high-performance sodium metal batteries.

2.
Small ; 20(17): e2309593, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38126566

RESUMEN

The clinical application of oncology therapy is hampered by high glutathione concentrations, hypoxia, and inefficient activation of cell death mechanisms in cancer cells. In this study, Fe and Mo bimetallic sulfide nanomaterial (FeS2@MoS2) based on metal-organic framework structure is rationally prepared with peroxidase (POD)-, catalase (CAT)-, superoxide dismutase (SOD)-like activities and glutathione depletion ability, which can confer versatility for treating tumors and mending wounds. In the lesion area, FeS2@MoS2 with SOD-like activity can facilitate the transformation of superoxide anions (O2 -) to hydrogen peroxide (H2O2), and then the resulting H2O2 serves as a substrate for the Fenton reaction with FMS to produce highly toxic hydroxyl radicals (∙OH). Simultaneously, FeS2@MoS2 has an ability to deplete glutathione (GSH) and catalyze the decomposition of nicotinamide adenine dinucleotide phosphate (NADPH) to curb the regeneration of GSH from the source. Thus it can realize effective tumor elimination through synergistic apoptosis-ferroptosis strategy. Based on the alteration of the H2O2 system, free radical production, glutathione depletion and the alleviation of hypoxia in the tumor microenvironment, FeS2@MoS2 NPS can not only significantly inhibit tumors in vivo and in vitro, but also inhibit multidrug-resistant bacteria and hasten wound healing. It may open the door to the development of cascade nanoplatforms for effective tumor treatment and overcoming wound infection.


Asunto(s)
Antineoplásicos , Estructuras Metalorgánicas , Humanos , Antineoplásicos/farmacología , Antineoplásicos/química , Estructuras Metalorgánicas/química , Estructuras Metalorgánicas/farmacología , Animales , Antiinfecciosos/farmacología , Antiinfecciosos/química , Peróxido de Hidrógeno/metabolismo , Peróxido de Hidrógeno/química , Línea Celular Tumoral , Ratones , Glutatión/metabolismo , Hierro/química , Hierro/metabolismo , Apoptosis/efectos de los fármacos , Molibdeno/química , Molibdeno/farmacología , Nanoestructuras/química , Ferroptosis/efectos de los fármacos
3.
Plant Biotechnol J ; 22(8): 2333-2347, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38600703

RESUMEN

Sterols have long been associated with diverse fields, such as cancer treatment, drug development, and plant growth; however, their underlying mechanisms and functions remain enigmatic. Here, we unveil a critical role played by a GmNF-YC9-mediated CCAAT-box transcription complex in modulating the steroid metabolism pathway within soybeans. Specifically, this complex directly activates squalene monooxygenase (GmSQE1), which is a rate-limiting enzyme in steroid synthesis. Our findings demonstrate that overexpression of either GmNF-YC9 or GmSQE1 significantly enhances soybean stress tolerance, while the inhibition of SQE weakens this tolerance. Field experiments conducted over two seasons further reveal increased yields per plant in both GmNF-YC9 and GmSQE1 overexpressing plants under drought stress conditions. This enhanced stress tolerance is attributed to the reduction of abiotic stress-induced cell oxidative damage. Transcriptome and metabolome analyses shed light on the upregulation of multiple sterol compounds, including fucosterol and soyasaponin II, in GmNF-YC9 and GmSQE1 overexpressing soybean plants under stress conditions. Intriguingly, the application of soybean steroids, including fucosterol and soyasaponin II, significantly improves drought tolerance in soybean, wheat, foxtail millet, and maize. These findings underscore the pivotal role of soybean steroids in countering oxidative stress in plants and offer a new research strategy for enhancing crop stress tolerance and quality from gene regulation to chemical intervention.


Asunto(s)
Glycine max , Estrés Fisiológico , Glycine max/genética , Glycine max/fisiología , Glycine max/metabolismo , Estrés Fisiológico/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Plantas Modificadas Genéticamente , Esteroides/metabolismo , Sequías , Productos Agrícolas/genética , Productos Agrícolas/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética
4.
Opt Express ; 32(2): 2281-2292, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38297762

RESUMEN

High-frequency, high-power picosecond lasers have important and wide-ranging applications in laser ranging, optoelectronic countermeasures, and ultrafine industrial processing. Pulse compression based on stimulated Brillouin scattering (SBS) can achieve a highly efficient picosecond laser output, while improving the peak power and beam quality of the laser. In this paper, a generator-amplifier two-cell structure with frequency-detuning was proposed to achieve a pulse output that combines high compression ratio and high energy reflectivity. The experiment proved that under a pump pulse width of 15 ns and repetition frequency of 10 Hz, when the generator cell and amplifier cell media were selected as HT-230, the highest energy reflectivity of 46% and narrowest compression pulse width of 1.1 ns were achieved, and the pulse compression ratio was 13.6. When the amplifier cell was selected as FC-770 and the generator cell was selected as HT-230, an energy reflectivity of 52% and a compression pulse width of 840 ps could be achieved simultaneously, and the pulse compression ratio was 18.

5.
Opt Lett ; 49(10): 2825-2828, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38748171

RESUMEN

Based on the longitudinal manipulation of polarization, a special vector optical beam (VOB) with customized polarization variation in propagation direction can be generated, whose properties and applications remain to be studied. Here, the self-healing propagation behaviors of the longitudinally varying VOB after an opaque object are investigated, and the localized polarization responses on the object distance are revealed. On this basis, characteristic parameters are defined to measure the distance of object, achieving a minimum relative error of 0.63% in a longitudinal range of 300 mm. Besides, the correlations and uncoupling methods of object distance and size are discussed. Our studies open new ways to use the structural properties of VOB and may be instructive for laser measurement.

6.
Opt Lett ; 49(8): 2073-2076, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38621079

RESUMEN

A self-mode-locked Ho:GdVO4 laser with the GHz pulse repetition frequency oscillation near 2.06 µm was demonstrated for the first time to our knowledge. The output performances of the self-mode-locked Ho:GdVO4 laser were investigated for a few output coupler transmittances at the pulse repetition frequency of 1.89 GHz. At the incident pump power of 8.12 W, the maximum average output power was as high as 2.28 W, corresponding to the slope efficiency and optical-to-optical efficiency of 36.3% and 28.1%, respectively. This is the maximum average output for the 2 µm self-mode-locked solid-state laser with a GHz pulse repetition frequency. This work provides a new way for generating an efficient and a high-power ultrafast pulse laser with a GHz repetition frequency in the 2 µm wave band.

7.
Opt Lett ; 49(12): 3316-3319, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38875609

RESUMEN

A dual-wavelength synchronously self-mode-locked Ho:LLF laser operating at 2068.5 and 2069.2 nm was demonstrated. The maximum average output power was as high as 2.6 W with a pulse repetition frequency of 3.03 GHz. Meanwhile, the output power ratio of the dual-wavelength lasers can be effectively controlled by varying the incident pump power. To the best of our knowledge, this is the first dual-wavelength synchronously self-mode-locked Ho-doped fluoride solid state laser; moreover, our current experimental results represent the highest average output power from a GHz self-mode-locked oscillator in the 2 µm wave band.

8.
Altern Ther Health Med ; 30(1): 426-433, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37820670

RESUMEN

Objective: The objective of this study was to analyze the correlation between central vein smoke ultrasonography (CVSU) and thrombus elasticity graphy (TEG). Methods: A retrospective analysis was made on 300 severe patients with smoky echo changes (SECs) in the internal jugular and femoral veins who were admitted to the hospital from January 2021 to March 2022. According to the ultrasound results, all patients were divided into Group A (n = 75), Group B (n = 75), Group C (n = 75), and Group D (n = 75). TEG examination, ultrasound examination, routine coagulation test were received. The coagulation function and TEG index were compared and analyzed in each group, and their correlation was analyzed. Results: The trends of R value and K value of TEG index of patients in different groups were the same. The R value and K value in group D were the highest, followed by group C, and the lowest in group A; while those in groups C and D exhibited great differences with P < .05 to those in groups A and B. The PT, TT, APTT, and FIB of patients in groups C and D were much higher based on the values in groups A and B. R-value was positively correlated with APACHEII (0.678), TT (0.198), and APTT (0.187), and negatively associated with PT (-0.008), D-D (-0.315), and FDP (-0.298). K value presented a positive correlation with APACHEII (0.692) and TT (0.342) but a negative correlation with PT (-0.187), APTT (-0.053), D-D (-0.497), and FDP (-0.453). Positive correlations were observed between α and PT (0.198), APTT (0.046), D-D (0.602), and FDP (0.532), while negative correlations were found between α and APACHEII (-0.398) and TT (-0.315). MA was positively correlated with PT, D-D, and FDP but negatively with APACHEII, TT, and APTT. Conclusion: TEG parameters had an obvious correlation with the coagulation function test, which can effectively evaluate the CVSU in severe patients. The ultrasonic signs can be undertaken as clinical hypercoagulability detection indicators in severe patients and intervention indicators for early thrombosis prevention in the future, they can guide clinicians to make the best treatment plan for severe patients.


Asunto(s)
Tromboelastografía , Trombosis , Humanos , Estudios Retrospectivos , Humo , Pruebas de Coagulación Sanguínea , Trombosis/diagnóstico por imagen
9.
Mikrochim Acta ; 191(1): 79, 2024 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-38183441

RESUMEN

Antibiotic residues in the environment pose a serious threat to ecosystems and human health. Therefore, it is important to develop sensitive and rapid in situ detection methods. In this work, the designed nanozymes, with excellent four enzyme activities, were proved to be constituted of unique hollow nanocage structures (CoZnSe@CN HCs). Based on the peroxidase-like enzymes, a portable colorimetric sensor was constructed for the on-site determination of tetracycline (TC) in real samples. The linear range of TC detection was 0.1-100 µM, and the detection limit was 0.02 µM. At the same time, colorimetric detection and smartphones have also been combined for on-site colorimetric detection of TC. In-depth exploration of the detection mechanism showed that TC could be bound with the material, inhibiting the production of oxidized 3,3',5,5'-tetramethylbenzidine. The sensor was also used for the detection of TC in environmental soil and water samples. This study can provide an intelligent detection method for environmental monitoring.


Asunto(s)
Ecosistema , Realidad Virtual , Humanos , Teléfono Inteligente , Tetraciclina , Antibacterianos
10.
Pak J Med Sci ; 40(7): 1355-1360, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39092033

RESUMEN

Objective: To investigate the pathogen distribution and clinical characteristics of acute community-acquired lower respiratory tract infections (CALRTIs). Methods: This was a retrospective study. The clinical data of 218 patients with CALRTIs admitted to Baoding No.1 Central Hospital from December 2021 to December 2022 were retrospectively collected and were divided into two groups according to the results of polymerase chain reaction(PCR) testing using a nasopharyngeal swab: streptococcus pneumoniae positive group(observation group) and non-streptococcus pneumoniae positive group(control group). Clinical symptoms, blood gas analysis indicators were compared between the two groups. Results: Haemophilus influenzae and Staphylococcus aureus, as well as virus and atypical pathogen infection, were the predominant pathogenic bacteria in both groups. No statistically significant differences were observed in the positive rates of sputum smear, sputum culture, respiratory virus detection and atypical pathogen detection between the two groups(P>0.05). However, the control group had a higher detection rate of gram-positive bacteria, gram-negative bacteria and Legionella pneumophila in sputum smears than the observation group, with a statistically significant difference(P<0.05). One death occurred in each group, with no significant difference in mortality and six in each group left the hospital or were transferred due to deterioration, with no significant difference in improved discharge rates. Conclusion: Acute community-acquired lower respiratory tract infections(CALRTIs) take bacteria, viruses and atypical pathogens as its leading pathogenic bacteria. In the treatment of patients with acute CALRTIs, early pathogenic examination should be performed to assist in guiding antibiotic therapy for rapid control, early recovery and ameliorated clinical outcomes.

11.
Pak J Med Sci ; 40(7): 1533-1538, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39092044

RESUMEN

Objective: To evaluate the clinical efficacy, safety and compliance of quality nursing intervention in the treatment of chronic heart failure combined with respiratory tract infections. Methods: This was a retrospective study. One hundred and twenty patients with chronic heart failure combined with respiratory tract infections were recruited at Baoding No.1 Central Hospital from June 2021 to March 2023 and randomly divided into the control group (n=60) and the experimental group (n=60). Patients in the control group were given regular specialist care on the basis of basic treatment, while those in the experimental group were given a quality care intervention model. The differences in clinical efficacy, improvement time of symptoms after treatment, etc. between the two groups were compared and analyzed. Results: The response rate of the experimental group was 88%, which was significantly higher than that of the control group (73%), with a statistically significant difference (P=0.04). The time of fever reduction, cough subsidence and lung rales disappearance in the experimental group were significantly shorter than those of the control group, with statistically significant differences (P<0.05). The incidence of nursing related adverse events in the experimental group was 8%, which was lower than that of 23% in the control group, with a statistically significant difference(P=0.03). Conclusion: Quality nursing intervention is an effective treatment for patients with chronic heart failure combined with respiratory infections, boasting a variety of benefits such as reduced nursing risk, improved quality of nursing, and increased patient compliance and satisfaction. It contributes to rapid symptom improvement and significant clinical efficacy.

12.
Angew Chem Int Ed Engl ; : e202412401, 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39243107

RESUMEN

All-solid-state potassium metal batteries have caught increasing interest owing to their abundance, cost-effectiveness, and high energy/power density. However, their development is generally constrained by the lack of suitable solid-state electrolytes. Herein, we report a new complex KCB9H10 ⋅ 2C3H4N2, synthesized by grinding and heating the mixture of potassium decahydrido-monocarba-closo-decaborate (KCB9H10) and imidazole (C3H4N2) under mild conditions, to achieve the K-ion superionic solid-state electrolyte. The crystal structure was revealed as an orthorhombic lattice with the space group of Pna21 by FOX software. The diffusion properties for K+ in the crystal structure were calculated using the climbing image nudged elastic band (CI-NEB) method. KCB9H10 ⋅ 2C3H4N2 exhibited a high ionic conductivity of 1.3×10-4 S cm-1 at 30 °C, four orders of magnitude higher than that of KCB9H10. This ionic conductivity is also the highest value of hydridoborate-based K+ conductors reported. Moreover, KCB9H10 ⋅ 2C3H4N2 demonstrated a K+ transference number of 0.96, an electrochemical stability window of 1.2 to 3.2 V vs. K/K+, and good stability against the K metal coated by a layer of potassium imidazolate (KIm). These great performances make KCB9H10 ⋅ 2C3H4N2 a promising K-ion solid-state electrolyte.

13.
Angew Chem Int Ed Engl ; 63(17): e202401480, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38351436

RESUMEN

All-solid-state sodium metal batteries are promising for large-scale energy storage applications owing to their intrinsic safety and cost-effectiveness. However, they generally suffer from sodium dendrite growth or rapid capacity fading, especially at high rates, mainly due to poor wettability, sluggish ionic transport, or low interfacial stability of the solid electrolytes. Herein, we report a novel composite, NaB3H8 ⋅ xNH3@NaB3H8 (x<1), as a new class of solid electrolyte for high-rate batteries. NaB3H8 ⋅ xNH3@NaB3H8 is obtained from the sticky NaB3H8 ⋅ NH3 after removal of NH3 partially at room temperature. It delivers an ionic conductivity of 0.84 mS cm-1 at 25 °C and reaches 20.64 mS cm-1 at 45 °C after an order-disorder phase transformation. It also reveals a good capability of dendrite suppression and remarkable stability against sodium metal. These performances enable the all-solid-state Na//TiS2 battery with a high capacity of 232.4 mAh g-1 (97.2 % of theoretical capacity) and long-term cycling stability at 1 C. Notably, this battery shows superior long-life cycling stability even at 5 and 10 C, which has been rarely reported in all-solid-state sodium metal batteries. This work opens a new group of solid electrolytes, contributing to fast-charging or high-power-density sodium metal batteries.

14.
BMC Genomics ; 24(1): 669, 2023 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-37936069

RESUMEN

BACKGROUND: Purple curl leaf disease brings a significant threat to the development of agave industry, the underlying mechanism of disease-resistant Agave sisalana. hybrid 11648 (A. H11648R) is still unknown. RESULTS: To excavate the crucial disease-resistant genes against purple curl leaf disease, we performed an RNA-seq analysis for A.H11648R and A.H11648 during different stages of purple curl leaf disease. The DEGs (differentially expressed genes) were mainly enriched in linolenic acid metabolism, starch and sucrose mechanism, phenylpropanoid biosynthesis, hypersensitive response (HR) and systemic acquired resistance. Further analysis suggested that eight candidate genes (4'OMT2, ACLY, NCS1, GTE10, SMO2, FLS2, SQE1 and RCOM) identified by WGCNA (weighted gene co-expression network analysis) may mediate the resistance to agave purple curl disease by participating the biosynthesis of benzylisoquinoline alkaloids, steroid, sterols and flavonoids, and the regulation of plant innate immunity and systemic acquired resistance. After qPCR verification, we found that AsRCOM, coding a glycosyltransferase and relevant to the regulation of plant innate immunity and systemic acquired resistance, may be the most critical disease-resistant gene. Finally, the overexpression of AsRCOM gene in agave could significantly enhance the resistance to purple curl disease with abundant reactive oxygen species (ROS) accumulations. CONCLUSIONS: Integrative RNA-seq analysis found that HR may be an important pathway affecting the resistance to purple curl leaf disease in agave, and identified glycosyltransferase AsRCOM as the crucial gene that could significantly enhance the resistance to purple curl leaf disease in agave, with obvious ROS accumulations.


Asunto(s)
Agave , Agave/genética , Especies Reactivas de Oxígeno , Perfilación de la Expresión Génica , Inmunidad de la Planta/genética , Hojas de la Planta/genética , Enfermedades de las Plantas/genética , Resistencia a la Enfermedad/genética
15.
Opt Express ; 31(11): 18039-18049, 2023 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-37381522

RESUMEN

In this paper, residual stress and plastic deformation of TC4 titanium alloys and AA7075 aluminum alloys after laser shock peening (LSP) with the laser pulses that have the same energy and peak intensity but different time profiles have been studied. The results show that the time profile of the laser pulse has a significant influence on LSP. The difference between the results of LSP with varying laser input mode has been contributed to the shock wave caused by different laser pulse. In LSP, the laser pulse with a positive-slope triangular time profile could induce a more intense and deeper residual stress distribution in metal targets. Residual stress distribution changing with laser time profiles suggests that shaping the laser time profile is a potential residual stress control strategy for LSP. This paper comprises the first step of this strategy.

16.
Opt Express ; 31(2): 1878-1887, 2023 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-36785213

RESUMEN

A high temporal waveform fidelity stimulated Brillouin scattering phase conjugate mirror (SBS-PCM) with high energy efficiency, based on a novel medium, Novec-7500, is proposed and practically achieved in this study. A theoretical analysis reveals that the temporal-domain waveform distortion is caused by the inherent pulse duration compression effect of the SBS, and this undesirable phenomenon can be significantly suppressed by decreasing the compression coefficient (CC afterwards), which is defined as the gain coefficient divided by the phonon lifetime, which coefficient and is identified as the key parameter for high waveform-fidelity in SBS-PCM. The feasibility of this approach was demonstrated experimentally, in which a reflected pulse with waveform symmetry equals to the pump and an average pulse duration of 0.974 τp (τp is the duration of pump) with an energy efficiency of over 90% was achieved using Novec-7500.

17.
Opt Express ; 31(2): 2942-2955, 2023 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-36785296

RESUMEN

Free-space Brillouin lasers (BLs) are capable of generating high-power, narrow-linewidth laser outputs at specific wavelengths. Although there have been impressive experimental demonstrations of these lasers, there is an absence of a corresponding theory that describes the dynamic processes that occur within them. This paper presents a time-independent analytical model that describes the generation of the first-order Stokes field within free-space BLs. This model is based on the cavity resonance enhancement theory and coupled wave equations that govern the processes of stimulated Brillouin scattering (SBS). This model is validated using an experimental diamond BL to numerically simulate the influence of the cavity design parameters on the SBS threshold, pump enhancement characteristics, and power of the generated Stokes field. Specifically, the model is used to determine the SBS cavity coupler reflectance to yield the maximum Stokes field output power and efficiency, which is also a function of the pump power and other cavity design parameters. This analysis shows that the appropriate choice of Brillouin cavity coupler reflectance maximizes the Stokes field output power for a given pump power. Furthermore, the onset of higher-order Stokes fields that are undesirable in the context of single-frequency laser operation were inhibited. This study aids in understanding the relationship between the cavity parameters and resultant laser characteristics for the design and optimization of laser systems.

18.
Opt Express ; 31(4): 5699-5707, 2023 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-36823843

RESUMEN

Stimulated Brillouin scattering (SBS) is a non-linear process which has the capacity to improve the beam quality and pulse characteristics of laser beams. In this paper, we theoretically and experimentally study the process of SBS in fused silica. In particular, we examine the energy reflection and pulse compression of input laser pulses as functions of focus position, pump energy and beam diameter. We utilized coupled wave equations and a distributed noise model to simulate the reflected energy and time waveform under different gain parameters. An experimental system is constructed and used to qualify the numerical simulations. The results reveal that the threshold for the SBS process and the energy reflectivity significantly change with laser focus position under the same pump and focusing parameters. Ultimately, the gain characteristics of the SBS material is the primary factor that influences the SBS output. This work presented here offers insight into the operation of short-length solid-state SBS lasers and serves as a basis for the design and optimization of such systems.

19.
Opt Express ; 31(19): 30030-30039, 2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37710555

RESUMEN

Analyzing the longitudinal-mode of a pump can significantly prevent optical damage to solid media and expand the applications of solid media in high repetition rate stimulated Brillouin scattering (SBS). In this study, a Fabry-Pérot etalon was used to control the number of longitudinal-mode in a pump laser output. We studied the output characteristics of SBS in fused silica by considering both single- and multi-longitudinal-mode pumping. We analyzed and compared variations in the SBS threshold, energy reflectivity, linewidth, and waveform characteristics. The experimental results indicated that a pump operating in a single-longitudinal-mode had a 14% lower SBS threshold than one operating in a multi-longitudinal-mode. The proportion of the weak longitudinal-mode in the multi-longitudinal-mode was close to the threshold difference. The damage threshold of the multi-longitudinal-mode pumps was approximately 35 mJ (@12 ns, f = 300 mm). The Stokes linewidth and waveform exhibited opposite trends as the energy changed. Due to the time-bandwidth product, the linewidth and waveform tended to converge towards the pump. This study emphasizes the importance of using a single-longitudinal-mode pump in the development and use of solid-state SBS gain media.

20.
Phys Rev Lett ; 131(20): 202502, 2023 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-38039451

RESUMEN

Traditional photonuclear reactions primarily excite giant dipole resonances, making the measurement of isovector giant resonances with higher multipolarities a great challenge. In this Letter, the manipulation of collective excitations of different multipole transitions in even-even nuclei via vortex γ photons is investigated. We develop the calculation method for photonuclear cross sections induced by the vortex γ photon beam using the fully self-consistent random-phase approximation plus particle-vibration coupling (RPA+PVC) model based on Skyrme density functional. We find that the electromagnetic transitions with multipolarity J<|m_{γ}| are forbidden for vortex γ photons due to the angular momentum conservation, with m_{γ} being the projection of total angular momentum of γ photon on its propagation direction. For instance, this allows for probing the isovector giant quadrupole resonance without interference from dipole transitions using vortex γ photons with m_{γ}=2. Furthermore, the electromagnetic transition with J=|m_{γ}|+1 vanishes at a specific polar angle. Therefore, the giant resonances with specific multipolarity can be extracted via vortex γ photons. Moreover, the vortex properties of γ photons can be meticulously diagnosed by measuring the nuclear photon-absorption cross section. Our method opens new avenues for photonuclear excitations, generation of coherent γ photon laser and precise detection of vortex particles, and consequently, has significant impact on nuclear physics, nuclear astrophysics and strong laser physics.

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