对珠子参中皂苷类成分进行定性鉴别分析,建立珠子参皂苷类多成分含量测定方法。采用超高效液相色谱-飞行时间质谱(UPLC-Q-TOF-MS/MS)技术对珠子参进行正、负离子模式扫描,使用UNIFI天然产物信息平台对珠子参所含的化学成分进行定性鉴别...对珠子参中皂苷类成分进行定性鉴别分析,建立珠子参皂苷类多成分含量测定方法。采用超高效液相色谱-飞行时间质谱(UPLC-Q-TOF-MS/MS)技术对珠子参进行正、负离子模式扫描,使用UNIFI天然产物信息平台对珠子参所含的化学成分进行定性鉴别分析;以0.1%磷酸水-乙腈溶液为流动相进行梯度洗脱,柱温30℃,流速0.3 mL/min,进行珠子参皂苷类多成分含量测定。珠子参中共鉴定出39个化学成分,包括37个皂苷类化合物和2个皂苷母核,并总结了皂苷类化合物的裂解规律,建立了UPLC同时测定珠子参中人参皂苷Rb1、人参皂苷Ro、人参皂苷Rb3、竹节参皂苷IV、竹节参皂苷IVa、人参皂苷Rd、姜状三七皂苷R1和金盏花苷E的多指标含量测定方法,该方法中8个待测成分在检测质量浓度范围内线性关系良好,精密度、重复性、稳定性的相对标准偏差(relative standard deviation,RSD)均小于3.0%,样品中人参皂苷Rb1、人参皂苷Ro、人参皂苷Rb3、竹节参皂苷IV、竹节参皂苷IVa、人参皂苷Rd、姜状三七皂苷R1和金盏花苷E的平均加样回收率分别为102.4%、103.1%、97.97%、99.42%、102.7%、102.1%、95.23%、100.5%,RSD分别为1.0%、0.98%、0.81%、2.3%、0.81%、1.9%、0.96%、1.8%。该研究建立的方法可快速、准确地对珠子参中的皂苷类成分进行定性及定量分析。展开更多
首次采用超高效液相色谱-四极杆-飞行时间串联质谱(ultra performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry,UPLC-Q-TOF-MS/MS)结合全球天然产物分子网络集群(global natural products social mo...首次采用超高效液相色谱-四极杆-飞行时间串联质谱(ultra performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry,UPLC-Q-TOF-MS/MS)结合全球天然产物分子网络集群(global natural products social molecular networking,GNPS)平台的分子网络技术,对雷公藤根中的两类生物碱活性成分进行系统分析和鉴定,为雷公藤及其生物碱类活性成分的深入研发与应用奠定坚实基础。采用Hypersil GOLD^(TM)C_(18)(100 mm×2.1 mm,1.9μm),以甲醇-0.1%甲酸水溶液为流动相进行梯度洗脱,流速:0.25 m L/min,柱温:40℃,在正离子模式下,收集雷公藤根95%乙醇回流提取物的质谱数据,上传至GNPS平台进行计算分析,并运用Cytoscape 3.7. 1软件构建可视化分子网络。依据对照品、精确的相对分子质量、特征碎片离子和参考文献等信息,成功鉴定出83个生物碱成分,其中大环内酯类新生物碱14个,大环多胺类新生物碱6个,特别是新颖的13-羟基大环多胺生物碱1个,首次从雷公藤属中鉴定的大环内酯类生物碱4个。研究结果丰富了雷公藤的化学成分,为进一步分离纯化这些新化合物以及药效研究提供了明确的指导,也进一步验证了UPLC-Q-TOF-MS/MS联合GNPS分子网络技术在复杂天然产物高效分析鉴定中的应用优势与价值。展开更多
Surface engineering plays a crucial role in improving the performance of high energy materials,and polydopamine(PDA)is widely used in the field of energetic materials for surface modification and functionalization.In ...Surface engineering plays a crucial role in improving the performance of high energy materials,and polydopamine(PDA)is widely used in the field of energetic materials for surface modification and functionalization.In order to obtain high-quality HMX@PDA-based PBX explosives with high sphericity and a narrow particle size distribution,composite microspheres were prepared using co-axial droplet microfluidic technology.The formation mechanism,thermal behavior,mechanical sensitivity,electrostatic spark sensitivity,compressive strength,and combustion performance of the microspheres were investigated.The results show that PDA can effectively enhance the interfacial interaction between the explosive particles and the binder under the synergistic effect of chemical bonds and the physical"mechanical interlocking"structure.Interface reinforcement causes the thermal decomposition temperature of the sample microspheres to move to a higher temperature,with the sensitivity to impact,friction,and electrostatic sparks(for S-1)increasing by 12.5%,31.3%,and 81.5%respectively,and the compressive strength also increased by 30.7%,effectively enhancing the safety performance of the microspheres.Therefore,this study provides an effective and universal strategy for preparing high-quality functional explosives,and also provides some reference for the safe use of energetic materials in practical applications.展开更多
In recent years,perovskite solar cells(PSCs)have garnered significant attention as a potential mainstream technology in the future photovol-taic(PV)market.This is primarily attributed to their salient advantages inclu...In recent years,perovskite solar cells(PSCs)have garnered significant attention as a potential mainstream technology in the future photovol-taic(PV)market.This is primarily attributed to their salient advantages including high efficiency,low cost,and ease of preparation.Nota-bly,the power conversion efficiency(PCE)of PSCs has experienced a remarkable increase from 3.8%in 2009 to over 26%at present.Conse-quently,the adoption of roll-to-roll(R2R)technology for PSCs is considered a crucial step towards their successful commercialization.This arti-de reviews the diverse substrates,scalable deposition techniques(such as solution-based knife-coating and spraying technology),and optimiza.tion procedures employed in recent years to enhance device performance within the R2R process.Additionally,novel perspectives are presented to enrich the existing knowledge in this field.展开更多
In this work,the generation of high signal-to-noise ratio(SNR)single-frequency microwave signal without noise sidebands is demonstrated based on the interaction of integrated all-fiber lasers.The microwave signals are...In this work,the generation of high signal-to-noise ratio(SNR)single-frequency microwave signal without noise sidebands is demonstrated based on the interaction of integrated all-fiber lasers.The microwave signals are generated by the interference between a narrow linewidth Brillouin pump light from a single-frequency laser and the Stokes light generated by it.Firstly,the linewidths of the Stokes lights are compressed to~43 Hz based on the stimulated Brillouin scattering(SBS)effect,which ensures that the frequency noise is as low as possible.And then,the relative intensity noise(RIN)of the first order Stokes light is reduced by 21 dB/Hz based on the noise dynamics principle in cascaded SBS effect.By simultaneously reducing the frequency noise and the intensity noise of the coherent signals,the noise sidebands of microwave signals are completely suppressed.As result,the SNR of the microwave signal is improved from 48 dB to 84 dB at the first-order Brillouin frequency shift of 9.415 GHz.Meanwhile,a microwave signal with a SNR of 70 dB is generated at the second-order Brillouin frequency shift of 18.827 GHz.This kind of microwave signals with narrow linewidth and high SNR can provide higher detection resolution and higher transmission efficiency for applications on radar,satellite communication and so on.展开更多
Taoren and Xingren are commonly used herbs in East Asian medicine with different medication functions but huge economic differences,and there are cases of adulterated sales in market transactions.An effective adultera...Taoren and Xingren are commonly used herbs in East Asian medicine with different medication functions but huge economic differences,and there are cases of adulterated sales in market transactions.An effective adulteration recognition based on hyperspectral technology and machine learning was designed as a non-destructive testing method in this paper.A hyperspectral dataset comprising 500 Taoren and 500 Xingren samples was established;six feature selection methods were considered in the modeling of radial basis function-support vector machine(RBF-SVM),whose interaction between the two optimization methods was further researched.Two mixed metaheuristics modeling methods,Mixed-PSO and Mixed-SA,were designed,which fused both band selection and hyperparameter optimization from two-stage into one with detailed process analysis.The metrics of this mixed model were improved by comparing with traditional two-stage method.The accuracy of Mixed-PSO was 89.2%in five-floods crossvalidation that increased 4.818%than vanilla RBF-SVM;the accuracy of Mixed-SA was 88.7%which could reach the same as the traditional two-stage method,but it only relied on 48 crux bands in full 100 bands in RBF-SVM model fitting.展开更多
The self-healing function is considered one of the effective ways to address structural damage and improve interfacial bonding in Energetic composite materials(ECMs).However,the currently prepared ECMs with self-heali...The self-healing function is considered one of the effective ways to address structural damage and improve interfacial bonding in Energetic composite materials(ECMs).However,the currently prepared ECMs with self-healing function have problems such as irregular particle shape and uneven distribution of components,which affect the efficient play of self-healing function.In this paper,HMX-based energetic microspheres with self-healing function were successfully prepared by microchannel technology,which showed excellent self-healing effect in both Polymer-bonded explosives(PBXs)and Composite solid propellants(CSPs).The experimental results show that the HMX-based energetic microspheres with different binder contents prepared by microchannel technology show regular shape,HMX crystal particles are uniformly wrapped by self-healing binder(GAPU).When the content of GAPU in HMX-based energetic microspheres is 10%,PBXs show excellent self-healing effect and mechanical safety is improved by 400%(raw HMX vs S4,5 J vs 25 J).As a high-energy component,the burning rate of CSPs is increased by 359.4%,the time(burning temperature>1700℃)is prolonged by 333.3%,and the maximum impulse force is increased by 107.3%(CSP-H vs CSP-S4,0.84 mm/s vs 3.87 mm/s,0.06 s vs 0.26 s,0.82 m N vs 1.70 m N).It also has excellent storage performance.The preparation of HMX-based energetic microspheres with self-healing function by microchannel technology provides a new strategy to improve the storage performance of ECMs and the combustion performance of CSPs.展开更多
文摘对珠子参中皂苷类成分进行定性鉴别分析,建立珠子参皂苷类多成分含量测定方法。采用超高效液相色谱-飞行时间质谱(UPLC-Q-TOF-MS/MS)技术对珠子参进行正、负离子模式扫描,使用UNIFI天然产物信息平台对珠子参所含的化学成分进行定性鉴别分析;以0.1%磷酸水-乙腈溶液为流动相进行梯度洗脱,柱温30℃,流速0.3 mL/min,进行珠子参皂苷类多成分含量测定。珠子参中共鉴定出39个化学成分,包括37个皂苷类化合物和2个皂苷母核,并总结了皂苷类化合物的裂解规律,建立了UPLC同时测定珠子参中人参皂苷Rb1、人参皂苷Ro、人参皂苷Rb3、竹节参皂苷IV、竹节参皂苷IVa、人参皂苷Rd、姜状三七皂苷R1和金盏花苷E的多指标含量测定方法,该方法中8个待测成分在检测质量浓度范围内线性关系良好,精密度、重复性、稳定性的相对标准偏差(relative standard deviation,RSD)均小于3.0%,样品中人参皂苷Rb1、人参皂苷Ro、人参皂苷Rb3、竹节参皂苷IV、竹节参皂苷IVa、人参皂苷Rd、姜状三七皂苷R1和金盏花苷E的平均加样回收率分别为102.4%、103.1%、97.97%、99.42%、102.7%、102.1%、95.23%、100.5%,RSD分别为1.0%、0.98%、0.81%、2.3%、0.81%、1.9%、0.96%、1.8%。该研究建立的方法可快速、准确地对珠子参中的皂苷类成分进行定性及定量分析。
文摘首次采用超高效液相色谱-四极杆-飞行时间串联质谱(ultra performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry,UPLC-Q-TOF-MS/MS)结合全球天然产物分子网络集群(global natural products social molecular networking,GNPS)平台的分子网络技术,对雷公藤根中的两类生物碱活性成分进行系统分析和鉴定,为雷公藤及其生物碱类活性成分的深入研发与应用奠定坚实基础。采用Hypersil GOLD^(TM)C_(18)(100 mm×2.1 mm,1.9μm),以甲醇-0.1%甲酸水溶液为流动相进行梯度洗脱,流速:0.25 m L/min,柱温:40℃,在正离子模式下,收集雷公藤根95%乙醇回流提取物的质谱数据,上传至GNPS平台进行计算分析,并运用Cytoscape 3.7. 1软件构建可视化分子网络。依据对照品、精确的相对分子质量、特征碎片离子和参考文献等信息,成功鉴定出83个生物碱成分,其中大环内酯类新生物碱14个,大环多胺类新生物碱6个,特别是新颖的13-羟基大环多胺生物碱1个,首次从雷公藤属中鉴定的大环内酯类生物碱4个。研究结果丰富了雷公藤的化学成分,为进一步分离纯化这些新化合物以及药效研究提供了明确的指导,也进一步验证了UPLC-Q-TOF-MS/MS联合GNPS分子网络技术在复杂天然产物高效分析鉴定中的应用优势与价值。
基金supported by the National Natural Science Foundation of China(Grant No.22005275).
文摘Surface engineering plays a crucial role in improving the performance of high energy materials,and polydopamine(PDA)is widely used in the field of energetic materials for surface modification and functionalization.In order to obtain high-quality HMX@PDA-based PBX explosives with high sphericity and a narrow particle size distribution,composite microspheres were prepared using co-axial droplet microfluidic technology.The formation mechanism,thermal behavior,mechanical sensitivity,electrostatic spark sensitivity,compressive strength,and combustion performance of the microspheres were investigated.The results show that PDA can effectively enhance the interfacial interaction between the explosive particles and the binder under the synergistic effect of chemical bonds and the physical"mechanical interlocking"structure.Interface reinforcement causes the thermal decomposition temperature of the sample microspheres to move to a higher temperature,with the sensitivity to impact,friction,and electrostatic sparks(for S-1)increasing by 12.5%,31.3%,and 81.5%respectively,and the compressive strength also increased by 30.7%,effectively enhancing the safety performance of the microspheres.Therefore,this study provides an effective and universal strategy for preparing high-quality functional explosives,and also provides some reference for the safe use of energetic materials in practical applications.
文摘In recent years,perovskite solar cells(PSCs)have garnered significant attention as a potential mainstream technology in the future photovol-taic(PV)market.This is primarily attributed to their salient advantages including high efficiency,low cost,and ease of preparation.Nota-bly,the power conversion efficiency(PCE)of PSCs has experienced a remarkable increase from 3.8%in 2009 to over 26%at present.Conse-quently,the adoption of roll-to-roll(R2R)technology for PSCs is considered a crucial step towards their successful commercialization.This arti-de reviews the diverse substrates,scalable deposition techniques(such as solution-based knife-coating and spraying technology),and optimiza.tion procedures employed in recent years to enhance device performance within the R2R process.Additionally,novel perspectives are presented to enrich the existing knowledge in this field.
文摘In this work,the generation of high signal-to-noise ratio(SNR)single-frequency microwave signal without noise sidebands is demonstrated based on the interaction of integrated all-fiber lasers.The microwave signals are generated by the interference between a narrow linewidth Brillouin pump light from a single-frequency laser and the Stokes light generated by it.Firstly,the linewidths of the Stokes lights are compressed to~43 Hz based on the stimulated Brillouin scattering(SBS)effect,which ensures that the frequency noise is as low as possible.And then,the relative intensity noise(RIN)of the first order Stokes light is reduced by 21 dB/Hz based on the noise dynamics principle in cascaded SBS effect.By simultaneously reducing the frequency noise and the intensity noise of the coherent signals,the noise sidebands of microwave signals are completely suppressed.As result,the SNR of the microwave signal is improved from 48 dB to 84 dB at the first-order Brillouin frequency shift of 9.415 GHz.Meanwhile,a microwave signal with a SNR of 70 dB is generated at the second-order Brillouin frequency shift of 18.827 GHz.This kind of microwave signals with narrow linewidth and high SNR can provide higher detection resolution and higher transmission efficiency for applications on radar,satellite communication and so on.
基金Supported by the Natural Science Foundation of Heilongjiang Province(LH2020C003)。
文摘Taoren and Xingren are commonly used herbs in East Asian medicine with different medication functions but huge economic differences,and there are cases of adulterated sales in market transactions.An effective adulteration recognition based on hyperspectral technology and machine learning was designed as a non-destructive testing method in this paper.A hyperspectral dataset comprising 500 Taoren and 500 Xingren samples was established;six feature selection methods were considered in the modeling of radial basis function-support vector machine(RBF-SVM),whose interaction between the two optimization methods was further researched.Two mixed metaheuristics modeling methods,Mixed-PSO and Mixed-SA,were designed,which fused both band selection and hyperparameter optimization from two-stage into one with detailed process analysis.The metrics of this mixed model were improved by comparing with traditional two-stage method.The accuracy of Mixed-PSO was 89.2%in five-floods crossvalidation that increased 4.818%than vanilla RBF-SVM;the accuracy of Mixed-SA was 88.7%which could reach the same as the traditional two-stage method,but it only relied on 48 crux bands in full 100 bands in RBF-SVM model fitting.
基金support given by the Fundamental Research Program of Shanxi Province(Grant No.202203021212152)。
文摘The self-healing function is considered one of the effective ways to address structural damage and improve interfacial bonding in Energetic composite materials(ECMs).However,the currently prepared ECMs with self-healing function have problems such as irregular particle shape and uneven distribution of components,which affect the efficient play of self-healing function.In this paper,HMX-based energetic microspheres with self-healing function were successfully prepared by microchannel technology,which showed excellent self-healing effect in both Polymer-bonded explosives(PBXs)and Composite solid propellants(CSPs).The experimental results show that the HMX-based energetic microspheres with different binder contents prepared by microchannel technology show regular shape,HMX crystal particles are uniformly wrapped by self-healing binder(GAPU).When the content of GAPU in HMX-based energetic microspheres is 10%,PBXs show excellent self-healing effect and mechanical safety is improved by 400%(raw HMX vs S4,5 J vs 25 J).As a high-energy component,the burning rate of CSPs is increased by 359.4%,the time(burning temperature>1700℃)is prolonged by 333.3%,and the maximum impulse force is increased by 107.3%(CSP-H vs CSP-S4,0.84 mm/s vs 3.87 mm/s,0.06 s vs 0.26 s,0.82 m N vs 1.70 m N).It also has excellent storage performance.The preparation of HMX-based energetic microspheres with self-healing function by microchannel technology provides a new strategy to improve the storage performance of ECMs and the combustion performance of CSPs.
