期刊文献+
共找到79,375篇文章
< 1 2 250 >
每页显示 20 50 100
A polarization sensitive interferometer:Delta interferometer
1
作者 卫超奇 刘建彬 +7 位作者 董翼飞 孙雨农 周宇 郑淮斌 刘严严 闫秀生 李福利 徐卓 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期369-377,共9页
A new type of polarization sensitive interferometer is proposed,named the Delta interferometer,inspired by its geometry resembling the Greek letter Delta.The main difference between the Delta interferometer and other ... A new type of polarization sensitive interferometer is proposed,named the Delta interferometer,inspired by its geometry resembling the Greek letter Delta.The main difference between the Delta interferometer and other existing interferometers,such as Michelson,Mach-Zehnder and Young's double-slit interferometers,is that the two interfering paths are asymmetrical in the Delta interferometer.The visibility of the first-order interference pattern observed in the Delta interferometer is dependent on the polarization of the incidental light.Optical coherence theory is employed to interpret this phenomenon and single-mode continuous-wave laser light is employed to verify the theoretical predictions.The theoretical and experimental results are consistent.The Delta interferometer is a perfect tool to study the reflection of electromagnetic fields in different polarizations and may find applications in polarization-sensitive scenarios. 展开更多
关键词 phase sensitive interferometer Fresnel formula first-order interference
下载PDF
Linear dichroism transition and polarization-sensitive photodetector of quasi-one-dimensional palladium bromide
2
作者 朱万里 甄伟立 +5 位作者 牛瑞 焦珂珂 岳智来 胡慧杰 薛飞 张昌锦 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期532-539,共8页
Perpendicular optical reversal of the linear dichroism transition has promising applications in polarization-sensitive optoelectronic devices. We perform a systematical study on the in-plane optical anisotropy of quas... Perpendicular optical reversal of the linear dichroism transition has promising applications in polarization-sensitive optoelectronic devices. We perform a systematical study on the in-plane optical anisotropy of quasi-one-dimensional PdBr_(2) by using combined measurements of the angle-resolved polarized Raman spectroscopy(ARPRS) and anisotropic optical absorption spectrum. The analyses of ARPRS data validate the anisotropic Raman properties of the PdBr_(2) flake.And anisotropic optical absorption spectrum of PdBr_(2) nanoflake demonstrates distinct optical linear dichroism reversal. Photodetector constructed by PdBr_(2) nanowire exhibits high responsivity of 747 A·W^(-1) and specific detectivity of 5.8×10^(12) Jones. And the photodetector demonstrates prominent polarization-sensitive photoresponsivity under 405-nm light irradiation with large photocurrent anisotropy ratio of 1.56, which is superior to those of most of previously reported quasi-one-dimensional counterparts. Our study offers fundamental insights into the strong optical anisotropy exhibited by PdBr_(2), establishing it as a promising candidate for miniaturization and integration trends of polarization-related applications. 展开更多
关键词 linear dichroism reversal polarization sensitivity ANISOTROPY polarized photodetector
下载PDF
A semi-analytical model for coupled flow in stress-sensitive multi-scale shale reservoirs with fractal characteristics
3
作者 Qian Zhang Wen-Dong Wang +4 位作者 Yu-Liang Su Wei Chen Zheng-Dong Lei Lei Li Yong-Mao Hao 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期327-342,共16页
A large number of nanopores and complex fracture structures in shale reservoirs results in multi-scale flow of oil. With the development of shale oil reservoirs, the permeability of multi-scale media undergoes changes... A large number of nanopores and complex fracture structures in shale reservoirs results in multi-scale flow of oil. With the development of shale oil reservoirs, the permeability of multi-scale media undergoes changes due to stress sensitivity, which plays a crucial role in controlling pressure propagation and oil flow. This paper proposes a multi-scale coupled flow mathematical model of matrix nanopores, induced fractures, and hydraulic fractures. In this model, the micro-scale effects of shale oil flow in fractal nanopores, fractal induced fracture network, and stress sensitivity of multi-scale media are considered. We solved the model iteratively using Pedrosa transform, semi-analytic Segmented Bessel function, Laplace transform. The results of this model exhibit good agreement with the numerical solution and field production data, confirming the high accuracy of the model. As well, the influence of stress sensitivity on permeability, pressure and production is analyzed. It is shown that the permeability and production decrease significantly when induced fractures are weakly supported. Closed induced fractures can inhibit interporosity flow in the stimulated reservoir volume (SRV). It has been shown in sensitivity analysis that hydraulic fractures are beneficial to early production, and induced fractures in SRV are beneficial to middle production. The model can characterize multi-scale flow characteristics of shale oil, providing theoretical guidance for rapid productivity evaluation. 展开更多
关键词 Multi-scale coupled flow Stress sensitivity Shale oil Micro-scale effect Fractal theory
下载PDF
Synthesis and Charcterization of Silane Crosslinked Hydrogel to pH Sensitive Study
4
作者 Muhammad Awais Shahid Abdul Haseeb Tahir +1 位作者 Zeeshan Ahmad Muhammad Arslan 《American Journal of Analytical Chemistry》 CAS 2024年第5期165-176,共12页
Eco-friendly and biodegradable novel hydrogel were prepared by blending and solution casting method. The designed hydrogel is based on chitosan/ PEG600/Gurgam with carbon nanofiller along silane crosslinked (TEOS) wit... Eco-friendly and biodegradable novel hydrogel were prepared by blending and solution casting method. The designed hydrogel is based on chitosan/ PEG600/Gurgam with carbon nanofiller along silane crosslinked (TEOS) with pH sensitive response to controlled release of drug in biomedical materials and agriculture industry. The various concentration of carbon nanofiller is used to analyze its effect on the fabricated hydrogel characteristics by using FTIR, SEM, TGA, swelling studies (water, buffer and ionic solution). Spectra of FTIR reflected both established and newly developed groups (like hydrogel). COOH group presence is clearly observed in this range in the carbon filler reinforced hydrogel. The SEM micrographs show that CPG0.003 had a collection of polysaccharide chains as thin helices, which is attributed to the increase in the size of porosity. TGA shows to increase concentration of nanofiller enhanced the thermal stability of the designed hydrogels at temperature 25˚C to 550˚C mass loss percentage decrease upto 20% and increase thermal stability. This pH response made these resultant hydrogels as fruitful competitor against the many reported controlled release application. 展开更多
关键词 CHITOSAN Guargum HYDROGEL Carbon Nano Filler Silane Cross Linker pH sensitive
下载PDF
Evidence-Based Nursing Practice of Reducing Immune-Related Skin Toxicity of Tumor Patients Guided by Sensitive Indicators
5
作者 Lingling Tang Qiong Wen 《Journal of Biosciences and Medicines》 2024年第4期210-215,共6页
Purpose research on nursing sensitive indicators in tumor Patients application effect in immune-related skin toxicity management. Method select our hospital April to June, 202360 cases patients with immune therapy set... Purpose research on nursing sensitive indicators in tumor Patients application effect in immune-related skin toxicity management. Method select our hospital April to June, 202360 cases patients with immune therapy settings as the control group. August-October, 2023 60 cases the patients treated with immune therapy were the experimental group. The control group adopted regular nursing methods, while the experimental group sensitive Indicators, evidence-based give preventive care. The social situation, psychological state, physical function, quality of life score, incidence of skin toxicity caused by immune checkpoint inhibitors, moderate and above of the two groups of patients were compared. Incidence of skin toxicity. Result: experience group SAS score, SDS score higher than the control group, the difference was statistically significant (P < 0.05);The incidence of skin toxic reactions caused by immune checkpoint inhibitors and the incidence of moderate and above skin toxic reactions in the experimental group are lower than those in the control group, and the difference is statistically significant (P < 0.05). Conclusion: sensitive indicator guidance evidence-based preventive care can reduce the degree of immune-related skin toxicity, improve the psychological state and quality of life of tumor patients treated with immune therapy and reduce the incidence of adverse reactions, improve nursing quality and patient satisfaction. 展开更多
关键词 sensitive Indicators Immune-Related Skin Toxicity Evidence-Based Practice Tumor
下载PDF
Sensitive Information Security Based on Elliptic Curves
6
作者 Nadine Nibigira Vincent Havyarimana Zhu Xiao 《World Journal of Engineering and Technology》 2024年第2期274-285,共12页
The elliptic curve cryptography algorithm represents a major advancement in the field of computer security. This innovative algorithm uses elliptic curves to encrypt and secure data, providing an exceptional level of ... The elliptic curve cryptography algorithm represents a major advancement in the field of computer security. This innovative algorithm uses elliptic curves to encrypt and secure data, providing an exceptional level of security while optimizing the efficiency of computer resources. This study focuses on how elliptic curves cryptography helps to protect sensitive data. Text is encrypted using the elliptic curve technique because it provides great security with a smaller key on devices with limited resources, such as mobile phones. The elliptic curves cryptography of this study is better than using a 256-bit RSA key. To achieve equivalent protection by using the elliptic curves cryptography, several Python libraries such as cryptography, pycryptodome, pyQt5, secp256k1, etc. were used. These technologies are used to develop a software based on elliptic curves. If built, the software helps to encrypt and decrypt data such as a text messages and it offers the authentication for the communication. 展开更多
关键词 CRYPTOGRAPHY Elliptic Curves Digital Security Data sensitive Data IMPLEMENTATION
下载PDF
Dual pH and microbial-sensitive galactosylated polymeric nanocargoes for multi-level targeting to combat ulcerative colitis
7
作者 Mahira Zeeshan Qurat Ul Ain +3 位作者 Benno Weigmann Darren Story Bryan R.Smith Hussain Ali 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2023年第4期124-141,共18页
Ulcerative colitis(UC)is a type of inflammatory bowel disease characterized by inflammation,ulcers and irritation of the mucosal lining.Oral drug delivery in UC encounters challenges because of multifaceted barriers.D... Ulcerative colitis(UC)is a type of inflammatory bowel disease characterized by inflammation,ulcers and irritation of the mucosal lining.Oral drug delivery in UC encounters challenges because of multifaceted barriers.Dexamethasone-loaded galactosylated-PLGA/Eudragit S100/pullulan nanocargoes(Dexa-GP/ES/Pu NCs)have been developed with a dual stimuli-sensitive coating responsive to both colonic pH and microbiota,and an underneath galactosylated-PLGA core(GP).The galactose ligand of the GP preferentially binds to the macrophage galactose type-lectin-C(MGL-2)surface receptor.Therefore,both stimuli and ligand-mediated targeting facilitate nanocargoes to deliver Dexa specifically to the colon with enhanced macrophage uptake.Modified emulsion method coupled with a solvent evaporation coating technique was employed to prepare Dexa-GP/ES/Pu NCs.The nanocargoes were tested using in vitro,ex vivo techniques and dextran sodium sulfate(DSS)induced UC model.Prepared nanocargoes had desired physicochemical properties,drug release,cell uptake and cellular viability.Investigations using a DSS-colitis model showed high localization and mitigation of colitis with downregulation of NF-ĸB and COX-2,and restoration of clinical,histopathological,biochemical indices,antioxidant balance,microbial alterations,FTIR spectra,and epithelial junctions’integrity.Thus,Dexa-GP/ES/Pu NCs found to be biocompatible nanocargoes capable of delivering drugs to the inflamed colon with unique targeting properties for prolonged duration. 展开更多
关键词 Galactosylated nanocargoes pH-sensitive drug delivery PULLULAN Microbial sensitive Ulcerative colitis Macrophage galactose type-lectin C
下载PDF
Recent Trends of In-Vehicle Time Sensitive Networking Technologies, Applications and Challenges
8
作者 Yanli Xu Jian Shang Hao Tang 《China Communications》 SCIE CSCD 2023年第11期30-55,共26页
With the vigorous development of automobile industry,in-vehicle network is also constantly upgraded to meet data transmission requirements of emerging applications.The main transmission requirements are low latency an... With the vigorous development of automobile industry,in-vehicle network is also constantly upgraded to meet data transmission requirements of emerging applications.The main transmission requirements are low latency and certainty especially for autonomous driving.Time sensitive networking(TSN)based on Ethernet gives a possible solution to these requirements.Previous surveys usually investigated TSN from a general perspective,which referred to TSN of various application fields.In this paper,we focus on the application of TSN to the in-vehicle networks.For in-vehicle networks,we discuss all related TSN standards specified by IEEE 802.1 work group up to now.We further overview and analyze recent literature on various aspects of TSN for automotive applications,including synchronization,resource reservation,scheduling,certainty,software and hardware.Application scenarios of TSN for in-vehicle networks are analyzed one by one.Since TSN of in-vehicle network is still at a very initial stage,this paper also gives insights on open issues,future research directions and possible solutions. 展开更多
关键词 automobile industry deterministic transmission in-vehicle network low latency time sensitive networking(TSN)
下载PDF
Enhanced phase sensitive amplification towards improving noise immunity
9
作者 郭辉 李治 +2 位作者 孙恒信 刘奎 郜江瑞 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期126-130,共5页
Quantum states are essential resource for quantum-enhanced applications.Loss incurred in the distribution channel,however,dissipates the high signal-to-noise ratio advantage enjoyed by the squeezed state.Here,we first... Quantum states are essential resource for quantum-enhanced applications.Loss incurred in the distribution channel,however,dissipates the high signal-to-noise ratio advantage enjoyed by the squeezed state.Here,we first demonstrate noise immunity enhancement by using phase-sensitive amplifier(PSA)with measurement-based noiseless linear amplifier(MB-NLA).We explore the signal transfer capability with the amplifier in a noisy channel.The MB-NLA enhanced PSA has obvious suppression effect on channel noises,especially it has improvement for the noise contaminated signal.Better performance can be achieved by flexibly adjusting amplifier parameters.With the amplifier,it is promising to overcome the entanglement-distribution loss and show its superiority in squeezing based quantum sensing. 展开更多
关键词 phase sensitive amplification noiseless linear amplification quantum sensing
下载PDF
Flexible broadband WS_(2)/Si optical position-sensitive detector with high sensitivity and fast speed
10
作者 Yunjie Liu Yupeng Wu +5 位作者 Fuhai Guo Yingming Liu Shirong Zhao Siqi Li Weizhuo Yu Lanzhong Hao 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第6期1217-1224,共8页
Si-based optical position-sensitive detectors(PSDs)have stimulated the interest of researchers due to their wide range of practical applications.However,due to the rigidity and fragility of Si crystals,the application... Si-based optical position-sensitive detectors(PSDs)have stimulated the interest of researchers due to their wide range of practical applications.However,due to the rigidity and fragility of Si crystals,the applications of flexible PSDs have been limited.Therefore,we presented a flexible broadband PSD based on a WS_(2)/Si heterostructure for the first time.A scalable sputtering method was used to deposit WS_(2)thin films onto the etched ultrathin crystalline Si surface.The fabricated flexible PSD device has a broad spectral response in the wavelength range of 450-1350 nm,with a high position sensitivity of~539.8 mV·mm^(−1)and a fast response of 2.3μs,thanks to the strong light absorption,the built-in electrical field at the WS_(2)/Si interface,and facilitated transport.Furthermore,mechanical-bending tests revealed that after 200 mechanical-bending cycles,the WS_(2)/Si PSDs have excellent mechanical flexibility,stability,and durability,demonstrating the great potential in wearable PSDs with competitive performance. 展开更多
关键词 FLEXIBLE position-sensitive detectors WS^(2)heterostructure broad spectral response high sensitivity
下载PDF
The strain rate sensitive and anisotropic behavior of rare-earth magnesium alloy ZEK100 sheet
11
作者 H.Wang X.Sun +4 位作者 S.Kurukuri M.J.Worswick D.Y.Li Y.H.Peng P.D.Wu 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第3期882-891,共10页
To overcome the limitation in formability at room temperature,manufacturers have developed magnesium alloys with remarkable properties by adding rare-earth elements.The rare-earth magnesium alloys behave differently f... To overcome the limitation in formability at room temperature,manufacturers have developed magnesium alloys with remarkable properties by adding rare-earth elements.The rare-earth magnesium alloys behave differently from the conventional alloys,especially with respect to their coupled anisotropic and strain rate sensitive behavior.In the current work,such behavior of the rare-earth Mg alloy ZEK100 sheet at room temperature is investigated with the aid of the elastic viscoplastic self-consistent polycrystal plasticity model.Different strain rate sensitivities(SRSs)for various deformation modes are employed by the model to simulate the strain rate sensitive behaviors under different loading directions and loading rates.Good agreement between the experiments and simulations reveals the importance and necessity of using different SRSs for each deformation mode in hexagonal close-packed metals.Furthermore,the relative activities of each deformation mode and the texture evolution during different loadings are discussed.The anisotropic and strain rate sensitive behavior is ascribed to the various operating deformation modes with different SRSs during loading along different directions. 展开更多
关键词 Rare-earth magnesium alloy Strain rate sensitivity TWINNING Crystal plasticity
下载PDF
Highly sensitive and stable probe refractometer based on configurable plasmonic resonance with nano-modified fiber core
12
作者 Jianying Jing Kun Liu +3 位作者 Junfeng Jiang Tianhua Xu Shuang Wang Tiegen Liu 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2023年第6期38-51,共14页
A dispersion model is developed to provide a generic tool for configuring plasmonic resonance spectral characteristics.The customized design of the resonance curve aiming at specific detection requirements can be achi... A dispersion model is developed to provide a generic tool for configuring plasmonic resonance spectral characteristics.The customized design of the resonance curve aiming at specific detection requirements can be achieved.According to the model,a probe-type nano-modified fiber optic configurable plasmonic resonance(NMF-CPR)sensor with tip hot spot enhancement is demonstrated for the measurement of the refractive index in the range of 1.3332-1.3432 corresponding to the low-concentration biomarker solution.The new-type sensing structure avoids excessive broadening and redshift of the resonance dip,which provides more possibilities for the surface modification of other functional nanomaterials.The tip hot spots in nanogaps between the Au layer and Au nanostars(AuNSs),the tip electric field enhancement of AuNSs,and the high carrier mobility of the WSe_(2)layer synergistically and significantly enhance the sensitivity of the sensor.Ex-perimental results show that the sensitivity and the figure of merit of the tip hot spot enhanced fiber NMF-CPR sensor can achieve up to 2995.70 nm/RIU and 25.04 RIU^(−1),respectively,which are 1.68 times and 1.29 times higher than those of the conventional fiber plasmonic resonance sensor.The results achieve good agreements with numerical simulations,demonstrate a better level compared to similar reported studies,and verify the correctness of the dispersion model.The detection resolution of the sensor reaches up to 2.00×10^(−5)RIU,which is obviously higher than that of the conventional side-polished fiber plasmonic resonance sensor.This indicates a high detection accuracy of the sensor.The dense Au layer effectively prevents the intermediate nanomaterials from shedding and chemical degradation,which enables the sensor with high stability.Furthermore,the terminal reflective sensing structure can be used as a practical probe and can allow a more convenient operation. 展开更多
关键词 fiber photonics sensor customized plasmonic resonance curve nano-modified fiber core tip hot spot effect high sensitivity and stability
下载PDF
Uncharted Territory: Frequent Relapsing, Steroid Sensitive Secondary Minimal Change Nephrotic Syndrome Cause by Solid Tumor of the Gastro-Esophageal Junction —(Case Presentation and Review of the Literature)
13
作者 Awad Magbri Mariam El-Magbri +1 位作者 Reshma Shamnarine Pablo Abrego Hernandez 《Open Journal of Nephrology》 CAS 2023年第1期13-19,共7页
We reported a biopsy proved case of minimal change nephrotic syndrome in a 72-year-old patient. The minimal change nephrotic syndrome has been steroid sensitive, but the patient had 7 relapses over a span of 5 years. ... We reported a biopsy proved case of minimal change nephrotic syndrome in a 72-year-old patient. The minimal change nephrotic syndrome has been steroid sensitive, but the patient had 7 relapses over a span of 5 years. Each time the dose of steroid is tapered, a relapse of the nephrotic syndrome occurred. Eventually, the patient was complaining of dysphagia and difficulty swallowing. Hospital work-up with barium swallow, endoscopy, and CT of the chest, abdomen and pelvis, revealed a focal stenotic lesion with mild to moderate esophageal dysmotility 7/15/2022. A diagnosis of an ulcerating lesion with biopsy confirmed a neuro-endocrine carcinoma of the gastro-esophageal junction was entertained. The CT of the chest/abdomen/pelvis, 7/19/2022, has shown, an esophageal mass of 5.1 × 5.6 × 7 cm of the gastro-esophageal junction with ulceration. No evidence of spread beyond the esophagus and stomach. The histology revealed a poorly differentiated neuroendocrine tumor of the gastro-esophageal junction. The patient underwent several rounds of chemotherapy, radiation, and surgery culminating in tumor control. His nephrotic syndrome was resolved after the tumor has been controlled by surgery and chemotherapy. 展开更多
关键词 Frequent Relapsing Nephrotic Syndrome Steroid sensitive Nephrotic Syndrome Secondary Nephrotic Syndrome Solid Gastro-Intestinal Tumor Minimal Change Nephrotic Syndrome Neuro-Endocrine Tumor of the Gastro-Esophageal Junction Paraneoplastic Glomerulopathy
下载PDF
Establishing Standardized Nursing Quality Sensitive Indicators
14
作者 Shumukh Mohammed Khulayf Alshammari Hisham Abid Aldabbagh +3 位作者 Gharam Hulayyil Al Anazi Abdullah Mohammed Bukhari Majdi Al Sayed Mahmoud Waleed Seif Eldin Mohamed Mostafa 《Open Journal of Nursing》 2023年第8期551-582,共32页
This is a pilot research project was prepared to assess the impact of implementing essential standardized nursing quality sensitive indicators in monitoring, evaluating, and controlling the nursing services and activi... This is a pilot research project was prepared to assess the impact of implementing essential standardized nursing quality sensitive indicators in monitoring, evaluating, and controlling the nursing services and activities which implemented in daily nursing care works with the patients in a health institute, aiming for emphasizing the concept of “nursing quality sensitive indicators” which is valuable to elaborate nursing care performance, and for continuous upgrading of daily nursing care, which hopefully will result in more beneficial outcomes, and lesser negative or undesirable outcomes in all aspects of nursing care, and consequently the health care process, particularly regarding patient safety, patient satisfaction and nursing performance improvement. This pilot research project for the essential standardized nursing quality sensitive indicators was applied in intensive care unit (ICU) department in Qurayyat general hospital, and resulted in excellent improvement of all outcomes correlated with the essential standardized nursing quality sensitive indicators. These essential standardized nursing quality sensitive indicators are hopefully be accepted and accredited by the higher health authorities as standardized nursing quality sensitive indicators in health institutes. 展开更多
关键词 Standardized NURSING QUALITY sensitive INDICATORS
下载PDF
Influencing Factors and Solutions of Oily Sensitive Skin
15
作者 Yang Suping Zhao Wenxuan 《China Detergent & Cosmetics》 CAS 2023年第4期37-43,共7页
The influence factors of oily sensitive skin were reviewed.Some solutions were proposed for the development of skin care formulations that aim at solving the oily sensitive skin problems more effectively,such as repai... The influence factors of oily sensitive skin were reviewed.Some solutions were proposed for the development of skin care formulations that aim at solving the oily sensitive skin problems more effectively,such as repairing the skin permeability barrier,controlling oil,inhibiting sebum oxidation,relieving keratinization abnormalities,regulating the skin microecology and alleviating skin inflammatory reactions.It was concluded that future research should focus on precise skin care by designing targeted product formulations according to the characteristics of oily sensitive skin. 展开更多
关键词 oily sensitive skin ACNE COSMETICS
下载PDF
鱼类产卵敏感期河流生态流速的分区分类阈值研究 被引量:1
16
作者 杨泽凡 胡鹏 +2 位作者 王玉莲 刘欢 闫肖瑶 《水利学报》 EI CSCD 北大核心 2024年第2期190-201,共12页
敏感生态流量目标的合理制定是生态流量管理的重难点问题。针对目前敏感生态流量目标制定中存在的计算方法繁杂、关键参数缺乏等问题,本文以鱼类产卵期为重点,提出了分区分类河流敏感期生态流速和生态流量核算方法,制定了不同区域(东北... 敏感生态流量目标的合理制定是生态流量管理的重难点问题。针对目前敏感生态流量目标制定中存在的计算方法繁杂、关键参数缺乏等问题,本文以鱼类产卵期为重点,提出了分区分类河流敏感期生态流速和生态流量核算方法,制定了不同区域(东北、黄淮海、西南、长江中下游和东南沿海)、不同类型(按集水面积、山区河段和平原河段等划分)河流敏感期生态流速阈值。结果显示,全部分区分类推荐流速平均值为0.66 m/s,其中山区大站平均值为0.94 m/s、山区小站平均值为0.62 m/s、平原大站平均值为0.63 m/s、平原小站平均值为0.46 m/s。基于阈值核算了全国217个鱼类产卵生境保护河段的敏感期生态流量目标,并结合部分断面湿周法结果对阈值合理性与适应性进行了验证,验证结果表明相关阈值和方法适应于不同类型、不同规模河流,可为我国现阶段河流敏感生态流量管控提供参考。 展开更多
关键词 敏感生态流量 鱼类产卵 生态流量占比 生态流速 阈值
下载PDF
大气氚释放剂量评价参数灵敏度分析
17
作者 杨洁 岳琪 +2 位作者 顾志杰 廉冰 王彦 《辐射防护》 CAS CSCD 北大核心 2024年第3期257-264,共8页
国内外目前对于大气氚释放剂量的评价多采用比活度模型,模型选取参数的不确定性会造成剂量评价结果的差异。考虑不同场址环境参数的差异性,对大气氚剂量评价模型中关键参数进行灵敏度分析与剂量评价结果的不确定性分析。结果显示场址环... 国内外目前对于大气氚释放剂量的评价多采用比活度模型,模型选取参数的不确定性会造成剂量评价结果的差异。考虑不同场址环境参数的差异性,对大气氚剂量评价模型中关键参数进行灵敏度分析与剂量评价结果的不确定性分析。结果显示场址环境空气湿度对大气氚的剂量评价结果影响最大,随着场址湿度的升高,大气氚排放所致食入内照射剂量逐渐降低,剂量计算结果不确定性逐渐降低。同时,研究表明在低湿度场址环境下,应重点关注土壤中HTO留存比例经验常数的测量与选取,在高湿度场址环境下,应重点关注作物水当量因子以及摄入HTO活度浓度在吸收水分氚中所占比例的测量与选取,以尽可能降低剂量评价结果的不确定性。 展开更多
关键词 评价 参数灵敏度分析
下载PDF
放射性氙高灵敏度现场快速自动化监测系统研制
18
作者 龙斌 周国庆 +5 位作者 田言杰 雷卫国 陈伟 苏川英 王雪梅 冯淑娟 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第2期481-488,共8页
放射性氙监测是禁核试核查现场视察和核设施安全监测的重要项目之一,能够快速准确地甄别违约核活动和预警识别核设施的泄漏。本文综合运用超低温动态吸附、中空纤维膜除杂和现场低本底测量等技术,研制了一套放射性氙高灵敏度现场快速自... 放射性氙监测是禁核试核查现场视察和核设施安全监测的重要项目之一,能够快速准确地甄别违约核活动和预警识别核设施的泄漏。本文综合运用超低温动态吸附、中空纤维膜除杂和现场低本底测量等技术,研制了一套放射性氙高灵敏度现场快速自动化监测系统,用于放射性氙现场取样、分离和测量。测试结果表明,该系统在氡浓度为20 Bq/m^(3)、采样体积为2 m^(3)、分析周期不大于120 min时,氙回收率为79.9%,对^(133) Xe的最小可探测活度浓度(MDC)小于0.26 Bq/m^(3),测量结果的不确定度小于±12%。该系统具有灵敏度高、分析周期短、全流程自动化的特点,能够应用于核设施安全监测、现场视察放射性氙监测、核应急放射性气体监测等场合。 展开更多
关键词 放射性氙 高灵敏度 快速 现场 自动化监测
下载PDF
欧盟致敏性香精香料管理对我国化妆品原料管理的启示
19
作者 裴新荣 黄湘鹭 +1 位作者 卢家灿 邢书霞 《香料香精化妆品》 CAS 2024年第1期26-35,146,共11页
香精香料是化妆品中的常见原料,同时也是容易引发接触性皮炎的致敏成分。为了确保消费者的安全,有必要进一步加强对致敏性香精香料的管理。欧盟消费者安全科学委员(SCCS)会多次对致敏性香料香精成分进行评估,欧盟委员会根据评估意见调... 香精香料是化妆品中的常见原料,同时也是容易引发接触性皮炎的致敏成分。为了确保消费者的安全,有必要进一步加强对致敏性香精香料的管理。欧盟消费者安全科学委员(SCCS)会多次对致敏性香料香精成分进行评估,欧盟委员会根据评估意见调整了需单独标注的致敏性香精香料成分名单。以欧盟对化妆品中致敏性香精香料的管理为参考,结合我国相关原料的使用规定,为我国香精香料类原料的管理提出建议。 展开更多
关键词 香精香料 致敏性 化妆品 安全
下载PDF
六盘山地形及相对湿度对微波辐射计反演气温的影响
20
作者 邱玉珺 舒志亮 +2 位作者 陆春松 林彤 党张利 《大气科学》 CSCD 北大核心 2024年第2期659-670,共12页
利用2018年4月至2019年11月的六盘山隆德站微波辐射计探测资料与平凉站探空资料,研究了微波辐射计反演温度(TM)对空气相对湿度的敏感性。首次提出湿度敏感性系数(HSR)和零度漂移度(ZDD)概念,利用这两个参量在不同高度层的分布特征,研究... 利用2018年4月至2019年11月的六盘山隆德站微波辐射计探测资料与平凉站探空资料,研究了微波辐射计反演温度(TM)对空气相对湿度的敏感性。首次提出湿度敏感性系数(HSR)和零度漂移度(ZDD)概念,利用这两个参量在不同高度层的分布特征,研究了六盘山地形对空气相对湿度和温度的影响,主要结论如下:(1)非降水天气条件下,空气相对湿度越大,HSR与1.0的差别越大,ZDD也越大。(2)六盘山地形对大气层的湿度垂直分布影响较大。爬坡气流或抬升气流明显增加了3 km以下气层湿度水平,晴天和阴天条件下空气相对湿度分别在山顶以上0.5 km气层和1.0~2.0 km气层达到最大,TM比实际温度最大能偏低2.7℃。(3)地形对气层湿度的影响进一步影响了空气温度的垂直分布,阴天条件下的大气逆辐射加热使得3 km以下气层平均升温2.3℃,因湿度敏感性产生的温度影响平均达到0.9℃,最高能达到1.7℃。 展开更多
关键词 微波辐射计 温度 敏感性 六盘山 地形
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部