6 results on '"Zhu, Z.-L."'
Search Results
2. Design of Dual-Mode Loop Resonator-Based Microwave Diplexers with Enhanced Performance
- Author
-
Zhu, Z. L. and Li, J. L.
- Subjects
dual-mode resonator ,Microwave diplexer ,loop resonator ,microstrip resonator ,Electrical and Electronic Engineering - Abstract
In this paper, a dual-mode loop resonator based circuit topology is studied for microwave diplexer applications. Several diplexers, with dense and sparse channel separations, are further discussed based on the introduced topology, featuring capable of controlling transmission zeros flexibly. Hence microwave diplexers with high selectivity and good channel isolation can be realized by placing transmission zeros of the channel filters at the desired channels. With the use of the proposed topology, the achieved center frequency ratio between two channels can be from 1.03 to 1.35 with good isolations, high selectivity and compact size. The demonstration diplexers are realized on PCB processes, but can be implemented with other media including MMIC. Experimental validations on the developed demonstrator are presented in the paper, and measured responses match well the full-wave electromagnetic simulated results. The developed UMTS diplexer demonstrator achieves the measured minimum passband insertion losses of 2.55 and 2.7 dB with return losses better than 15 dB and channel isolations over 40 dB at the two channels.
- Published
- 2022
3. [Clinical application value of modified Lee grading system to evaluate the degree of foraminal stenosis in patients with intervertebral foraminal lumbar disc herniation].
- Author
-
Li SL, Zhang GW, Qu DX, Li X, Zhu ZL, Tan JW, Qu ZW, Tang XF, and Liu XL
- Subjects
- Male, Female, Humans, Adult, Middle Aged, Aged, Aged, 80 and over, Reproducibility of Results, Constriction, Pathologic, Retrospective Studies, Lumbar Vertebrae, Magnetic Resonance Imaging methods, Intervertebral Disc Displacement, Spinal Stenosis, Intervertebral Disc
- Abstract
Objective: To investigate the clinical application value of the modified Lee grading system (abbreviated as the modified system) in evaluating the degree of intervertebral foraminal stenosis(IFS) in patients with foraminal lumbar disc herniations(FLDH). Methods: MRI data of 83 patients with FLDH-IFS (34 patients in the operation group and 49 patients in the conservative group) in Yantai Affiliated Hospital of Binzhou Medical University and Yantai Yantaishan Hospital from March 2018 to February 2021 were retrospectively collected. There were 43 males and 40 females, ranged from 34 to 82 years old, with an average of (61±10) years. MRI images of selected patients were independently evaluated and recorded by two radiologists in a blind method, using both the Lee grading system (abbreviated as Lee system) and the modified system, respectively and each method was evaluated twice. The difference between the evaluation level of the two systems, and the agreement of observer assessments of the two systems were compared, and the correlation between the evaluation level of the two grading systems and the clinical treatment modalities was analyzed. Results: The percentage of nongrade 3 (grade 0-2) patients with effective conservative treatment according to the two grading systems was 94.6 % (139/147) and 64.2 % (170/265), respectively. The percentage of grade 3 patients requiring surgical treatment according to the two grading systems was 69.2 % (128/185) and 61.2 % (41/67), respectively. There was a statistically significant difference between the evaluation levels of the modified system and the Lee system ( Z =-5.16, P =0.001). In the Lee system, the intra-observer observation consistency Kappa values of the two radiologists were 0.735 and 0.542, respectively, which were highly and moderately consistent; and the inter-observer observation consistency Kappa values were 0.426-0.521, which were moderate consistency. In the modified system, the intra-observer consistency Kappa values of the two radiologists were 0.900 and 0.921, respectively, and the consistency was almost completely consistent; and the inter-observer consistency Kappa values were 0.783-0.861, which were highly consistent or almost completely consistent. Lee system and clinical treatment modalities was correlative ( r
s =0.39, P <0.001), and modified system and clinical treatment modalities was correlative ( rs =0.61, P <0.001). Conclusion: According to FLDH-IFS, the modified system can comprehensively and accurately grade, with high reliability and reproducibility. The evaluation level has a more significant correlation with clinical treatment modalities.- Published
- 2023
- Full Text
- View/download PDF
4. [Analysis of volatile organic components of organic solvents used in Bao'an District of Shenzhen].
- Author
-
Wang LH, Zhu ZL, Dai ZT, Feng J, and Weng SF
- Subjects
- Hexanes, Solvents, Industry, Benzene analysis, Trichloroethylene
- Abstract
Objective: To understand the volatile organic components in the organic solvents used by enterprises in Baoan District, Shenzhen. Methods: From January to December 2020, a total of 541 organic solvent samples used by 86 companies were collected for volatile organic component analysis, and the main volatile components and high-risk occupational hazards in organic solvents used in different industries were analyzed. Results: A total of 201 volatile organic components were detected in 541 organic solvents. The top 5 components detected include xylene (29.76%, 116/541), toluene (21.81%, 118/541), methanol (20.70%, 112/541), n-hexane (14.79%, 80/541) and ethylbenzene (14.23%, 77/541). The detection rates of benzene, trichloroethylene, n-hexane, and 1, 2-dichloroethane, which were high-risk occupational hazards, were 2.40% (13/541), 3.70% (20/541), 14.79% (80/541), and 1.66% (9/541), respectively. The volatile components in organic solvents used in different industries was different. Benzene is more frequently detected in organic solvents used in the printing industry, trichloroethylene was more frequently detected in organic solvents used in the electronics industry, and n-hexane was more commonly found in organic solvents used in the electronics industry, printing and other industries, and 1, 2-dichloroethane has been more frequently detected in organic solvents used in the machinery industry. Conclusion: There are many types of organic solvents used by enterprises in Bao'an District, with complex components and differences in different industries.
- Published
- 2022
- Full Text
- View/download PDF
5. [Molluscicidal effect of 25% wettable powder of pyriclobenzuron sulphate in hilly schistosomiasis-endemic regions].
- Author
-
Zhu ZL, Luo BR, Liu YH, Hao YW, Tian T, Wang Q, Duan LP, and Li SZ
- Subjects
- Animals, China epidemiology, Ethanolamine pharmacology, Ethanolamines pharmacology, Niclosamide pharmacology, Organic Chemicals, Powders pharmacology, Snails, Sulfates pharmacology, Water, Molluscacides pharmacology, Schistosomiasis drug therapy, Schistosomiasis epidemiology, Schistosomiasis prevention & control
- Abstract
Objective: To evaluate the molluscicidal effect of 25% wettable powder of pyriclobenzuron sulphate (WPPS) against Oncomelania snails in hilly schistosomiasis-endemic regions and test its toxicity to fish., Methods: In October 2020, a snail-infested setting which had been cleared was selected in Nanjian County, Yunnan Province and divided into several blocks, and the natural snail mortality was estimated. 25% WPPS was prepared into solutions at concentrations of 1 and 2 g/L, and 25% wettable powder of niclosamide ethanolamine salt (WPNES) was prepared into solutions at a concentration of 2 g/L. The different concentrations of drugs were sprayed evenly, and the same amount of water was used as blank control. Snails were surveyed using the systematic sampling method 1, 3 and 7 days post-treatment, and snail survival was observed. A fish pond was selected in Nanjian County, and 2 kg 25% WPPS was evenly sprayed on the water surface to allow the effective concentration of 20 g/L. Fish mortality was estimated 8, 24, 48 and 72 h post-treatment., Results: One-day treatment with 1 and 2 g/L WPPS and 2 g/L WPNES resulted in 97.99%, 97.99% and 94.11% adjusted snail mortality rates ( χ
2 values > 0.05), and the adjusted snail mortality was all 100% 3 d post-treatment with 1 and 2 g/L WPPS and 2 g/L WPNES, while 7-day treatment with 1 and 2 g/L WPPS and 2 g/L WPNES resulted in 91.75%, 86.57% and 57.76% adjusted snail mortality rates ( P values > 0.05), and the adjusted snail mortality was all 100% 3 d post-treatment with 1 and 2 g/L WPPS and 2 g/L WPNES, while 7-day treatment with 1 and 2 g/L WPPS and 2 g/L WPNES resulted in 91.75%, 86.57% and 57.76% adjusted snail mortality rates ( χ values < 0.05). Treatment with 2 g/L WPPS for 72 h resulted in a 0.67% cumulative mortality rate of fish.2 = 14.893 and 42.284, both P values < 0.05). Treatment with 2 g/L WPPS for 72 h resulted in a 0.67% cumulative mortality rate of fish., Conclusions: 25% WPPS is effective for snail control and highly safe for fish, which is feasible for use in hilly schistosomiasis-endemic regions.- Published
- 2022
- Full Text
- View/download PDF
6. [Analysis on the incidence of occupational diseases in Bao'an District of Shenzhen city from 2006 to 2019].
- Author
-
Zhou RY, Wang LH, Chen AJ, and Zhu ZL
- Subjects
- China epidemiology, Humans, Incidence, Industry, Manufacturing Industry, Occupational Diseases, Pneumoconiosis
- Abstract
Objective: To analyze the characteristics of occupational diseases in Bao'an District of Shenzhen from 2006 to 2019, so as to provide scientific basis for formulating occupational disease prevention policies and measures. Methods: In September 2020, the information of new occupational disease cases in Bao'an District of Shenzhen from 2006 to 2019 was collected through the national occupational disease and occupational health information monitoring system, and the classification, disease type distribution, population distribution and industry and enterprise scale distribution of new occupational disease cases were analyzed. Results: From 2006 to 2019, a total of 762 new occupational diseases were reported in Bao'an District of Shenzhen, of which the top three were occupational ear, nose, throat and oral diseases (233 cases, accounting for 30.58%) , occupational chemical poisoning diseases (219 cases, accounting for 28.74%) , occupational pneumoconiosis and other respiratory diseases (127 cases, accounting for 16.67%) . The classification composition of occupational diseases was different in different years, and the difference was statistically significant ( P <0.05) . New occupational diseases are mainly distributed in the manufacturing industry (394 Eaterprises, caccouling 93.59%) , concentrated in (346 cases, accounting for 47.66%) and medium-sized enterprises (199 cases, accounting for 27.4%) small enterprises. Conclusion: New occupational diseases in Bao'an District of Shenzhen should focus on small and medium-sized manufacturing enterprises, carry out risk assessment of occupational hazards, implement classified and hierarchical supervision of occupational health, and implement occupational health protection.
- Published
- 2021
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.