Study on the Integration Mechanism of Heritage Conservation and Sustainable Development of Historical Cities along the “Maritime Silk Road” — Take the Group City “Guangzhou-Hong Kong” as an Example

Yan Wang,Yawen Liang 한국전통문화대학교 한국전통문화연구소 2021 한국전통문화연구 Vol.2021 No.S

According to reports from international agencies such as the United Nations, the World Bank, the Asian Development Bank and the African Development Bank, by 2050, more than 90 percent of global urbanization will be concentrated in Asia and Africa, with about 2.5 billion people entering cities from rural areas. This will have a fundamental impact on the world urban structure. Asian countries are experiencing unprecedented rapid urbanization, and the sustainable development of cities in the future exists in the constantly updated historical environment. How can the historical experi-ence be summed up reasonably, and then push the countermeasures on a path to future development? This research focuses on Guangzhou-Hong Kong as the core node and typical type of the Chinese section of the Maritime Silk Road. The Group city is not only interdependent in spatial geography, but also a combination of trade, culture and history. The research studies the historical patterns of interactive development between Guangzhou and Hong Kong under the influence of "Sea-River." It analyzes the characteristics of urbanization mode determined by natural geography and the types of secondary city clusters driven by the trade and economy. It explores the internal logic and motivation, and deeply understands the interaction between the region's history and culture, economy and trade, natural environment, national policy and urban structure. It explores the new development mode of historical culture and local resources conservation and utilization, and puts forward the integration mechanism of historical urban heritage conservation and sustainable development in the future.

The effects of cigarettes and alcohol on intestinal microbiota in healthy men

Lin Renbin,Zhang Yawen,Chen Luyi,Qi Yadong,He Jiamin,Hu Mengjia,Zhang Ying,Fan Lina,Yang Tao,Wang Lan,Si Misi,Chen Shujie 한국미생물학회 2020 The journal of microbiology Vol.58 No.11

Human intestinal microbiota is affected by the exogenous microenvironment. This study aimed to determine the effects of cigarettes and alcohol on the gut microbiota of healthy men. In total, 116 healthy male subjects were enrolled and divided into four groups: non-smoking and non-drinking (Group A), smoking only (Group B), drinking only (Group C), and smoking and drinking combined (Group D). Fecal samples were collected and sequenced using 16S rRNA to analyze the microbial composition. Short-chain fatty acid (SCFAs) levels in feces were determined by gas chromatography. We found that cigarette and alcohol consumptions can alter overall composition of gut microbiota in healthy men. The relative abundances of phylum Bacteroidetes and Firmicutes and more than 40 genera were changed with cigarette and alcohol consumptions. SCFAs decreased with smoking and alcohol consumption. Multivariate analysis indicated that when compared with group A, group B/C/D had higher Bacteroides, and lower Phascolarctobacterium, Ruminococcaceae_ UCG-002, Ruminococcaceae_UCG-003, and Ruminiclostridium_ 9 regardless of BMI and age. Additionally, the abundance of Bacteroides was positively correlated with the smoking pack-year (r = 0.207, p < 0.05), the abundance of predicted pathway of bacterial toxins (r = 0.3672, p < 0.001) and the level of carcinoembryonic antigen in host (r = 0.318, p < 0.01). Group D shared similar microbial construction with group B, but exerted differences far from group C with lower abundance of Haemophilus. These results demonstrated that cigarette and alcohol consumption separately affected the intestinal microbiota and function in healthy men; furthermore, the co-occurrence of cigarette and alcohol didn’t exacerbate the dysbiosis and cigarette played the predominated role on the alteration.

A Target-Oriented Path Generation Method based on Concolic Testing

Zhang Xuzhou,Gong Yunzhan,Wang Yawen,Xing Ying 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.6

The space explosion caused by loop structure in path exploration makes it difficult to find a target-oriented path during code coverage testing. In this paper, a method named target-oriented concolic testing(TOCT) is introduced to tackle the problem of generating a path to cover a target in a loop structure. First, the static analysis method static prefix path search (SPSS) is used to generate a prefix path. Solving the constraints on the prefix path obtains a test case, with which concrete execution is carried out as an input. Meanwhile the execution trace is captured. The trace is used to unfold the loop into a feasible path. Finally SPPS is adopted again for the next prefix-path until a feasible path containing the target is achieved. Experimental results show that the proposed strategy reached a higher coverage when the targets are in loop structure and demonstrate that it is applicable in engineering.

Psychosocial Work Conditions During the COVID-19 Pandemic and Their Influences on Mental Health Risk and Intention to Leave Among Public Health Workers: A Cross-sectional and Follow-up Study in Taiwan

Lin Ming-Wei,Wang Yi-Ting,Cheng Yawen 한국산업안전보건공단 산업안전보건연구원 2023 Safety and health at work Vol.14 No.4

Background: To examine the influences of psychosocial work conditions on mental health risk and intention to leave the public sector among workers of public health agencies in Taiwan. Methods: We surveyed 492 public health workers in March 2022 during the COVID-19 pandemic. Information on job demands, job control, workplace justice, experiences of workplace violence and its type and origin, and mental health status (assessed by the 5-item Brief Symptom Rating Scale, BSRS-5) was obtained. Of them, 192 participated in a follow-up survey conducted in May 2023 that assessed mental health status, employment changes, and intention to leave. Results: In the initial survey, 32.93% of participants reported poor mental health status, defined by having a score of BSRS-5 ≧ 10, and 48.17% experienced some form of workplace violence over the past year. Notably, high psychosocial job demands (OR = 3.64, 95% CI = 1.93–6.87), low workplace justice (OR = 2.58, 95% CI = 1.45–4.58), and workplace violence (OR = 2.38, 95% CI = 1.51–3.77) were significantly associated with increased risk of mental disorders. Among those who participated in the follow-up survey, 22.40% had persistent poor mental health, and 30.73% considered leaving or have left the public sector. Longitudinal analyses indicated that job demands predicted persistent mental disorders and intention to leave the public sector, and the experience of workplace violence added additional mental health risks. Conclusion: The public health workforce is crucial for effective and resilient public health systems. Our findings that public health workers were at high mental health risk and had a high intention to leave the job warrant attention and policy interventions.

Nodule Rich Protein 2 modulates nodule number in Medicago truncatula

Junhui Yan,Xinwei Yang,Yawen Wang,Liangliang Yu,Li Luo 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.1

Symbiotic nitrogen fxation is beneft to sustainable agriculture and global nitrogen cycle. Many small peptides were identifed as regulators involving in the interaction between rhizobia and legume. Here we reported Nodule Rich Protein 2 (MtNRP2) encoding a small peptide in Medicago truncatula, belonged to a group of nodule rich protein restricted in legume species. MtNRP2 expressed highly in root nodule and its promoter was active during the initiation and development of root nodule and lateral root. To investigate the function of MtNRP2 in nodulation, we generated MtNRP2-overexpression and MtNRP2- knockdown transgenic Medicago. MtNRP2-overexpression transgenic lines performed normal nodulation phenotype compared with vector control. However, in the MtNRP2-RNAi transgenic plants, the decrease of MtNRP2 expression lead to the increase of infection threads number (7 day post inoculation) and nodules number (3 week post inoculation); meanwhile, the expression of MtRGF3 and MtPUB1 was inhibited. These results suggested that MtNRP2 negatively regulated nodulation in Medicago truncatula.

Ultrathin Biocompatible Electrospun Fiber Films for Self-Powered Human Motion Sensor

Gengrui Zhao,Shaobo Gong,Honggang Wang,Junfang Ren,Na Wang,Yawen Yang,Gui Gao,Shengsheng Chen,Linlin Li 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.3

In recent years, triboelectric nanogenerator (TENG) has been proven to be an effective and simple solution for self-powered wearable sensing, and a wide variety of materials and methods have been applied to TENG based sensors. In this study, an ultrathin fiber film with nanoporous brain-like structure (BUF) was obtained by cold-pressing the electrospun biocompatible fiber mats, and a wearable TENG sensor based on the BUF films that could sensitively detect human motion was demonstrated. This simply designed self-powered sensor was composed of Kapton as the shell and ultrathin, biocompatible poly L-lactic acid and ethyl cellulose (EC) fiber films as the triboelectric layers, prepared by convenient electrospinning method and cold-pressing. Compared to as-spun fiber mats, cold-pressed fiber membranes not only acquire overall compact structure but also remained porous surface morphology, which improved the triboelectric outputs and operational stability of TENG. Three TENGs were fabricated to evaluate the effects of different triboelectric layers on triboelectric outputs, and the BUF-TENG had the maximum triboelectric outputs (19 V, 630 nA at 3.5 Hz) and longer life than as-spun fiber mats based TENG. The BUF-TENG had linear relationship between triboelectric outputs and frequency, and sensitivities of 32.4, 0.94 and 0.22 V Hz−1 in the range of 0.1–0.35, 0.35–2 and 2–3.5 Hz, respectively. Moreover, a self-powered sensor based on the BUF-TENG was proposed to sensitively detect human walking state and limbs motion. With convenient preparation process and biocompatible materials, the BUF-TENG sensor could be a potential self-powered wearable and portable sensor in future health care and monitoring field.

Computational Studies on Mesh Stiffness of Paralleled Helical Beveloid Gear Pair

Ruihua Sun,Chaosheng Song,Caichao Zhu,Yawen Wang,Xingyu Yang 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.1

Considering the asymmetrical left and right tooth profiles including the transient curve at the tooth root region and the varying thickness along the axial direction due to the cone angle, we build the accurate profile curve model including the transient curve at the tooth root of helical beveloid gear with machining parameters to solve the problem of non-applicability of real digital model. According to the feature of gear shape varying along tooth width direction, we introduced the slicing method and derived its grouping formula. Finally, the efficient and accurate slicing-based mesh stiff ness calculation model of paralleled helical beveloid gears was proposed using potential energy theory. Then, mesh stiff ness was calculated using finite element contact model for comparison and verification. Finally, the impacts of macro geometry parameters including cone angle, normal pressure angle, helix angle, tooth width and addendum coefficient on single and total mesh stiff ness were analyzed. The calculated mesh stiff ness correlates well with the results from FEM with the maximum peak error is 4.8%. Results show that the tooth width shows an obvious incremental impact on average total mesh stiff ness. When the pressure angle, helix angle, cone angle and addendum coefficient increase, the average total mesh stiff ness increases first and then decreases. For the fluctuating value, it increases as the tooth width, helix angle and cone angle increase. However, the pressure angle and addendum coefficient show an opposite impact on the fluctuating value.

Pulsed-laser-diode Intermittently Pumped 2-μm Acousto-optic Q-switched Tm:LuAG Laser

Ya Wen,Yan Jiang,Hao Zheng,Hongliang Zhang,Chao Wang,Chunting Wu,Guangyong Jin 한국광학회 2020 Current Optics and Photonics Vol.4 No.3

The heat distribution in crystals in a 2-µm acousto-optic Q-switched Tm:LuAG laser pumped by pulsed-laser-diode (pulsed-LD) intermittent-pumping technology was analyzed using COMSOL software. The thermal lensing effect of the Tm:LuAG crystal can be mitigated by pulsed-LD intermittent-pumping techniques. An experimental setup using this kind of approach achieved maximum output energy of 8.31 mJ, minimum pulse width of 101.9 ns, and highest peak power of 81.55 kW, reached at a Q-switched repetition rate of 200 Hz. It offers significant improvement of performance of the output laser beam, compared to pulsed-LD double-ended pumping technology at the same repetition rate.