Convenient Synthesis of N-Methylpyrrolidine-2-thione and Some Thioamides

Zong, Zhi-Min,Peng, Yao-Li,Liu, Zhi-Gang,Zhou, Shi-Lu,Wu, Lin,Wang, Xiao-Hua,Wei, Xian-Yong,Lee, Chul Wee 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.2

The synthesis of thioamides and thiolactams, which are used as important organic intermediates, has attracted great attention. However, expensive reagents, severe reaction conditions and low yields of the target products made conventional methods inconvenient and economically infeasible. To overcome these disadvantages, we investigated a new process for synthesizing thioamides and thiolactams. We examine thermal reactions of CS_2 with N-methyl-2-pyrrolidinones, formylamide, acetamide and N, N-dimethylformylamide, respectively. The results show that under optimum conditions N-methylpyttolidine-2-thione and the corresponding thioamides can be obtained in good to excellent yields by the above thionation reactions.

Design optimization of a nuclear main steam safety valve based on an E-AHF ensemble surrogate model

Zong Chaoyong,Shi Maolin,Li Qingye,Liu Fuwen,Zhou Weihao,Song Xueguan 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.11

Main steam safety valves are commonly used in nuclear power plants to provide final protections from overpressure events. Blowdown and dynamic stability are two critical characteristics of safety valves. However, due to the parameter sensitivity and multi-parameter features of safety valves, using traditional method to design and/or optimize them is generally difficult and/or inefficient. To overcome these problems, a surrogate model-based valve design optimization is carried out in this study, of particular interest are methods of valve surrogate modeling, valve parameters global sensitivity analysis and valve performance optimization. To construct the surrogate model, Design of Experiments (DoE) and Computational Fluid Dynamics (CFD) simulations of the safety valve were performed successively, thereby an ensemble surrogate model (E-AHF) was built for valve blowdown and stability predictions. With the developed E-AHF model, global sensitivity analysis (GSA) on the valve parameters was performed, thereby five primary parameters that affect valve performance were identified. Finally, the ksigma method is used to conduct the robust optimization on the valve. After optimization, the valve remains stable, the minimum blowdown of the safety valve is reduced greatly from 13.30% to 2.70%, and the corresponding variance is reduced from 1.04 to 0.65 as well, confirming the feasibility and effectiveness of the optimization method proposed in this paper

RANDOMLY ORTHOGONAL FACTORIZATIONS OF (0,mf - (m - 1)r)-GRAPHS

Zhou, Sizhong,Zong, Minggang Korean Mathematical Society 2008 대한수학회지 Vol.45 No.6

Let G be a graph with vertex set V(G) and edge set E(G), and let g, f be two nonnegative integer-valued functions defined on V(G) such that $g(x)\;{\leq}\;f(x)$ for every vertex x of V(G). We use $d_G(x)$ to denote the degree of a vertex x of G. A (g, f)-factor of G is a spanning subgraph F of G such that $g(x)\;{\leq}\;d_F(x)\;{\leq}\;f(x)$ for every vertex x of V(F). In particular, G is called a (g, f)-graph if G itself is a (g, f)-factor. A (g, f)-factorization of G is a partition of E(G) into edge-disjoint (g, f)-factors. Let F = {$F_1$, $F_2$, ..., $F_m$} be a factorization of G and H be a subgraph of G with mr edges. If $F_i$, $1\;{\leq}\;i\;{\leq}\;m$, has exactly r edges in common with H, we say that F is r-orthogonal to H. If for any partition {$A_1$, $A_2$, ..., $A_m$} of E(H) with $|A_i|=r$ there is a (g, f)-factorization F = {$F_1$, $F_2$, ..., $F_m$} of G such that $A_i\;{\subseteq}E(F_i)$, $1\;{\leq}\;i\;{\leq}\;m$, then we say that G has (g, f)-factorizations randomly r-orthogonal to H. In this paper it is proved that every (0, mf - (m - 1)r)-graph has (0, f)-factorizations randomly r-orthogonal to any given subgraph with mr edges if $f(x)\;{\geq}\;3r\;-\;1$ for any $x\;{\in}\;V(G)$.

Preoperative Serum CEA and CA19-9 in Gastric Cancer - a Single Tertiary Hospital Study of 1,075 Cases

Zhou, Yang-Chun,Zhao, Hai-Jian,Shen, Li-Zong Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

To evaluate the clinical impact of preoperative serum CEA and CA19-9 on resectable gastric cancer (GC), a total of 1,075 consecutive cases with gastric adenocarcinoma were obtained retrospectively from January 2012 and December 2013 in a single tertiary hospital, and the relationships between serum CEA, CA19-9 and clinicopathologic features were investigated. Positive preoperative serum rates of CEA and CA19-9 were 22.4% and 12.3% respectively, levels significantly correlating with each other and depth of invasion, lymph node involvement, pTNM and stage. The CEA level also presented a remarkable association with lymphovascular invasion. Both CEA and CA19-9 positivity significantly and positively correlated with depth of invasion, nodal involvement, pTNM stage, lymphovascular invasion, tumor size and tumor location. Stratified analyses according to gender or tumor location showed preoperative CEA or CA19-9 had different associations with clinicopathologic features in different gender subgroups or location subgroups. Preoperative serum CA19-9 positivity may be more meaningful for tumor size rather than CEA. In conclusion, preoperative serum CEA and CA19-9 correlate with disease progression of GC, and may have applications in aiding more accurate estimation of tumor stage, decision of treatment choice and prognosis evaluation.

RANDOMLY ORTHOGONAL FACTORIZATIONS OF (0,mf − (m− 1)r)-GRAPHS

Sizhong Zhou,Minggang Zong 대한수학회 2008 대한수학회지 Vol.45 No.6

Let G be a graph with vertex set V (G) and edge set E(G), and let g, f be two nonnegative integer-valued functions defined on V (G) such that g(x) ≤ f(x) for every vertex x of V (G). We use dG(x) to denote the degree of a vertex x of G. A (g, f)-factor of G is a spanning subgraph F of G such that g(x) ≤ dF (x) ≤ f(x) for every vertex x of V (F). In particular, G is called a (g, f)-graph if G itself is a (g, f)-factor. A (g, f)- factorization of G is a partition of E(G) into edge-disjoint (g, f)-factors. Let F = {F₁, F₂, . . . , Fm} be a factorization of G and H be a subgraph of G with mr edges. If Fi, 1 ≤ i ≤ m, has exactly r edges in common with H, we say that F is r-orthogonal to H. If for any partition {A₁,A₂, . . . ,Am} of E(H) with |Ai| = r there is a (g, f)-factorization F = {F₁, F₂, . . . , Fm} of G such that Ai ⊆ E(Fi), 1 ≤ i ≤ m, then we say that G has (g, f)- factorizations randomly r-orthogonal to H. In this paper it is proved that every (0,mf − (m − 1)r)-graph has (0, f)-factorizations randomly r-orthogonal to any given subgraph with mr edges if f(x) ≥ 3r − 1 for any x ∈ V (G). Let G be a graph with vertex set V (G) and edge set E(G), and let g, f be two nonnegative integer-valued functions defined on V (G) such that g(x) ≤ f(x) for every vertex x of V (G). We use dG(x) to denote the degree of a vertex x of G. A (g, f)-factor of G is a spanning subgraph F of G such that g(x) ≤ dF (x) ≤ f(x) for every vertex x of V (F). In particular, G is called a (g, f)-graph if G itself is a (g, f)-factor. A (g, f)- factorization of G is a partition of E(G) into edge-disjoint (g, f)-factors. Let F = {F₁, F₂, . . . , Fm} be a factorization of G and H be a subgraph of G with mr edges. If Fi, 1 ≤ i ≤ m, has exactly r edges in common with H, we say that F is r-orthogonal to H. If for any partition {A₁,A₂, . . . ,Am} of E(H) with |Ai| = r there is a (g, f)-factorization F = {F₁, F₂, . . . , Fm} of G such that Ai ⊆ E(Fi), 1 ≤ i ≤ m, then we say that G has (g, f)- factorizations randomly r-orthogonal to H. In this paper it is proved that every (0,mf − (m − 1)r)-graph has (0, f)-factorizations randomly r-orthogonal to any given subgraph with mr edges if f(x) ≥ 3r − 1 for any x ∈ V (G).

Effects of whole-plant corn and hairy vetch (Vicia villosa Roth) mixture on silage quality and microbial communities

Yaqian Zong,Kai Zhou,Xinhui Duan,Bo Han,Hua Jiang,Chenggang He Asian Australasian Association of Animal Productio 2023 Animal Bioscience Vol.36 No.12

Objective: Hairy vetch is considered to improve the nutritional value of corn because of its high protein and mineral levels. To better understand the mechanism underlying hairy vetch regulated whole-plant corn silage fermentation, this experiment investigated the fermentation quality and bacterial community of whole-plant corn and hairy vetch mixture. Methods: Whole-plant corn and hairy vetch were mixed at ratios of 10:0 (Mix 10:0), 8:2 (Mix 8:2), 6:4 (Mix 6:4), 4:6 (Mix 4:6), 2:8 (Mix 2:8), and 0:10 (Mix 0:10) on a fresh weight basis. After ensiling 60 days, samples were collected to examine the fermentation dynamics, ensiling characteristics, and bacterial communities. Results: Mix 0:10, Mix 2:8, and Mix 4:6 showed poor fermentation characteristics. Mix 8:2 and Mix 6:4 silages showed high quality, based on the low pH, acetic acid, and ammonia nitrogen levels and the high lactic acid, crude protein, and crude fat contents. The bacterial diversity was affected by the mixing ratio of the two forage species. The genus Lactobacillus dominated the bacterial community in Mix 10:0 silage, whereas with the addition of hairy vetch, the relative abundance of unclassified-Enterobacter increased from 7.67% to 41.84%, and the abundance of Lactobacillus decreased from 50.66% to 13.76%. Conclusion: The silage quality of whole-plant corn can be improved with inclusion levels of hairy vetch from 20% to 40%.

Applicability of Waste Rubber Particles as Buried Pipe Backfill Material

Enquan Zhou,Zhixin Zong 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.5

The primary purpose of this work is to evaluate the viability of using waste rubber particles as buried pipe backfill. By applying confined compression test and model test, this research studied the compressibility of sand and rubber-sand mixtures (RSM) and also, investigated the behavior of pipe surrounded by sand and RSM subjected to impact loading. The findings are as follows: 1) The vertical elastic strain and plastic strain of compression test samples increase with rubber content, and the elastic strain and plastic strain of saturated samples are greater than those of dry samples. 2) The settlement of RSM model soil is greater than that of pure sand model soil subjected to impact loading. The addition of rubber particles to pure sand reduces the earth pressure increment. The cumulative strain of pipe surrounded by dry RSM is less than that surrounded by dry pure sand. However, the cumulative strain of pipe surrounded by saturated RSM is greater than that surrounded by saturated pure sand. This investigation provides an environmentally friendly approach for recycling waste tire particles in geotechnical engineering.

Output-only modal parameter identification of civil engineering structures

Wei-Xin Ren,Zhou-Hong Zong 국제구조공학회 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.17 No.3-4

The ambient vibration measurement is a kind of output data-only dynamic testing where the traffics and winds are used as agents responsible for natural or environmental excitation. Therefore an experimental modal analysis procedure for ambient vibration testing will need to base itself on output-only data. The modal analysis involving output-only measurements presents a challenge that requires the use of special modal identification technique, which can deal with very small magnitude of ambient vibration contaminated by noise. Two complementary modal analysis methods are implemented. They are rather simple peak picking (PP) method in frequency domain and more advanced stochastic subspace identification (SSI) method in time domain. This paper presents the application of ambient vibration testing and experimental modal analysis on large civil engineering structures. A 15 storey reinforced concrete shear core building and a concrete filled steel tubular arch bridge have been chosen as two case studies. The results have shown that both techniques can identify the frequencies effectively. The stochastic subspace identification technique can detect frequencies that may possibly be missed by the peak picking method and gives a more reasonable mode shapes in most cases.

Decentralized Adaptive Event-triggered Control for Nonlinear Interconnected Systems in Strict-feedback Form

Yuehui Ji,Hailiang Zhou,Qun Zong 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.4

The decentralized event triggered control problem is investigated for nonlinear interconnected systems in strict-feedback form subjected to parametric uncertainty. For each subsystem in the interconnected systems, the decentralized adaptive backstepping controller is designed to guarantee that the tracking error is semi-globally ultimately bounded. The control update and parameter estimate action are aperiodical executed only when the desired control specifications cannot be ensured, drastically reducing the computational burden and the transmission cost. It can be proved that zeno phenomenon is avoided as a positive lower bound on the minimal inter-sample time exists. The impulsive dynamical systems tools and Lyapunov analysis are introduced to prove the stability property for closed-loop system. Finally, a numerical simulation example is included to validate the effectiveness of the control scheme.

Activated Carbon-Catalyzed Hydrogen Transfer to &agr;,&ohgr;-Diarylalkanes

Sun, L.-B.,Zong, Z.-M.,Kou, J.-H.,Liu, G.-F.,Sun, X.,Wei, X.-Y.,Zhou, G.-J.,Lee, C. W. American Chemical Society 2005 Energy & fuels Vol.19 No.1