PROPER CONDITIONS OF MESHING FOR Hy-Vo SILENT CHAIN AND SPROCKET

Proper meshing of Hy-Vo silent chain and sprocket is important for realizing the transmission of the silent chain with more efficiency and less noise. Based on the study of the meshing theory of the Hy-Vo silent chain with the sprocket and the roll cutting machining principle of the sprocket with the hob, the proper conditions of the meshing for the Hy-Vo silent chain and the sprocket are put forward with the variable pitch characteristic of the Hy-Vo silent chain taken into consideration, and the proper meshing design method on the condition that the value of the link tooth pressure angle is unequal to the value of the sprocket tooth pressure angle is studied. Experiments show that this new design method is feasible. In addition, the design of the pitch, the sprocket tooth pressure angle and the fillet radius of the sprocket addendum circle are studied. It is crucial for guiding the design of the hob which cuts the Hy-Vo silent chain sprocket.

Three-dimensional Motion of Multichain-Buoy Mooring System in shallow Water and Survival Conditions

An engineering numerical model for three dimensional motion of multichain-buoy mooring system in shallow water and survival condition is given in this paper. Shooting-aim method is employed for solving the dynamic equations of chain system in order to match the computation of buoy motion. The responses of buoy and chain have been computed for different wind-wave-current directions and different rigidity of chain. The results show that the present numerical model is reasonable.

Matching Boundary Conditions for a Heterogeneous Atomic Chain

We propose accurate boundary treatments for a heterogeneous atomic chain, in terms of matching boundary conditions （MBCs）. The main challenge lies in reproducing the physical reflection across the boundary to a correct amount. With reflection coefficients we demonstrate that the accuracy is improved when more atoms are used under the boundary condition. The inclusion of an atom in the embedded sublattice B may considerably enhance the performance. Numerical testing illustrates the effectiveness of the proposed MBCs.

Chain Conditions on Essetial Subacts

Let S be a semigroup with zero and an S-act be a centered left S-act. This paper is devoted to the study of chain conditions on PS-acts. We prove that a PS-act having finite decomposition has ACC （DCC） on all subacts if it has ACC （DCC） on essential subacts. Moreover, a PS-act with ACC （DCC） on essential subacts has ACC （DCC） on all subacts if and only if it has finite decomposition. We characterize the structure of a PS-act and generalize some results of the Goldie dimension and semisimple S-acts.

Optimization of Candida tropicalis Fermentation Conditions to Produce Long-chain Dibasic Acids

[Objectives] The fermentation conditions of Candida tropicalis 1798-pxa1 were optimized to further improve its yield of long-chain dibasic acids. [Methods] The strains used in the study were C. tropicalis 1798, C. tropicalis 1798-pxa1 and C. tropicalis 1798-pxa1 p2. First, through single factor experiments, the activated three fungi were cultured in different carbon sources, and the absorbance was measured every 2 h. The growth curve was drawn by software, and finally the most suitable substance for the substrate was selected, i.e., dodecane. Then, the composition of the fermentation medium and the fermentation process parameters were determined through the PB experiment of the single-deletion C. tropicalis 1798-pxa1. [Results] The experiment determined the important components affecting the synthesis of long-chain dibasic acids, namely(NH_4)_2SO_4, NaCl and dodecane. After optimization of the culture conditions, the yield of long-chain dibasic acids of C. tropicalis 1798-pxa1 increased from 5.6 to 10.1 g/L. [Conclusions] The scheme has been verified to be capable of greatly increasing the yield of the corresponding long-chain dibasic acids of the C. tropicalis engineering strain.

Double Conditional Expectation

The concept of double conditional expectation is introduced. A series of properties for the double conditional expectation are obtained several convergence theorems and Jensen inequality are proved. Finally we discuss the special cases and application for double conditional expectation. Key words double conditional expectation - covergence theorem - Jensen inequality - branching chain in random environment CLC number O 211.6 Foundation item: Supported by the National Science Foundation of China (10371092) and the Foundation of Wuhan UniversityBiography: HU Di-he (1935-), male, Professor, research direction: stochastic processes and random fractals.

TEST AND CHARACTERIZATION FOR THE INCOMPRESSIBLE HYPERELASTIC PROPERTIES OF CONDITIONED RUBBERS UNDER MODERATE FINITE DEFORMATION

In this paper, the automated grid method is applied to test for the mechanical properties of conditioned rubbers under the moderate ?nite deformation (not exceeding 100%). More accurate stress-strain curves of conditioned rubber specimens under di?erent conditioned strains are obtained. Test results show di?erences between these curves. Based on an analysis of the classical constitutive models, a new modi?ed eight-chain model is proposed, which takes account of both the locking stretch of chains and the interaction e?ect in the network. Fitting test data shows that the modi?ed model well characterizes the incompressible hyperelastic mechanical behavior of conditioned rubbers under the moderate ?nite deformation as well as under the large deformation.

Joint optimization of sampling interval and control for condition-based maintenance using availability maximization criterion

Most of the maintenance optimization models in condition-based maintenance(CBM) consider the cost-optimal criterion, but few papers have dealt with availability maximization for maintenance applications. A novel optimal Bayesian control approach is presented for maintenance decision making. The system deterioration evolves as a three-state continuous time hidden semi-Markov process. Considering the optimal maintenance policy, the multivariate Bayesian control scheme based on the hidden semi-Markov model(HSMM) is developed, the objective is to maximize the long-run expected average availability per unit time. The proposed approach can optimize the sampling interval and control limit jointly. A case study using Markov chain Monte Carlo(MCMC)simulation is provided and a comparison with the Bayesian control scheme based on hidden Markov model(HMM), the age-based replacement policy, Hotelling’s T2, multivariate exponentially weihted moving average(MEWMA) and multivariate cumulative sum(MCUSUM) control charts is given, which illustrates the effectiveness of the proposed method.

Mathematical Modeling of Possibility Markov Chains by Possibility Theory

Statistical regression models are input-oriented estimation models that account for observation errors. On the other hand, an output-oriented possibility regression model that accounts for system fluctuations is proposed. Furthermore, the possibility Markov chain is proposed, which has a disidentifiable state (posterior) and a nondiscriminable state (prior). In this paper, we first take up the entity efficiency evaluation problem as a case study of the posterior non-discriminable production possibility region and mention Fuzzy DEA with fuzzy constraints. Next, the case study of the ex-ante non-discriminable event setting is discussed. Finally, we introduce the measure of the fuzzy number and the equality relation and attempt to model the possibility Markov chain mathematically. Furthermore, we show that under ergodic conditions, the direct sum state can be decomposed and reintegrated using fuzzy OR logic. We had already constructed the Possibility Markov process based on the indifferent state of this world. In this paper, we try to extend it to the indifferent event in another world. It should be noted that we can obtain the possibility transfer matrix by full use of possibility theory.

Entanglement in an anisotropic spin-1 Heisenberg chain

The entanglement in an anisotropic spin-1 Heisenberg chain with a uniform magnetic field is investigated. The ground-state entanglement will undergo two different kinds of transitions when the anisotropy △ and the amplitude of the magnetic field B are varied. The thermal entanglement of the nearest neighbour always declines when B increases no matter what the value of the anisotropy is. It is very interesting to note that the entanglement of the next-nearest neighbour can increase to a maximum at a certain magnetic field. Regardless of the boundary condition, the nearestneighbour entanglement always decreases and approaches to a constant value when the size of the system is very large. The constant value of open boundary condition is much larger than that of periodic boundary condition.

Synthesis,Structure,and Luminescent and Dielectric Properties of Two Novel 1D Chains Based on a T-Shaped Tripodal Ligand 4-(4,5-Dicarboxy-1H-imidazol-2-yl)pyridine Loxide

Two 1D chain metal-organic framework complexes, {Co[（C10H5N3O5）- （H2O）2？H2O]}n （1） and {Cd[（C10H5N3O5）（H2O）2]}n （2）, based on a T-shaped tripodal ligand 4-（4,5-dicarboxy- 1H-imidazol-2-yl） pyridine 1-oxide （H3DCImPyO） have been reacted under hydrothermal conditions, and were characterized by single-crystal X-ray structure analysis, fluorescent analysis and thermal gravimetric analysis. According to single-crystal X-ray determination, complex 1 crystallizes in the monoclinic system, space group P21/n with a = 9.4930（13）, b = 13.2024（18）, c = 10.5203（14） A^°, β = 98.402（2）°, Z = 4, V = 1304.4（3）A^°3; and complex 2 crystallizes in the monoclinic system, space group C2/c with a = 13.557（3）, b = 13.568（3）, c = 6.7804（13） A^°, β = 105.095（2）°, Z = 4 and V = 1204.2（4） A^°3. Fluorescent analysis of complex 2 showed an intense emission band at 466 nm when the exciting radiation was set at 360 nm. Dielectric constants of complexes 1 and 2 were measured at different frequencies with temperature variation.

老年重症肺炎合并呼吸衰竭患者血清Gal-3、MICA、25(OH)D水平及其对病情、预后的影响

目的探讨老年重症肺炎(SP)合并呼吸衰竭(RF)患者血清半乳糖凝集素-3(Gal-3)、主要组织相容性复合体Ⅰ相关分子A(MICA)、25-羟维生素D[25(OH)D]水平及其对病情、预后的影响。方法选取2022年8月—2024年7月北大荒集团总医院重症医学科收治的老年SP患者342例为研究对象,根据是否合并RF将患者分为RF组171例和非RF组171例。根据急性生理学及慢性健康状况评分Ⅱ(APACHEⅡ)将老年SP合并RF患者分为低危亚组41例、中危亚组77例、高危亚组53例;根据随访28 d预后情况将老年SP合并RF患者分为死亡亚组51例和生存亚组120例。采用ELISA法检测血清Gal-3、MICA水平,采用高效液相色谱—串联质谱法(LC-MS/MS)检测血清25(OH)D水平;采用Spearman法分析血清Gal-3、MICA、25(OH)D水平与病情程度的相关性;多因素Logistic回归分析老年SP合并RF患者预后死亡的影响因素;受试者工作特征(ROC)曲线评价血清Gal-3、MICA、25(OH)D水平对老年SP合并RF患者预后死亡的预测价值。结果RF组血清Gal-3、MICA水平高于非RF组,血清25(OH)D水平低于非RF组(t/P=12.674/<0.001、20.954/<0.001、22.872/<0.001);伴随病情加重,老年SP合并RF患者血清Gal-3、MICA水平逐渐升高,血清25(OH)D水平逐渐降低(F/P=41.512/<0.001、221.162/<0.001、165.574/<0.001);Spearman相关性分析显示,老年SP合并RF患者病情严重程度与血清Gal-3、MICA水平呈正相关(r=0.682、0.726,P均<0.001),与血清25(OH)D水平呈负相关(r=-0.733,P<0.001);随访28 d,171例老年SP合并RF患者死亡发生率为29.82%(51/171)。死亡亚组氧合指数(PaO_(2)/FiO_(2))、血清25(OH)D水平低于生存亚组,机械通气时间、APACHEⅡ评分、血清Gal-3、MICA水平高于生存亚组(t/P=2.392/0.018、13.242/<0.001、2.235/0.027、10.805/<0.001、7.852/<0.001、16.923/<0.001);多因素Logistic回归分析结果显示,机械通气时间长、APACHEⅡ评分高、Gal-3高、MICA高为老年SP合并RF患者预后死亡的独立危险因素[OR(95%CI)=2.518(1.385~4.578)、3.157(1.849~5.391)、3.264(1.863~5.717)、4.116(2.025~8.368)],PaO_(2)/FiO_(2)高、25(OH)D高为独立保护因素[OR(95%CI)=0.549(0.346~0.870)、0.426(0.272~0.667)];血清Gal-3、MICA、25(OH)D水平及三者联合预测老年SP合并RF患者预后死亡的曲线下面积(AUC)分别为0.855、0.850、0.835、0.968,三者联合的AUC大于血清Gal-3、MICA、25(OH)D水平单独预测(Z=3.600、3.652、4.001,P均<0.001)。结论老年SP合并RF患者血清Gal-3、MICA水平升高,25(OH)D水平降低,三者水平与老年SP合并RF患者病情严重程度密切相关,三者联合预测老年SP合并RF患者预后死亡的价值较高。

Markov Chain Monte Carlo Solution of Laplace’s Equation in Axisymmetric Homogeneous Domain

With increasing complexity of today’s electromagnetic problems, the need and opportunity to reduce domain sizes, memory requirement, computational time and possibility of errors abound for symmetric domains. With several competing computational methods in recent times, methods with little or no iterations are generally preferred as they tend to consume less computer memory resources and time. This paper presents the application of simple and efficient Markov Chain Monte Carlo (MCMC) method to the Laplace’s equation in axisymmetric homogeneous domains. Two cases of axisymmetric homogeneous problems are considered. Simulation results for analytical, finite difference and MCMC solutions are reported. The results obtained from the MCMC method agree with analytical and finite difference solutions. However, the MCMC method has the advantage that its implementation is simple and fast.

土壤固碳微生物的绝对定量检测实验设计

为了定量检测土壤中的固碳微生物,设计以功能基因cbbL为靶标的固碳微生物微滴数字聚合酶链式反应(ddPCR)检测方法。选择合适的引物探针,从退火温度、探针浓度以及引物浓度进行反应条件的优化,分析ddPCR检测方法的线性范围、敏感性、重复性和特异性。结果显示,当退火温度为55.8℃、探针与引物浓度分别为350、750 nmol/L时,建立的cbbL-ddPCR扩增反应效率最高,阴阳性微滴分布界限最明显,平均拷贝数较高;检测的线性范围为2.3×10^(0)~2.3×10^(5)copies/μL-DNA,曲线方程y=0.1077x-95.562,相关系数R^(2)为0.9997,检出限为0.5 copy/μL-DNA,21个重复的变异系数仅为3.92%,与其他4种非固碳微生物DNA未发生交叉反应。所建立的cbbL-ddPCR方法可用于土壤微生物固碳潜能测定。

高职制冷专业科教融汇的实践探索

科教融汇是职业教育发展的新方向。其核心在于如何“融”、怎样“汇”。顺德职业技术学院制冷与空调技术专业在多年政校企合作、产学研结合的实践基础上,初步形成了“产品价值链-人才培养链-技术平台链-创新价值链”四链贯通的科教融汇模式,将人才培养与技术创新有效链接,既实现了教学与科研的协同发展,也实现了专业与产业协同发展。

嵌入区块链信息传递功能的绿色供应链决策

针对消费者不完全信任绿色产品及供应链高交易成本问题,基于区块链的技术效应特征构建绿色供应链博弈模型,对比分析绿色供应链未实施和实施区块链两种情形下的决策,并从不同价值目标视角探讨绿色供应链实施区块链的充分条件。研究表明,当实施区块链所产生的价值增益较高或价值增益较低但绿色产品潜在市场规模削弱因子大于一定程度时,绿色供应链才有足够的动力实施区块链。通过算例分析进一步发现,绿色产品的价格弹性系数、制造商绿色努力成本系数以及消费者绿色偏好度之间的关系将影响绿色供应链实施区块链的条件。实施区块链后,制造商和零售商均将提高销售价格。实施区块链所产生的价值增益越大,产品批发价格越高,但对产品零售价格的影响具有差异性。

基于区块链的农产品供应链溯源数据多条件查询优化方法研究

随着基于区块链的农产品溯源系统迅速发展,区块链查询能力面临着巨大挑战。对于供应链参与方来说,区块链中保存的数据多为编码或序列化的数据,使得供应链参与方的审计和监督等存在多条件查询的工作变得十分困难。通常情况下,原生区块链并未提供满足多条件查询的查询方式。因此,为了实现多条件查询并提高查询效率,本研究提出一种农产品溯源数据多条件查询优化方法。首先,该方法采用一种优化的Merkle树结构(n-Tree)对交易信息进行重构,从而提供更高效的条件验证能力。其次,通过自适应多条件区块布隆过滤器判断交易信息中查询条件的存在性,进而快速过滤区块。最后,提出一种应用TWTN-Heap(Time weight and transaction number based heap)结构的索引构建方法,以区块权重为序构建主条件相关的区块号索引列表。产品数据的查询过程包括遍历区块号索引列表、过滤非相关区块以及验证特定查询条件,从而获得条件查询结果。实验结果表明,本研究提出的产品数据条件查询优化方法能够有效地解决农产品供应链面临的条件查询问题,同时保证查询时间消耗维持在15 ms左右,查询效率较默克尔语义字典树(Merkle semantic trie, MST)方法提高60.9%,较原始遍历(Orignal traverse, OT)方法提高87.7%。

面向采购文件的跨模态图片文本命名实体识别

智慧供应链的数智化采购环节能够提高采购工作效率,节省大量人力成本。采购文件中包括大量证照资质等文件,针对其中图片文本中文字排版参差不齐、扫描图像不清晰等问题,设计了基于深度学习的端到端跨模态命名实体识别模型O2V2BLC(OCR-Vector-Bi-LSTM-CRF),从图片文本中识别命名实体。该模型针对光学字符识别技术识别出的图片文本字符,定义连续文本字符边界,将边界内每个文本字符映射为向量,设计双向长短期记忆(Bi-LSTM)网络捕获边界内字符序列的上下文语义,计算字符状态分数矩阵,并通过条件随机场约束字符标记序列规则,获得全局最优标记序列。针对训练集计算命名实体预测误差,动态优化O2V2BLC模型的参数,实现命名实体识别。将该方法应用于采购文件资质类型等图片文本数据,能够有效识别图片中的投标单位、专家姓名、专业名称等命名实体,与条件随机场、隐马尔可夫算法、Bert-Bi-LSTM-CRF模型进行对比,显著提高了实体识别准确率,为智慧供应链的数智化采购提供支持。

Weight hierarchies of linear codes satisfying the almost chain condition

The weight hierarchy of a linear [n, k;q] code C over GF(q) is the sequence (d1,d2,..., dk) where dr is the size of the smallest support of an r-dimensional subcode of C. An [n,k;q] code satisfies the chain condition if there exists subcodes D1 D2 … Dk = C of C such that Dr has dimension r and support of size dr for all r. Further, C satisfies the almost chain condition if it does not satisfy the chain condition, but there exist subcodes Dr of dimension r and support of size dr for all r such that D2 D3 Dk = C and D1 D3. A simple necessary condition for a sequence to be the weight hierarchy of a code satisfying the almost chain condition is given. Further, explicit constructions of such codes are given, showing that in almost all cases, the necessary conditions are also sufficient.

论煤-水-土多资源协调开发

煤炭及其伴生资源是地质体的重要组成部分,大规模和高强度开采会引起近地表岩石圈、土壤圈、水圈的联动响应,进而反向制约煤炭及其伴生资源的安全开采与开发。围绕煤矿区的煤-水-土多资源协调开发,基于多学科知识交叉的地球关键带理念,阐述煤-水-土协调开发的必要性以及多圈层、多过程、多尺度、多目标的耦合关系,为煤炭安全绿色开发和生态环境可持续发展提供战略思考。(1)立足煤炭安全高效开采、土壤-水资源安全和生态环境保护多目标多维度角度,剖析大规模、高强度开发背景下采前、采中、采后地质条件动态演化、多资源时空关系、生态环境响应特征,提出煤炭资源开发生命周期条件下的煤炭资源区的地质调查战略和开发策略。(2)开展煤-水-土多资源量的系统调查和地质结构精细表征,全面理解和综合评价煤-水-土赋存特征和相互依存关系,形成集资源禀赋、生态环境、人口经济等于一体的地质调查评价体系和方法,提出基于煤炭开发、多资源利用、水土保护、生态屏障、土地安全等一体化的全链条调控措施和开发策略与开发政策。(3)监控开发过程中地层地质功能结构变化,理解煤-水-土空间组合结构及分层界面效应和煤(岩)-水-土相互作用的动态演化规律,构建复杂地层结构煤炭安全开采和水-土资源协调开发覆岩变形的演化模型,厘清煤-水-土空间结构及其对开采活动的约束效应,发展地球科学、采矿学、生态学、水文学等多学科交叉的煤炭绿色开发地质保障理论与技术。煤-水-土协调开发研究服务于煤炭安全开采与地质环境保护协调发展,破解多资源开发瓶颈及其地质环境制约之间矛盾,通过对煤炭开采全生命周期内的地质条件和环境效应的关键影响因素、状态参数阈值、演化驱动机制的理解,构建地质环境约束、开采模式调控、系统规划利用的煤-水-土多资源协调开发时空格局。